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TOMOYO Linux Cross Reference
Linux/fs/btrfs/ioctl.c

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  1 // SPDX-License-Identifier: GPL-2.0
  2 /*
  3  * Copyright (C) 2007 Oracle.  All rights reserved.
  4  */
  5 
  6 #include <linux/kernel.h>
  7 #include <linux/bio.h>
  8 #include <linux/file.h>
  9 #include <linux/fs.h>
 10 #include <linux/fsnotify.h>
 11 #include <linux/pagemap.h>
 12 #include <linux/highmem.h>
 13 #include <linux/time.h>
 14 #include <linux/string.h>
 15 #include <linux/backing-dev.h>
 16 #include <linux/mount.h>
 17 #include <linux/namei.h>
 18 #include <linux/writeback.h>
 19 #include <linux/compat.h>
 20 #include <linux/security.h>
 21 #include <linux/xattr.h>
 22 #include <linux/mm.h>
 23 #include <linux/slab.h>
 24 #include <linux/blkdev.h>
 25 #include <linux/uuid.h>
 26 #include <linux/btrfs.h>
 27 #include <linux/uaccess.h>
 28 #include <linux/iversion.h>
 29 #include "ctree.h"
 30 #include "disk-io.h"
 31 #include "transaction.h"
 32 #include "btrfs_inode.h"
 33 #include "print-tree.h"
 34 #include "volumes.h"
 35 #include "locking.h"
 36 #include "inode-map.h"
 37 #include "backref.h"
 38 #include "rcu-string.h"
 39 #include "send.h"
 40 #include "dev-replace.h"
 41 #include "props.h"
 42 #include "sysfs.h"
 43 #include "qgroup.h"
 44 #include "tree-log.h"
 45 #include "compression.h"
 46 
 47 #ifdef CONFIG_64BIT
 48 /* If we have a 32-bit userspace and 64-bit kernel, then the UAPI
 49  * structures are incorrect, as the timespec structure from userspace
 50  * is 4 bytes too small. We define these alternatives here to teach
 51  * the kernel about the 32-bit struct packing.
 52  */
 53 struct btrfs_ioctl_timespec_32 {
 54         __u64 sec;
 55         __u32 nsec;
 56 } __attribute__ ((__packed__));
 57 
 58 struct btrfs_ioctl_received_subvol_args_32 {
 59         char    uuid[BTRFS_UUID_SIZE];  /* in */
 60         __u64   stransid;               /* in */
 61         __u64   rtransid;               /* out */
 62         struct btrfs_ioctl_timespec_32 stime; /* in */
 63         struct btrfs_ioctl_timespec_32 rtime; /* out */
 64         __u64   flags;                  /* in */
 65         __u64   reserved[16];           /* in */
 66 } __attribute__ ((__packed__));
 67 
 68 #define BTRFS_IOC_SET_RECEIVED_SUBVOL_32 _IOWR(BTRFS_IOCTL_MAGIC, 37, \
 69                                 struct btrfs_ioctl_received_subvol_args_32)
 70 #endif
 71 
 72 #if defined(CONFIG_64BIT) && defined(CONFIG_COMPAT)
 73 struct btrfs_ioctl_send_args_32 {
 74         __s64 send_fd;                  /* in */
 75         __u64 clone_sources_count;      /* in */
 76         compat_uptr_t clone_sources;    /* in */
 77         __u64 parent_root;              /* in */
 78         __u64 flags;                    /* in */
 79         __u64 reserved[4];              /* in */
 80 } __attribute__ ((__packed__));
 81 
 82 #define BTRFS_IOC_SEND_32 _IOW(BTRFS_IOCTL_MAGIC, 38, \
 83                                struct btrfs_ioctl_send_args_32)
 84 #endif
 85 
 86 static int btrfs_clone(struct inode *src, struct inode *inode,
 87                        u64 off, u64 olen, u64 olen_aligned, u64 destoff,
 88                        int no_time_update);
 89 
 90 /* Mask out flags that are inappropriate for the given type of inode. */
 91 static unsigned int btrfs_mask_fsflags_for_type(struct inode *inode,
 92                 unsigned int flags)
 93 {
 94         if (S_ISDIR(inode->i_mode))
 95                 return flags;
 96         else if (S_ISREG(inode->i_mode))
 97                 return flags & ~FS_DIRSYNC_FL;
 98         else
 99                 return flags & (FS_NODUMP_FL | FS_NOATIME_FL);
100 }
101 
102 /*
103  * Export internal inode flags to the format expected by the FS_IOC_GETFLAGS
104  * ioctl.
105  */
106 static unsigned int btrfs_inode_flags_to_fsflags(unsigned int flags)
107 {
108         unsigned int iflags = 0;
109 
110         if (flags & BTRFS_INODE_SYNC)
111                 iflags |= FS_SYNC_FL;
112         if (flags & BTRFS_INODE_IMMUTABLE)
113                 iflags |= FS_IMMUTABLE_FL;
114         if (flags & BTRFS_INODE_APPEND)
115                 iflags |= FS_APPEND_FL;
116         if (flags & BTRFS_INODE_NODUMP)
117                 iflags |= FS_NODUMP_FL;
118         if (flags & BTRFS_INODE_NOATIME)
119                 iflags |= FS_NOATIME_FL;
120         if (flags & BTRFS_INODE_DIRSYNC)
121                 iflags |= FS_DIRSYNC_FL;
122         if (flags & BTRFS_INODE_NODATACOW)
123                 iflags |= FS_NOCOW_FL;
124 
125         if (flags & BTRFS_INODE_NOCOMPRESS)
126                 iflags |= FS_NOCOMP_FL;
127         else if (flags & BTRFS_INODE_COMPRESS)
128                 iflags |= FS_COMPR_FL;
129 
130         return iflags;
131 }
132 
133 /*
134  * Update inode->i_flags based on the btrfs internal flags.
135  */
136 void btrfs_sync_inode_flags_to_i_flags(struct inode *inode)
137 {
138         struct btrfs_inode *binode = BTRFS_I(inode);
139         unsigned int new_fl = 0;
140 
141         if (binode->flags & BTRFS_INODE_SYNC)
142                 new_fl |= S_SYNC;
143         if (binode->flags & BTRFS_INODE_IMMUTABLE)
144                 new_fl |= S_IMMUTABLE;
145         if (binode->flags & BTRFS_INODE_APPEND)
146                 new_fl |= S_APPEND;
147         if (binode->flags & BTRFS_INODE_NOATIME)
148                 new_fl |= S_NOATIME;
149         if (binode->flags & BTRFS_INODE_DIRSYNC)
150                 new_fl |= S_DIRSYNC;
151 
152         set_mask_bits(&inode->i_flags,
153                       S_SYNC | S_APPEND | S_IMMUTABLE | S_NOATIME | S_DIRSYNC,
154                       new_fl);
155 }
156 
157 static int btrfs_ioctl_getflags(struct file *file, void __user *arg)
158 {
159         struct btrfs_inode *binode = BTRFS_I(file_inode(file));
160         unsigned int flags = btrfs_inode_flags_to_fsflags(binode->flags);
161 
162         if (copy_to_user(arg, &flags, sizeof(flags)))
163                 return -EFAULT;
164         return 0;
165 }
166 
167 /* Check if @flags are a supported and valid set of FS_*_FL flags */
168 static int check_fsflags(unsigned int flags)
169 {
170         if (flags & ~(FS_IMMUTABLE_FL | FS_APPEND_FL | \
171                       FS_NOATIME_FL | FS_NODUMP_FL | \
172                       FS_SYNC_FL | FS_DIRSYNC_FL | \
173                       FS_NOCOMP_FL | FS_COMPR_FL |
174                       FS_NOCOW_FL))
175                 return -EOPNOTSUPP;
176 
177         if ((flags & FS_NOCOMP_FL) && (flags & FS_COMPR_FL))
178                 return -EINVAL;
179 
180         return 0;
181 }
182 
183 static int btrfs_ioctl_setflags(struct file *file, void __user *arg)
184 {
185         struct inode *inode = file_inode(file);
186         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
187         struct btrfs_inode *binode = BTRFS_I(inode);
188         struct btrfs_root *root = binode->root;
189         struct btrfs_trans_handle *trans;
190         unsigned int fsflags, old_fsflags;
191         int ret;
192         u64 old_flags;
193         unsigned int old_i_flags;
194         umode_t mode;
195 
196         if (!inode_owner_or_capable(inode))
197                 return -EPERM;
198 
199         if (btrfs_root_readonly(root))
200                 return -EROFS;
201 
202         if (copy_from_user(&fsflags, arg, sizeof(fsflags)))
203                 return -EFAULT;
204 
205         ret = check_fsflags(fsflags);
206         if (ret)
207                 return ret;
208 
209         ret = mnt_want_write_file(file);
210         if (ret)
211                 return ret;
212 
213         inode_lock(inode);
214 
215         old_flags = binode->flags;
216         old_i_flags = inode->i_flags;
217         mode = inode->i_mode;
218 
219         fsflags = btrfs_mask_fsflags_for_type(inode, fsflags);
220         old_fsflags = btrfs_inode_flags_to_fsflags(binode->flags);
221         if ((fsflags ^ old_fsflags) & (FS_APPEND_FL | FS_IMMUTABLE_FL)) {
222                 if (!capable(CAP_LINUX_IMMUTABLE)) {
223                         ret = -EPERM;
224                         goto out_unlock;
225                 }
226         }
227 
228         if (fsflags & FS_SYNC_FL)
229                 binode->flags |= BTRFS_INODE_SYNC;
230         else
231                 binode->flags &= ~BTRFS_INODE_SYNC;
232         if (fsflags & FS_IMMUTABLE_FL)
233                 binode->flags |= BTRFS_INODE_IMMUTABLE;
234         else
235                 binode->flags &= ~BTRFS_INODE_IMMUTABLE;
236         if (fsflags & FS_APPEND_FL)
237                 binode->flags |= BTRFS_INODE_APPEND;
238         else
239                 binode->flags &= ~BTRFS_INODE_APPEND;
240         if (fsflags & FS_NODUMP_FL)
241                 binode->flags |= BTRFS_INODE_NODUMP;
242         else
243                 binode->flags &= ~BTRFS_INODE_NODUMP;
244         if (fsflags & FS_NOATIME_FL)
245                 binode->flags |= BTRFS_INODE_NOATIME;
246         else
247                 binode->flags &= ~BTRFS_INODE_NOATIME;
248         if (fsflags & FS_DIRSYNC_FL)
249                 binode->flags |= BTRFS_INODE_DIRSYNC;
250         else
251                 binode->flags &= ~BTRFS_INODE_DIRSYNC;
252         if (fsflags & FS_NOCOW_FL) {
253                 if (S_ISREG(mode)) {
254                         /*
255                          * It's safe to turn csums off here, no extents exist.
256                          * Otherwise we want the flag to reflect the real COW
257                          * status of the file and will not set it.
258                          */
259                         if (inode->i_size == 0)
260                                 binode->flags |= BTRFS_INODE_NODATACOW
261                                               | BTRFS_INODE_NODATASUM;
262                 } else {
263                         binode->flags |= BTRFS_INODE_NODATACOW;
264                 }
265         } else {
266                 /*
267                  * Revert back under same assumptions as above
268                  */
269                 if (S_ISREG(mode)) {
270                         if (inode->i_size == 0)
271                                 binode->flags &= ~(BTRFS_INODE_NODATACOW
272                                              | BTRFS_INODE_NODATASUM);
273                 } else {
274                         binode->flags &= ~BTRFS_INODE_NODATACOW;
275                 }
276         }
277 
278         /*
279          * The COMPRESS flag can only be changed by users, while the NOCOMPRESS
280          * flag may be changed automatically if compression code won't make
281          * things smaller.
282          */
283         if (fsflags & FS_NOCOMP_FL) {
284                 binode->flags &= ~BTRFS_INODE_COMPRESS;
285                 binode->flags |= BTRFS_INODE_NOCOMPRESS;
286 
287                 ret = btrfs_set_prop(inode, "btrfs.compression", NULL, 0, 0);
288                 if (ret && ret != -ENODATA)
289                         goto out_drop;
290         } else if (fsflags & FS_COMPR_FL) {
291                 const char *comp;
292 
293                 binode->flags |= BTRFS_INODE_COMPRESS;
294                 binode->flags &= ~BTRFS_INODE_NOCOMPRESS;
295 
296                 comp = btrfs_compress_type2str(fs_info->compress_type);
297                 if (!comp || comp[0] == 0)
298                         comp = btrfs_compress_type2str(BTRFS_COMPRESS_ZLIB);
299 
300                 ret = btrfs_set_prop(inode, "btrfs.compression",
301                                      comp, strlen(comp), 0);
302                 if (ret)
303                         goto out_drop;
304 
305         } else {
306                 ret = btrfs_set_prop(inode, "btrfs.compression", NULL, 0, 0);
307                 if (ret && ret != -ENODATA)
308                         goto out_drop;
309                 binode->flags &= ~(BTRFS_INODE_COMPRESS | BTRFS_INODE_NOCOMPRESS);
310         }
311 
312         trans = btrfs_start_transaction(root, 1);
313         if (IS_ERR(trans)) {
314                 ret = PTR_ERR(trans);
315                 goto out_drop;
316         }
317 
318         btrfs_sync_inode_flags_to_i_flags(inode);
319         inode_inc_iversion(inode);
320         inode->i_ctime = current_time(inode);
321         ret = btrfs_update_inode(trans, root, inode);
322 
323         btrfs_end_transaction(trans);
324  out_drop:
325         if (ret) {
326                 binode->flags = old_flags;
327                 inode->i_flags = old_i_flags;
328         }
329 
330  out_unlock:
331         inode_unlock(inode);
332         mnt_drop_write_file(file);
333         return ret;
334 }
335 
336 /*
337  * Translate btrfs internal inode flags to xflags as expected by the
338  * FS_IOC_FSGETXATT ioctl. Filter only the supported ones, unknown flags are
339  * silently dropped.
340  */
341 static unsigned int btrfs_inode_flags_to_xflags(unsigned int flags)
342 {
343         unsigned int xflags = 0;
344 
345         if (flags & BTRFS_INODE_APPEND)
346                 xflags |= FS_XFLAG_APPEND;
347         if (flags & BTRFS_INODE_IMMUTABLE)
348                 xflags |= FS_XFLAG_IMMUTABLE;
349         if (flags & BTRFS_INODE_NOATIME)
350                 xflags |= FS_XFLAG_NOATIME;
351         if (flags & BTRFS_INODE_NODUMP)
352                 xflags |= FS_XFLAG_NODUMP;
353         if (flags & BTRFS_INODE_SYNC)
354                 xflags |= FS_XFLAG_SYNC;
355 
356         return xflags;
357 }
358 
359 /* Check if @flags are a supported and valid set of FS_XFLAGS_* flags */
360 static int check_xflags(unsigned int flags)
361 {
362         if (flags & ~(FS_XFLAG_APPEND | FS_XFLAG_IMMUTABLE | FS_XFLAG_NOATIME |
363                       FS_XFLAG_NODUMP | FS_XFLAG_SYNC))
364                 return -EOPNOTSUPP;
365         return 0;
366 }
367 
368 /*
369  * Set the xflags from the internal inode flags. The remaining items of fsxattr
370  * are zeroed.
371  */
372 static int btrfs_ioctl_fsgetxattr(struct file *file, void __user *arg)
373 {
374         struct btrfs_inode *binode = BTRFS_I(file_inode(file));
375         struct fsxattr fa;
376 
377         memset(&fa, 0, sizeof(fa));
378         fa.fsx_xflags = btrfs_inode_flags_to_xflags(binode->flags);
379 
380         if (copy_to_user(arg, &fa, sizeof(fa)))
381                 return -EFAULT;
382 
383         return 0;
384 }
385 
386 static int btrfs_ioctl_fssetxattr(struct file *file, void __user *arg)
387 {
388         struct inode *inode = file_inode(file);
389         struct btrfs_inode *binode = BTRFS_I(inode);
390         struct btrfs_root *root = binode->root;
391         struct btrfs_trans_handle *trans;
392         struct fsxattr fa;
393         unsigned old_flags;
394         unsigned old_i_flags;
395         int ret = 0;
396 
397         if (!inode_owner_or_capable(inode))
398                 return -EPERM;
399 
400         if (btrfs_root_readonly(root))
401                 return -EROFS;
402 
403         memset(&fa, 0, sizeof(fa));
404         if (copy_from_user(&fa, arg, sizeof(fa)))
405                 return -EFAULT;
406 
407         ret = check_xflags(fa.fsx_xflags);
408         if (ret)
409                 return ret;
410 
411         if (fa.fsx_extsize != 0 || fa.fsx_projid != 0 || fa.fsx_cowextsize != 0)
412                 return -EOPNOTSUPP;
413 
414         ret = mnt_want_write_file(file);
415         if (ret)
416                 return ret;
417 
418         inode_lock(inode);
419 
420         old_flags = binode->flags;
421         old_i_flags = inode->i_flags;
422 
423         /* We need the capabilities to change append-only or immutable inode */
424         if (((old_flags & (BTRFS_INODE_APPEND | BTRFS_INODE_IMMUTABLE)) ||
425              (fa.fsx_xflags & (FS_XFLAG_APPEND | FS_XFLAG_IMMUTABLE))) &&
426             !capable(CAP_LINUX_IMMUTABLE)) {
427                 ret = -EPERM;
428                 goto out_unlock;
429         }
430 
431         if (fa.fsx_xflags & FS_XFLAG_SYNC)
432                 binode->flags |= BTRFS_INODE_SYNC;
433         else
434                 binode->flags &= ~BTRFS_INODE_SYNC;
435         if (fa.fsx_xflags & FS_XFLAG_IMMUTABLE)
436                 binode->flags |= BTRFS_INODE_IMMUTABLE;
437         else
438                 binode->flags &= ~BTRFS_INODE_IMMUTABLE;
439         if (fa.fsx_xflags & FS_XFLAG_APPEND)
440                 binode->flags |= BTRFS_INODE_APPEND;
441         else
442                 binode->flags &= ~BTRFS_INODE_APPEND;
443         if (fa.fsx_xflags & FS_XFLAG_NODUMP)
444                 binode->flags |= BTRFS_INODE_NODUMP;
445         else
446                 binode->flags &= ~BTRFS_INODE_NODUMP;
447         if (fa.fsx_xflags & FS_XFLAG_NOATIME)
448                 binode->flags |= BTRFS_INODE_NOATIME;
449         else
450                 binode->flags &= ~BTRFS_INODE_NOATIME;
451 
452         /* 1 item for the inode */
453         trans = btrfs_start_transaction(root, 1);
454         if (IS_ERR(trans)) {
455                 ret = PTR_ERR(trans);
456                 goto out_unlock;
457         }
458 
459         btrfs_sync_inode_flags_to_i_flags(inode);
460         inode_inc_iversion(inode);
461         inode->i_ctime = current_time(inode);
462         ret = btrfs_update_inode(trans, root, inode);
463 
464         btrfs_end_transaction(trans);
465 
466 out_unlock:
467         if (ret) {
468                 binode->flags = old_flags;
469                 inode->i_flags = old_i_flags;
470         }
471 
472         inode_unlock(inode);
473         mnt_drop_write_file(file);
474 
475         return ret;
476 }
477 
478 static int btrfs_ioctl_getversion(struct file *file, int __user *arg)
479 {
480         struct inode *inode = file_inode(file);
481 
482         return put_user(inode->i_generation, arg);
483 }
484 
485 static noinline int btrfs_ioctl_fitrim(struct file *file, void __user *arg)
486 {
487         struct inode *inode = file_inode(file);
488         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
489         struct btrfs_device *device;
490         struct request_queue *q;
491         struct fstrim_range range;
492         u64 minlen = ULLONG_MAX;
493         u64 num_devices = 0;
494         int ret;
495 
496         if (!capable(CAP_SYS_ADMIN))
497                 return -EPERM;
498 
499         rcu_read_lock();
500         list_for_each_entry_rcu(device, &fs_info->fs_devices->devices,
501                                 dev_list) {
502                 if (!device->bdev)
503                         continue;
504                 q = bdev_get_queue(device->bdev);
505                 if (blk_queue_discard(q)) {
506                         num_devices++;
507                         minlen = min_t(u64, q->limits.discard_granularity,
508                                      minlen);
509                 }
510         }
511         rcu_read_unlock();
512 
513         if (!num_devices)
514                 return -EOPNOTSUPP;
515         if (copy_from_user(&range, arg, sizeof(range)))
516                 return -EFAULT;
517 
518         /*
519          * NOTE: Don't truncate the range using super->total_bytes.  Bytenr of
520          * block group is in the logical address space, which can be any
521          * sectorsize aligned bytenr in  the range [0, U64_MAX].
522          */
523         if (range.len < fs_info->sb->s_blocksize)
524                 return -EINVAL;
525 
526         range.minlen = max(range.minlen, minlen);
527         ret = btrfs_trim_fs(fs_info, &range);
528         if (ret < 0)
529                 return ret;
530 
531         if (copy_to_user(arg, &range, sizeof(range)))
532                 return -EFAULT;
533 
534         return 0;
535 }
536 
537 int btrfs_is_empty_uuid(u8 *uuid)
538 {
539         int i;
540 
541         for (i = 0; i < BTRFS_UUID_SIZE; i++) {
542                 if (uuid[i])
543                         return 0;
544         }
545         return 1;
546 }
547 
548 static noinline int create_subvol(struct inode *dir,
549                                   struct dentry *dentry,
550                                   const char *name, int namelen,
551                                   u64 *async_transid,
552                                   struct btrfs_qgroup_inherit *inherit)
553 {
554         struct btrfs_fs_info *fs_info = btrfs_sb(dir->i_sb);
555         struct btrfs_trans_handle *trans;
556         struct btrfs_key key;
557         struct btrfs_root_item *root_item;
558         struct btrfs_inode_item *inode_item;
559         struct extent_buffer *leaf;
560         struct btrfs_root *root = BTRFS_I(dir)->root;
561         struct btrfs_root *new_root;
562         struct btrfs_block_rsv block_rsv;
563         struct timespec64 cur_time = current_time(dir);
564         struct inode *inode;
565         int ret;
566         int err;
567         u64 objectid;
568         u64 new_dirid = BTRFS_FIRST_FREE_OBJECTID;
569         u64 index = 0;
570         uuid_le new_uuid;
571 
572         root_item = kzalloc(sizeof(*root_item), GFP_KERNEL);
573         if (!root_item)
574                 return -ENOMEM;
575 
576         ret = btrfs_find_free_objectid(fs_info->tree_root, &objectid);
577         if (ret)
578                 goto fail_free;
579 
580         /*
581          * Don't create subvolume whose level is not zero. Or qgroup will be
582          * screwed up since it assumes subvolume qgroup's level to be 0.
583          */
584         if (btrfs_qgroup_level(objectid)) {
585                 ret = -ENOSPC;
586                 goto fail_free;
587         }
588 
589         btrfs_init_block_rsv(&block_rsv, BTRFS_BLOCK_RSV_TEMP);
590         /*
591          * The same as the snapshot creation, please see the comment
592          * of create_snapshot().
593          */
594         ret = btrfs_subvolume_reserve_metadata(root, &block_rsv, 8, false);
595         if (ret)
596                 goto fail_free;
597 
598         trans = btrfs_start_transaction(root, 0);
599         if (IS_ERR(trans)) {
600                 ret = PTR_ERR(trans);
601                 btrfs_subvolume_release_metadata(fs_info, &block_rsv);
602                 goto fail_free;
603         }
604         trans->block_rsv = &block_rsv;
605         trans->bytes_reserved = block_rsv.size;
606 
607         ret = btrfs_qgroup_inherit(trans, 0, objectid, inherit);
608         if (ret)
609                 goto fail;
610 
611         leaf = btrfs_alloc_tree_block(trans, root, 0, objectid, NULL, 0, 0, 0);
612         if (IS_ERR(leaf)) {
613                 ret = PTR_ERR(leaf);
614                 goto fail;
615         }
616 
617         btrfs_mark_buffer_dirty(leaf);
618 
619         inode_item = &root_item->inode;
620         btrfs_set_stack_inode_generation(inode_item, 1);
621         btrfs_set_stack_inode_size(inode_item, 3);
622         btrfs_set_stack_inode_nlink(inode_item, 1);
623         btrfs_set_stack_inode_nbytes(inode_item,
624                                      fs_info->nodesize);
625         btrfs_set_stack_inode_mode(inode_item, S_IFDIR | 0755);
626 
627         btrfs_set_root_flags(root_item, 0);
628         btrfs_set_root_limit(root_item, 0);
629         btrfs_set_stack_inode_flags(inode_item, BTRFS_INODE_ROOT_ITEM_INIT);
630 
631         btrfs_set_root_bytenr(root_item, leaf->start);
632         btrfs_set_root_generation(root_item, trans->transid);
633         btrfs_set_root_level(root_item, 0);
634         btrfs_set_root_refs(root_item, 1);
635         btrfs_set_root_used(root_item, leaf->len);
636         btrfs_set_root_last_snapshot(root_item, 0);
637 
638         btrfs_set_root_generation_v2(root_item,
639                         btrfs_root_generation(root_item));
640         uuid_le_gen(&new_uuid);
641         memcpy(root_item->uuid, new_uuid.b, BTRFS_UUID_SIZE);
642         btrfs_set_stack_timespec_sec(&root_item->otime, cur_time.tv_sec);
643         btrfs_set_stack_timespec_nsec(&root_item->otime, cur_time.tv_nsec);
644         root_item->ctime = root_item->otime;
645         btrfs_set_root_ctransid(root_item, trans->transid);
646         btrfs_set_root_otransid(root_item, trans->transid);
647 
648         btrfs_tree_unlock(leaf);
649         free_extent_buffer(leaf);
650         leaf = NULL;
651 
652         btrfs_set_root_dirid(root_item, new_dirid);
653 
654         key.objectid = objectid;
655         key.offset = 0;
656         key.type = BTRFS_ROOT_ITEM_KEY;
657         ret = btrfs_insert_root(trans, fs_info->tree_root, &key,
658                                 root_item);
659         if (ret)
660                 goto fail;
661 
662         key.offset = (u64)-1;
663         new_root = btrfs_read_fs_root_no_name(fs_info, &key);
664         if (IS_ERR(new_root)) {
665                 ret = PTR_ERR(new_root);
666                 btrfs_abort_transaction(trans, ret);
667                 goto fail;
668         }
669 
670         btrfs_record_root_in_trans(trans, new_root);
671 
672         ret = btrfs_create_subvol_root(trans, new_root, root, new_dirid);
673         if (ret) {
674                 /* We potentially lose an unused inode item here */
675                 btrfs_abort_transaction(trans, ret);
676                 goto fail;
677         }
678 
679         mutex_lock(&new_root->objectid_mutex);
680         new_root->highest_objectid = new_dirid;
681         mutex_unlock(&new_root->objectid_mutex);
682 
683         /*
684          * insert the directory item
685          */
686         ret = btrfs_set_inode_index(BTRFS_I(dir), &index);
687         if (ret) {
688                 btrfs_abort_transaction(trans, ret);
689                 goto fail;
690         }
691 
692         ret = btrfs_insert_dir_item(trans, name, namelen, BTRFS_I(dir), &key,
693                                     BTRFS_FT_DIR, index);
694         if (ret) {
695                 btrfs_abort_transaction(trans, ret);
696                 goto fail;
697         }
698 
699         btrfs_i_size_write(BTRFS_I(dir), dir->i_size + namelen * 2);
700         ret = btrfs_update_inode(trans, root, dir);
701         BUG_ON(ret);
702 
703         ret = btrfs_add_root_ref(trans, objectid, root->root_key.objectid,
704                                  btrfs_ino(BTRFS_I(dir)), index, name, namelen);
705         BUG_ON(ret);
706 
707         ret = btrfs_uuid_tree_add(trans, root_item->uuid,
708                                   BTRFS_UUID_KEY_SUBVOL, objectid);
709         if (ret)
710                 btrfs_abort_transaction(trans, ret);
711 
712 fail:
713         kfree(root_item);
714         trans->block_rsv = NULL;
715         trans->bytes_reserved = 0;
716         btrfs_subvolume_release_metadata(fs_info, &block_rsv);
717 
718         if (async_transid) {
719                 *async_transid = trans->transid;
720                 err = btrfs_commit_transaction_async(trans, 1);
721                 if (err)
722                         err = btrfs_commit_transaction(trans);
723         } else {
724                 err = btrfs_commit_transaction(trans);
725         }
726         if (err && !ret)
727                 ret = err;
728 
729         if (!ret) {
730                 inode = btrfs_lookup_dentry(dir, dentry);
731                 if (IS_ERR(inode))
732                         return PTR_ERR(inode);
733                 d_instantiate(dentry, inode);
734         }
735         return ret;
736 
737 fail_free:
738         kfree(root_item);
739         return ret;
740 }
741 
742 static int create_snapshot(struct btrfs_root *root, struct inode *dir,
743                            struct dentry *dentry,
744                            u64 *async_transid, bool readonly,
745                            struct btrfs_qgroup_inherit *inherit)
746 {
747         struct btrfs_fs_info *fs_info = btrfs_sb(dir->i_sb);
748         struct inode *inode;
749         struct btrfs_pending_snapshot *pending_snapshot;
750         struct btrfs_trans_handle *trans;
751         int ret;
752         bool snapshot_force_cow = false;
753 
754         if (!test_bit(BTRFS_ROOT_REF_COWS, &root->state))
755                 return -EINVAL;
756 
757         pending_snapshot = kzalloc(sizeof(*pending_snapshot), GFP_KERNEL);
758         if (!pending_snapshot)
759                 return -ENOMEM;
760 
761         pending_snapshot->root_item = kzalloc(sizeof(struct btrfs_root_item),
762                         GFP_KERNEL);
763         pending_snapshot->path = btrfs_alloc_path();
764         if (!pending_snapshot->root_item || !pending_snapshot->path) {
765                 ret = -ENOMEM;
766                 goto free_pending;
767         }
768 
769         /*
770          * Force new buffered writes to reserve space even when NOCOW is
771          * possible. This is to avoid later writeback (running dealloc) to
772          * fallback to COW mode and unexpectedly fail with ENOSPC.
773          */
774         atomic_inc(&root->will_be_snapshotted);
775         smp_mb__after_atomic();
776         /* wait for no snapshot writes */
777         wait_event(root->subv_writers->wait,
778                    percpu_counter_sum(&root->subv_writers->counter) == 0);
779 
780         ret = btrfs_start_delalloc_snapshot(root);
781         if (ret)
782                 goto dec_and_free;
783 
784         /*
785          * All previous writes have started writeback in NOCOW mode, so now
786          * we force future writes to fallback to COW mode during snapshot
787          * creation.
788          */
789         atomic_inc(&root->snapshot_force_cow);
790         snapshot_force_cow = true;
791 
792         btrfs_wait_ordered_extents(root, U64_MAX, 0, (u64)-1);
793 
794         btrfs_init_block_rsv(&pending_snapshot->block_rsv,
795                              BTRFS_BLOCK_RSV_TEMP);
796         /*
797          * 1 - parent dir inode
798          * 2 - dir entries
799          * 1 - root item
800          * 2 - root ref/backref
801          * 1 - root of snapshot
802          * 1 - UUID item
803          */
804         ret = btrfs_subvolume_reserve_metadata(BTRFS_I(dir)->root,
805                                         &pending_snapshot->block_rsv, 8,
806                                         false);
807         if (ret)
808                 goto dec_and_free;
809 
810         pending_snapshot->dentry = dentry;
811         pending_snapshot->root = root;
812         pending_snapshot->readonly = readonly;
813         pending_snapshot->dir = dir;
814         pending_snapshot->inherit = inherit;
815 
816         trans = btrfs_start_transaction(root, 0);
817         if (IS_ERR(trans)) {
818                 ret = PTR_ERR(trans);
819                 goto fail;
820         }
821 
822         spin_lock(&fs_info->trans_lock);
823         list_add(&pending_snapshot->list,
824                  &trans->transaction->pending_snapshots);
825         spin_unlock(&fs_info->trans_lock);
826         if (async_transid) {
827                 *async_transid = trans->transid;
828                 ret = btrfs_commit_transaction_async(trans, 1);
829                 if (ret)
830                         ret = btrfs_commit_transaction(trans);
831         } else {
832                 ret = btrfs_commit_transaction(trans);
833         }
834         if (ret)
835                 goto fail;
836 
837         ret = pending_snapshot->error;
838         if (ret)
839                 goto fail;
840 
841         ret = btrfs_orphan_cleanup(pending_snapshot->snap);
842         if (ret)
843                 goto fail;
844 
845         inode = btrfs_lookup_dentry(d_inode(dentry->d_parent), dentry);
846         if (IS_ERR(inode)) {
847                 ret = PTR_ERR(inode);
848                 goto fail;
849         }
850 
851         d_instantiate(dentry, inode);
852         ret = 0;
853 fail:
854         btrfs_subvolume_release_metadata(fs_info, &pending_snapshot->block_rsv);
855 dec_and_free:
856         if (snapshot_force_cow)
857                 atomic_dec(&root->snapshot_force_cow);
858         if (atomic_dec_and_test(&root->will_be_snapshotted))
859                 wake_up_var(&root->will_be_snapshotted);
860 free_pending:
861         kfree(pending_snapshot->root_item);
862         btrfs_free_path(pending_snapshot->path);
863         kfree(pending_snapshot);
864 
865         return ret;
866 }
867 
868 /*  copy of may_delete in fs/namei.c()
869  *      Check whether we can remove a link victim from directory dir, check
870  *  whether the type of victim is right.
871  *  1. We can't do it if dir is read-only (done in permission())
872  *  2. We should have write and exec permissions on dir
873  *  3. We can't remove anything from append-only dir
874  *  4. We can't do anything with immutable dir (done in permission())
875  *  5. If the sticky bit on dir is set we should either
876  *      a. be owner of dir, or
877  *      b. be owner of victim, or
878  *      c. have CAP_FOWNER capability
879  *  6. If the victim is append-only or immutable we can't do anything with
880  *     links pointing to it.
881  *  7. If we were asked to remove a directory and victim isn't one - ENOTDIR.
882  *  8. If we were asked to remove a non-directory and victim isn't one - EISDIR.
883  *  9. We can't remove a root or mountpoint.
884  * 10. We don't allow removal of NFS sillyrenamed files; it's handled by
885  *     nfs_async_unlink().
886  */
887 
888 static int btrfs_may_delete(struct inode *dir, struct dentry *victim, int isdir)
889 {
890         int error;
891 
892         if (d_really_is_negative(victim))
893                 return -ENOENT;
894 
895         BUG_ON(d_inode(victim->d_parent) != dir);
896         audit_inode_child(dir, victim, AUDIT_TYPE_CHILD_DELETE);
897 
898         error = inode_permission(dir, MAY_WRITE | MAY_EXEC);
899         if (error)
900                 return error;
901         if (IS_APPEND(dir))
902                 return -EPERM;
903         if (check_sticky(dir, d_inode(victim)) || IS_APPEND(d_inode(victim)) ||
904             IS_IMMUTABLE(d_inode(victim)) || IS_SWAPFILE(d_inode(victim)))
905                 return -EPERM;
906         if (isdir) {
907                 if (!d_is_dir(victim))
908                         return -ENOTDIR;
909                 if (IS_ROOT(victim))
910                         return -EBUSY;
911         } else if (d_is_dir(victim))
912                 return -EISDIR;
913         if (IS_DEADDIR(dir))
914                 return -ENOENT;
915         if (victim->d_flags & DCACHE_NFSFS_RENAMED)
916                 return -EBUSY;
917         return 0;
918 }
919 
920 /* copy of may_create in fs/namei.c() */
921 static inline int btrfs_may_create(struct inode *dir, struct dentry *child)
922 {
923         if (d_really_is_positive(child))
924                 return -EEXIST;
925         if (IS_DEADDIR(dir))
926                 return -ENOENT;
927         return inode_permission(dir, MAY_WRITE | MAY_EXEC);
928 }
929 
930 /*
931  * Create a new subvolume below @parent.  This is largely modeled after
932  * sys_mkdirat and vfs_mkdir, but we only do a single component lookup
933  * inside this filesystem so it's quite a bit simpler.
934  */
935 static noinline int btrfs_mksubvol(const struct path *parent,
936                                    const char *name, int namelen,
937                                    struct btrfs_root *snap_src,
938                                    u64 *async_transid, bool readonly,
939                                    struct btrfs_qgroup_inherit *inherit)
940 {
941         struct inode *dir = d_inode(parent->dentry);
942         struct btrfs_fs_info *fs_info = btrfs_sb(dir->i_sb);
943         struct dentry *dentry;
944         int error;
945 
946         error = down_write_killable_nested(&dir->i_rwsem, I_MUTEX_PARENT);
947         if (error == -EINTR)
948                 return error;
949 
950         dentry = lookup_one_len(name, parent->dentry, namelen);
951         error = PTR_ERR(dentry);
952         if (IS_ERR(dentry))
953                 goto out_unlock;
954 
955         error = btrfs_may_create(dir, dentry);
956         if (error)
957                 goto out_dput;
958 
959         /*
960          * even if this name doesn't exist, we may get hash collisions.
961          * check for them now when we can safely fail
962          */
963         error = btrfs_check_dir_item_collision(BTRFS_I(dir)->root,
964                                                dir->i_ino, name,
965                                                namelen);
966         if (error)
967                 goto out_dput;
968 
969         down_read(&fs_info->subvol_sem);
970 
971         if (btrfs_root_refs(&BTRFS_I(dir)->root->root_item) == 0)
972                 goto out_up_read;
973 
974         if (snap_src) {
975                 error = create_snapshot(snap_src, dir, dentry,
976                                         async_transid, readonly, inherit);
977         } else {
978                 error = create_subvol(dir, dentry, name, namelen,
979                                       async_transid, inherit);
980         }
981         if (!error)
982                 fsnotify_mkdir(dir, dentry);
983 out_up_read:
984         up_read(&fs_info->subvol_sem);
985 out_dput:
986         dput(dentry);
987 out_unlock:
988         inode_unlock(dir);
989         return error;
990 }
991 
992 /*
993  * When we're defragging a range, we don't want to kick it off again
994  * if it is really just waiting for delalloc to send it down.
995  * If we find a nice big extent or delalloc range for the bytes in the
996  * file you want to defrag, we return 0 to let you know to skip this
997  * part of the file
998  */
999 static int check_defrag_in_cache(struct inode *inode, u64 offset, u32 thresh)
1000 {
1001         struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
1002         struct extent_map *em = NULL;
1003         struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
1004         u64 end;
1005 
1006         read_lock(&em_tree->lock);
1007         em = lookup_extent_mapping(em_tree, offset, PAGE_SIZE);
1008         read_unlock(&em_tree->lock);
1009 
1010         if (em) {
1011                 end = extent_map_end(em);
1012                 free_extent_map(em);
1013                 if (end - offset > thresh)
1014                         return 0;
1015         }
1016         /* if we already have a nice delalloc here, just stop */
1017         thresh /= 2;
1018         end = count_range_bits(io_tree, &offset, offset + thresh,
1019                                thresh, EXTENT_DELALLOC, 1);
1020         if (end >= thresh)
1021                 return 0;
1022         return 1;
1023 }
1024 
1025 /*
1026  * helper function to walk through a file and find extents
1027  * newer than a specific transid, and smaller than thresh.
1028  *
1029  * This is used by the defragging code to find new and small
1030  * extents
1031  */
1032 static int find_new_extents(struct btrfs_root *root,
1033                             struct inode *inode, u64 newer_than,
1034                             u64 *off, u32 thresh)
1035 {
1036         struct btrfs_path *path;
1037         struct btrfs_key min_key;
1038         struct extent_buffer *leaf;
1039         struct btrfs_file_extent_item *extent;
1040         int type;
1041         int ret;
1042         u64 ino = btrfs_ino(BTRFS_I(inode));
1043 
1044         path = btrfs_alloc_path();
1045         if (!path)
1046                 return -ENOMEM;
1047 
1048         min_key.objectid = ino;
1049         min_key.type = BTRFS_EXTENT_DATA_KEY;
1050         min_key.offset = *off;
1051 
1052         while (1) {
1053                 ret = btrfs_search_forward(root, &min_key, path, newer_than);
1054                 if (ret != 0)
1055                         goto none;
1056 process_slot:
1057                 if (min_key.objectid != ino)
1058                         goto none;
1059                 if (min_key.type != BTRFS_EXTENT_DATA_KEY)
1060                         goto none;
1061 
1062                 leaf = path->nodes[0];
1063                 extent = btrfs_item_ptr(leaf, path->slots[0],
1064                                         struct btrfs_file_extent_item);
1065 
1066                 type = btrfs_file_extent_type(leaf, extent);
1067                 if (type == BTRFS_FILE_EXTENT_REG &&
1068                     btrfs_file_extent_num_bytes(leaf, extent) < thresh &&
1069                     check_defrag_in_cache(inode, min_key.offset, thresh)) {
1070                         *off = min_key.offset;
1071                         btrfs_free_path(path);
1072                         return 0;
1073                 }
1074 
1075                 path->slots[0]++;
1076                 if (path->slots[0] < btrfs_header_nritems(leaf)) {
1077                         btrfs_item_key_to_cpu(leaf, &min_key, path->slots[0]);
1078                         goto process_slot;
1079                 }
1080 
1081                 if (min_key.offset == (u64)-1)
1082                         goto none;
1083 
1084                 min_key.offset++;
1085                 btrfs_release_path(path);
1086         }
1087 none:
1088         btrfs_free_path(path);
1089         return -ENOENT;
1090 }
1091 
1092 static struct extent_map *defrag_lookup_extent(struct inode *inode, u64 start)
1093 {
1094         struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
1095         struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
1096         struct extent_map *em;
1097         u64 len = PAGE_SIZE;
1098 
1099         /*
1100          * hopefully we have this extent in the tree already, try without
1101          * the full extent lock
1102          */
1103         read_lock(&em_tree->lock);
1104         em = lookup_extent_mapping(em_tree, start, len);
1105         read_unlock(&em_tree->lock);
1106 
1107         if (!em) {
1108                 struct extent_state *cached = NULL;
1109                 u64 end = start + len - 1;
1110 
1111                 /* get the big lock and read metadata off disk */
1112                 lock_extent_bits(io_tree, start, end, &cached);
1113                 em = btrfs_get_extent(BTRFS_I(inode), NULL, 0, start, len, 0);
1114                 unlock_extent_cached(io_tree, start, end, &cached);
1115 
1116                 if (IS_ERR(em))
1117                         return NULL;
1118         }
1119 
1120         return em;
1121 }
1122 
1123 static bool defrag_check_next_extent(struct inode *inode, struct extent_map *em)
1124 {
1125         struct extent_map *next;
1126         bool ret = true;
1127 
1128         /* this is the last extent */
1129         if (em->start + em->len >= i_size_read(inode))
1130                 return false;
1131 
1132         next = defrag_lookup_extent(inode, em->start + em->len);
1133         if (!next || next->block_start >= EXTENT_MAP_LAST_BYTE)
1134                 ret = false;
1135         else if ((em->block_start + em->block_len == next->block_start) &&
1136                  (em->block_len > SZ_128K && next->block_len > SZ_128K))
1137                 ret = false;
1138 
1139         free_extent_map(next);
1140         return ret;
1141 }
1142 
1143 static int should_defrag_range(struct inode *inode, u64 start, u32 thresh,
1144                                u64 *last_len, u64 *skip, u64 *defrag_end,
1145                                int compress)
1146 {
1147         struct extent_map *em;
1148         int ret = 1;
1149         bool next_mergeable = true;
1150         bool prev_mergeable = true;
1151 
1152         /*
1153          * make sure that once we start defragging an extent, we keep on
1154          * defragging it
1155          */
1156         if (start < *defrag_end)
1157                 return 1;
1158 
1159         *skip = 0;
1160 
1161         em = defrag_lookup_extent(inode, start);
1162         if (!em)
1163                 return 0;
1164 
1165         /* this will cover holes, and inline extents */
1166         if (em->block_start >= EXTENT_MAP_LAST_BYTE) {
1167                 ret = 0;
1168                 goto out;
1169         }
1170 
1171         if (!*defrag_end)
1172                 prev_mergeable = false;
1173 
1174         next_mergeable = defrag_check_next_extent(inode, em);
1175         /*
1176          * we hit a real extent, if it is big or the next extent is not a
1177          * real extent, don't bother defragging it
1178          */
1179         if (!compress && (*last_len == 0 || *last_len >= thresh) &&
1180             (em->len >= thresh || (!next_mergeable && !prev_mergeable)))
1181                 ret = 0;
1182 out:
1183         /*
1184          * last_len ends up being a counter of how many bytes we've defragged.
1185          * every time we choose not to defrag an extent, we reset *last_len
1186          * so that the next tiny extent will force a defrag.
1187          *
1188          * The end result of this is that tiny extents before a single big
1189          * extent will force at least part of that big extent to be defragged.
1190          */
1191         if (ret) {
1192                 *defrag_end = extent_map_end(em);
1193         } else {
1194                 *last_len = 0;
1195                 *skip = extent_map_end(em);
1196                 *defrag_end = 0;
1197         }
1198 
1199         free_extent_map(em);
1200         return ret;
1201 }
1202 
1203 /*
1204  * it doesn't do much good to defrag one or two pages
1205  * at a time.  This pulls in a nice chunk of pages
1206  * to COW and defrag.
1207  *
1208  * It also makes sure the delalloc code has enough
1209  * dirty data to avoid making new small extents as part
1210  * of the defrag
1211  *
1212  * It's a good idea to start RA on this range
1213  * before calling this.
1214  */
1215 static int cluster_pages_for_defrag(struct inode *inode,
1216                                     struct page **pages,
1217                                     unsigned long start_index,
1218                                     unsigned long num_pages)
1219 {
1220         unsigned long file_end;
1221         u64 isize = i_size_read(inode);
1222         u64 page_start;
1223         u64 page_end;
1224         u64 page_cnt;
1225         int ret;
1226         int i;
1227         int i_done;
1228         struct btrfs_ordered_extent *ordered;
1229         struct extent_state *cached_state = NULL;
1230         struct extent_io_tree *tree;
1231         struct extent_changeset *data_reserved = NULL;
1232         gfp_t mask = btrfs_alloc_write_mask(inode->i_mapping);
1233 
1234         file_end = (isize - 1) >> PAGE_SHIFT;
1235         if (!isize || start_index > file_end)
1236                 return 0;
1237 
1238         page_cnt = min_t(u64, (u64)num_pages, (u64)file_end - start_index + 1);
1239 
1240         ret = btrfs_delalloc_reserve_space(inode, &data_reserved,
1241                         start_index << PAGE_SHIFT,
1242                         page_cnt << PAGE_SHIFT);
1243         if (ret)
1244                 return ret;
1245         i_done = 0;
1246         tree = &BTRFS_I(inode)->io_tree;
1247 
1248         /* step one, lock all the pages */
1249         for (i = 0; i < page_cnt; i++) {
1250                 struct page *page;
1251 again:
1252                 page = find_or_create_page(inode->i_mapping,
1253                                            start_index + i, mask);
1254                 if (!page)
1255                         break;
1256 
1257                 page_start = page_offset(page);
1258                 page_end = page_start + PAGE_SIZE - 1;
1259                 while (1) {
1260                         lock_extent_bits(tree, page_start, page_end,
1261                                          &cached_state);
1262                         ordered = btrfs_lookup_ordered_extent(inode,
1263                                                               page_start);
1264                         unlock_extent_cached(tree, page_start, page_end,
1265                                              &cached_state);
1266                         if (!ordered)
1267                                 break;
1268 
1269                         unlock_page(page);
1270                         btrfs_start_ordered_extent(inode, ordered, 1);
1271                         btrfs_put_ordered_extent(ordered);
1272                         lock_page(page);
1273                         /*
1274                          * we unlocked the page above, so we need check if
1275                          * it was released or not.
1276                          */
1277                         if (page->mapping != inode->i_mapping) {
1278                                 unlock_page(page);
1279                                 put_page(page);
1280                                 goto again;
1281                         }
1282                 }
1283 
1284                 if (!PageUptodate(page)) {
1285                         btrfs_readpage(NULL, page);
1286                         lock_page(page);
1287                         if (!PageUptodate(page)) {
1288                                 unlock_page(page);
1289                                 put_page(page);
1290                                 ret = -EIO;
1291                                 break;
1292                         }
1293                 }
1294 
1295                 if (page->mapping != inode->i_mapping) {
1296                         unlock_page(page);
1297                         put_page(page);
1298                         goto again;
1299                 }
1300 
1301                 pages[i] = page;
1302                 i_done++;
1303         }
1304         if (!i_done || ret)
1305                 goto out;
1306 
1307         if (!(inode->i_sb->s_flags & SB_ACTIVE))
1308                 goto out;
1309 
1310         /*
1311          * so now we have a nice long stream of locked
1312          * and up to date pages, lets wait on them
1313          */
1314         for (i = 0; i < i_done; i++)
1315                 wait_on_page_writeback(pages[i]);
1316 
1317         page_start = page_offset(pages[0]);
1318         page_end = page_offset(pages[i_done - 1]) + PAGE_SIZE;
1319 
1320         lock_extent_bits(&BTRFS_I(inode)->io_tree,
1321                          page_start, page_end - 1, &cached_state);
1322         clear_extent_bit(&BTRFS_I(inode)->io_tree, page_start,
1323                           page_end - 1, EXTENT_DIRTY | EXTENT_DELALLOC |
1324                           EXTENT_DO_ACCOUNTING | EXTENT_DEFRAG, 0, 0,
1325                           &cached_state);
1326 
1327         if (i_done != page_cnt) {
1328                 spin_lock(&BTRFS_I(inode)->lock);
1329                 btrfs_mod_outstanding_extents(BTRFS_I(inode), 1);
1330                 spin_unlock(&BTRFS_I(inode)->lock);
1331                 btrfs_delalloc_release_space(inode, data_reserved,
1332                                 start_index << PAGE_SHIFT,
1333                                 (page_cnt - i_done) << PAGE_SHIFT, true);
1334         }
1335 
1336 
1337         set_extent_defrag(&BTRFS_I(inode)->io_tree, page_start, page_end - 1,
1338                           &cached_state);
1339 
1340         unlock_extent_cached(&BTRFS_I(inode)->io_tree,
1341                              page_start, page_end - 1, &cached_state);
1342 
1343         for (i = 0; i < i_done; i++) {
1344                 clear_page_dirty_for_io(pages[i]);
1345                 ClearPageChecked(pages[i]);
1346                 set_page_extent_mapped(pages[i]);
1347                 set_page_dirty(pages[i]);
1348                 unlock_page(pages[i]);
1349                 put_page(pages[i]);
1350         }
1351         btrfs_delalloc_release_extents(BTRFS_I(inode), page_cnt << PAGE_SHIFT,
1352                                        false);
1353         extent_changeset_free(data_reserved);
1354         return i_done;
1355 out:
1356         for (i = 0; i < i_done; i++) {
1357                 unlock_page(pages[i]);
1358                 put_page(pages[i]);
1359         }
1360         btrfs_delalloc_release_space(inode, data_reserved,
1361                         start_index << PAGE_SHIFT,
1362                         page_cnt << PAGE_SHIFT, true);
1363         btrfs_delalloc_release_extents(BTRFS_I(inode), page_cnt << PAGE_SHIFT,
1364                                        true);
1365         extent_changeset_free(data_reserved);
1366         return ret;
1367 
1368 }
1369 
1370 int btrfs_defrag_file(struct inode *inode, struct file *file,
1371                       struct btrfs_ioctl_defrag_range_args *range,
1372                       u64 newer_than, unsigned long max_to_defrag)
1373 {
1374         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
1375         struct btrfs_root *root = BTRFS_I(inode)->root;
1376         struct file_ra_state *ra = NULL;
1377         unsigned long last_index;
1378         u64 isize = i_size_read(inode);
1379         u64 last_len = 0;
1380         u64 skip = 0;
1381         u64 defrag_end = 0;
1382         u64 newer_off = range->start;
1383         unsigned long i;
1384         unsigned long ra_index = 0;
1385         int ret;
1386         int defrag_count = 0;
1387         int compress_type = BTRFS_COMPRESS_ZLIB;
1388         u32 extent_thresh = range->extent_thresh;
1389         unsigned long max_cluster = SZ_256K >> PAGE_SHIFT;
1390         unsigned long cluster = max_cluster;
1391         u64 new_align = ~((u64)SZ_128K - 1);
1392         struct page **pages = NULL;
1393         bool do_compress = range->flags & BTRFS_DEFRAG_RANGE_COMPRESS;
1394 
1395         if (isize == 0)
1396                 return 0;
1397 
1398         if (range->start >= isize)
1399                 return -EINVAL;
1400 
1401         if (do_compress) {
1402                 if (range->compress_type > BTRFS_COMPRESS_TYPES)
1403                         return -EINVAL;
1404                 if (range->compress_type)
1405                         compress_type = range->compress_type;
1406         }
1407 
1408         if (extent_thresh == 0)
1409                 extent_thresh = SZ_256K;
1410 
1411         /*
1412          * If we were not given a file, allocate a readahead context. As
1413          * readahead is just an optimization, defrag will work without it so
1414          * we don't error out.
1415          */
1416         if (!file) {
1417                 ra = kzalloc(sizeof(*ra), GFP_KERNEL);
1418                 if (ra)
1419                         file_ra_state_init(ra, inode->i_mapping);
1420         } else {
1421                 ra = &file->f_ra;
1422         }
1423 
1424         pages = kmalloc_array(max_cluster, sizeof(struct page *), GFP_KERNEL);
1425         if (!pages) {
1426                 ret = -ENOMEM;
1427                 goto out_ra;
1428         }
1429 
1430         /* find the last page to defrag */
1431         if (range->start + range->len > range->start) {
1432                 last_index = min_t(u64, isize - 1,
1433                          range->start + range->len - 1) >> PAGE_SHIFT;
1434         } else {
1435                 last_index = (isize - 1) >> PAGE_SHIFT;
1436         }
1437 
1438         if (newer_than) {
1439                 ret = find_new_extents(root, inode, newer_than,
1440                                        &newer_off, SZ_64K);
1441                 if (!ret) {
1442                         range->start = newer_off;
1443                         /*
1444                          * we always align our defrag to help keep
1445                          * the extents in the file evenly spaced
1446                          */
1447                         i = (newer_off & new_align) >> PAGE_SHIFT;
1448                 } else
1449                         goto out_ra;
1450         } else {
1451                 i = range->start >> PAGE_SHIFT;
1452         }
1453         if (!max_to_defrag)
1454                 max_to_defrag = last_index - i + 1;
1455 
1456         /*
1457          * make writeback starts from i, so the defrag range can be
1458          * written sequentially.
1459          */
1460         if (i < inode->i_mapping->writeback_index)
1461                 inode->i_mapping->writeback_index = i;
1462 
1463         while (i <= last_index && defrag_count < max_to_defrag &&
1464                (i < DIV_ROUND_UP(i_size_read(inode), PAGE_SIZE))) {
1465                 /*
1466                  * make sure we stop running if someone unmounts
1467                  * the FS
1468                  */
1469                 if (!(inode->i_sb->s_flags & SB_ACTIVE))
1470                         break;
1471 
1472                 if (btrfs_defrag_cancelled(fs_info)) {
1473                         btrfs_debug(fs_info, "defrag_file cancelled");
1474                         ret = -EAGAIN;
1475                         break;
1476                 }
1477 
1478                 if (!should_defrag_range(inode, (u64)i << PAGE_SHIFT,
1479                                          extent_thresh, &last_len, &skip,
1480                                          &defrag_end, do_compress)){
1481                         unsigned long next;
1482                         /*
1483                          * the should_defrag function tells us how much to skip
1484                          * bump our counter by the suggested amount
1485                          */
1486                         next = DIV_ROUND_UP(skip, PAGE_SIZE);
1487                         i = max(i + 1, next);
1488                         continue;
1489                 }
1490 
1491                 if (!newer_than) {
1492                         cluster = (PAGE_ALIGN(defrag_end) >>
1493                                    PAGE_SHIFT) - i;
1494                         cluster = min(cluster, max_cluster);
1495                 } else {
1496                         cluster = max_cluster;
1497                 }
1498 
1499                 if (i + cluster > ra_index) {
1500                         ra_index = max(i, ra_index);
1501                         if (ra)
1502                                 page_cache_sync_readahead(inode->i_mapping, ra,
1503                                                 file, ra_index, cluster);
1504                         ra_index += cluster;
1505                 }
1506 
1507                 inode_lock(inode);
1508                 if (do_compress)
1509                         BTRFS_I(inode)->defrag_compress = compress_type;
1510                 ret = cluster_pages_for_defrag(inode, pages, i, cluster);
1511                 if (ret < 0) {
1512                         inode_unlock(inode);
1513                         goto out_ra;
1514                 }
1515 
1516                 defrag_count += ret;
1517                 balance_dirty_pages_ratelimited(inode->i_mapping);
1518                 inode_unlock(inode);
1519 
1520                 if (newer_than) {
1521                         if (newer_off == (u64)-1)
1522                                 break;
1523 
1524                         if (ret > 0)
1525                                 i += ret;
1526 
1527                         newer_off = max(newer_off + 1,
1528                                         (u64)i << PAGE_SHIFT);
1529 
1530                         ret = find_new_extents(root, inode, newer_than,
1531                                                &newer_off, SZ_64K);
1532                         if (!ret) {
1533                                 range->start = newer_off;
1534                                 i = (newer_off & new_align) >> PAGE_SHIFT;
1535                         } else {
1536                                 break;
1537                         }
1538                 } else {
1539                         if (ret > 0) {
1540                                 i += ret;
1541                                 last_len += ret << PAGE_SHIFT;
1542                         } else {
1543                                 i++;
1544                                 last_len = 0;
1545                         }
1546                 }
1547         }
1548 
1549         if ((range->flags & BTRFS_DEFRAG_RANGE_START_IO)) {
1550                 filemap_flush(inode->i_mapping);
1551                 if (test_bit(BTRFS_INODE_HAS_ASYNC_EXTENT,
1552                              &BTRFS_I(inode)->runtime_flags))
1553                         filemap_flush(inode->i_mapping);
1554         }
1555 
1556         if (range->compress_type == BTRFS_COMPRESS_LZO) {
1557                 btrfs_set_fs_incompat(fs_info, COMPRESS_LZO);
1558         } else if (range->compress_type == BTRFS_COMPRESS_ZSTD) {
1559                 btrfs_set_fs_incompat(fs_info, COMPRESS_ZSTD);
1560         }
1561 
1562         ret = defrag_count;
1563 
1564 out_ra:
1565         if (do_compress) {
1566                 inode_lock(inode);
1567                 BTRFS_I(inode)->defrag_compress = BTRFS_COMPRESS_NONE;
1568                 inode_unlock(inode);
1569         }
1570         if (!file)
1571                 kfree(ra);
1572         kfree(pages);
1573         return ret;
1574 }
1575 
1576 static noinline int btrfs_ioctl_resize(struct file *file,
1577                                         void __user *arg)
1578 {
1579         struct inode *inode = file_inode(file);
1580         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
1581         u64 new_size;
1582         u64 old_size;
1583         u64 devid = 1;
1584         struct btrfs_root *root = BTRFS_I(inode)->root;
1585         struct btrfs_ioctl_vol_args *vol_args;
1586         struct btrfs_trans_handle *trans;
1587         struct btrfs_device *device = NULL;
1588         char *sizestr;
1589         char *retptr;
1590         char *devstr = NULL;
1591         int ret = 0;
1592         int mod = 0;
1593 
1594         if (!capable(CAP_SYS_ADMIN))
1595                 return -EPERM;
1596 
1597         ret = mnt_want_write_file(file);
1598         if (ret)
1599                 return ret;
1600 
1601         if (test_and_set_bit(BTRFS_FS_EXCL_OP, &fs_info->flags)) {
1602                 mnt_drop_write_file(file);
1603                 return BTRFS_ERROR_DEV_EXCL_RUN_IN_PROGRESS;
1604         }
1605 
1606         vol_args = memdup_user(arg, sizeof(*vol_args));
1607         if (IS_ERR(vol_args)) {
1608                 ret = PTR_ERR(vol_args);
1609                 goto out;
1610         }
1611 
1612         vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
1613 
1614         sizestr = vol_args->name;
1615         devstr = strchr(sizestr, ':');
1616         if (devstr) {
1617                 sizestr = devstr + 1;
1618                 *devstr = '\0';
1619                 devstr = vol_args->name;
1620                 ret = kstrtoull(devstr, 10, &devid);
1621                 if (ret)
1622                         goto out_free;
1623                 if (!devid) {
1624                         ret = -EINVAL;
1625                         goto out_free;
1626                 }
1627                 btrfs_info(fs_info, "resizing devid %llu", devid);
1628         }
1629 
1630         device = btrfs_find_device(fs_info, devid, NULL, NULL);
1631         if (!device) {
1632                 btrfs_info(fs_info, "resizer unable to find device %llu",
1633                            devid);
1634                 ret = -ENODEV;
1635                 goto out_free;
1636         }
1637 
1638         if (!test_bit(BTRFS_DEV_STATE_WRITEABLE, &device->dev_state)) {
1639                 btrfs_info(fs_info,
1640                            "resizer unable to apply on readonly device %llu",
1641                        devid);
1642                 ret = -EPERM;
1643                 goto out_free;
1644         }
1645 
1646         if (!strcmp(sizestr, "max"))
1647                 new_size = device->bdev->bd_inode->i_size;
1648         else {
1649                 if (sizestr[0] == '-') {
1650                         mod = -1;
1651                         sizestr++;
1652                 } else if (sizestr[0] == '+') {
1653                         mod = 1;
1654                         sizestr++;
1655                 }
1656                 new_size = memparse(sizestr, &retptr);
1657                 if (*retptr != '\0' || new_size == 0) {
1658                         ret = -EINVAL;
1659                         goto out_free;
1660                 }
1661         }
1662 
1663         if (test_bit(BTRFS_DEV_STATE_REPLACE_TGT, &device->dev_state)) {
1664                 ret = -EPERM;
1665                 goto out_free;
1666         }
1667 
1668         old_size = btrfs_device_get_total_bytes(device);
1669 
1670         if (mod < 0) {
1671                 if (new_size > old_size) {
1672                         ret = -EINVAL;
1673                         goto out_free;
1674                 }
1675                 new_size = old_size - new_size;
1676         } else if (mod > 0) {
1677                 if (new_size > ULLONG_MAX - old_size) {
1678                         ret = -ERANGE;
1679                         goto out_free;
1680                 }
1681                 new_size = old_size + new_size;
1682         }
1683 
1684         if (new_size < SZ_256M) {
1685                 ret = -EINVAL;
1686                 goto out_free;
1687         }
1688         if (new_size > device->bdev->bd_inode->i_size) {
1689                 ret = -EFBIG;
1690                 goto out_free;
1691         }
1692 
1693         new_size = round_down(new_size, fs_info->sectorsize);
1694 
1695         btrfs_info_in_rcu(fs_info, "new size for %s is %llu",
1696                           rcu_str_deref(device->name), new_size);
1697 
1698         if (new_size > old_size) {
1699                 trans = btrfs_start_transaction(root, 0);
1700                 if (IS_ERR(trans)) {
1701                         ret = PTR_ERR(trans);
1702                         goto out_free;
1703                 }
1704                 ret = btrfs_grow_device(trans, device, new_size);
1705                 btrfs_commit_transaction(trans);
1706         } else if (new_size < old_size) {
1707                 ret = btrfs_shrink_device(device, new_size);
1708         } /* equal, nothing need to do */
1709 
1710 out_free:
1711         kfree(vol_args);
1712 out:
1713         clear_bit(BTRFS_FS_EXCL_OP, &fs_info->flags);
1714         mnt_drop_write_file(file);
1715         return ret;
1716 }
1717 
1718 static noinline int btrfs_ioctl_snap_create_transid(struct file *file,
1719                                 const char *name, unsigned long fd, int subvol,
1720                                 u64 *transid, bool readonly,
1721                                 struct btrfs_qgroup_inherit *inherit)
1722 {
1723         int namelen;
1724         int ret = 0;
1725 
1726         if (!S_ISDIR(file_inode(file)->i_mode))
1727                 return -ENOTDIR;
1728 
1729         ret = mnt_want_write_file(file);
1730         if (ret)
1731                 goto out;
1732 
1733         namelen = strlen(name);
1734         if (strchr(name, '/')) {
1735                 ret = -EINVAL;
1736                 goto out_drop_write;
1737         }
1738 
1739         if (name[0] == '.' &&
1740            (namelen == 1 || (name[1] == '.' && namelen == 2))) {
1741                 ret = -EEXIST;
1742                 goto out_drop_write;
1743         }
1744 
1745         if (subvol) {
1746                 ret = btrfs_mksubvol(&file->f_path, name, namelen,
1747                                      NULL, transid, readonly, inherit);
1748         } else {
1749                 struct fd src = fdget(fd);
1750                 struct inode *src_inode;
1751                 if (!src.file) {
1752                         ret = -EINVAL;
1753                         goto out_drop_write;
1754                 }
1755 
1756                 src_inode = file_inode(src.file);
1757                 if (src_inode->i_sb != file_inode(file)->i_sb) {
1758                         btrfs_info(BTRFS_I(file_inode(file))->root->fs_info,
1759                                    "Snapshot src from another FS");
1760                         ret = -EXDEV;
1761                 } else if (!inode_owner_or_capable(src_inode)) {
1762                         /*
1763                          * Subvolume creation is not restricted, but snapshots
1764                          * are limited to own subvolumes only
1765                          */
1766                         ret = -EPERM;
1767                 } else {
1768                         ret = btrfs_mksubvol(&file->f_path, name, namelen,
1769                                              BTRFS_I(src_inode)->root,
1770                                              transid, readonly, inherit);
1771                 }
1772                 fdput(src);
1773         }
1774 out_drop_write:
1775         mnt_drop_write_file(file);
1776 out:
1777         return ret;
1778 }
1779 
1780 static noinline int btrfs_ioctl_snap_create(struct file *file,
1781                                             void __user *arg, int subvol)
1782 {
1783         struct btrfs_ioctl_vol_args *vol_args;
1784         int ret;
1785 
1786         if (!S_ISDIR(file_inode(file)->i_mode))
1787                 return -ENOTDIR;
1788 
1789         vol_args = memdup_user(arg, sizeof(*vol_args));
1790         if (IS_ERR(vol_args))
1791                 return PTR_ERR(vol_args);
1792         vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
1793 
1794         ret = btrfs_ioctl_snap_create_transid(file, vol_args->name,
1795                                               vol_args->fd, subvol,
1796                                               NULL, false, NULL);
1797 
1798         kfree(vol_args);
1799         return ret;
1800 }
1801 
1802 static noinline int btrfs_ioctl_snap_create_v2(struct file *file,
1803                                                void __user *arg, int subvol)
1804 {
1805         struct btrfs_ioctl_vol_args_v2 *vol_args;
1806         int ret;
1807         u64 transid = 0;
1808         u64 *ptr = NULL;
1809         bool readonly = false;
1810         struct btrfs_qgroup_inherit *inherit = NULL;
1811 
1812         if (!S_ISDIR(file_inode(file)->i_mode))
1813                 return -ENOTDIR;
1814 
1815         vol_args = memdup_user(arg, sizeof(*vol_args));
1816         if (IS_ERR(vol_args))
1817                 return PTR_ERR(vol_args);
1818         vol_args->name[BTRFS_SUBVOL_NAME_MAX] = '\0';
1819 
1820         if (vol_args->flags &
1821             ~(BTRFS_SUBVOL_CREATE_ASYNC | BTRFS_SUBVOL_RDONLY |
1822               BTRFS_SUBVOL_QGROUP_INHERIT)) {
1823                 ret = -EOPNOTSUPP;
1824                 goto free_args;
1825         }
1826 
1827         if (vol_args->flags & BTRFS_SUBVOL_CREATE_ASYNC)
1828                 ptr = &transid;
1829         if (vol_args->flags & BTRFS_SUBVOL_RDONLY)
1830                 readonly = true;
1831         if (vol_args->flags & BTRFS_SUBVOL_QGROUP_INHERIT) {
1832                 if (vol_args->size > PAGE_SIZE) {
1833                         ret = -EINVAL;
1834                         goto free_args;
1835                 }
1836                 inherit = memdup_user(vol_args->qgroup_inherit, vol_args->size);
1837                 if (IS_ERR(inherit)) {
1838                         ret = PTR_ERR(inherit);
1839                         goto free_args;
1840                 }
1841         }
1842 
1843         ret = btrfs_ioctl_snap_create_transid(file, vol_args->name,
1844                                               vol_args->fd, subvol, ptr,
1845                                               readonly, inherit);
1846         if (ret)
1847                 goto free_inherit;
1848 
1849         if (ptr && copy_to_user(arg +
1850                                 offsetof(struct btrfs_ioctl_vol_args_v2,
1851                                         transid),
1852                                 ptr, sizeof(*ptr)))
1853                 ret = -EFAULT;
1854 
1855 free_inherit:
1856         kfree(inherit);
1857 free_args:
1858         kfree(vol_args);
1859         return ret;
1860 }
1861 
1862 static noinline int btrfs_ioctl_subvol_getflags(struct file *file,
1863                                                 void __user *arg)
1864 {
1865         struct inode *inode = file_inode(file);
1866         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
1867         struct btrfs_root *root = BTRFS_I(inode)->root;
1868         int ret = 0;
1869         u64 flags = 0;
1870 
1871         if (btrfs_ino(BTRFS_I(inode)) != BTRFS_FIRST_FREE_OBJECTID)
1872                 return -EINVAL;
1873 
1874         down_read(&fs_info->subvol_sem);
1875         if (btrfs_root_readonly(root))
1876                 flags |= BTRFS_SUBVOL_RDONLY;
1877         up_read(&fs_info->subvol_sem);
1878 
1879         if (copy_to_user(arg, &flags, sizeof(flags)))
1880                 ret = -EFAULT;
1881 
1882         return ret;
1883 }
1884 
1885 static noinline int btrfs_ioctl_subvol_setflags(struct file *file,
1886                                               void __user *arg)
1887 {
1888         struct inode *inode = file_inode(file);
1889         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
1890         struct btrfs_root *root = BTRFS_I(inode)->root;
1891         struct btrfs_trans_handle *trans;
1892         u64 root_flags;
1893         u64 flags;
1894         int ret = 0;
1895 
1896         if (!inode_owner_or_capable(inode))
1897                 return -EPERM;
1898 
1899         ret = mnt_want_write_file(file);
1900         if (ret)
1901                 goto out;
1902 
1903         if (btrfs_ino(BTRFS_I(inode)) != BTRFS_FIRST_FREE_OBJECTID) {
1904                 ret = -EINVAL;
1905                 goto out_drop_write;
1906         }
1907 
1908         if (copy_from_user(&flags, arg, sizeof(flags))) {
1909                 ret = -EFAULT;
1910                 goto out_drop_write;
1911         }
1912 
1913         if (flags & BTRFS_SUBVOL_CREATE_ASYNC) {
1914                 ret = -EINVAL;
1915                 goto out_drop_write;
1916         }
1917 
1918         if (flags & ~BTRFS_SUBVOL_RDONLY) {
1919                 ret = -EOPNOTSUPP;
1920                 goto out_drop_write;
1921         }
1922 
1923         down_write(&fs_info->subvol_sem);
1924 
1925         /* nothing to do */
1926         if (!!(flags & BTRFS_SUBVOL_RDONLY) == btrfs_root_readonly(root))
1927                 goto out_drop_sem;
1928 
1929         root_flags = btrfs_root_flags(&root->root_item);
1930         if (flags & BTRFS_SUBVOL_RDONLY) {
1931                 btrfs_set_root_flags(&root->root_item,
1932                                      root_flags | BTRFS_ROOT_SUBVOL_RDONLY);
1933         } else {
1934                 /*
1935                  * Block RO -> RW transition if this subvolume is involved in
1936                  * send
1937                  */
1938                 spin_lock(&root->root_item_lock);
1939                 if (root->send_in_progress == 0) {
1940                         btrfs_set_root_flags(&root->root_item,
1941                                      root_flags & ~BTRFS_ROOT_SUBVOL_RDONLY);
1942                         spin_unlock(&root->root_item_lock);
1943                 } else {
1944                         spin_unlock(&root->root_item_lock);
1945                         btrfs_warn(fs_info,
1946                                    "Attempt to set subvolume %llu read-write during send",
1947                                    root->root_key.objectid);
1948                         ret = -EPERM;
1949                         goto out_drop_sem;
1950                 }
1951         }
1952 
1953         trans = btrfs_start_transaction(root, 1);
1954         if (IS_ERR(trans)) {
1955                 ret = PTR_ERR(trans);
1956                 goto out_reset;
1957         }
1958 
1959         ret = btrfs_update_root(trans, fs_info->tree_root,
1960                                 &root->root_key, &root->root_item);
1961         if (ret < 0) {
1962                 btrfs_end_transaction(trans);
1963                 goto out_reset;
1964         }
1965 
1966         ret = btrfs_commit_transaction(trans);
1967 
1968 out_reset:
1969         if (ret)
1970                 btrfs_set_root_flags(&root->root_item, root_flags);
1971 out_drop_sem:
1972         up_write(&fs_info->subvol_sem);
1973 out_drop_write:
1974         mnt_drop_write_file(file);
1975 out:
1976         return ret;
1977 }
1978 
1979 static noinline int key_in_sk(struct btrfs_key *key,
1980                               struct btrfs_ioctl_search_key *sk)
1981 {
1982         struct btrfs_key test;
1983         int ret;
1984 
1985         test.objectid = sk->min_objectid;
1986         test.type = sk->min_type;
1987         test.offset = sk->min_offset;
1988 
1989         ret = btrfs_comp_cpu_keys(key, &test);
1990         if (ret < 0)
1991                 return 0;
1992 
1993         test.objectid = sk->max_objectid;
1994         test.type = sk->max_type;
1995         test.offset = sk->max_offset;
1996 
1997         ret = btrfs_comp_cpu_keys(key, &test);
1998         if (ret > 0)
1999                 return 0;
2000         return 1;
2001 }
2002 
2003 static noinline int copy_to_sk(struct btrfs_path *path,
2004                                struct btrfs_key *key,
2005                                struct btrfs_ioctl_search_key *sk,
2006                                size_t *buf_size,
2007                                char __user *ubuf,
2008                                unsigned long *sk_offset,
2009                                int *num_found)
2010 {
2011         u64 found_transid;
2012         struct extent_buffer *leaf;
2013         struct btrfs_ioctl_search_header sh;
2014         struct btrfs_key test;
2015         unsigned long item_off;
2016         unsigned long item_len;
2017         int nritems;
2018         int i;
2019         int slot;
2020         int ret = 0;
2021 
2022         leaf = path->nodes[0];
2023         slot = path->slots[0];
2024         nritems = btrfs_header_nritems(leaf);
2025 
2026         if (btrfs_header_generation(leaf) > sk->max_transid) {
2027                 i = nritems;
2028                 goto advance_key;
2029         }
2030         found_transid = btrfs_header_generation(leaf);
2031 
2032         for (i = slot; i < nritems; i++) {
2033                 item_off = btrfs_item_ptr_offset(leaf, i);
2034                 item_len = btrfs_item_size_nr(leaf, i);
2035 
2036                 btrfs_item_key_to_cpu(leaf, key, i);
2037                 if (!key_in_sk(key, sk))
2038                         continue;
2039 
2040                 if (sizeof(sh) + item_len > *buf_size) {
2041                         if (*num_found) {
2042                                 ret = 1;
2043                                 goto out;
2044                         }
2045 
2046                         /*
2047                          * return one empty item back for v1, which does not
2048                          * handle -EOVERFLOW
2049                          */
2050 
2051                         *buf_size = sizeof(sh) + item_len;
2052                         item_len = 0;
2053                         ret = -EOVERFLOW;
2054                 }
2055 
2056                 if (sizeof(sh) + item_len + *sk_offset > *buf_size) {
2057                         ret = 1;
2058                         goto out;
2059                 }
2060 
2061                 sh.objectid = key->objectid;
2062                 sh.offset = key->offset;
2063                 sh.type = key->type;
2064                 sh.len = item_len;
2065                 sh.transid = found_transid;
2066 
2067                 /* copy search result header */
2068                 if (copy_to_user(ubuf + *sk_offset, &sh, sizeof(sh))) {
2069                         ret = -EFAULT;
2070                         goto out;
2071                 }
2072 
2073                 *sk_offset += sizeof(sh);
2074 
2075                 if (item_len) {
2076                         char __user *up = ubuf + *sk_offset;
2077                         /* copy the item */
2078                         if (read_extent_buffer_to_user(leaf, up,
2079                                                        item_off, item_len)) {
2080                                 ret = -EFAULT;
2081                                 goto out;
2082                         }
2083 
2084                         *sk_offset += item_len;
2085                 }
2086                 (*num_found)++;
2087 
2088                 if (ret) /* -EOVERFLOW from above */
2089                         goto out;
2090 
2091                 if (*num_found >= sk->nr_items) {
2092                         ret = 1;
2093                         goto out;
2094                 }
2095         }
2096 advance_key:
2097         ret = 0;
2098         test.objectid = sk->max_objectid;
2099         test.type = sk->max_type;
2100         test.offset = sk->max_offset;
2101         if (btrfs_comp_cpu_keys(key, &test) >= 0)
2102                 ret = 1;
2103         else if (key->offset < (u64)-1)
2104                 key->offset++;
2105         else if (key->type < (u8)-1) {
2106                 key->offset = 0;
2107                 key->type++;
2108         } else if (key->objectid < (u64)-1) {
2109                 key->offset = 0;
2110                 key->type = 0;
2111                 key->objectid++;
2112         } else
2113                 ret = 1;
2114 out:
2115         /*
2116          *  0: all items from this leaf copied, continue with next
2117          *  1: * more items can be copied, but unused buffer is too small
2118          *     * all items were found
2119          *     Either way, it will stops the loop which iterates to the next
2120          *     leaf
2121          *  -EOVERFLOW: item was to large for buffer
2122          *  -EFAULT: could not copy extent buffer back to userspace
2123          */
2124         return ret;
2125 }
2126 
2127 static noinline int search_ioctl(struct inode *inode,
2128                                  struct btrfs_ioctl_search_key *sk,
2129                                  size_t *buf_size,
2130                                  char __user *ubuf)
2131 {
2132         struct btrfs_fs_info *info = btrfs_sb(inode->i_sb);
2133         struct btrfs_root *root;
2134         struct btrfs_key key;
2135         struct btrfs_path *path;
2136         int ret;
2137         int num_found = 0;
2138         unsigned long sk_offset = 0;
2139 
2140         if (*buf_size < sizeof(struct btrfs_ioctl_search_header)) {
2141                 *buf_size = sizeof(struct btrfs_ioctl_search_header);
2142                 return -EOVERFLOW;
2143         }
2144 
2145         path = btrfs_alloc_path();
2146         if (!path)
2147                 return -ENOMEM;
2148 
2149         if (sk->tree_id == 0) {
2150                 /* search the root of the inode that was passed */
2151                 root = BTRFS_I(inode)->root;
2152         } else {
2153                 key.objectid = sk->tree_id;
2154                 key.type = BTRFS_ROOT_ITEM_KEY;
2155                 key.offset = (u64)-1;
2156                 root = btrfs_read_fs_root_no_name(info, &key);
2157                 if (IS_ERR(root)) {
2158                         btrfs_free_path(path);
2159                         return PTR_ERR(root);
2160                 }
2161         }
2162 
2163         key.objectid = sk->min_objectid;
2164         key.type = sk->min_type;
2165         key.offset = sk->min_offset;
2166 
2167         while (1) {
2168                 ret = btrfs_search_forward(root, &key, path, sk->min_transid);
2169                 if (ret != 0) {
2170                         if (ret > 0)
2171                                 ret = 0;
2172                         goto err;
2173                 }
2174                 ret = copy_to_sk(path, &key, sk, buf_size, ubuf,
2175                                  &sk_offset, &num_found);
2176                 btrfs_release_path(path);
2177                 if (ret)
2178                         break;
2179 
2180         }
2181         if (ret > 0)
2182                 ret = 0;
2183 err:
2184         sk->nr_items = num_found;
2185         btrfs_free_path(path);
2186         return ret;
2187 }
2188 
2189 static noinline int btrfs_ioctl_tree_search(struct file *file,
2190                                            void __user *argp)
2191 {
2192         struct btrfs_ioctl_search_args __user *uargs;
2193         struct btrfs_ioctl_search_key sk;
2194         struct inode *inode;
2195         int ret;
2196         size_t buf_size;
2197 
2198         if (!capable(CAP_SYS_ADMIN))
2199                 return -EPERM;
2200 
2201         uargs = (struct btrfs_ioctl_search_args __user *)argp;
2202 
2203         if (copy_from_user(&sk, &uargs->key, sizeof(sk)))
2204                 return -EFAULT;
2205 
2206         buf_size = sizeof(uargs->buf);
2207 
2208         inode = file_inode(file);
2209         ret = search_ioctl(inode, &sk, &buf_size, uargs->buf);
2210 
2211         /*
2212          * In the origin implementation an overflow is handled by returning a
2213          * search header with a len of zero, so reset ret.
2214          */
2215         if (ret == -EOVERFLOW)
2216                 ret = 0;
2217 
2218         if (ret == 0 && copy_to_user(&uargs->key, &sk, sizeof(sk)))
2219                 ret = -EFAULT;
2220         return ret;
2221 }
2222 
2223 static noinline int btrfs_ioctl_tree_search_v2(struct file *file,
2224                                                void __user *argp)
2225 {
2226         struct btrfs_ioctl_search_args_v2 __user *uarg;
2227         struct btrfs_ioctl_search_args_v2 args;
2228         struct inode *inode;
2229         int ret;
2230         size_t buf_size;
2231         const size_t buf_limit = SZ_16M;
2232 
2233         if (!capable(CAP_SYS_ADMIN))
2234                 return -EPERM;
2235 
2236         /* copy search header and buffer size */
2237         uarg = (struct btrfs_ioctl_search_args_v2 __user *)argp;
2238         if (copy_from_user(&args, uarg, sizeof(args)))
2239                 return -EFAULT;
2240 
2241         buf_size = args.buf_size;
2242 
2243         /* limit result size to 16MB */
2244         if (buf_size > buf_limit)
2245                 buf_size = buf_limit;
2246 
2247         inode = file_inode(file);
2248         ret = search_ioctl(inode, &args.key, &buf_size,
2249                            (char __user *)(&uarg->buf[0]));
2250         if (ret == 0 && copy_to_user(&uarg->key, &args.key, sizeof(args.key)))
2251                 ret = -EFAULT;
2252         else if (ret == -EOVERFLOW &&
2253                 copy_to_user(&uarg->buf_size, &buf_size, sizeof(buf_size)))
2254                 ret = -EFAULT;
2255 
2256         return ret;
2257 }
2258 
2259 /*
2260  * Search INODE_REFs to identify path name of 'dirid' directory
2261  * in a 'tree_id' tree. and sets path name to 'name'.
2262  */
2263 static noinline int btrfs_search_path_in_tree(struct btrfs_fs_info *info,
2264                                 u64 tree_id, u64 dirid, char *name)
2265 {
2266         struct btrfs_root *root;
2267         struct btrfs_key key;
2268         char *ptr;
2269         int ret = -1;
2270         int slot;
2271         int len;
2272         int total_len = 0;
2273         struct btrfs_inode_ref *iref;
2274         struct extent_buffer *l;
2275         struct btrfs_path *path;
2276 
2277         if (dirid == BTRFS_FIRST_FREE_OBJECTID) {
2278                 name[0]='\0';
2279                 return 0;
2280         }
2281 
2282         path = btrfs_alloc_path();
2283         if (!path)
2284                 return -ENOMEM;
2285 
2286         ptr = &name[BTRFS_INO_LOOKUP_PATH_MAX - 1];
2287 
2288         key.objectid = tree_id;
2289         key.type = BTRFS_ROOT_ITEM_KEY;
2290         key.offset = (u64)-1;
2291         root = btrfs_read_fs_root_no_name(info, &key);
2292         if (IS_ERR(root)) {
2293                 ret = PTR_ERR(root);
2294                 goto out;
2295         }
2296 
2297         key.objectid = dirid;
2298         key.type = BTRFS_INODE_REF_KEY;
2299         key.offset = (u64)-1;
2300 
2301         while (1) {
2302                 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
2303                 if (ret < 0)
2304                         goto out;
2305                 else if (ret > 0) {
2306                         ret = btrfs_previous_item(root, path, dirid,
2307                                                   BTRFS_INODE_REF_KEY);
2308                         if (ret < 0)
2309                                 goto out;
2310                         else if (ret > 0) {
2311                                 ret = -ENOENT;
2312                                 goto out;
2313                         }
2314                 }
2315 
2316                 l = path->nodes[0];
2317                 slot = path->slots[0];
2318                 btrfs_item_key_to_cpu(l, &key, slot);
2319 
2320                 iref = btrfs_item_ptr(l, slot, struct btrfs_inode_ref);
2321                 len = btrfs_inode_ref_name_len(l, iref);
2322                 ptr -= len + 1;
2323                 total_len += len + 1;
2324                 if (ptr < name) {
2325                         ret = -ENAMETOOLONG;
2326                         goto out;
2327                 }
2328 
2329                 *(ptr + len) = '/';
2330                 read_extent_buffer(l, ptr, (unsigned long)(iref + 1), len);
2331 
2332                 if (key.offset == BTRFS_FIRST_FREE_OBJECTID)
2333                         break;
2334 
2335                 btrfs_release_path(path);
2336                 key.objectid = key.offset;
2337                 key.offset = (u64)-1;
2338                 dirid = key.objectid;
2339         }
2340         memmove(name, ptr, total_len);
2341         name[total_len] = '\0';
2342         ret = 0;
2343 out:
2344         btrfs_free_path(path);
2345         return ret;
2346 }
2347 
2348 static int btrfs_search_path_in_tree_user(struct inode *inode,
2349                                 struct btrfs_ioctl_ino_lookup_user_args *args)
2350 {
2351         struct btrfs_fs_info *fs_info = BTRFS_I(inode)->root->fs_info;
2352         struct super_block *sb = inode->i_sb;
2353         struct btrfs_key upper_limit = BTRFS_I(inode)->location;
2354         u64 treeid = BTRFS_I(inode)->root->root_key.objectid;
2355         u64 dirid = args->dirid;
2356         unsigned long item_off;
2357         unsigned long item_len;
2358         struct btrfs_inode_ref *iref;
2359         struct btrfs_root_ref *rref;
2360         struct btrfs_root *root;
2361         struct btrfs_path *path;
2362         struct btrfs_key key, key2;
2363         struct extent_buffer *leaf;
2364         struct inode *temp_inode;
2365         char *ptr;
2366         int slot;
2367         int len;
2368         int total_len = 0;
2369         int ret;
2370 
2371         path = btrfs_alloc_path();
2372         if (!path)
2373                 return -ENOMEM;
2374 
2375         /*
2376          * If the bottom subvolume does not exist directly under upper_limit,
2377          * construct the path in from the bottom up.
2378          */
2379         if (dirid != upper_limit.objectid) {
2380                 ptr = &args->path[BTRFS_INO_LOOKUP_USER_PATH_MAX - 1];
2381 
2382                 key.objectid = treeid;
2383                 key.type = BTRFS_ROOT_ITEM_KEY;
2384                 key.offset = (u64)-1;
2385                 root = btrfs_read_fs_root_no_name(fs_info, &key);
2386                 if (IS_ERR(root)) {
2387                         ret = PTR_ERR(root);
2388                         goto out;
2389                 }
2390 
2391                 key.objectid = dirid;
2392                 key.type = BTRFS_INODE_REF_KEY;
2393                 key.offset = (u64)-1;
2394                 while (1) {
2395                         ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
2396                         if (ret < 0) {
2397                                 goto out;
2398                         } else if (ret > 0) {
2399                                 ret = btrfs_previous_item(root, path, dirid,
2400                                                           BTRFS_INODE_REF_KEY);
2401                                 if (ret < 0) {
2402                                         goto out;
2403                                 } else if (ret > 0) {
2404                                         ret = -ENOENT;
2405                                         goto out;
2406                                 }
2407                         }
2408 
2409                         leaf = path->nodes[0];
2410                         slot = path->slots[0];
2411                         btrfs_item_key_to_cpu(leaf, &key, slot);
2412 
2413                         iref = btrfs_item_ptr(leaf, slot, struct btrfs_inode_ref);
2414                         len = btrfs_inode_ref_name_len(leaf, iref);
2415                         ptr -= len + 1;
2416                         total_len += len + 1;
2417                         if (ptr < args->path) {
2418                                 ret = -ENAMETOOLONG;
2419                                 goto out;
2420                         }
2421 
2422                         *(ptr + len) = '/';
2423                         read_extent_buffer(leaf, ptr,
2424                                         (unsigned long)(iref + 1), len);
2425 
2426                         /* Check the read+exec permission of this directory */
2427                         ret = btrfs_previous_item(root, path, dirid,
2428                                                   BTRFS_INODE_ITEM_KEY);
2429                         if (ret < 0) {
2430                                 goto out;
2431                         } else if (ret > 0) {
2432                                 ret = -ENOENT;
2433                                 goto out;
2434                         }
2435 
2436                         leaf = path->nodes[0];
2437                         slot = path->slots[0];
2438                         btrfs_item_key_to_cpu(leaf, &key2, slot);
2439                         if (key2.objectid != dirid) {
2440                                 ret = -ENOENT;
2441                                 goto out;
2442                         }
2443 
2444                         temp_inode = btrfs_iget(sb, &key2, root, NULL);
2445                         if (IS_ERR(temp_inode)) {
2446                                 ret = PTR_ERR(temp_inode);
2447                                 goto out;
2448                         }
2449                         ret = inode_permission(temp_inode, MAY_READ | MAY_EXEC);
2450                         iput(temp_inode);
2451                         if (ret) {
2452                                 ret = -EACCES;
2453                                 goto out;
2454                         }
2455 
2456                         if (key.offset == upper_limit.objectid)
2457                                 break;
2458                         if (key.objectid == BTRFS_FIRST_FREE_OBJECTID) {
2459                                 ret = -EACCES;
2460                                 goto out;
2461                         }
2462 
2463                         btrfs_release_path(path);
2464                         key.objectid = key.offset;
2465                         key.offset = (u64)-1;
2466                         dirid = key.objectid;
2467                 }
2468 
2469                 memmove(args->path, ptr, total_len);
2470                 args->path[total_len] = '\0';
2471                 btrfs_release_path(path);
2472         }
2473 
2474         /* Get the bottom subvolume's name from ROOT_REF */
2475         root = fs_info->tree_root;
2476         key.objectid = treeid;
2477         key.type = BTRFS_ROOT_REF_KEY;
2478         key.offset = args->treeid;
2479         ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
2480         if (ret < 0) {
2481                 goto out;
2482         } else if (ret > 0) {
2483                 ret = -ENOENT;
2484                 goto out;
2485         }
2486 
2487         leaf = path->nodes[0];
2488         slot = path->slots[0];
2489         btrfs_item_key_to_cpu(leaf, &key, slot);
2490 
2491         item_off = btrfs_item_ptr_offset(leaf, slot);
2492         item_len = btrfs_item_size_nr(leaf, slot);
2493         /* Check if dirid in ROOT_REF corresponds to passed dirid */
2494         rref = btrfs_item_ptr(leaf, slot, struct btrfs_root_ref);
2495         if (args->dirid != btrfs_root_ref_dirid(leaf, rref)) {
2496                 ret = -EINVAL;
2497                 goto out;
2498         }
2499 
2500         /* Copy subvolume's name */
2501         item_off += sizeof(struct btrfs_root_ref);
2502         item_len -= sizeof(struct btrfs_root_ref);
2503         read_extent_buffer(leaf, args->name, item_off, item_len);
2504         args->name[item_len] = 0;
2505 
2506 out:
2507         btrfs_free_path(path);
2508         return ret;
2509 }
2510 
2511 static noinline int btrfs_ioctl_ino_lookup(struct file *file,
2512                                            void __user *argp)
2513 {
2514         struct btrfs_ioctl_ino_lookup_args *args;
2515         struct inode *inode;
2516         int ret = 0;
2517 
2518         args = memdup_user(argp, sizeof(*args));
2519         if (IS_ERR(args))
2520                 return PTR_ERR(args);
2521 
2522         inode = file_inode(file);
2523 
2524         /*
2525          * Unprivileged query to obtain the containing subvolume root id. The
2526          * path is reset so it's consistent with btrfs_search_path_in_tree.
2527          */
2528         if (args->treeid == 0)
2529                 args->treeid = BTRFS_I(inode)->root->root_key.objectid;
2530 
2531         if (args->objectid == BTRFS_FIRST_FREE_OBJECTID) {
2532                 args->name[0] = 0;
2533                 goto out;
2534         }
2535 
2536         if (!capable(CAP_SYS_ADMIN)) {
2537                 ret = -EPERM;
2538                 goto out;
2539         }
2540 
2541         ret = btrfs_search_path_in_tree(BTRFS_I(inode)->root->fs_info,
2542                                         args->treeid, args->objectid,
2543                                         args->name);
2544 
2545 out:
2546         if (ret == 0 && copy_to_user(argp, args, sizeof(*args)))
2547                 ret = -EFAULT;
2548 
2549         kfree(args);
2550         return ret;
2551 }
2552 
2553 /*
2554  * Version of ino_lookup ioctl (unprivileged)
2555  *
2556  * The main differences from ino_lookup ioctl are:
2557  *
2558  *   1. Read + Exec permission will be checked using inode_permission() during
2559  *      path construction. -EACCES will be returned in case of failure.
2560  *   2. Path construction will be stopped at the inode number which corresponds
2561  *      to the fd with which this ioctl is called. If constructed path does not
2562  *      exist under fd's inode, -EACCES will be returned.
2563  *   3. The name of bottom subvolume is also searched and filled.
2564  */
2565 static int btrfs_ioctl_ino_lookup_user(struct file *file, void __user *argp)
2566 {
2567         struct btrfs_ioctl_ino_lookup_user_args *args;
2568         struct inode *inode;
2569         int ret;
2570 
2571         args = memdup_user(argp, sizeof(*args));
2572         if (IS_ERR(args))
2573                 return PTR_ERR(args);
2574 
2575         inode = file_inode(file);
2576 
2577         if (args->dirid == BTRFS_FIRST_FREE_OBJECTID &&
2578             BTRFS_I(inode)->location.objectid != BTRFS_FIRST_FREE_OBJECTID) {
2579                 /*
2580                  * The subvolume does not exist under fd with which this is
2581                  * called
2582                  */
2583                 kfree(args);
2584                 return -EACCES;
2585         }
2586 
2587         ret = btrfs_search_path_in_tree_user(inode, args);
2588 
2589         if (ret == 0 && copy_to_user(argp, args, sizeof(*args)))
2590                 ret = -EFAULT;
2591 
2592         kfree(args);
2593         return ret;
2594 }
2595 
2596 /* Get the subvolume information in BTRFS_ROOT_ITEM and BTRFS_ROOT_BACKREF */
2597 static int btrfs_ioctl_get_subvol_info(struct file *file, void __user *argp)
2598 {
2599         struct btrfs_ioctl_get_subvol_info_args *subvol_info;
2600         struct btrfs_fs_info *fs_info;
2601         struct btrfs_root *root;
2602         struct btrfs_path *path;
2603         struct btrfs_key key;
2604         struct btrfs_root_item *root_item;
2605         struct btrfs_root_ref *rref;
2606         struct extent_buffer *leaf;
2607         unsigned long item_off;
2608         unsigned long item_len;
2609         struct inode *inode;
2610         int slot;
2611         int ret = 0;
2612 
2613         path = btrfs_alloc_path();
2614         if (!path)
2615                 return -ENOMEM;
2616 
2617         subvol_info = kzalloc(sizeof(*subvol_info), GFP_KERNEL);
2618         if (!subvol_info) {
2619                 btrfs_free_path(path);
2620                 return -ENOMEM;
2621         }
2622 
2623         inode = file_inode(file);
2624         fs_info = BTRFS_I(inode)->root->fs_info;
2625 
2626         /* Get root_item of inode's subvolume */
2627         key.objectid = BTRFS_I(inode)->root->root_key.objectid;
2628         key.type = BTRFS_ROOT_ITEM_KEY;
2629         key.offset = (u64)-1;
2630         root = btrfs_read_fs_root_no_name(fs_info, &key);
2631         if (IS_ERR(root)) {
2632                 ret = PTR_ERR(root);
2633                 goto out;
2634         }
2635         root_item = &root->root_item;
2636 
2637         subvol_info->treeid = key.objectid;
2638 
2639         subvol_info->generation = btrfs_root_generation(root_item);
2640         subvol_info->flags = btrfs_root_flags(root_item);
2641 
2642         memcpy(subvol_info->uuid, root_item->uuid, BTRFS_UUID_SIZE);
2643         memcpy(subvol_info->parent_uuid, root_item->parent_uuid,
2644                                                     BTRFS_UUID_SIZE);
2645         memcpy(subvol_info->received_uuid, root_item->received_uuid,
2646                                                     BTRFS_UUID_SIZE);
2647 
2648         subvol_info->ctransid = btrfs_root_ctransid(root_item);
2649         subvol_info->ctime.sec = btrfs_stack_timespec_sec(&root_item->ctime);
2650         subvol_info->ctime.nsec = btrfs_stack_timespec_nsec(&root_item->ctime);
2651 
2652         subvol_info->otransid = btrfs_root_otransid(root_item);
2653         subvol_info->otime.sec = btrfs_stack_timespec_sec(&root_item->otime);
2654         subvol_info->otime.nsec = btrfs_stack_timespec_nsec(&root_item->otime);
2655 
2656         subvol_info->stransid = btrfs_root_stransid(root_item);
2657         subvol_info->stime.sec = btrfs_stack_timespec_sec(&root_item->stime);
2658         subvol_info->stime.nsec = btrfs_stack_timespec_nsec(&root_item->stime);
2659 
2660         subvol_info->rtransid = btrfs_root_rtransid(root_item);
2661         subvol_info->rtime.sec = btrfs_stack_timespec_sec(&root_item->rtime);
2662         subvol_info->rtime.nsec = btrfs_stack_timespec_nsec(&root_item->rtime);
2663 
2664         if (key.objectid != BTRFS_FS_TREE_OBJECTID) {
2665                 /* Search root tree for ROOT_BACKREF of this subvolume */
2666                 root = fs_info->tree_root;
2667 
2668                 key.type = BTRFS_ROOT_BACKREF_KEY;
2669                 key.offset = 0;
2670                 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
2671                 if (ret < 0) {
2672                         goto out;
2673                 } else if (path->slots[0] >=
2674                            btrfs_header_nritems(path->nodes[0])) {
2675                         ret = btrfs_next_leaf(root, path);
2676                         if (ret < 0) {
2677                                 goto out;
2678                         } else if (ret > 0) {
2679                                 ret = -EUCLEAN;
2680                                 goto out;
2681                         }
2682                 }
2683 
2684                 leaf = path->nodes[0];
2685                 slot = path->slots[0];
2686                 btrfs_item_key_to_cpu(leaf, &key, slot);
2687                 if (key.objectid == subvol_info->treeid &&
2688                     key.type == BTRFS_ROOT_BACKREF_KEY) {
2689                         subvol_info->parent_id = key.offset;
2690 
2691                         rref = btrfs_item_ptr(leaf, slot, struct btrfs_root_ref);
2692                         subvol_info->dirid = btrfs_root_ref_dirid(leaf, rref);
2693 
2694                         item_off = btrfs_item_ptr_offset(leaf, slot)
2695                                         + sizeof(struct btrfs_root_ref);
2696                         item_len = btrfs_item_size_nr(leaf, slot)
2697                                         - sizeof(struct btrfs_root_ref);
2698                         read_extent_buffer(leaf, subvol_info->name,
2699                                            item_off, item_len);
2700                 } else {
2701                         ret = -ENOENT;
2702                         goto out;
2703                 }
2704         }
2705 
2706         if (copy_to_user(argp, subvol_info, sizeof(*subvol_info)))
2707                 ret = -EFAULT;
2708 
2709 out:
2710         btrfs_free_path(path);
2711         kzfree(subvol_info);
2712         return ret;
2713 }
2714 
2715 /*
2716  * Return ROOT_REF information of the subvolume containing this inode
2717  * except the subvolume name.
2718  */
2719 static int btrfs_ioctl_get_subvol_rootref(struct file *file, void __user *argp)
2720 {
2721         struct btrfs_ioctl_get_subvol_rootref_args *rootrefs;
2722         struct btrfs_root_ref *rref;
2723         struct btrfs_root *root;
2724         struct btrfs_path *path;
2725         struct btrfs_key key;
2726         struct extent_buffer *leaf;
2727         struct inode *inode;
2728         u64 objectid;
2729         int slot;
2730         int ret;
2731         u8 found;
2732 
2733         path = btrfs_alloc_path();
2734         if (!path)
2735                 return -ENOMEM;
2736 
2737         rootrefs = memdup_user(argp, sizeof(*rootrefs));
2738         if (IS_ERR(rootrefs)) {
2739                 btrfs_free_path(path);
2740                 return PTR_ERR(rootrefs);
2741         }
2742 
2743         inode = file_inode(file);
2744         root = BTRFS_I(inode)->root->fs_info->tree_root;
2745         objectid = BTRFS_I(inode)->root->root_key.objectid;
2746 
2747         key.objectid = objectid;
2748         key.type = BTRFS_ROOT_REF_KEY;
2749         key.offset = rootrefs->min_treeid;
2750         found = 0;
2751 
2752         ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
2753         if (ret < 0) {
2754                 goto out;
2755         } else if (path->slots[0] >=
2756                    btrfs_header_nritems(path->nodes[0])) {
2757                 ret = btrfs_next_leaf(root, path);
2758                 if (ret < 0) {
2759                         goto out;
2760                 } else if (ret > 0) {
2761                         ret = -EUCLEAN;
2762                         goto out;
2763                 }
2764         }
2765         while (1) {
2766                 leaf = path->nodes[0];
2767                 slot = path->slots[0];
2768 
2769                 btrfs_item_key_to_cpu(leaf, &key, slot);
2770                 if (key.objectid != objectid || key.type != BTRFS_ROOT_REF_KEY) {
2771                         ret = 0;
2772                         goto out;
2773                 }
2774 
2775                 if (found == BTRFS_MAX_ROOTREF_BUFFER_NUM) {
2776                         ret = -EOVERFLOW;
2777                         goto out;
2778                 }
2779 
2780                 rref = btrfs_item_ptr(leaf, slot, struct btrfs_root_ref);
2781                 rootrefs->rootref[found].treeid = key.offset;
2782                 rootrefs->rootref[found].dirid =
2783                                   btrfs_root_ref_dirid(leaf, rref);
2784                 found++;
2785 
2786                 ret = btrfs_next_item(root, path);
2787                 if (ret < 0) {
2788                         goto out;
2789                 } else if (ret > 0) {
2790                         ret = -EUCLEAN;
2791                         goto out;
2792                 }
2793         }
2794 
2795 out:
2796         if (!ret || ret == -EOVERFLOW) {
2797                 rootrefs->num_items = found;
2798                 /* update min_treeid for next search */
2799                 if (found)
2800                         rootrefs->min_treeid =
2801                                 rootrefs->rootref[found - 1].treeid + 1;
2802                 if (copy_to_user(argp, rootrefs, sizeof(*rootrefs)))
2803                         ret = -EFAULT;
2804         }
2805 
2806         kfree(rootrefs);
2807         btrfs_free_path(path);
2808 
2809         return ret;
2810 }
2811 
2812 static noinline int btrfs_ioctl_snap_destroy(struct file *file,
2813                                              void __user *arg)
2814 {
2815         struct dentry *parent = file->f_path.dentry;
2816         struct btrfs_fs_info *fs_info = btrfs_sb(parent->d_sb);
2817         struct dentry *dentry;
2818         struct inode *dir = d_inode(parent);
2819         struct inode *inode;
2820         struct btrfs_root *root = BTRFS_I(dir)->root;
2821         struct btrfs_root *dest = NULL;
2822         struct btrfs_ioctl_vol_args *vol_args;
2823         int namelen;
2824         int err = 0;
2825 
2826         if (!S_ISDIR(dir->i_mode))
2827                 return -ENOTDIR;
2828 
2829         vol_args = memdup_user(arg, sizeof(*vol_args));
2830         if (IS_ERR(vol_args))
2831                 return PTR_ERR(vol_args);
2832 
2833         vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
2834         namelen = strlen(vol_args->name);
2835         if (strchr(vol_args->name, '/') ||
2836             strncmp(vol_args->name, "..", namelen) == 0) {
2837                 err = -EINVAL;
2838                 goto out;
2839         }
2840 
2841         err = mnt_want_write_file(file);
2842         if (err)
2843                 goto out;
2844 
2845 
2846         err = down_write_killable_nested(&dir->i_rwsem, I_MUTEX_PARENT);
2847         if (err == -EINTR)
2848                 goto out_drop_write;
2849         dentry = lookup_one_len(vol_args->name, parent, namelen);
2850         if (IS_ERR(dentry)) {
2851                 err = PTR_ERR(dentry);
2852                 goto out_unlock_dir;
2853         }
2854 
2855         if (d_really_is_negative(dentry)) {
2856                 err = -ENOENT;
2857                 goto out_dput;
2858         }
2859 
2860         inode = d_inode(dentry);
2861         dest = BTRFS_I(inode)->root;
2862         if (!capable(CAP_SYS_ADMIN)) {
2863                 /*
2864                  * Regular user.  Only allow this with a special mount
2865                  * option, when the user has write+exec access to the
2866                  * subvol root, and when rmdir(2) would have been
2867                  * allowed.
2868                  *
2869                  * Note that this is _not_ check that the subvol is
2870                  * empty or doesn't contain data that we wouldn't
2871                  * otherwise be able to delete.
2872                  *
2873                  * Users who want to delete empty subvols should try
2874                  * rmdir(2).
2875                  */
2876                 err = -EPERM;
2877                 if (!btrfs_test_opt(fs_info, USER_SUBVOL_RM_ALLOWED))
2878                         goto out_dput;
2879 
2880                 /*
2881                  * Do not allow deletion if the parent dir is the same
2882                  * as the dir to be deleted.  That means the ioctl
2883                  * must be called on the dentry referencing the root
2884                  * of the subvol, not a random directory contained
2885                  * within it.
2886                  */
2887                 err = -EINVAL;
2888                 if (root == dest)
2889                         goto out_dput;
2890 
2891                 err = inode_permission(inode, MAY_WRITE | MAY_EXEC);
2892                 if (err)
2893                         goto out_dput;
2894         }
2895 
2896         /* check if subvolume may be deleted by a user */
2897         err = btrfs_may_delete(dir, dentry, 1);
2898         if (err)
2899                 goto out_dput;
2900 
2901         if (btrfs_ino(BTRFS_I(inode)) != BTRFS_FIRST_FREE_OBJECTID) {
2902                 err = -EINVAL;
2903                 goto out_dput;
2904         }
2905 
2906         inode_lock(inode);
2907         err = btrfs_delete_subvolume(dir, dentry);
2908         inode_unlock(inode);
2909         if (!err)
2910                 d_delete(dentry);
2911 
2912 out_dput:
2913         dput(dentry);
2914 out_unlock_dir:
2915         inode_unlock(dir);
2916 out_drop_write:
2917         mnt_drop_write_file(file);
2918 out:
2919         kfree(vol_args);
2920         return err;
2921 }
2922 
2923 static int btrfs_ioctl_defrag(struct file *file, void __user *argp)
2924 {
2925         struct inode *inode = file_inode(file);
2926         struct btrfs_root *root = BTRFS_I(inode)->root;
2927         struct btrfs_ioctl_defrag_range_args *range;
2928         int ret;
2929 
2930         ret = mnt_want_write_file(file);
2931         if (ret)
2932                 return ret;
2933 
2934         if (btrfs_root_readonly(root)) {
2935                 ret = -EROFS;
2936                 goto out;
2937         }
2938 
2939         switch (inode->i_mode & S_IFMT) {
2940         case S_IFDIR:
2941                 if (!capable(CAP_SYS_ADMIN)) {
2942                         ret = -EPERM;
2943                         goto out;
2944                 }
2945                 ret = btrfs_defrag_root(root);
2946                 break;
2947         case S_IFREG:
2948                 /*
2949                  * Note that this does not check the file descriptor for write
2950                  * access. This prevents defragmenting executables that are
2951                  * running and allows defrag on files open in read-only mode.
2952                  */
2953                 if (!capable(CAP_SYS_ADMIN) &&
2954                     inode_permission(inode, MAY_WRITE)) {
2955                         ret = -EPERM;
2956                         goto out;
2957                 }
2958 
2959                 range = kzalloc(sizeof(*range), GFP_KERNEL);
2960                 if (!range) {
2961                         ret = -ENOMEM;
2962                         goto out;
2963                 }
2964 
2965                 if (argp) {
2966                         if (copy_from_user(range, argp,
2967                                            sizeof(*range))) {
2968                                 ret = -EFAULT;
2969                                 kfree(range);
2970                                 goto out;
2971                         }
2972                         /* compression requires us to start the IO */
2973                         if ((range->flags & BTRFS_DEFRAG_RANGE_COMPRESS)) {
2974                                 range->flags |= BTRFS_DEFRAG_RANGE_START_IO;
2975                                 range->extent_thresh = (u32)-1;
2976                         }
2977                 } else {
2978                         /* the rest are all set to zero by kzalloc */
2979                         range->len = (u64)-1;
2980                 }
2981                 ret = btrfs_defrag_file(file_inode(file), file,
2982                                         range, BTRFS_OLDEST_GENERATION, 0);
2983                 if (ret > 0)
2984                         ret = 0;
2985                 kfree(range);
2986                 break;
2987         default:
2988                 ret = -EINVAL;
2989         }
2990 out:
2991         mnt_drop_write_file(file);
2992         return ret;
2993 }
2994 
2995 static long btrfs_ioctl_add_dev(struct btrfs_fs_info *fs_info, void __user *arg)
2996 {
2997         struct btrfs_ioctl_vol_args *vol_args;
2998         int ret;
2999 
3000         if (!capable(CAP_SYS_ADMIN))
3001                 return -EPERM;
3002 
3003         if (test_and_set_bit(BTRFS_FS_EXCL_OP, &fs_info->flags))
3004                 return BTRFS_ERROR_DEV_EXCL_RUN_IN_PROGRESS;
3005 
3006         vol_args = memdup_user(arg, sizeof(*vol_args));
3007         if (IS_ERR(vol_args)) {
3008                 ret = PTR_ERR(vol_args);
3009                 goto out;
3010         }
3011 
3012         vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
3013         ret = btrfs_init_new_device(fs_info, vol_args->name);
3014 
3015         if (!ret)
3016                 btrfs_info(fs_info, "disk added %s", vol_args->name);
3017 
3018         kfree(vol_args);
3019 out:
3020         clear_bit(BTRFS_FS_EXCL_OP, &fs_info->flags);
3021         return ret;
3022 }
3023 
3024 static long btrfs_ioctl_rm_dev_v2(struct file *file, void __user *arg)
3025 {
3026         struct inode *inode = file_inode(file);
3027         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
3028         struct btrfs_ioctl_vol_args_v2 *vol_args;
3029         int ret;
3030 
3031         if (!capable(CAP_SYS_ADMIN))
3032                 return -EPERM;
3033 
3034         ret = mnt_want_write_file(file);
3035         if (ret)
3036                 return ret;
3037 
3038         vol_args = memdup_user(arg, sizeof(*vol_args));
3039         if (IS_ERR(vol_args)) {
3040                 ret = PTR_ERR(vol_args);
3041                 goto err_drop;
3042         }
3043 
3044         /* Check for compatibility reject unknown flags */
3045         if (vol_args->flags & ~BTRFS_VOL_ARG_V2_FLAGS_SUPPORTED) {
3046                 ret = -EOPNOTSUPP;
3047                 goto out;
3048         }
3049 
3050         if (test_and_set_bit(BTRFS_FS_EXCL_OP, &fs_info->flags)) {
3051                 ret = BTRFS_ERROR_DEV_EXCL_RUN_IN_PROGRESS;
3052                 goto out;
3053         }
3054 
3055         if (vol_args->flags & BTRFS_DEVICE_SPEC_BY_ID) {
3056                 ret = btrfs_rm_device(fs_info, NULL, vol_args->devid);
3057         } else {
3058                 vol_args->name[BTRFS_SUBVOL_NAME_MAX] = '\0';
3059                 ret = btrfs_rm_device(fs_info, vol_args->name, 0);
3060         }
3061         clear_bit(BTRFS_FS_EXCL_OP, &fs_info->flags);
3062 
3063         if (!ret) {
3064                 if (vol_args->flags & BTRFS_DEVICE_SPEC_BY_ID)
3065                         btrfs_info(fs_info, "device deleted: id %llu",
3066                                         vol_args->devid);
3067                 else
3068                         btrfs_info(fs_info, "device deleted: %s",
3069                                         vol_args->name);
3070         }
3071 out:
3072         kfree(vol_args);
3073 err_drop:
3074         mnt_drop_write_file(file);
3075         return ret;
3076 }
3077 
3078 static long btrfs_ioctl_rm_dev(struct file *file, void __user *arg)
3079 {
3080         struct inode *inode = file_inode(file);
3081         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
3082         struct btrfs_ioctl_vol_args *vol_args;
3083         int ret;
3084 
3085         if (!capable(CAP_SYS_ADMIN))
3086                 return -EPERM;
3087 
3088         ret = mnt_want_write_file(file);
3089         if (ret)
3090                 return ret;
3091 
3092         if (test_and_set_bit(BTRFS_FS_EXCL_OP, &fs_info->flags)) {
3093                 ret = BTRFS_ERROR_DEV_EXCL_RUN_IN_PROGRESS;
3094                 goto out_drop_write;
3095         }
3096 
3097         vol_args = memdup_user(arg, sizeof(*vol_args));
3098         if (IS_ERR(vol_args)) {
3099                 ret = PTR_ERR(vol_args);
3100                 goto out;
3101         }
3102 
3103         vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
3104         ret = btrfs_rm_device(fs_info, vol_args->name, 0);
3105 
3106         if (!ret)
3107                 btrfs_info(fs_info, "disk deleted %s", vol_args->name);
3108         kfree(vol_args);
3109 out:
3110         clear_bit(BTRFS_FS_EXCL_OP, &fs_info->flags);
3111 out_drop_write:
3112         mnt_drop_write_file(file);
3113 
3114         return ret;
3115 }
3116 
3117 static long btrfs_ioctl_fs_info(struct btrfs_fs_info *fs_info,
3118                                 void __user *arg)
3119 {
3120         struct btrfs_ioctl_fs_info_args *fi_args;
3121         struct btrfs_device *device;
3122         struct btrfs_fs_devices *fs_devices = fs_info->fs_devices;
3123         int ret = 0;
3124 
3125         fi_args = kzalloc(sizeof(*fi_args), GFP_KERNEL);
3126         if (!fi_args)
3127                 return -ENOMEM;
3128 
3129         rcu_read_lock();
3130         fi_args->num_devices = fs_devices->num_devices;
3131 
3132         list_for_each_entry_rcu(device, &fs_devices->devices, dev_list) {
3133                 if (device->devid > fi_args->max_id)
3134                         fi_args->max_id = device->devid;
3135         }
3136         rcu_read_unlock();
3137 
3138         memcpy(&fi_args->fsid, fs_info->fsid, sizeof(fi_args->fsid));
3139         fi_args->nodesize = fs_info->nodesize;
3140         fi_args->sectorsize = fs_info->sectorsize;
3141         fi_args->clone_alignment = fs_info->sectorsize;
3142 
3143         if (copy_to_user(arg, fi_args, sizeof(*fi_args)))
3144                 ret = -EFAULT;
3145 
3146         kfree(fi_args);
3147         return ret;
3148 }
3149 
3150 static long btrfs_ioctl_dev_info(struct btrfs_fs_info *fs_info,
3151                                  void __user *arg)
3152 {
3153         struct btrfs_ioctl_dev_info_args *di_args;
3154         struct btrfs_device *dev;
3155         int ret = 0;
3156         char *s_uuid = NULL;
3157 
3158         di_args = memdup_user(arg, sizeof(*di_args));
3159         if (IS_ERR(di_args))
3160                 return PTR_ERR(di_args);
3161 
3162         if (!btrfs_is_empty_uuid(di_args->uuid))
3163                 s_uuid = di_args->uuid;
3164 
3165         rcu_read_lock();
3166         dev = btrfs_find_device(fs_info, di_args->devid, s_uuid, NULL);
3167 
3168         if (!dev) {
3169                 ret = -ENODEV;
3170                 goto out;
3171         }
3172 
3173         di_args->devid = dev->devid;
3174         di_args->bytes_used = btrfs_device_get_bytes_used(dev);
3175         di_args->total_bytes = btrfs_device_get_total_bytes(dev);
3176         memcpy(di_args->uuid, dev->uuid, sizeof(di_args->uuid));
3177         if (dev->name) {
3178                 strncpy(di_args->path, rcu_str_deref(dev->name),
3179                                 sizeof(di_args->path) - 1);
3180                 di_args->path[sizeof(di_args->path) - 1] = 0;
3181         } else {
3182                 di_args->path[0] = '\0';
3183         }
3184 
3185 out:
3186         rcu_read_unlock();
3187         if (ret == 0 && copy_to_user(arg, di_args, sizeof(*di_args)))
3188                 ret = -EFAULT;
3189 
3190         kfree(di_args);
3191         return ret;
3192 }
3193 
3194 static struct page *extent_same_get_page(struct inode *inode, pgoff_t index)
3195 {
3196         struct page *page;
3197 
3198         page = grab_cache_page(inode->i_mapping, index);
3199         if (!page)
3200                 return ERR_PTR(-ENOMEM);
3201 
3202         if (!PageUptodate(page)) {
3203                 int ret;
3204 
3205                 ret = btrfs_readpage(NULL, page);
3206                 if (ret)
3207                         return ERR_PTR(ret);
3208                 lock_page(page);
3209                 if (!PageUptodate(page)) {
3210                         unlock_page(page);
3211                         put_page(page);
3212                         return ERR_PTR(-EIO);
3213                 }
3214                 if (page->mapping != inode->i_mapping) {
3215                         unlock_page(page);
3216                         put_page(page);
3217                         return ERR_PTR(-EAGAIN);
3218                 }
3219         }
3220 
3221         return page;
3222 }
3223 
3224 static int gather_extent_pages(struct inode *inode, struct page **pages,
3225                                int num_pages, u64 off)
3226 {
3227         int i;
3228         pgoff_t index = off >> PAGE_SHIFT;
3229 
3230         for (i = 0; i < num_pages; i++) {
3231 again:
3232                 pages[i] = extent_same_get_page(inode, index + i);
3233                 if (IS_ERR(pages[i])) {
3234                         int err = PTR_ERR(pages[i]);
3235 
3236                         if (err == -EAGAIN)
3237                                 goto again;
3238                         pages[i] = NULL;
3239                         return err;
3240                 }
3241         }
3242         return 0;
3243 }
3244 
3245 static int lock_extent_range(struct inode *inode, u64 off, u64 len,
3246                              bool retry_range_locking)
3247 {
3248         /*
3249          * Do any pending delalloc/csum calculations on inode, one way or
3250          * another, and lock file content.
3251          * The locking order is:
3252          *
3253          *   1) pages
3254          *   2) range in the inode's io tree
3255          */
3256         while (1) {
3257                 struct btrfs_ordered_extent *ordered;
3258                 lock_extent(&BTRFS_I(inode)->io_tree, off, off + len - 1);
3259                 ordered = btrfs_lookup_first_ordered_extent(inode,
3260                                                             off + len - 1);
3261                 if ((!ordered ||
3262                      ordered->file_offset + ordered->len <= off ||
3263                      ordered->file_offset >= off + len) &&
3264                     !test_range_bit(&BTRFS_I(inode)->io_tree, off,
3265                                     off + len - 1, EXTENT_DELALLOC, 0, NULL)) {
3266                         if (ordered)
3267                                 btrfs_put_ordered_extent(ordered);
3268                         break;
3269                 }
3270                 unlock_extent(&BTRFS_I(inode)->io_tree, off, off + len - 1);
3271                 if (ordered)
3272                         btrfs_put_ordered_extent(ordered);
3273                 if (!retry_range_locking)
3274                         return -EAGAIN;
3275                 btrfs_wait_ordered_range(inode, off, len);
3276         }
3277         return 0;
3278 }
3279 
3280 static void btrfs_double_inode_unlock(struct inode *inode1, struct inode *inode2)
3281 {
3282         inode_unlock(inode1);
3283         inode_unlock(inode2);
3284 }
3285 
3286 static void btrfs_double_inode_lock(struct inode *inode1, struct inode *inode2)
3287 {
3288         if (inode1 < inode2)
3289                 swap(inode1, inode2);
3290 
3291         inode_lock_nested(inode1, I_MUTEX_PARENT);
3292         inode_lock_nested(inode2, I_MUTEX_CHILD);
3293 }
3294 
3295 static void btrfs_double_extent_unlock(struct inode *inode1, u64 loff1,
3296                                       struct inode *inode2, u64 loff2, u64 len)
3297 {
3298         unlock_extent(&BTRFS_I(inode1)->io_tree, loff1, loff1 + len - 1);
3299         unlock_extent(&BTRFS_I(inode2)->io_tree, loff2, loff2 + len - 1);
3300 }
3301 
3302 static int btrfs_double_extent_lock(struct inode *inode1, u64 loff1,
3303                                     struct inode *inode2, u64 loff2, u64 len,
3304                                     bool retry_range_locking)
3305 {
3306         int ret;
3307 
3308         if (inode1 < inode2) {
3309                 swap(inode1, inode2);
3310                 swap(loff1, loff2);
3311         }
3312         ret = lock_extent_range(inode1, loff1, len, retry_range_locking);
3313         if (ret)
3314                 return ret;
3315         ret = lock_extent_range(inode2, loff2, len, retry_range_locking);
3316         if (ret)
3317                 unlock_extent(&BTRFS_I(inode1)->io_tree, loff1,
3318                               loff1 + len - 1);
3319         return ret;
3320 }
3321 
3322 struct cmp_pages {
3323         int             num_pages;
3324         struct page     **src_pages;
3325         struct page     **dst_pages;
3326 };
3327 
3328 static void btrfs_cmp_data_free(struct cmp_pages *cmp)
3329 {
3330         int i;
3331         struct page *pg;
3332 
3333         for (i = 0; i < cmp->num_pages; i++) {
3334                 pg = cmp->src_pages[i];
3335                 if (pg) {
3336                         unlock_page(pg);
3337                         put_page(pg);
3338                         cmp->src_pages[i] = NULL;
3339                 }
3340                 pg = cmp->dst_pages[i];
3341                 if (pg) {
3342                         unlock_page(pg);
3343                         put_page(pg);
3344                         cmp->dst_pages[i] = NULL;
3345                 }
3346         }
3347 }
3348 
3349 static int btrfs_cmp_data_prepare(struct inode *src, u64 loff,
3350                                   struct inode *dst, u64 dst_loff,
3351                                   u64 len, struct cmp_pages *cmp)
3352 {
3353         int ret;
3354         int num_pages = PAGE_ALIGN(len) >> PAGE_SHIFT;
3355 
3356         cmp->num_pages = num_pages;
3357 
3358         ret = gather_extent_pages(src, cmp->src_pages, num_pages, loff);
3359         if (ret)
3360                 goto out;
3361 
3362         ret = gather_extent_pages(dst, cmp->dst_pages, num_pages, dst_loff);
3363 
3364 out:
3365         if (ret)
3366                 btrfs_cmp_data_free(cmp);
3367         return ret;
3368 }
3369 
3370 static int btrfs_cmp_data(u64 len, struct cmp_pages *cmp)
3371 {
3372         int ret = 0;
3373         int i;
3374         struct page *src_page, *dst_page;
3375         unsigned int cmp_len = PAGE_SIZE;
3376         void *addr, *dst_addr;
3377 
3378         i = 0;
3379         while (len) {
3380                 if (len < PAGE_SIZE)
3381                         cmp_len = len;
3382 
3383                 BUG_ON(i >= cmp->num_pages);
3384 
3385                 src_page = cmp->src_pages[i];
3386                 dst_page = cmp->dst_pages[i];
3387                 ASSERT(PageLocked(src_page));
3388                 ASSERT(PageLocked(dst_page));
3389 
3390                 addr = kmap_atomic(src_page);
3391                 dst_addr = kmap_atomic(dst_page);
3392 
3393                 flush_dcache_page(src_page);
3394                 flush_dcache_page(dst_page);
3395 
3396                 if (memcmp(addr, dst_addr, cmp_len))
3397                         ret = -EBADE;
3398 
3399                 kunmap_atomic(addr);
3400                 kunmap_atomic(dst_addr);
3401 
3402                 if (ret)
3403                         break;
3404 
3405                 len -= cmp_len;
3406                 i++;
3407         }
3408 
3409         return ret;
3410 }
3411 
3412 static int extent_same_check_offsets(struct inode *inode, u64 off, u64 *plen,
3413                                      u64 olen)
3414 {
3415         u64 len = *plen;
3416         u64 bs = BTRFS_I(inode)->root->fs_info->sb->s_blocksize;
3417 
3418         if (off + olen > inode->i_size || off + olen < off)
3419                 return -EINVAL;
3420 
3421         /* if we extend to eof, continue to block boundary */
3422         if (off + len == inode->i_size)
3423                 *plen = len = ALIGN(inode->i_size, bs) - off;
3424 
3425         /* Check that we are block aligned - btrfs_clone() requires this */
3426         if (!IS_ALIGNED(off, bs) || !IS_ALIGNED(off + len, bs))
3427                 return -EINVAL;
3428 
3429         return 0;
3430 }
3431 
3432 static int btrfs_extent_same_range(struct inode *src, u64 loff, u64 olen,
3433                                    struct inode *dst, u64 dst_loff,
3434                                    struct cmp_pages *cmp)
3435 {
3436         int ret;
3437         u64 len = olen;
3438         bool same_inode = (src == dst);
3439         u64 same_lock_start = 0;
3440         u64 same_lock_len = 0;
3441 
3442         ret = extent_same_check_offsets(src, loff, &len, olen);
3443         if (ret)
3444                 return ret;
3445 
3446         ret = extent_same_check_offsets(dst, dst_loff, &len, olen);
3447         if (ret)
3448                 return ret;
3449 
3450         if (same_inode) {
3451                 /*
3452                  * Single inode case wants the same checks, except we
3453                  * don't want our length pushed out past i_size as
3454                  * comparing that data range makes no sense.
3455                  *
3456                  * extent_same_check_offsets() will do this for an
3457                  * unaligned length at i_size, so catch it here and
3458                  * reject the request.
3459                  *
3460                  * This effectively means we require aligned extents
3461                  * for the single-inode case, whereas the other cases
3462                  * allow an unaligned length so long as it ends at
3463                  * i_size.
3464                  */
3465                 if (len != olen)
3466                         return -EINVAL;
3467 
3468                 /* Check for overlapping ranges */
3469                 if (dst_loff + len > loff && dst_loff < loff + len)
3470                         return -EINVAL;
3471 
3472                 same_lock_start = min_t(u64, loff, dst_loff);
3473                 same_lock_len = max_t(u64, loff, dst_loff) + len - same_lock_start;
3474         } else {
3475                 /*
3476                  * If the source and destination inodes are different, the
3477                  * source's range end offset matches the source's i_size, that
3478                  * i_size is not a multiple of the sector size, and the
3479                  * destination range does not go past the destination's i_size,
3480                  * we must round down the length to the nearest sector size
3481                  * multiple. If we don't do this adjustment we end replacing
3482                  * with zeroes the bytes in the range that starts at the
3483                  * deduplication range's end offset and ends at the next sector
3484                  * size multiple.
3485                  */
3486                 if (loff + olen == i_size_read(src) &&
3487                     dst_loff + len < i_size_read(dst)) {
3488                         const u64 sz = BTRFS_I(src)->root->fs_info->sectorsize;
3489 
3490                         len = round_down(i_size_read(src), sz) - loff;
3491                         if (len == 0)
3492                                 return 0;
3493                         olen = len;
3494                 }
3495         }
3496 
3497 again:
3498         ret = btrfs_cmp_data_prepare(src, loff, dst, dst_loff, olen, cmp);
3499         if (ret)
3500                 return ret;
3501 
3502         if (same_inode)
3503                 ret = lock_extent_range(src, same_lock_start, same_lock_len,
3504                                         false);
3505         else
3506                 ret = btrfs_double_extent_lock(src, loff, dst, dst_loff, len,
3507                                                false);
3508         /*
3509          * If one of the inodes has dirty pages in the respective range or
3510          * ordered extents, we need to flush dellaloc and wait for all ordered
3511          * extents in the range. We must unlock the pages and the ranges in the
3512          * io trees to avoid deadlocks when flushing delalloc (requires locking
3513          * pages) and when waiting for ordered extents to complete (they require
3514          * range locking).
3515          */
3516         if (ret == -EAGAIN) {
3517                 /*
3518                  * Ranges in the io trees already unlocked. Now unlock all
3519                  * pages before waiting for all IO to complete.
3520                  */
3521                 btrfs_cmp_data_free(cmp);
3522                 if (same_inode) {
3523                         btrfs_wait_ordered_range(src, same_lock_start,
3524                                                  same_lock_len);
3525                 } else {
3526                         btrfs_wait_ordered_range(src, loff, len);
3527                         btrfs_wait_ordered_range(dst, dst_loff, len);
3528                 }
3529                 goto again;
3530         }
3531         ASSERT(ret == 0);
3532         if (WARN_ON(ret)) {
3533                 /* ranges in the io trees already unlocked */
3534                 btrfs_cmp_data_free(cmp);
3535                 return ret;
3536         }
3537 
3538         /* pass original length for comparison so we stay within i_size */
3539         ret = btrfs_cmp_data(olen, cmp);
3540         if (ret == 0)
3541                 ret = btrfs_clone(src, dst, loff, olen, len, dst_loff, 1);
3542 
3543         if (same_inode)
3544                 unlock_extent(&BTRFS_I(src)->io_tree, same_lock_start,
3545                               same_lock_start + same_lock_len - 1);
3546         else
3547                 btrfs_double_extent_unlock(src, loff, dst, dst_loff, len);
3548 
3549         btrfs_cmp_data_free(cmp);
3550 
3551         return ret;
3552 }
3553 
3554 #define BTRFS_MAX_DEDUPE_LEN    SZ_16M
3555 
3556 static int btrfs_extent_same(struct inode *src, u64 loff, u64 olen,
3557                              struct inode *dst, u64 dst_loff)
3558 {
3559         int ret;
3560         struct cmp_pages cmp;
3561         int num_pages = PAGE_ALIGN(BTRFS_MAX_DEDUPE_LEN) >> PAGE_SHIFT;
3562         bool same_inode = (src == dst);
3563         u64 i, tail_len, chunk_count;
3564 
3565         if (olen == 0)
3566                 return 0;
3567 
3568         if (same_inode)
3569                 inode_lock(src);
3570         else
3571                 btrfs_double_inode_lock(src, dst);
3572 
3573         /* don't make the dst file partly checksummed */
3574         if ((BTRFS_I(src)->flags & BTRFS_INODE_NODATASUM) !=
3575             (BTRFS_I(dst)->flags & BTRFS_INODE_NODATASUM)) {
3576                 ret = -EINVAL;
3577                 goto out_unlock;
3578         }
3579 
3580         tail_len = olen % BTRFS_MAX_DEDUPE_LEN;
3581         chunk_count = div_u64(olen, BTRFS_MAX_DEDUPE_LEN);
3582         if (chunk_count == 0)
3583                 num_pages = PAGE_ALIGN(tail_len) >> PAGE_SHIFT;
3584 
3585         /*
3586          * If deduping ranges in the same inode, locking rules make it
3587          * mandatory to always lock pages in ascending order to avoid deadlocks
3588          * with concurrent tasks (such as starting writeback/delalloc).
3589          */
3590         if (same_inode && dst_loff < loff)
3591                 swap(loff, dst_loff);
3592 
3593         /*
3594          * We must gather up all the pages before we initiate our extent
3595          * locking. We use an array for the page pointers. Size of the array is
3596          * bounded by len, which is in turn bounded by BTRFS_MAX_DEDUPE_LEN.
3597          */
3598         cmp.src_pages = kvmalloc_array(num_pages, sizeof(struct page *),
3599                                        GFP_KERNEL | __GFP_ZERO);
3600         cmp.dst_pages = kvmalloc_array(num_pages, sizeof(struct page *),
3601                                        GFP_KERNEL | __GFP_ZERO);
3602         if (!cmp.src_pages || !cmp.dst_pages) {
3603                 ret = -ENOMEM;
3604                 goto out_free;
3605         }
3606 
3607         for (i = 0; i < chunk_count; i++) {
3608                 ret = btrfs_extent_same_range(src, loff, BTRFS_MAX_DEDUPE_LEN,
3609                                               dst, dst_loff, &cmp);
3610                 if (ret)
3611                         goto out_free;
3612 
3613                 loff += BTRFS_MAX_DEDUPE_LEN;
3614                 dst_loff += BTRFS_MAX_DEDUPE_LEN;
3615         }
3616 
3617         if (tail_len > 0)
3618                 ret = btrfs_extent_same_range(src, loff, tail_len, dst,
3619                                               dst_loff, &cmp);
3620 
3621 out_free:
3622         kvfree(cmp.src_pages);
3623         kvfree(cmp.dst_pages);
3624 
3625 out_unlock:
3626         if (same_inode)
3627                 inode_unlock(src);
3628         else
3629                 btrfs_double_inode_unlock(src, dst);
3630 
3631         return ret;
3632 }
3633 
3634 static int clone_finish_inode_update(struct btrfs_trans_handle *trans,
3635                                      struct inode *inode,
3636                                      u64 endoff,
3637                                      const u64 destoff,
3638                                      const u64 olen,
3639                                      int no_time_update)
3640 {
3641         struct btrfs_root *root = BTRFS_I(inode)->root;
3642         int ret;
3643 
3644         inode_inc_iversion(inode);
3645         if (!no_time_update)
3646                 inode->i_mtime = inode->i_ctime = current_time(inode);
3647         /*
3648          * We round up to the block size at eof when determining which
3649          * extents to clone above, but shouldn't round up the file size.
3650          */
3651         if (endoff > destoff + olen)
3652                 endoff = destoff + olen;
3653         if (endoff > inode->i_size)
3654                 btrfs_i_size_write(BTRFS_I(inode), endoff);
3655 
3656         ret = btrfs_update_inode(trans, root, inode);
3657         if (ret) {
3658                 btrfs_abort_transaction(trans, ret);
3659                 btrfs_end_transaction(trans);
3660                 goto out;
3661         }
3662         ret = btrfs_end_transaction(trans);
3663 out:
3664         return ret;
3665 }
3666 
3667 static void clone_update_extent_map(struct btrfs_inode *inode,
3668                                     const struct btrfs_trans_handle *trans,
3669                                     const struct btrfs_path *path,
3670                                     const u64 hole_offset,
3671                                     const u64 hole_len)
3672 {
3673         struct extent_map_tree *em_tree = &inode->extent_tree;
3674         struct extent_map *em;
3675         int ret;
3676 
3677         em = alloc_extent_map();
3678         if (!em) {
3679                 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC, &inode->runtime_flags);
3680                 return;
3681         }
3682 
3683         if (path) {
3684                 struct btrfs_file_extent_item *fi;
3685 
3686                 fi = btrfs_item_ptr(path->nodes[0], path->slots[0],
3687                                     struct btrfs_file_extent_item);
3688                 btrfs_extent_item_to_extent_map(inode, path, fi, false, em);
3689                 em->generation = -1;
3690                 if (btrfs_file_extent_type(path->nodes[0], fi) ==
3691                     BTRFS_FILE_EXTENT_INLINE)
3692                         set_bit(BTRFS_INODE_NEEDS_FULL_SYNC,
3693                                         &inode->runtime_flags);
3694         } else {
3695                 em->start = hole_offset;
3696                 em->len = hole_len;
3697                 em->ram_bytes = em->len;
3698                 em->orig_start = hole_offset;
3699                 em->block_start = EXTENT_MAP_HOLE;
3700                 em->block_len = 0;
3701                 em->orig_block_len = 0;
3702                 em->compress_type = BTRFS_COMPRESS_NONE;
3703                 em->generation = trans->transid;
3704         }
3705 
3706         while (1) {
3707                 write_lock(&em_tree->lock);
3708                 ret = add_extent_mapping(em_tree, em, 1);
3709                 write_unlock(&em_tree->lock);
3710                 if (ret != -EEXIST) {
3711                         free_extent_map(em);
3712                         break;
3713                 }
3714                 btrfs_drop_extent_cache(inode, em->start,
3715                                         em->start + em->len - 1, 0);
3716         }
3717 
3718         if (ret)
3719                 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC, &inode->runtime_flags);
3720 }
3721 
3722 /*
3723  * Make sure we do not end up inserting an inline extent into a file that has
3724  * already other (non-inline) extents. If a file has an inline extent it can
3725  * not have any other extents and the (single) inline extent must start at the
3726  * file offset 0. Failing to respect these rules will lead to file corruption,
3727  * resulting in EIO errors on read/write operations, hitting BUG_ON's in mm, etc
3728  *
3729  * We can have extents that have been already written to disk or we can have
3730  * dirty ranges still in delalloc, in which case the extent maps and items are
3731  * created only when we run delalloc, and the delalloc ranges might fall outside
3732  * the range we are currently locking in the inode's io tree. So we check the
3733  * inode's i_size because of that (i_size updates are done while holding the
3734  * i_mutex, which we are holding here).
3735  * We also check to see if the inode has a size not greater than "datal" but has
3736  * extents beyond it, due to an fallocate with FALLOC_FL_KEEP_SIZE (and we are
3737  * protected against such concurrent fallocate calls by the i_mutex).
3738  *
3739  * If the file has no extents but a size greater than datal, do not allow the
3740  * copy because we would need turn the inline extent into a non-inline one (even
3741  * with NO_HOLES enabled). If we find our destination inode only has one inline
3742  * extent, just overwrite it with the source inline extent if its size is less
3743  * than the source extent's size, or we could copy the source inline extent's
3744  * data into the destination inode's inline extent if the later is greater then
3745  * the former.
3746  */
3747 static int clone_copy_inline_extent(struct inode *dst,
3748                                     struct btrfs_trans_handle *trans,
3749                                     struct btrfs_path *path,
3750                                     struct btrfs_key *new_key,
3751                                     const u64 drop_start,
3752                                     const u64 datal,
3753                                     const u64 skip,
3754                                     const u64 size,
3755                                     char *inline_data)
3756 {
3757         struct btrfs_fs_info *fs_info = btrfs_sb(dst->i_sb);
3758         struct btrfs_root *root = BTRFS_I(dst)->root;
3759         const u64 aligned_end = ALIGN(new_key->offset + datal,
3760                                       fs_info->sectorsize);
3761         int ret;
3762         struct btrfs_key key;
3763 
3764         if (new_key->offset > 0)
3765                 return -EOPNOTSUPP;
3766 
3767         key.objectid = btrfs_ino(BTRFS_I(dst));
3768         key.type = BTRFS_EXTENT_DATA_KEY;
3769         key.offset = 0;
3770         ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
3771         if (ret < 0) {
3772                 return ret;
3773         } else if (ret > 0) {
3774                 if (path->slots[0] >= btrfs_header_nritems(path->nodes[0])) {
3775                         ret = btrfs_next_leaf(root, path);
3776                         if (ret < 0)
3777                                 return ret;
3778                         else if (ret > 0)
3779                                 goto copy_inline_extent;
3780                 }
3781                 btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]);
3782                 if (key.objectid == btrfs_ino(BTRFS_I(dst)) &&
3783                     key.type == BTRFS_EXTENT_DATA_KEY) {
3784                         ASSERT(key.offset > 0);
3785                         return -EOPNOTSUPP;
3786                 }
3787         } else if (i_size_read(dst) <= datal) {
3788                 struct btrfs_file_extent_item *ei;
3789                 u64 ext_len;
3790 
3791                 /*
3792                  * If the file size is <= datal, make sure there are no other
3793                  * extents following (can happen do to an fallocate call with
3794                  * the flag FALLOC_FL_KEEP_SIZE).
3795                  */
3796                 ei = btrfs_item_ptr(path->nodes[0], path->slots[0],
3797                                     struct btrfs_file_extent_item);
3798                 /*
3799                  * If it's an inline extent, it can not have other extents
3800                  * following it.
3801                  */
3802                 if (btrfs_file_extent_type(path->nodes[0], ei) ==
3803                     BTRFS_FILE_EXTENT_INLINE)
3804                         goto copy_inline_extent;
3805 
3806                 ext_len = btrfs_file_extent_num_bytes(path->nodes[0], ei);
3807                 if (ext_len > aligned_end)
3808                         return -EOPNOTSUPP;
3809 
3810                 ret = btrfs_next_item(root, path);
3811                 if (ret < 0) {
3812                         return ret;
3813                 } else if (ret == 0) {
3814                         btrfs_item_key_to_cpu(path->nodes[0], &key,
3815                                               path->slots[0]);
3816                         if (key.objectid == btrfs_ino(BTRFS_I(dst)) &&
3817                             key.type == BTRFS_EXTENT_DATA_KEY)
3818                                 return -EOPNOTSUPP;
3819                 }
3820         }
3821 
3822 copy_inline_extent:
3823         /*
3824          * We have no extent items, or we have an extent at offset 0 which may
3825          * or may not be inlined. All these cases are dealt the same way.
3826          */
3827         if (i_size_read(dst) > datal) {
3828                 /*
3829                  * If the destination inode has an inline extent...
3830                  * This would require copying the data from the source inline
3831                  * extent into the beginning of the destination's inline extent.
3832                  * But this is really complex, both extents can be compressed
3833                  * or just one of them, which would require decompressing and
3834                  * re-compressing data (which could increase the new compressed
3835                  * size, not allowing the compressed data to fit anymore in an
3836                  * inline extent).
3837                  * So just don't support this case for now (it should be rare,
3838                  * we are not really saving space when cloning inline extents).
3839                  */
3840                 return -EOPNOTSUPP;
3841         }
3842 
3843         btrfs_release_path(path);
3844         ret = btrfs_drop_extents(trans, root, dst, drop_start, aligned_end, 1);
3845         if (ret)
3846                 return ret;
3847         ret = btrfs_insert_empty_item(trans, root, path, new_key, size);
3848         if (ret)
3849                 return ret;
3850 
3851         if (skip) {
3852                 const u32 start = btrfs_file_extent_calc_inline_size(0);
3853 
3854                 memmove(inline_data + start, inline_data + start + skip, datal);
3855         }
3856 
3857         write_extent_buffer(path->nodes[0], inline_data,
3858                             btrfs_item_ptr_offset(path->nodes[0],
3859                                                   path->slots[0]),
3860                             size);
3861         inode_add_bytes(dst, datal);
3862 
3863         return 0;
3864 }
3865 
3866 /**
3867  * btrfs_clone() - clone a range from inode file to another
3868  *
3869  * @src: Inode to clone from
3870  * @inode: Inode to clone to
3871  * @off: Offset within source to start clone from
3872  * @olen: Original length, passed by user, of range to clone
3873  * @olen_aligned: Block-aligned value of olen
3874  * @destoff: Offset within @inode to start clone
3875  * @no_time_update: Whether to update mtime/ctime on the target inode
3876  */
3877 static int btrfs_clone(struct inode *src, struct inode *inode,
3878                        const u64 off, const u64 olen, const u64 olen_aligned,
3879                        const u64 destoff, int no_time_update)
3880 {
3881         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
3882         struct btrfs_root *root = BTRFS_I(inode)->root;
3883         struct btrfs_path *path = NULL;
3884         struct extent_buffer *leaf;
3885         struct btrfs_trans_handle *trans;
3886         char *buf = NULL;
3887         struct btrfs_key key;
3888         u32 nritems;
3889         int slot;
3890         int ret;
3891         const u64 len = olen_aligned;
3892         u64 last_dest_end = destoff;
3893 
3894         ret = -ENOMEM;
3895         buf = kvmalloc(fs_info->nodesize, GFP_KERNEL);
3896         if (!buf)
3897                 return ret;
3898 
3899         path = btrfs_alloc_path();
3900         if (!path) {
3901                 kvfree(buf);
3902                 return ret;
3903         }
3904 
3905         path->reada = READA_FORWARD;
3906         /* clone data */
3907         key.objectid = btrfs_ino(BTRFS_I(src));
3908         key.type = BTRFS_EXTENT_DATA_KEY;
3909         key.offset = off;
3910 
3911         while (1) {
3912                 u64 next_key_min_offset = key.offset + 1;
3913 
3914                 /*
3915                  * note the key will change type as we walk through the
3916                  * tree.
3917                  */
3918                 path->leave_spinning = 1;
3919                 ret = btrfs_search_slot(NULL, BTRFS_I(src)->root, &key, path,
3920                                 0, 0);
3921                 if (ret < 0)
3922                         goto out;
3923                 /*
3924                  * First search, if no extent item that starts at offset off was
3925                  * found but the previous item is an extent item, it's possible
3926                  * it might overlap our target range, therefore process it.
3927                  */
3928                 if (key.offset == off && ret > 0 && path->slots[0] > 0) {
3929                         btrfs_item_key_to_cpu(path->nodes[0], &key,
3930                                               path->slots[0] - 1);
3931                         if (key.type == BTRFS_EXTENT_DATA_KEY)
3932                                 path->slots[0]--;
3933                 }
3934 
3935                 nritems = btrfs_header_nritems(path->nodes[0]);
3936 process_slot:
3937                 if (path->slots[0] >= nritems) {
3938                         ret = btrfs_next_leaf(BTRFS_I(src)->root, path);
3939                         if (ret < 0)
3940                                 goto out;
3941                         if (ret > 0)
3942                                 break;
3943                         nritems = btrfs_header_nritems(path->nodes[0]);
3944                 }
3945                 leaf = path->nodes[0];
3946                 slot = path->slots[0];
3947 
3948                 btrfs_item_key_to_cpu(leaf, &key, slot);
3949                 if (key.type > BTRFS_EXTENT_DATA_KEY ||
3950                     key.objectid != btrfs_ino(BTRFS_I(src)))
3951                         break;
3952 
3953                 if (key.type == BTRFS_EXTENT_DATA_KEY) {
3954                         struct btrfs_file_extent_item *extent;
3955                         int type;
3956                         u32 size;
3957                         struct btrfs_key new_key;
3958                         u64 disko = 0, diskl = 0;
3959                         u64 datao = 0, datal = 0;
3960                         u8 comp;
3961                         u64 drop_start;
3962 
3963                         extent = btrfs_item_ptr(leaf, slot,
3964                                                 struct btrfs_file_extent_item);
3965                         comp = btrfs_file_extent_compression(leaf, extent);
3966                         type = btrfs_file_extent_type(leaf, extent);
3967                         if (type == BTRFS_FILE_EXTENT_REG ||
3968                             type == BTRFS_FILE_EXTENT_PREALLOC) {
3969                                 disko = btrfs_file_extent_disk_bytenr(leaf,
3970                                                                       extent);
3971                                 diskl = btrfs_file_extent_disk_num_bytes(leaf,
3972                                                                  extent);
3973                                 datao = btrfs_file_extent_offset(leaf, extent);
3974                                 datal = btrfs_file_extent_num_bytes(leaf,
3975                                                                     extent);
3976                         } else if (type == BTRFS_FILE_EXTENT_INLINE) {
3977                                 /* take upper bound, may be compressed */
3978                                 datal = btrfs_file_extent_ram_bytes(leaf,
3979                                                                     extent);
3980                         }
3981 
3982                         /*
3983                          * The first search might have left us at an extent
3984                          * item that ends before our target range's start, can
3985                          * happen if we have holes and NO_HOLES feature enabled.
3986                          */
3987                         if (key.offset + datal <= off) {
3988                                 path->slots[0]++;
3989                                 goto process_slot;
3990                         } else if (key.offset >= off + len) {
3991                                 break;
3992                         }
3993                         next_key_min_offset = key.offset + datal;
3994                         size = btrfs_item_size_nr(leaf, slot);
3995                         read_extent_buffer(leaf, buf,
3996                                            btrfs_item_ptr_offset(leaf, slot),
3997                                            size);
3998 
3999                         btrfs_release_path(path);
4000                         path->leave_spinning = 0;
4001 
4002                         memcpy(&new_key, &key, sizeof(new_key));
4003                         new_key.objectid = btrfs_ino(BTRFS_I(inode));
4004                         if (off <= key.offset)
4005                                 new_key.offset = key.offset + destoff - off;
4006                         else
4007                                 new_key.offset = destoff;
4008 
4009                         /*
4010                          * Deal with a hole that doesn't have an extent item
4011                          * that represents it (NO_HOLES feature enabled).
4012                          * This hole is either in the middle of the cloning
4013                          * range or at the beginning (fully overlaps it or
4014                          * partially overlaps it).
4015                          */
4016                         if (new_key.offset != last_dest_end)
4017                                 drop_start = last_dest_end;
4018                         else
4019                                 drop_start = new_key.offset;
4020 
4021                         /*
4022                          * 1 - adjusting old extent (we may have to split it)
4023                          * 1 - add new extent
4024                          * 1 - inode update
4025                          */
4026                         trans = btrfs_start_transaction(root, 3);
4027                         if (IS_ERR(trans)) {
4028                                 ret = PTR_ERR(trans);
4029                                 goto out;
4030                         }
4031 
4032                         if (type == BTRFS_FILE_EXTENT_REG ||
4033                             type == BTRFS_FILE_EXTENT_PREALLOC) {
4034                                 /*
4035                                  *    a  | --- range to clone ---|  b
4036                                  * | ------------- extent ------------- |
4037                                  */
4038 
4039                                 /* subtract range b */
4040                                 if (key.offset + datal > off + len)
4041                                         datal = off + len - key.offset;
4042 
4043                                 /* subtract range a */
4044                                 if (off > key.offset) {
4045                                         datao += off - key.offset;
4046                                         datal -= off - key.offset;
4047                                 }
4048 
4049                                 ret = btrfs_drop_extents(trans, root, inode,
4050                                                          drop_start,
4051                                                          new_key.offset + datal,
4052                                                          1);
4053                                 if (ret) {
4054                                         if (ret != -EOPNOTSUPP)
4055                                                 btrfs_abort_transaction(trans,
4056                                                                         ret);
4057                                         btrfs_end_transaction(trans);
4058                                         goto out;
4059                                 }
4060 
4061                                 ret = btrfs_insert_empty_item(trans, root, path,
4062                                                               &new_key, size);
4063                                 if (ret) {
4064                                         btrfs_abort_transaction(trans, ret);
4065                                         btrfs_end_transaction(trans);
4066                                         goto out;
4067                                 }
4068 
4069                                 leaf = path->nodes[0];
4070                                 slot = path->slots[0];
4071                                 write_extent_buffer(leaf, buf,
4072                                             btrfs_item_ptr_offset(leaf, slot),
4073                                             size);
4074 
4075                                 extent = btrfs_item_ptr(leaf, slot,
4076                                                 struct btrfs_file_extent_item);
4077 
4078                                 /* disko == 0 means it's a hole */
4079                                 if (!disko)
4080                                         datao = 0;
4081 
4082                                 btrfs_set_file_extent_offset(leaf, extent,
4083                                                              datao);
4084                                 btrfs_set_file_extent_num_bytes(leaf, extent,
4085                                                                 datal);
4086 
4087                                 if (disko) {
4088                                         inode_add_bytes(inode, datal);
4089                                         ret = btrfs_inc_extent_ref(trans,
4090                                                         root,
4091                                                         disko, diskl, 0,
4092                                                         root->root_key.objectid,
4093                                                         btrfs_ino(BTRFS_I(inode)),
4094                                                         new_key.offset - datao);
4095                                         if (ret) {
4096                                                 btrfs_abort_transaction(trans,
4097                                                                         ret);
4098                                                 btrfs_end_transaction(trans);
4099                                                 goto out;
4100 
4101                                         }
4102                                 }
4103                         } else if (type == BTRFS_FILE_EXTENT_INLINE) {
4104                                 u64 skip = 0;
4105                                 u64 trim = 0;
4106 
4107                                 if (off > key.offset) {
4108                                         skip = off - key.offset;
4109                                         new_key.offset += skip;
4110                                 }
4111 
4112                                 if (key.offset + datal > off + len)
4113                                         trim = key.offset + datal - (off + len);
4114 
4115                                 if (comp && (skip || trim)) {
4116                                         ret = -EINVAL;
4117                                         btrfs_end_transaction(trans);
4118                                         goto out;
4119                                 }
4120                                 size -= skip + trim;
4121                                 datal -= skip + trim;
4122 
4123                                 ret = clone_copy_inline_extent(inode,
4124                                                                trans, path,
4125                                                                &new_key,
4126                                                                drop_start,
4127                                                                datal,
4128                                                                skip, size, buf);
4129                                 if (ret) {
4130                                         if (ret != -EOPNOTSUPP)
4131                                                 btrfs_abort_transaction(trans,
4132                                                                         ret);
4133                                         btrfs_end_transaction(trans);
4134                                         goto out;
4135                                 }
4136                                 leaf = path->nodes[0];
4137                                 slot = path->slots[0];
4138                         }
4139 
4140                         /* If we have an implicit hole (NO_HOLES feature). */
4141                         if (drop_start < new_key.offset)
4142                                 clone_update_extent_map(BTRFS_I(inode), trans,
4143                                                 NULL, drop_start,
4144                                                 new_key.offset - drop_start);
4145 
4146                         clone_update_extent_map(BTRFS_I(inode), trans,
4147                                         path, 0, 0);
4148 
4149                         btrfs_mark_buffer_dirty(leaf);
4150                         btrfs_release_path(path);
4151 
4152                         last_dest_end = ALIGN(new_key.offset + datal,
4153                                               fs_info->sectorsize);
4154                         ret = clone_finish_inode_update(trans, inode,
4155                                                         last_dest_end,
4156                                                         destoff, olen,
4157                                                         no_time_update);
4158                         if (ret)
4159                                 goto out;
4160                         if (new_key.offset + datal >= destoff + len)
4161                                 break;
4162                 }
4163                 btrfs_release_path(path);
4164                 key.offset = next_key_min_offset;
4165 
4166                 if (fatal_signal_pending(current)) {
4167                         ret = -EINTR;
4168                         goto out;
4169                 }
4170         }
4171         ret = 0;
4172 
4173         if (last_dest_end < destoff + len) {
4174                 /*
4175                  * We have an implicit hole (NO_HOLES feature is enabled) that
4176                  * fully or partially overlaps our cloning range at its end.
4177                  */
4178                 btrfs_release_path(path);
4179 
4180                 /*
4181                  * 1 - remove extent(s)
4182                  * 1 - inode update
4183                  */
4184                 trans = btrfs_start_transaction(root, 2);
4185                 if (IS_ERR(trans)) {
4186                         ret = PTR_ERR(trans);
4187                         goto out;
4188                 }
4189                 ret = btrfs_drop_extents(trans, root, inode,
4190                                          last_dest_end, destoff + len, 1);
4191                 if (ret) {
4192                         if (ret != -EOPNOTSUPP)
4193                                 btrfs_abort_transaction(trans, ret);
4194                         btrfs_end_transaction(trans);
4195                         goto out;
4196                 }
4197                 clone_update_extent_map(BTRFS_I(inode), trans, NULL,
4198                                 last_dest_end,
4199                                 destoff + len - last_dest_end);
4200                 ret = clone_finish_inode_update(trans, inode, destoff + len,
4201                                                 destoff, olen, no_time_update);
4202         }
4203 
4204 out:
4205         btrfs_free_path(path);
4206         kvfree(buf);
4207         return ret;
4208 }
4209 
4210 static noinline int btrfs_clone_files(struct file *file, struct file *file_src,
4211                                         u64 off, u64 olen, u64 destoff)
4212 {
4213         struct inode *inode = file_inode(file);
4214         struct inode *src = file_inode(file_src);
4215         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
4216         struct btrfs_root *root = BTRFS_I(inode)->root;
4217         int ret;
4218         u64 len = olen;
4219         u64 bs = fs_info->sb->s_blocksize;
4220         int same_inode = src == inode;
4221 
4222         /*
4223          * TODO:
4224          * - split compressed inline extents.  annoying: we need to
4225          *   decompress into destination's address_space (the file offset
4226          *   may change, so source mapping won't do), then recompress (or
4227          *   otherwise reinsert) a subrange.
4228          *
4229          * - split destination inode's inline extents.  The inline extents can
4230          *   be either compressed or non-compressed.
4231          */
4232 
4233         if (btrfs_root_readonly(root))
4234                 return -EROFS;
4235 
4236         if (file_src->f_path.mnt != file->f_path.mnt ||
4237             src->i_sb != inode->i_sb)
4238                 return -EXDEV;
4239 
4240         if (S_ISDIR(src->i_mode) || S_ISDIR(inode->i_mode))
4241                 return -EISDIR;
4242 
4243         if (!same_inode) {
4244                 btrfs_double_inode_lock(src, inode);
4245         } else {
4246                 inode_lock(src);
4247         }
4248 
4249         /* don't make the dst file partly checksummed */
4250         if ((BTRFS_I(src)->flags & BTRFS_INODE_NODATASUM) !=
4251             (BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM)) {
4252                 ret = -EINVAL;
4253                 goto out_unlock;
4254         }
4255 
4256         /* determine range to clone */
4257         ret = -EINVAL;
4258         if (off + len > src->i_size || off + len < off)
4259                 goto out_unlock;
4260         if (len == 0)
4261                 olen = len = src->i_size - off;
4262         /*
4263          * If we extend to eof, continue to block boundary if and only if the
4264          * destination end offset matches the destination file's size, otherwise
4265          * we would be corrupting data by placing the eof block into the middle
4266          * of a file.
4267          */
4268         if (off + len == src->i_size) {
4269                 if (!IS_ALIGNED(len, bs) && destoff + len < inode->i_size)
4270                         goto out_unlock;
4271                 len = ALIGN(src->i_size, bs) - off;
4272         }
4273 
4274         if (len == 0) {
4275                 ret = 0;
4276                 goto out_unlock;
4277         }
4278 
4279         /* verify the end result is block aligned */
4280         if (!IS_ALIGNED(off, bs) || !IS_ALIGNED(off + len, bs) ||
4281             !IS_ALIGNED(destoff, bs))
4282                 goto out_unlock;
4283 
4284         /* verify if ranges are overlapped within the same file */
4285         if (same_inode) {
4286                 if (destoff + len > off && destoff < off + len)
4287                         goto out_unlock;
4288         }
4289 
4290         if (destoff > inode->i_size) {
4291                 ret = btrfs_cont_expand(inode, inode->i_size, destoff);
4292                 if (ret)
4293                         goto out_unlock;
4294         }
4295 
4296         /*
4297          * Lock the target range too. Right after we replace the file extent
4298          * items in the fs tree (which now point to the cloned data), we might
4299          * have a worker replace them with extent items relative to a write
4300          * operation that was issued before this clone operation (i.e. confront
4301          * with inode.c:btrfs_finish_ordered_io).
4302          */
4303         if (same_inode) {
4304                 u64 lock_start = min_t(u64, off, destoff);
4305                 u64 lock_len = max_t(u64, off, destoff) + len - lock_start;
4306 
4307                 ret = lock_extent_range(src, lock_start, lock_len, true);
4308         } else {
4309                 ret = btrfs_double_extent_lock(src, off, inode, destoff, len,
4310                                                true);
4311         }
4312         ASSERT(ret == 0);
4313         if (WARN_ON(ret)) {
4314                 /* ranges in the io trees already unlocked */
4315                 goto out_unlock;
4316         }
4317 
4318         ret = btrfs_clone(src, inode, off, olen, len, destoff, 0);
4319 
4320         if (same_inode) {
4321                 u64 lock_start = min_t(u64, off, destoff);
4322                 u64 lock_end = max_t(u64, off, destoff) + len - 1;
4323 
4324                 unlock_extent(&BTRFS_I(src)->io_tree, lock_start, lock_end);
4325         } else {
4326                 btrfs_double_extent_unlock(src, off, inode, destoff, len);
4327         }
4328         /*
4329          * Truncate page cache pages so that future reads will see the cloned
4330          * data immediately and not the previous data.
4331          */
4332         truncate_inode_pages_range(&inode->i_data,
4333                                 round_down(destoff, PAGE_SIZE),
4334                                 round_up(destoff + len, PAGE_SIZE) - 1);
4335 out_unlock:
4336         if (!same_inode)
4337                 btrfs_double_inode_unlock(src, inode);
4338         else
4339                 inode_unlock(src);
4340         return ret;
4341 }
4342 
4343 loff_t btrfs_remap_file_range(struct file *src_file, loff_t off,
4344                 struct file *dst_file, loff_t destoff, loff_t len,
4345                 unsigned int remap_flags)
4346 {
4347         int ret;
4348 
4349         if (remap_flags & ~(REMAP_FILE_DEDUP | REMAP_FILE_ADVISORY))
4350                 return -EINVAL;
4351 
4352         if (remap_flags & REMAP_FILE_DEDUP) {
4353                 struct inode *src = file_inode(src_file);
4354                 struct inode *dst = file_inode(dst_file);
4355                 u64 bs = BTRFS_I(src)->root->fs_info->sb->s_blocksize;
4356 
4357                 if (WARN_ON_ONCE(bs < PAGE_SIZE)) {
4358                         /*
4359                          * Btrfs does not support blocksize < page_size. As a
4360                          * result, btrfs_cmp_data() won't correctly handle
4361                          * this situation without an update.
4362                          */
4363                         return -EINVAL;
4364                 }
4365 
4366                 ret = btrfs_extent_same(src, off, len, dst, destoff);
4367         } else {
4368                 ret = btrfs_clone_files(dst_file, src_file, off, len, destoff);
4369         }
4370         return ret < 0 ? ret : len;
4371 }
4372 
4373 static long btrfs_ioctl_default_subvol(struct file *file, void __user *argp)
4374 {
4375         struct inode *inode = file_inode(file);
4376         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
4377         struct btrfs_root *root = BTRFS_I(inode)->root;
4378         struct btrfs_root *new_root;
4379         struct btrfs_dir_item *di;
4380         struct btrfs_trans_handle *trans;
4381         struct btrfs_path *path;
4382         struct btrfs_key location;
4383         struct btrfs_disk_key disk_key;
4384         u64 objectid = 0;
4385         u64 dir_id;
4386         int ret;
4387 
4388         if (!capable(CAP_SYS_ADMIN))
4389                 return -EPERM;
4390 
4391         ret = mnt_want_write_file(file);
4392         if (ret)
4393                 return ret;
4394 
4395         if (copy_from_user(&objectid, argp, sizeof(objectid))) {
4396                 ret = -EFAULT;
4397                 goto out;
4398         }
4399 
4400         if (!objectid)
4401                 objectid = BTRFS_FS_TREE_OBJECTID;
4402 
4403         location.objectid = objectid;
4404         location.type = BTRFS_ROOT_ITEM_KEY;
4405         location.offset = (u64)-1;
4406 
4407         new_root = btrfs_read_fs_root_no_name(fs_info, &location);
4408         if (IS_ERR(new_root)) {
4409                 ret = PTR_ERR(new_root);
4410                 goto out;
4411         }
4412         if (!is_fstree(new_root->root_key.objectid)) {
4413                 ret = -ENOENT;
4414                 goto out;
4415         }
4416 
4417         path = btrfs_alloc_path();
4418         if (!path) {
4419                 ret = -ENOMEM;
4420                 goto out;
4421         }
4422         path->leave_spinning = 1;
4423 
4424         trans = btrfs_start_transaction(root, 1);
4425         if (IS_ERR(trans)) {
4426                 btrfs_free_path(path);
4427                 ret = PTR_ERR(trans);
4428                 goto out;
4429         }
4430 
4431         dir_id = btrfs_super_root_dir(fs_info->super_copy);
4432         di = btrfs_lookup_dir_item(trans, fs_info->tree_root, path,
4433                                    dir_id, "default", 7, 1);
4434         if (IS_ERR_OR_NULL(di)) {
4435                 btrfs_free_path(path);
4436                 btrfs_end_transaction(trans);
4437                 btrfs_err(fs_info,
4438                           "Umm, you don't have the default diritem, this isn't going to work");
4439                 ret = -ENOENT;
4440                 goto out;
4441         }
4442 
4443         btrfs_cpu_key_to_disk(&disk_key, &new_root->root_key);
4444         btrfs_set_dir_item_key(path->nodes[0], di, &disk_key);
4445         btrfs_mark_buffer_dirty(path->nodes[0]);
4446         btrfs_free_path(path);
4447 
4448         btrfs_set_fs_incompat(fs_info, DEFAULT_SUBVOL);
4449         btrfs_end_transaction(trans);
4450 out:
4451         mnt_drop_write_file(file);
4452         return ret;
4453 }
4454 
4455 static void get_block_group_info(struct list_head *groups_list,
4456                                  struct btrfs_ioctl_space_info *space)
4457 {
4458         struct btrfs_block_group_cache *block_group;
4459 
4460         space->total_bytes = 0;
4461         space->used_bytes = 0;
4462         space->flags = 0;
4463         list_for_each_entry(block_group, groups_list, list) {
4464                 space->flags = block_group->flags;
4465                 space->total_bytes += block_group->key.offset;
4466                 space->used_bytes +=
4467                         btrfs_block_group_used(&block_group->item);
4468         }
4469 }
4470 
4471 static long btrfs_ioctl_space_info(struct btrfs_fs_info *fs_info,
4472                                    void __user *arg)
4473 {
4474         struct btrfs_ioctl_space_args space_args;
4475         struct btrfs_ioctl_space_info space;
4476         struct btrfs_ioctl_space_info *dest;
4477         struct btrfs_ioctl_space_info *dest_orig;
4478         struct btrfs_ioctl_space_info __user *user_dest;
4479         struct btrfs_space_info *info;
4480         static const u64 types[] = {
4481                 BTRFS_BLOCK_GROUP_DATA,
4482                 BTRFS_BLOCK_GROUP_SYSTEM,
4483                 BTRFS_BLOCK_GROUP_METADATA,
4484                 BTRFS_BLOCK_GROUP_DATA | BTRFS_BLOCK_GROUP_METADATA
4485         };
4486         int num_types = 4;
4487         int alloc_size;
4488         int ret = 0;
4489         u64 slot_count = 0;
4490         int i, c;
4491 
4492         if (copy_from_user(&space_args,
4493                            (struct btrfs_ioctl_space_args __user *)arg,
4494                            sizeof(space_args)))
4495                 return -EFAULT;
4496 
4497         for (i = 0; i < num_types; i++) {
4498                 struct btrfs_space_info *tmp;
4499 
4500                 info = NULL;
4501                 rcu_read_lock();
4502                 list_for_each_entry_rcu(tmp, &fs_info->space_info,
4503                                         list) {
4504                         if (tmp->flags == types[i]) {
4505                                 info = tmp;
4506                                 break;
4507                         }
4508                 }
4509                 rcu_read_unlock();
4510 
4511                 if (!info)
4512                         continue;
4513 
4514                 down_read(&info->groups_sem);
4515                 for (c = 0; c < BTRFS_NR_RAID_TYPES; c++) {
4516                         if (!list_empty(&info->block_groups[c]))
4517                                 slot_count++;
4518                 }
4519                 up_read(&info->groups_sem);
4520         }
4521 
4522         /*
4523          * Global block reserve, exported as a space_info
4524          */
4525         slot_count++;
4526 
4527         /* space_slots == 0 means they are asking for a count */
4528         if (space_args.space_slots == 0) {
4529                 space_args.total_spaces = slot_count;
4530                 goto out;
4531         }
4532 
4533         slot_count = min_t(u64, space_args.space_slots, slot_count);
4534 
4535         alloc_size = sizeof(*dest) * slot_count;
4536 
4537         /* we generally have at most 6 or so space infos, one for each raid
4538          * level.  So, a whole page should be more than enough for everyone
4539          */
4540         if (alloc_size > PAGE_SIZE)
4541                 return -ENOMEM;
4542 
4543         space_args.total_spaces = 0;
4544         dest = kmalloc(alloc_size, GFP_KERNEL);
4545         if (!dest)
4546                 return -ENOMEM;
4547         dest_orig = dest;
4548 
4549         /* now we have a buffer to copy into */
4550         for (i = 0; i < num_types; i++) {
4551                 struct btrfs_space_info *tmp;
4552 
4553                 if (!slot_count)
4554                         break;
4555 
4556                 info = NULL;
4557                 rcu_read_lock();
4558                 list_for_each_entry_rcu(tmp, &fs_info->space_info,
4559                                         list) {
4560                         if (tmp->flags == types[i]) {
4561                                 info = tmp;
4562                                 break;
4563                         }
4564                 }
4565                 rcu_read_unlock();
4566 
4567                 if (!info)
4568                         continue;
4569                 down_read(&info->groups_sem);
4570                 for (c = 0; c < BTRFS_NR_RAID_TYPES; c++) {
4571                         if (!list_empty(&info->block_groups[c])) {
4572                                 get_block_group_info(&info->block_groups[c],
4573                                                      &space);
4574                                 memcpy(dest, &space, sizeof(space));
4575                                 dest++;
4576                                 space_args.total_spaces++;
4577                                 slot_count--;
4578                         }
4579                         if (!slot_count)
4580                                 break;
4581                 }
4582                 up_read(&info->groups_sem);
4583         }
4584 
4585         /*
4586          * Add global block reserve
4587          */
4588         if (slot_count) {
4589                 struct btrfs_block_rsv *block_rsv = &fs_info->global_block_rsv;
4590 
4591                 spin_lock(&block_rsv->lock);
4592                 space.total_bytes = block_rsv->size;
4593                 space.used_bytes = block_rsv->size - block_rsv->reserved;
4594                 spin_unlock(&block_rsv->lock);
4595                 space.flags = BTRFS_SPACE_INFO_GLOBAL_RSV;
4596                 memcpy(dest, &space, sizeof(space));
4597                 space_args.total_spaces++;
4598         }
4599 
4600         user_dest = (struct btrfs_ioctl_space_info __user *)
4601                 (arg + sizeof(struct btrfs_ioctl_space_args));
4602 
4603         if (copy_to_user(user_dest, dest_orig, alloc_size))
4604                 ret = -EFAULT;
4605 
4606         kfree(dest_orig);
4607 out:
4608         if (ret == 0 && copy_to_user(arg, &space_args, sizeof(space_args)))
4609                 ret = -EFAULT;
4610 
4611         return ret;
4612 }
4613 
4614 static noinline long btrfs_ioctl_start_sync(struct btrfs_root *root,
4615                                             void __user *argp)
4616 {
4617         struct btrfs_trans_handle *trans;
4618         u64 transid;
4619         int ret;
4620 
4621         trans = btrfs_attach_transaction_barrier(root);
4622         if (IS_ERR(trans)) {
4623                 if (PTR_ERR(trans) != -ENOENT)
4624                         return PTR_ERR(trans);
4625 
4626                 /* No running transaction, don't bother */
4627                 transid = root->fs_info->last_trans_committed;
4628                 goto out;
4629         }
4630         transid = trans->transid;
4631         ret = btrfs_commit_transaction_async(trans, 0);
4632         if (ret) {
4633                 btrfs_end_transaction(trans);
4634                 return ret;
4635         }
4636 out:
4637         if (argp)
4638                 if (copy_to_user(argp, &transid, sizeof(transid)))
4639                         return -EFAULT;
4640         return 0;
4641 }
4642 
4643 static noinline long btrfs_ioctl_wait_sync(struct btrfs_fs_info *fs_info,
4644                                            void __user *argp)
4645 {
4646         u64 transid;
4647 
4648         if (argp) {
4649                 if (copy_from_user(&transid, argp, sizeof(transid)))
4650                         return -EFAULT;
4651         } else {
4652                 transid = 0;  /* current trans */
4653         }
4654         return btrfs_wait_for_commit(fs_info, transid);
4655 }
4656 
4657 static long btrfs_ioctl_scrub(struct file *file, void __user *arg)
4658 {
4659         struct btrfs_fs_info *fs_info = btrfs_sb(file_inode(file)->i_sb);
4660         struct btrfs_ioctl_scrub_args *sa;
4661         int ret;
4662 
4663         if (!capable(CAP_SYS_ADMIN))
4664                 return -EPERM;
4665 
4666         sa = memdup_user(arg, sizeof(*sa));
4667         if (IS_ERR(sa))
4668                 return PTR_ERR(sa);
4669 
4670         if (!(sa->flags & BTRFS_SCRUB_READONLY)) {
4671                 ret = mnt_want_write_file(file);
4672                 if (ret)
4673                         goto out;
4674         }
4675 
4676         ret = btrfs_scrub_dev(fs_info, sa->devid, sa->start, sa->end,
4677                               &sa->progress, sa->flags & BTRFS_SCRUB_READONLY,
4678                               0);
4679 
4680         if (copy_to_user(arg, sa, sizeof(*sa)))
4681                 ret = -EFAULT;
4682 
4683         if (!(sa->flags & BTRFS_SCRUB_READONLY))
4684                 mnt_drop_write_file(file);
4685 out:
4686         kfree(sa);
4687         return ret;
4688 }
4689 
4690 static long btrfs_ioctl_scrub_cancel(struct btrfs_fs_info *fs_info)
4691 {
4692         if (!capable(CAP_SYS_ADMIN))
4693                 return -EPERM;
4694 
4695         return btrfs_scrub_cancel(fs_info);
4696 }
4697 
4698 static long btrfs_ioctl_scrub_progress(struct btrfs_fs_info *fs_info,
4699                                        void __user *arg)
4700 {
4701         struct btrfs_ioctl_scrub_args *sa;
4702         int ret;
4703 
4704         if (!capable(CAP_SYS_ADMIN))
4705                 return -EPERM;
4706 
4707         sa = memdup_user(arg, sizeof(*sa));
4708         if (IS_ERR(sa))
4709                 return PTR_ERR(sa);
4710 
4711         ret = btrfs_scrub_progress(fs_info, sa->devid, &sa->progress);
4712 
4713         if (copy_to_user(arg, sa, sizeof(*sa)))
4714                 ret = -EFAULT;
4715 
4716         kfree(sa);
4717         return ret;
4718 }
4719 
4720 static long btrfs_ioctl_get_dev_stats(struct btrfs_fs_info *fs_info,
4721                                       void __user *arg)
4722 {
4723         struct btrfs_ioctl_get_dev_stats *sa;
4724         int ret;
4725 
4726         sa = memdup_user(arg, sizeof(*sa));
4727         if (IS_ERR(sa))
4728                 return PTR_ERR(sa);
4729 
4730         if ((sa->flags & BTRFS_DEV_STATS_RESET) && !capable(CAP_SYS_ADMIN)) {
4731                 kfree(sa);
4732                 return -EPERM;
4733         }
4734 
4735         ret = btrfs_get_dev_stats(fs_info, sa);
4736 
4737         if (copy_to_user(arg, sa, sizeof(*sa)))
4738                 ret = -EFAULT;
4739 
4740         kfree(sa);
4741         return ret;
4742 }
4743 
4744 static long btrfs_ioctl_dev_replace(struct btrfs_fs_info *fs_info,
4745                                     void __user *arg)
4746 {
4747         struct btrfs_ioctl_dev_replace_args *p;
4748         int ret;
4749 
4750         if (!capable(CAP_SYS_ADMIN))
4751                 return -EPERM;
4752 
4753         p = memdup_user(arg, sizeof(*p));
4754         if (IS_ERR(p))
4755                 return PTR_ERR(p);
4756 
4757         switch (p->cmd) {
4758         case BTRFS_IOCTL_DEV_REPLACE_CMD_START:
4759                 if (sb_rdonly(fs_info->sb)) {
4760                         ret = -EROFS;
4761                         goto out;
4762                 }
4763                 if (test_and_set_bit(BTRFS_FS_EXCL_OP, &fs_info->flags)) {
4764                         ret = BTRFS_ERROR_DEV_EXCL_RUN_IN_PROGRESS;
4765                 } else {
4766                         ret = btrfs_dev_replace_by_ioctl(fs_info, p);
4767                         clear_bit(BTRFS_FS_EXCL_OP, &fs_info->flags);
4768                 }
4769                 break;
4770         case BTRFS_IOCTL_DEV_REPLACE_CMD_STATUS:
4771                 btrfs_dev_replace_status(fs_info, p);
4772                 ret = 0;
4773                 break;
4774         case BTRFS_IOCTL_DEV_REPLACE_CMD_CANCEL:
4775                 p->result = btrfs_dev_replace_cancel(fs_info);
4776                 ret = 0;
4777                 break;
4778         default:
4779                 ret = -EINVAL;
4780                 break;
4781         }
4782 
4783         if (copy_to_user(arg, p, sizeof(*p)))
4784                 ret = -EFAULT;
4785 out:
4786         kfree(p);
4787         return ret;
4788 }
4789 
4790 static long btrfs_ioctl_ino_to_path(struct btrfs_root *root, void __user *arg)
4791 {
4792         int ret = 0;
4793         int i;
4794         u64 rel_ptr;
4795         int size;
4796         struct btrfs_ioctl_ino_path_args *ipa = NULL;
4797         struct inode_fs_paths *ipath = NULL;
4798         struct btrfs_path *path;
4799 
4800         if (!capable(CAP_DAC_READ_SEARCH))
4801                 return -EPERM;
4802 
4803         path = btrfs_alloc_path();
4804         if (!path) {
4805                 ret = -ENOMEM;
4806                 goto out;
4807         }
4808 
4809         ipa = memdup_user(arg, sizeof(*ipa));
4810         if (IS_ERR(ipa)) {
4811                 ret = PTR_ERR(ipa);
4812                 ipa = NULL;
4813                 goto out;
4814         }
4815 
4816         size = min_t(u32, ipa->size, 4096);
4817         ipath = init_ipath(size, root, path);
4818         if (IS_ERR(ipath)) {
4819                 ret = PTR_ERR(ipath);
4820                 ipath = NULL;
4821                 goto out;
4822         }
4823 
4824         ret = paths_from_inode(ipa->inum, ipath);
4825         if (ret < 0)
4826                 goto out;
4827 
4828         for (i = 0; i < ipath->fspath->elem_cnt; ++i) {
4829                 rel_ptr = ipath->fspath->val[i] -
4830                           (u64)(unsigned long)ipath->fspath->val;
4831                 ipath->fspath->val[i] = rel_ptr;
4832         }
4833 
4834         ret = copy_to_user((void __user *)(unsigned long)ipa->fspath,
4835                            ipath->fspath, size);
4836         if (ret) {
4837                 ret = -EFAULT;
4838                 goto out;
4839         }
4840 
4841 out:
4842         btrfs_free_path(path);
4843         free_ipath(ipath);
4844         kfree(ipa);
4845 
4846         return ret;
4847 }
4848 
4849 static int build_ino_list(u64 inum, u64 offset, u64 root, void *ctx)
4850 {
4851         struct btrfs_data_container *inodes = ctx;
4852         const size_t c = 3 * sizeof(u64);
4853 
4854         if (inodes->bytes_left >= c) {
4855                 inodes->bytes_left -= c;
4856                 inodes->val[inodes->elem_cnt] = inum;
4857                 inodes->val[inodes->elem_cnt + 1] = offset;
4858                 inodes->val[inodes->elem_cnt + 2] = root;
4859                 inodes->elem_cnt += 3;
4860         } else {
4861                 inodes->bytes_missing += c - inodes->bytes_left;
4862                 inodes->bytes_left = 0;
4863                 inodes->elem_missed += 3;
4864         }
4865 
4866         return 0;
4867 }
4868 
4869 static long btrfs_ioctl_logical_to_ino(struct btrfs_fs_info *fs_info,
4870                                         void __user *arg, int version)
4871 {
4872         int ret = 0;
4873         int size;
4874         struct btrfs_ioctl_logical_ino_args *loi;
4875         struct btrfs_data_container *inodes = NULL;
4876         struct btrfs_path *path = NULL;
4877         bool ignore_offset;
4878 
4879         if (!capable(CAP_SYS_ADMIN))
4880                 return -EPERM;
4881 
4882         loi = memdup_user(arg, sizeof(*loi));
4883         if (IS_ERR(loi))
4884                 return PTR_ERR(loi);
4885 
4886         if (version == 1) {
4887                 ignore_offset = false;
4888                 size = min_t(u32, loi->size, SZ_64K);
4889         } else {
4890                 /* All reserved bits must be 0 for now */
4891                 if (memchr_inv(loi->reserved, 0, sizeof(loi->reserved))) {
4892                         ret = -EINVAL;
4893                         goto out_loi;
4894                 }
4895                 /* Only accept flags we have defined so far */
4896                 if (loi->flags & ~(BTRFS_LOGICAL_INO_ARGS_IGNORE_OFFSET)) {
4897                         ret = -EINVAL;
4898                         goto out_loi;
4899                 }
4900                 ignore_offset = loi->flags & BTRFS_LOGICAL_INO_ARGS_IGNORE_OFFSET;
4901                 size = min_t(u32, loi->size, SZ_16M);
4902         }
4903 
4904         path = btrfs_alloc_path();
4905         if (!path) {
4906                 ret = -ENOMEM;
4907                 goto out;
4908         }
4909 
4910         inodes = init_data_container(size);
4911         if (IS_ERR(inodes)) {
4912                 ret = PTR_ERR(inodes);
4913                 inodes = NULL;
4914                 goto out;
4915         }
4916 
4917         ret = iterate_inodes_from_logical(loi->logical, fs_info, path,
4918                                           build_ino_list, inodes, ignore_offset);
4919         if (ret == -EINVAL)
4920                 ret = -ENOENT;
4921         if (ret < 0)
4922                 goto out;
4923 
4924         ret = copy_to_user((void __user *)(unsigned long)loi->inodes, inodes,
4925                            size);
4926         if (ret)
4927                 ret = -EFAULT;
4928 
4929 out:
4930         btrfs_free_path(path);
4931         kvfree(inodes);
4932 out_loi:
4933         kfree(loi);
4934 
4935         return ret;
4936 }
4937 
4938 void btrfs_update_ioctl_balance_args(struct btrfs_fs_info *fs_info,
4939                                struct btrfs_ioctl_balance_args *bargs)
4940 {
4941         struct btrfs_balance_control *bctl = fs_info->balance_ctl;
4942 
4943         bargs->flags = bctl->flags;
4944 
4945         if (test_bit(BTRFS_FS_BALANCE_RUNNING, &fs_info->flags))
4946                 bargs->state |= BTRFS_BALANCE_STATE_RUNNING;
4947         if (atomic_read(&fs_info->balance_pause_req))
4948                 bargs->state |= BTRFS_BALANCE_STATE_PAUSE_REQ;
4949         if (atomic_read(&fs_info->balance_cancel_req))
4950                 bargs->state |= BTRFS_BALANCE_STATE_CANCEL_REQ;
4951 
4952         memcpy(&bargs->data, &bctl->data, sizeof(bargs->data));
4953         memcpy(&bargs->meta, &bctl->meta, sizeof(bargs->meta));
4954         memcpy(&bargs->sys, &bctl->sys, sizeof(bargs->sys));
4955 
4956         spin_lock(&fs_info->balance_lock);
4957         memcpy(&bargs->stat, &bctl->stat, sizeof(bargs->stat));
4958         spin_unlock(&fs_info->balance_lock);
4959 }
4960 
4961 static long btrfs_ioctl_balance(struct file *file, void __user *arg)
4962 {
4963         struct btrfs_root *root = BTRFS_I(file_inode(file))->root;
4964         struct btrfs_fs_info *fs_info = root->fs_info;
4965         struct btrfs_ioctl_balance_args *bargs;
4966         struct btrfs_balance_control *bctl;
4967         bool need_unlock; /* for mut. excl. ops lock */
4968         int ret;
4969 
4970         if (!capable(CAP_SYS_ADMIN))
4971                 return -EPERM;
4972 
4973         ret = mnt_want_write_file(file);
4974         if (ret)
4975                 return ret;
4976 
4977 again:
4978         if (!test_and_set_bit(BTRFS_FS_EXCL_OP, &fs_info->flags)) {
4979                 mutex_lock(&fs_info->balance_mutex);
4980                 need_unlock = true;
4981                 goto locked;
4982         }
4983 
4984         /*
4985          * mut. excl. ops lock is locked.  Three possibilities:
4986          *   (1) some other op is running
4987          *   (2) balance is running
4988          *   (3) balance is paused -- special case (think resume)
4989          */
4990         mutex_lock(&fs_info->balance_mutex);
4991         if (fs_info->balance_ctl) {
4992                 /* this is either (2) or (3) */
4993                 if (!test_bit(BTRFS_FS_BALANCE_RUNNING, &fs_info->flags)) {
4994                         mutex_unlock(&fs_info->balance_mutex);
4995                         /*
4996                          * Lock released to allow other waiters to continue,
4997                          * we'll reexamine the status again.
4998                          */
4999                         mutex_lock(&fs_info->balance_mutex);
5000 
5001                         if (fs_info->balance_ctl &&
5002                             !test_bit(BTRFS_FS_BALANCE_RUNNING, &fs_info->flags)) {
5003                                 /* this is (3) */
5004                                 need_unlock = false;
5005                                 goto locked;
5006                         }
5007 
5008                         mutex_unlock(&fs_info->balance_mutex);
5009                         goto again;
5010                 } else {
5011                         /* this is (2) */
5012                         mutex_unlock(&fs_info->balance_mutex);
5013                         ret = -EINPROGRESS;
5014                         goto out;
5015                 }
5016         } else {
5017                 /* this is (1) */
5018                 mutex_unlock(&fs_info->balance_mutex);
5019                 ret = BTRFS_ERROR_DEV_EXCL_RUN_IN_PROGRESS;
5020                 goto out;
5021         }
5022 
5023 locked:
5024         BUG_ON(!test_bit(BTRFS_FS_EXCL_OP, &fs_info->flags));
5025 
5026         if (arg) {
5027                 bargs = memdup_user(arg, sizeof(*bargs));
5028                 if (IS_ERR(bargs)) {
5029                         ret = PTR_ERR(bargs);
5030                         goto out_unlock;
5031                 }
5032 
5033                 if (bargs->flags & BTRFS_BALANCE_RESUME) {
5034                         if (!fs_info->balance_ctl) {
5035                                 ret = -ENOTCONN;
5036                                 goto out_bargs;
5037                         }
5038 
5039                         bctl = fs_info->balance_ctl;
5040                         spin_lock(&fs_info->balance_lock);
5041                         bctl->flags |= BTRFS_BALANCE_RESUME;
5042                         spin_unlock(&fs_info->balance_lock);
5043 
5044                         goto do_balance;
5045                 }
5046         } else {
5047                 bargs = NULL;
5048         }
5049 
5050         if (fs_info->balance_ctl) {
5051                 ret = -EINPROGRESS;
5052                 goto out_bargs;
5053         }
5054 
5055         bctl = kzalloc(sizeof(*bctl), GFP_KERNEL);
5056         if (!bctl) {
5057                 ret = -ENOMEM;
5058                 goto out_bargs;
5059         }
5060 
5061         if (arg) {
5062                 memcpy(&bctl->data, &bargs->data, sizeof(bctl->data));
5063                 memcpy(&bctl->meta, &bargs->meta, sizeof(bctl->meta));
5064                 memcpy(&bctl->sys, &bargs->sys, sizeof(bctl->sys));
5065 
5066                 bctl->flags = bargs->flags;
5067         } else {
5068                 /* balance everything - no filters */
5069                 bctl->flags |= BTRFS_BALANCE_TYPE_MASK;
5070         }
5071 
5072         if (bctl->flags & ~(BTRFS_BALANCE_ARGS_MASK | BTRFS_BALANCE_TYPE_MASK)) {
5073                 ret = -EINVAL;
5074                 goto out_bctl;
5075         }
5076 
5077 do_balance:
5078         /*
5079          * Ownership of bctl and filesystem flag BTRFS_FS_EXCL_OP goes to
5080          * btrfs_balance.  bctl is freed in reset_balance_state, or, if
5081          * restriper was paused all the way until unmount, in free_fs_info.
5082          * The flag should be cleared after reset_balance_state.
5083          */
5084         need_unlock = false;
5085 
5086         ret = btrfs_balance(fs_info, bctl, bargs);
5087         bctl = NULL;
5088 
5089         if (arg) {
5090                 if (copy_to_user(arg, bargs, sizeof(*bargs)))
5091                         ret = -EFAULT;
5092         }
5093 
5094 out_bctl:
5095         kfree(bctl);
5096 out_bargs:
5097         kfree(bargs);
5098 out_unlock:
5099         mutex_unlock(&fs_info->balance_mutex);
5100         if (need_unlock)
5101                 clear_bit(BTRFS_FS_EXCL_OP, &fs_info->flags);
5102 out:
5103         mnt_drop_write_file(file);
5104         return ret;
5105 }
5106 
5107 static long btrfs_ioctl_balance_ctl(struct btrfs_fs_info *fs_info, int cmd)
5108 {
5109         if (!capable(CAP_SYS_ADMIN))
5110                 return -EPERM;
5111 
5112         switch (cmd) {
5113         case BTRFS_BALANCE_CTL_PAUSE:
5114                 return btrfs_pause_balance(fs_info);
5115         case BTRFS_BALANCE_CTL_CANCEL:
5116                 return btrfs_cancel_balance(fs_info);
5117         }
5118 
5119         return -EINVAL;
5120 }
5121 
5122 static long btrfs_ioctl_balance_progress(struct btrfs_fs_info *fs_info,
5123                                          void __user *arg)
5124 {
5125         struct btrfs_ioctl_balance_args *bargs;
5126         int ret = 0;
5127 
5128         if (!capable(CAP_SYS_ADMIN))
5129                 return -EPERM;
5130 
5131         mutex_lock(&fs_info->balance_mutex);
5132         if (!fs_info->balance_ctl) {
5133                 ret = -ENOTCONN;
5134                 goto out;
5135         }
5136 
5137         bargs = kzalloc(sizeof(*bargs), GFP_KERNEL);
5138         if (!bargs) {
5139                 ret = -ENOMEM;
5140                 goto out;
5141         }
5142 
5143         btrfs_update_ioctl_balance_args(fs_info, bargs);
5144 
5145         if (copy_to_user(arg, bargs, sizeof(*bargs)))
5146                 ret = -EFAULT;
5147 
5148         kfree(bargs);
5149 out:
5150         mutex_unlock(&fs_info->balance_mutex);
5151         return ret;
5152 }
5153 
5154 static long btrfs_ioctl_quota_ctl(struct file *file, void __user *arg)
5155 {
5156         struct inode *inode = file_inode(file);
5157         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
5158         struct btrfs_ioctl_quota_ctl_args *sa;
5159         int ret;
5160 
5161         if (!capable(CAP_SYS_ADMIN))
5162                 return -EPERM;
5163 
5164         ret = mnt_want_write_file(file);
5165         if (ret)
5166                 return ret;
5167 
5168         sa = memdup_user(arg, sizeof(*sa));
5169         if (IS_ERR(sa)) {
5170                 ret = PTR_ERR(sa);
5171                 goto drop_write;
5172         }
5173 
5174         down_write(&fs_info->subvol_sem);
5175 
5176         switch (sa->cmd) {
5177         case BTRFS_QUOTA_CTL_ENABLE:
5178                 ret = btrfs_quota_enable(fs_info);
5179                 break;
5180         case BTRFS_QUOTA_CTL_DISABLE:
5181                 ret = btrfs_quota_disable(fs_info);
5182                 break;
5183         default:
5184                 ret = -EINVAL;
5185                 break;
5186         }
5187 
5188         kfree(sa);
5189         up_write(&fs_info->subvol_sem);
5190 drop_write:
5191         mnt_drop_write_file(file);
5192         return ret;
5193 }
5194 
5195 static long btrfs_ioctl_qgroup_assign(struct file *file, void __user *arg)
5196 {
5197         struct inode *inode = file_inode(file);
5198         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
5199         struct btrfs_root *root = BTRFS_I(inode)->root;
5200         struct btrfs_ioctl_qgroup_assign_args *sa;
5201         struct btrfs_trans_handle *trans;
5202         int ret;
5203         int err;
5204 
5205         if (!capable(CAP_SYS_ADMIN))
5206                 return -EPERM;
5207 
5208         ret = mnt_want_write_file(file);
5209         if (ret)
5210                 return ret;
5211 
5212         sa = memdup_user(arg, sizeof(*sa));
5213         if (IS_ERR(sa)) {
5214                 ret = PTR_ERR(sa);
5215                 goto drop_write;
5216         }
5217 
5218         trans = btrfs_join_transaction(root);
5219         if (IS_ERR(trans)) {
5220                 ret = PTR_ERR(trans);
5221                 goto out;
5222         }
5223 
5224         if (sa->assign) {
5225                 ret = btrfs_add_qgroup_relation(trans, sa->src, sa->dst);
5226         } else {
5227                 ret = btrfs_del_qgroup_relation(trans, sa->src, sa->dst);
5228         }
5229 
5230         /* update qgroup status and info */
5231         err = btrfs_run_qgroups(trans);
5232         if (err < 0)
5233                 btrfs_handle_fs_error(fs_info, err,
5234                                       "failed to update qgroup status and info");
5235         err = btrfs_end_transaction(trans);
5236         if (err && !ret)
5237                 ret = err;
5238 
5239 out:
5240         kfree(sa);
5241 drop_write:
5242         mnt_drop_write_file(file);
5243         return ret;
5244 }
5245 
5246 static long btrfs_ioctl_qgroup_create(struct file *file, void __user *arg)
5247 {
5248         struct inode *inode = file_inode(file);
5249         struct btrfs_root *root = BTRFS_I(inode)->root;
5250         struct btrfs_ioctl_qgroup_create_args *sa;
5251         struct btrfs_trans_handle *trans;
5252         int ret;
5253         int err;
5254 
5255         if (!capable(CAP_SYS_ADMIN))
5256                 return -EPERM;
5257 
5258         ret = mnt_want_write_file(file);
5259         if (ret)
5260                 return ret;
5261 
5262         sa = memdup_user(arg, sizeof(*sa));
5263         if (IS_ERR(sa)) {
5264                 ret = PTR_ERR(sa);
5265                 goto drop_write;
5266         }
5267 
5268         if (!sa->qgroupid) {
5269                 ret = -EINVAL;
5270                 goto out;
5271         }
5272 
5273         trans = btrfs_join_transaction(root);
5274         if (IS_ERR(trans)) {
5275                 ret = PTR_ERR(trans);
5276                 goto out;
5277         }
5278 
5279         if (sa->create) {
5280                 ret = btrfs_create_qgroup(trans, sa->qgroupid);
5281         } else {
5282                 ret = btrfs_remove_qgroup(trans, sa->qgroupid);
5283         }
5284 
5285         err = btrfs_end_transaction(trans);
5286         if (err && !ret)
5287                 ret = err;
5288 
5289 out:
5290         kfree(sa);
5291 drop_write:
5292         mnt_drop_write_file(file);
5293         return ret;
5294 }
5295 
5296 static long btrfs_ioctl_qgroup_limit(struct file *file, void __user *arg)
5297 {
5298         struct inode *inode = file_inode(file);
5299         struct btrfs_root *root = BTRFS_I(inode)->root;
5300         struct btrfs_ioctl_qgroup_limit_args *sa;
5301         struct btrfs_trans_handle *trans;
5302         int ret;
5303         int err;
5304         u64 qgroupid;
5305 
5306         if (!capable(CAP_SYS_ADMIN))
5307                 return -EPERM;
5308 
5309         ret = mnt_want_write_file(file);
5310         if (ret)
5311                 return ret;
5312 
5313         sa = memdup_user(arg, sizeof(*sa));
5314         if (IS_ERR(sa)) {
5315                 ret = PTR_ERR(sa);
5316                 goto drop_write;
5317         }
5318 
5319         trans = btrfs_join_transaction(root);
5320         if (IS_ERR(trans)) {
5321                 ret = PTR_ERR(trans);
5322                 goto out;
5323         }
5324 
5325         qgroupid = sa->qgroupid;
5326         if (!qgroupid) {
5327                 /* take the current subvol as qgroup */
5328                 qgroupid = root->root_key.objectid;
5329         }
5330 
5331         ret = btrfs_limit_qgroup(trans, qgroupid, &sa->lim);
5332 
5333         err = btrfs_end_transaction(trans);
5334         if (err && !ret)
5335                 ret = err;
5336 
5337 out:
5338         kfree(sa);
5339 drop_write:
5340         mnt_drop_write_file(file);
5341         return ret;
5342 }
5343 
5344 static long btrfs_ioctl_quota_rescan(struct file *file, void __user *arg)
5345 {
5346         struct inode *inode = file_inode(file);
5347         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
5348         struct btrfs_ioctl_quota_rescan_args *qsa;
5349         int ret;
5350 
5351         if (!capable(CAP_SYS_ADMIN))
5352                 return -EPERM;
5353 
5354         ret = mnt_want_write_file(file);
5355         if (ret)
5356                 return ret;
5357 
5358         qsa = memdup_user(arg, sizeof(*qsa));
5359         if (IS_ERR(qsa)) {
5360                 ret = PTR_ERR(qsa);
5361                 goto drop_write;
5362         }
5363 
5364         if (qsa->flags) {
5365                 ret = -EINVAL;
5366                 goto out;
5367         }
5368 
5369         ret = btrfs_qgroup_rescan(fs_info);
5370 
5371 out:
5372         kfree(qsa);
5373 drop_write:
5374         mnt_drop_write_file(file);
5375         return ret;
5376 }
5377 
5378 static long btrfs_ioctl_quota_rescan_status(struct file *file, void __user *arg)
5379 {
5380         struct inode *inode = file_inode(file);
5381         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
5382         struct btrfs_ioctl_quota_rescan_args *qsa;
5383         int ret = 0;
5384 
5385         if (!capable(CAP_SYS_ADMIN))
5386                 return -EPERM;
5387 
5388         qsa = kzalloc(sizeof(*qsa), GFP_KERNEL);
5389         if (!qsa)
5390                 return -ENOMEM;
5391 
5392         if (fs_info->qgroup_flags & BTRFS_QGROUP_STATUS_FLAG_RESCAN) {
5393                 qsa->flags = 1;
5394                 qsa->progress = fs_info->qgroup_rescan_progress.objectid;
5395         }
5396 
5397         if (copy_to_user(arg, qsa, sizeof(*qsa)))
5398                 ret = -EFAULT;
5399 
5400         kfree(qsa);
5401         return ret;
5402 }
5403 
5404 static long btrfs_ioctl_quota_rescan_wait(struct file *file, void __user *arg)
5405 {
5406         struct inode *inode = file_inode(file);
5407         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
5408 
5409         if (!capable(CAP_SYS_ADMIN))
5410                 return -EPERM;
5411 
5412         return btrfs_qgroup_wait_for_completion(fs_info, true);
5413 }
5414 
5415 static long _btrfs_ioctl_set_received_subvol(struct file *file,
5416                                             struct btrfs_ioctl_received_subvol_args *sa)
5417 {
5418         struct inode *inode = file_inode(file);
5419         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
5420         struct btrfs_root *root = BTRFS_I(inode)->root;
5421         struct btrfs_root_item *root_item = &root->root_item;
5422         struct btrfs_trans_handle *trans;
5423         struct timespec64 ct = current_time(inode);
5424         int ret = 0;
5425         int received_uuid_changed;
5426 
5427         if (!inode_owner_or_capable(inode))
5428                 return -EPERM;
5429 
5430         ret = mnt_want_write_file(file);
5431         if (ret < 0)
5432                 return ret;
5433 
5434         down_write(&fs_info->subvol_sem);
5435 
5436         if (btrfs_ino(BTRFS_I(inode)) != BTRFS_FIRST_FREE_OBJECTID) {
5437                 ret = -EINVAL;
5438                 goto out;
5439         }
5440 
5441         if (btrfs_root_readonly(root)) {
5442                 ret = -EROFS;
5443                 goto out;
5444         }
5445 
5446         /*
5447          * 1 - root item
5448          * 2 - uuid items (received uuid + subvol uuid)
5449          */
5450         trans = btrfs_start_transaction(root, 3);
5451         if (IS_ERR(trans)) {
5452                 ret = PTR_ERR(trans);
5453                 trans = NULL;
5454                 goto out;
5455         }
5456 
5457         sa->rtransid = trans->transid;
5458         sa->rtime.sec = ct.tv_sec;
5459         sa->rtime.nsec = ct.tv_nsec;
5460 
5461         received_uuid_changed = memcmp(root_item->received_uuid, sa->uuid,
5462                                        BTRFS_UUID_SIZE);
5463         if (received_uuid_changed &&
5464             !btrfs_is_empty_uuid(root_item->received_uuid)) {
5465                 ret = btrfs_uuid_tree_remove(trans, root_item->received_uuid,
5466                                           BTRFS_UUID_KEY_RECEIVED_SUBVOL,
5467                                           root->root_key.objectid);
5468                 if (ret && ret != -ENOENT) {
5469                         btrfs_abort_transaction(trans, ret);
5470                         btrfs_end_transaction(trans);
5471                         goto out;
5472                 }
5473         }
5474         memcpy(root_item->received_uuid, sa->uuid, BTRFS_UUID_SIZE);
5475         btrfs_set_root_stransid(root_item, sa->stransid);
5476         btrfs_set_root_rtransid(root_item, sa->rtransid);
5477         btrfs_set_stack_timespec_sec(&root_item->stime, sa->stime.sec);
5478         btrfs_set_stack_timespec_nsec(&root_item->stime, sa->stime.nsec);
5479         btrfs_set_stack_timespec_sec(&root_item->rtime, sa->rtime.sec);
5480         btrfs_set_stack_timespec_nsec(&root_item->rtime, sa->rtime.nsec);
5481 
5482         ret = btrfs_update_root(trans, fs_info->tree_root,
5483                                 &root->root_key, &root->root_item);
5484         if (ret < 0) {
5485                 btrfs_end_transaction(trans);
5486                 goto out;
5487         }
5488         if (received_uuid_changed && !btrfs_is_empty_uuid(sa->uuid)) {
5489                 ret = btrfs_uuid_tree_add(trans, sa->uuid,
5490                                           BTRFS_UUID_KEY_RECEIVED_SUBVOL,
5491                                           root->root_key.objectid);
5492                 if (ret < 0 && ret != -EEXIST) {
5493                         btrfs_abort_transaction(trans, ret);
5494                         btrfs_end_transaction(trans);
5495                         goto out;
5496                 }
5497         }
5498         ret = btrfs_commit_transaction(trans);
5499 out:
5500         up_write(&fs_info->subvol_sem);
5501         mnt_drop_write_file(file);
5502         return ret;
5503 }
5504 
5505 #ifdef CONFIG_64BIT
5506 static long btrfs_ioctl_set_received_subvol_32(struct file *file,
5507                                                 void __user *arg)
5508 {
5509         struct btrfs_ioctl_received_subvol_args_32 *args32 = NULL;
5510         struct btrfs_ioctl_received_subvol_args *args64 = NULL;
5511         int ret = 0;
5512 
5513         args32 = memdup_user(arg, sizeof(*args32));
5514         if (IS_ERR(args32))
5515                 return PTR_ERR(args32);
5516 
5517         args64 = kmalloc(sizeof(*args64), GFP_KERNEL);
5518         if (!args64) {
5519                 ret = -ENOMEM;
5520                 goto out;
5521         }
5522 
5523         memcpy(args64->uuid, args32->uuid, BTRFS_UUID_SIZE);
5524         args64->stransid = args32->stransid;
5525         args64->rtransid = args32->rtransid;
5526         args64->stime.sec = args32->stime.sec;
5527         args64->stime.nsec = args32->stime.nsec;
5528         args64->rtime.sec = args32->rtime.sec;
5529         args64->rtime.nsec = args32->rtime.nsec;
5530         args64->flags = args32->flags;
5531 
5532         ret = _btrfs_ioctl_set_received_subvol(file, args64);
5533         if (ret)
5534                 goto out;
5535 
5536         memcpy(args32->uuid, args64->uuid, BTRFS_UUID_SIZE);
5537         args32->stransid = args64->stransid;
5538         args32->rtransid = args64->rtransid;
5539         args32->stime.sec = args64->stime.sec;
5540         args32->stime.nsec = args64->stime.nsec;
5541         args32->rtime.sec = args64->rtime.sec;
5542         args32->rtime.nsec = args64->rtime.nsec;
5543         args32->flags = args64->flags;
5544 
5545         ret = copy_to_user(arg, args32, sizeof(*args32));
5546         if (ret)
5547                 ret = -EFAULT;
5548 
5549 out:
5550         kfree(args32);
5551         kfree(args64);
5552         return ret;
5553 }
5554 #endif
5555 
5556 static long btrfs_ioctl_set_received_subvol(struct file *file,
5557                                             void __user *arg)
5558 {
5559         struct btrfs_ioctl_received_subvol_args *sa = NULL;
5560         int ret = 0;
5561 
5562         sa = memdup_user(arg, sizeof(*sa));
5563         if (IS_ERR(sa))
5564                 return PTR_ERR(sa);
5565 
5566         ret = _btrfs_ioctl_set_received_subvol(file, sa);
5567 
5568         if (ret)
5569                 goto out;
5570 
5571         ret = copy_to_user(arg, sa, sizeof(*sa));
5572         if (ret)
5573                 ret = -EFAULT;
5574 
5575 out:
5576         kfree(sa);
5577         return ret;
5578 }
5579 
5580 static int btrfs_ioctl_get_fslabel(struct file *file, void __user *arg)
5581 {
5582         struct inode *inode = file_inode(file);
5583         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
5584         size_t len;
5585         int ret;
5586         char label[BTRFS_LABEL_SIZE];
5587 
5588         spin_lock(&fs_info->super_lock);
5589         memcpy(label, fs_info->super_copy->label, BTRFS_LABEL_SIZE);
5590         spin_unlock(&fs_info->super_lock);
5591 
5592         len = strnlen(label, BTRFS_LABEL_SIZE);
5593 
5594         if (len == BTRFS_LABEL_SIZE) {
5595                 btrfs_warn(fs_info,
5596                            "label is too long, return the first %zu bytes",
5597                            --len);
5598         }
5599 
5600         ret = copy_to_user(arg, label, len);
5601 
5602         return ret ? -EFAULT : 0;
5603 }
5604 
5605 static int btrfs_ioctl_set_fslabel(struct file *file, void __user *arg)
5606 {
5607         struct inode *inode = file_inode(file);
5608         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
5609         struct btrfs_root *root = BTRFS_I(inode)->root;
5610         struct btrfs_super_block *super_block = fs_info->super_copy;
5611         struct btrfs_trans_handle *trans;
5612         char label[BTRFS_LABEL_SIZE];
5613         int ret;
5614 
5615         if (!capable(CAP_SYS_ADMIN))
5616                 return -EPERM;
5617 
5618         if (copy_from_user(label, arg, sizeof(label)))
5619                 return -EFAULT;
5620 
5621         if (strnlen(label, BTRFS_LABEL_SIZE) == BTRFS_LABEL_SIZE) {
5622                 btrfs_err(fs_info,
5623                           "unable to set label with more than %d bytes",
5624                           BTRFS_LABEL_SIZE - 1);
5625                 return -EINVAL;
5626         }
5627 
5628         ret = mnt_want_write_file(file);
5629         if (ret)
5630                 return ret;
5631 
5632         trans = btrfs_start_transaction(root, 0);
5633         if (IS_ERR(trans)) {
5634                 ret = PTR_ERR(trans);
5635                 goto out_unlock;
5636         }
5637 
5638         spin_lock(&fs_info->super_lock);
5639         strcpy(super_block->label, label);
5640         spin_unlock(&fs_info->super_lock);
5641         ret = btrfs_commit_transaction(trans);
5642 
5643 out_unlock:
5644         mnt_drop_write_file(file);
5645         return ret;
5646 }
5647 
5648 #define INIT_FEATURE_FLAGS(suffix) \
5649         { .compat_flags = BTRFS_FEATURE_COMPAT_##suffix, \
5650           .compat_ro_flags = BTRFS_FEATURE_COMPAT_RO_##suffix, \
5651           .incompat_flags = BTRFS_FEATURE_INCOMPAT_##suffix }
5652 
5653 int btrfs_ioctl_get_supported_features(void __user *arg)
5654 {
5655         static const struct btrfs_ioctl_feature_flags features[3] = {
5656                 INIT_FEATURE_FLAGS(SUPP),
5657                 INIT_FEATURE_FLAGS(SAFE_SET),
5658                 INIT_FEATURE_FLAGS(SAFE_CLEAR)
5659         };
5660 
5661         if (copy_to_user(arg, &features, sizeof(features)))
5662                 return -EFAULT;
5663 
5664         return 0;
5665 }
5666 
5667 static int btrfs_ioctl_get_features(struct file *file, void __user *arg)
5668 {
5669         struct inode *inode = file_inode(file);
5670         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
5671         struct btrfs_super_block *super_block = fs_info->super_copy;
5672         struct btrfs_ioctl_feature_flags features;
5673 
5674         features.compat_flags = btrfs_super_compat_flags(super_block);
5675         features.compat_ro_flags = btrfs_super_compat_ro_flags(super_block);
5676         features.incompat_flags = btrfs_super_incompat_flags(super_block);
5677 
5678         if (copy_to_user(arg, &features, sizeof(features)))
5679                 return -EFAULT;
5680 
5681         return 0;
5682 }
5683 
5684 static int check_feature_bits(struct btrfs_fs_info *fs_info,
5685                               enum btrfs_feature_set set,
5686                               u64 change_mask, u64 flags, u64 supported_flags,
5687                               u64 safe_set, u64 safe_clear)
5688 {
5689         const char *type = btrfs_feature_set_names[set];
5690         char *names;
5691         u64 disallowed, unsupported;
5692         u64 set_mask = flags & change_mask;
5693         u64 clear_mask = ~flags & change_mask;
5694 
5695         unsupported = set_mask & ~supported_flags;
5696         if (unsupported) {
5697                 names = btrfs_printable_features(set, unsupported);
5698                 if (names) {
5699                         btrfs_warn(fs_info,
5700                                    "this kernel does not support the %s feature bit%s",
5701                                    names, strchr(names, ',') ? "s" : "");
5702                         kfree(names);
5703                 } else
5704                         btrfs_warn(fs_info,
5705                                    "this kernel does not support %s bits 0x%llx",
5706                                    type, unsupported);
5707                 return -EOPNOTSUPP;
5708         }
5709 
5710         disallowed = set_mask & ~safe_set;
5711         if (disallowed) {
5712                 names = btrfs_printable_features(set, disallowed);
5713                 if (names) {
5714                         btrfs_warn(fs_info,
5715                                    "can't set the %s feature bit%s while mounted",
5716                                    names, strchr(names, ',') ? "s" : "");
5717                         kfree(names);
5718                 } else
5719                         btrfs_warn(fs_info,
5720                                    "can't set %s bits 0x%llx while mounted",
5721                                    type, disallowed);
5722                 return -EPERM;
5723         }
5724 
5725         disallowed = clear_mask & ~safe_clear;
5726         if (disallowed) {
5727                 names = btrfs_printable_features(set, disallowed);
5728                 if (names) {
5729                         btrfs_warn(fs_info,
5730                                    "can't clear the %s feature bit%s while mounted",
5731                                    names, strchr(names, ',') ? "s" : "");
5732                         kfree(names);
5733                 } else
5734                         btrfs_warn(fs_info,
5735                                    "can't clear %s bits 0x%llx while mounted",
5736                                    type, disallowed);
5737                 return -EPERM;
5738         }
5739 
5740         return 0;
5741 }
5742 
5743 #define check_feature(fs_info, change_mask, flags, mask_base)   \
5744 check_feature_bits(fs_info, FEAT_##mask_base, change_mask, flags,       \
5745                    BTRFS_FEATURE_ ## mask_base ## _SUPP,        \
5746                    BTRFS_FEATURE_ ## mask_base ## _SAFE_SET,    \
5747                    BTRFS_FEATURE_ ## mask_base ## _SAFE_CLEAR)
5748 
5749 static int btrfs_ioctl_set_features(struct file *file, void __user *arg)
5750 {
5751         struct inode *inode = file_inode(file);
5752         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
5753         struct btrfs_root *root = BTRFS_I(inode)->root;
5754         struct btrfs_super_block *super_block = fs_info->super_copy;
5755         struct btrfs_ioctl_feature_flags flags[2];
5756         struct btrfs_trans_handle *trans;
5757         u64 newflags;
5758         int ret;
5759 
5760         if (!capable(CAP_SYS_ADMIN))
5761                 return -EPERM;
5762 
5763         if (copy_from_user(flags, arg, sizeof(flags)))
5764                 return -EFAULT;
5765 
5766         /* Nothing to do */
5767         if (!flags[0].compat_flags && !flags[0].compat_ro_flags &&
5768             !flags[0].incompat_flags)
5769                 return 0;
5770 
5771         ret = check_feature(fs_info, flags[0].compat_flags,
5772                             flags[1].compat_flags, COMPAT);
5773         if (ret)
5774                 return ret;
5775 
5776         ret = check_feature(fs_info, flags[0].compat_ro_flags,
5777                             flags[1].compat_ro_flags, COMPAT_RO);
5778         if (ret)
5779                 return ret;
5780 
5781         ret = check_feature(fs_info, flags[0].incompat_flags,
5782                             flags[1].incompat_flags, INCOMPAT);
5783         if (ret)
5784                 return ret;
5785 
5786         ret = mnt_want_write_file(file);
5787         if (ret)
5788                 return ret;
5789 
5790         trans = btrfs_start_transaction(root, 0);
5791         if (IS_ERR(trans)) {
5792                 ret = PTR_ERR(trans);
5793                 goto out_drop_write;
5794         }
5795 
5796         spin_lock(&fs_info->super_lock);
5797         newflags = btrfs_super_compat_flags(super_block);
5798         newflags |= flags[0].compat_flags & flags[1].compat_flags;
5799         newflags &= ~(flags[0].compat_flags & ~flags[1].compat_flags);
5800         btrfs_set_super_compat_flags(super_block, newflags);
5801 
5802         newflags = btrfs_super_compat_ro_flags(super_block);
5803         newflags |= flags[0].compat_ro_flags & flags[1].compat_ro_flags;
5804         newflags &= ~(flags[0].compat_ro_flags & ~flags[1].compat_ro_flags);
5805         btrfs_set_super_compat_ro_flags(super_block, newflags);
5806 
5807         newflags = btrfs_super_incompat_flags(super_block);
5808         newflags |= flags[0].incompat_flags & flags[1].incompat_flags;
5809         newflags &= ~(flags[0].incompat_flags & ~flags[1].incompat_flags);
5810         btrfs_set_super_incompat_flags(super_block, newflags);
5811         spin_unlock(&fs_info->super_lock);
5812 
5813         ret = btrfs_commit_transaction(trans);
5814 out_drop_write:
5815         mnt_drop_write_file(file);
5816 
5817         return ret;
5818 }
5819 
5820 static int _btrfs_ioctl_send(struct file *file, void __user *argp, bool compat)
5821 {
5822         struct btrfs_ioctl_send_args *arg;
5823         int ret;
5824 
5825         if (compat) {
5826 #if defined(CONFIG_64BIT) && defined(CONFIG_COMPAT)
5827                 struct btrfs_ioctl_send_args_32 args32;
5828 
5829                 ret = copy_from_user(&args32, argp, sizeof(args32));
5830                 if (ret)
5831                         return -EFAULT;
5832                 arg = kzalloc(sizeof(*arg), GFP_KERNEL);
5833                 if (!arg)
5834                         return -ENOMEM;
5835                 arg->send_fd = args32.send_fd;
5836                 arg->clone_sources_count = args32.clone_sources_count;
5837                 arg->clone_sources = compat_ptr(args32.clone_sources);
5838                 arg->parent_root = args32.parent_root;
5839                 arg->flags = args32.flags;
5840                 memcpy(arg->reserved, args32.reserved,
5841                        sizeof(args32.reserved));
5842 #else
5843                 return -ENOTTY;
5844 #endif
5845         } else {
5846                 arg = memdup_user(argp, sizeof(*arg));
5847                 if (IS_ERR(arg))
5848                         return PTR_ERR(arg);
5849         }
5850         ret = btrfs_ioctl_send(file, arg);
5851         kfree(arg);
5852         return ret;
5853 }
5854 
5855 long btrfs_ioctl(struct file *file, unsigned int
5856                 cmd, unsigned long arg)
5857 {
5858         struct inode *inode = file_inode(file);
5859         struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
5860         struct btrfs_root *root = BTRFS_I(inode)->root;
5861         void __user *argp = (void __user *)arg;
5862 
5863         switch (cmd) {
5864         case FS_IOC_GETFLAGS:
5865                 return btrfs_ioctl_getflags(file, argp);
5866         case FS_IOC_SETFLAGS:
5867                 return btrfs_ioctl_setflags(file, argp);
5868         case FS_IOC_GETVERSION:
5869                 return btrfs_ioctl_getversion(file, argp);
5870         case FITRIM:
5871                 return btrfs_ioctl_fitrim(file, argp);
5872         case BTRFS_IOC_SNAP_CREATE:
5873                 return btrfs_ioctl_snap_create(file, argp, 0);
5874         case BTRFS_IOC_SNAP_CREATE_V2:
5875                 return btrfs_ioctl_snap_create_v2(file, argp, 0);
5876         case BTRFS_IOC_SUBVOL_CREATE:
5877                 return btrfs_ioctl_snap_create(file, argp, 1);
5878         case BTRFS_IOC_SUBVOL_CREATE_V2:
5879                 return btrfs_ioctl_snap_create_v2(file, argp, 1);
5880         case BTRFS_IOC_SNAP_DESTROY:
5881                 return btrfs_ioctl_snap_destroy(file, argp);
5882         case BTRFS_IOC_SUBVOL_GETFLAGS:
5883                 return btrfs_ioctl_subvol_getflags(file, argp);
5884         case BTRFS_IOC_SUBVOL_SETFLAGS:
5885                 return btrfs_ioctl_subvol_setflags(file, argp);
5886         case BTRFS_IOC_DEFAULT_SUBVOL:
5887                 return btrfs_ioctl_default_subvol(file, argp);
5888         case BTRFS_IOC_DEFRAG:
5889                 return btrfs_ioctl_defrag(file, NULL);
5890         case BTRFS_IOC_DEFRAG_RANGE:
5891                 return btrfs_ioctl_defrag(file, argp);
5892         case BTRFS_IOC_RESIZE:
5893                 return btrfs_ioctl_resize(file, argp);
5894         case BTRFS_IOC_ADD_DEV:
5895                 return btrfs_ioctl_add_dev(fs_info, argp);
5896         case BTRFS_IOC_RM_DEV:
5897                 return btrfs_ioctl_rm_dev(file, argp);
5898         case BTRFS_IOC_RM_DEV_V2:
5899                 return btrfs_ioctl_rm_dev_v2(file, argp);
5900         case BTRFS_IOC_FS_INFO:
5901                 return btrfs_ioctl_fs_info(fs_info, argp);
5902         case BTRFS_IOC_DEV_INFO:
5903                 return btrfs_ioctl_dev_info(fs_info, argp);
5904         case BTRFS_IOC_BALANCE:
5905                 return btrfs_ioctl_balance(file, NULL);
5906         case BTRFS_IOC_TREE_SEARCH:
5907                 return btrfs_ioctl_tree_search(file, argp);
5908         case BTRFS_IOC_TREE_SEARCH_V2:
5909                 return btrfs_ioctl_tree_search_v2(file, argp);
5910         case BTRFS_IOC_INO_LOOKUP:
5911                 return btrfs_ioctl_ino_lookup(file, argp);
5912         case BTRFS_IOC_INO_PATHS:
5913                 return btrfs_ioctl_ino_to_path(root, argp);
5914         case BTRFS_IOC_LOGICAL_INO:
5915                 return btrfs_ioctl_logical_to_ino(fs_info, argp, 1);
5916         case BTRFS_IOC_LOGICAL_INO_V2:
5917                 return btrfs_ioctl_logical_to_ino(fs_info, argp, 2);
5918         case BTRFS_IOC_SPACE_INFO:
5919                 return btrfs_ioctl_space_info(fs_info, argp);
5920         case BTRFS_IOC_SYNC: {
5921                 int ret;
5922 
5923                 ret = btrfs_start_delalloc_roots(fs_info, -1);
5924                 if (ret)
5925                         return ret;
5926                 ret = btrfs_sync_fs(inode->i_sb, 1);
5927                 /*
5928                  * The transaction thread may want to do more work,
5929                  * namely it pokes the cleaner kthread that will start
5930                  * processing uncleaned subvols.
5931                  */
5932                 wake_up_process(fs_info->transaction_kthread);
5933                 return ret;
5934         }
5935         case BTRFS_IOC_START_SYNC:
5936                 return btrfs_ioctl_start_sync(root, argp);
5937         case BTRFS_IOC_WAIT_SYNC:
5938                 return btrfs_ioctl_wait_sync(fs_info, argp);
5939         case BTRFS_IOC_SCRUB:
5940                 return btrfs_ioctl_scrub(file, argp);
5941         case BTRFS_IOC_SCRUB_CANCEL:
5942                 return btrfs_ioctl_scrub_cancel(fs_info);
5943         case BTRFS_IOC_SCRUB_PROGRESS:
5944                 return btrfs_ioctl_scrub_progress(fs_info, argp);
5945         case BTRFS_IOC_BALANCE_V2:
5946                 return btrfs_ioctl_balance(file, argp);
5947         case BTRFS_IOC_BALANCE_CTL:
5948                 return btrfs_ioctl_balance_ctl(fs_info, arg);
5949         case BTRFS_IOC_BALANCE_PROGRESS:
5950                 return btrfs_ioctl_balance_progress(fs_info, argp);
5951         case BTRFS_IOC_SET_RECEIVED_SUBVOL:
5952                 return btrfs_ioctl_set_received_subvol(file, argp);
5953 #ifdef CONFIG_64BIT
5954         case BTRFS_IOC_SET_RECEIVED_SUBVOL_32:
5955                 return btrfs_ioctl_set_received_subvol_32(file, argp);
5956 #endif
5957         case BTRFS_IOC_SEND:
5958                 return _btrfs_ioctl_send(file, argp, false);
5959 #if defined(CONFIG_64BIT) && defined(CONFIG_COMPAT)
5960         case BTRFS_IOC_SEND_32:
5961                 return _btrfs_ioctl_send(file, argp, true);
5962 #endif
5963         case BTRFS_IOC_GET_DEV_STATS:
5964                 return btrfs_ioctl_get_dev_stats(fs_info, argp);
5965         case BTRFS_IOC_QUOTA_CTL:
5966                 return btrfs_ioctl_quota_ctl(file, argp);
5967         case BTRFS_IOC_QGROUP_ASSIGN:
5968                 return btrfs_ioctl_qgroup_assign(file, argp);
5969         case BTRFS_IOC_QGROUP_CREATE:
5970                 return btrfs_ioctl_qgroup_create(file, argp);
5971         case BTRFS_IOC_QGROUP_LIMIT:
5972                 return btrfs_ioctl_qgroup_limit(file, argp);
5973         case BTRFS_IOC_QUOTA_RESCAN:
5974                 return btrfs_ioctl_quota_rescan(file, argp);
5975         case BTRFS_IOC_QUOTA_RESCAN_STATUS:
5976                 return btrfs_ioctl_quota_rescan_status(file, argp);
5977         case BTRFS_IOC_QUOTA_RESCAN_WAIT:
5978                 return btrfs_ioctl_quota_rescan_wait(file, argp);
5979         case BTRFS_IOC_DEV_REPLACE:
5980                 return btrfs_ioctl_dev_replace(fs_info, argp);
5981         case BTRFS_IOC_GET_FSLABEL:
5982                 return btrfs_ioctl_get_fslabel(file, argp);
5983         case BTRFS_IOC_SET_FSLABEL:
5984                 return btrfs_ioctl_set_fslabel(file, argp);
5985         case BTRFS_IOC_GET_SUPPORTED_FEATURES:
5986                 return btrfs_ioctl_get_supported_features(argp);
5987         case BTRFS_IOC_GET_FEATURES:
5988                 return btrfs_ioctl_get_features(file, argp);
5989         case BTRFS_IOC_SET_FEATURES:
5990                 return btrfs_ioctl_set_features(file, argp);
5991         case FS_IOC_FSGETXATTR:
5992                 return btrfs_ioctl_fsgetxattr(file, argp);
5993         case FS_IOC_FSSETXATTR:
5994                 return btrfs_ioctl_fssetxattr(file, argp);
5995         case BTRFS_IOC_GET_SUBVOL_INFO:
5996                 return btrfs_ioctl_get_subvol_info(file, argp);
5997         case BTRFS_IOC_GET_SUBVOL_ROOTREF:
5998                 return btrfs_ioctl_get_subvol_rootref(file, argp);
5999         case BTRFS_IOC_INO_LOOKUP_USER:
6000                 return btrfs_ioctl_ino_lookup_user(file, argp);
6001         }
6002 
6003         return -ENOTTY;
6004 }
6005 
6006 #ifdef CONFIG_COMPAT
6007 long btrfs_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
6008 {
6009         /*
6010          * These all access 32-bit values anyway so no further
6011          * handling is necessary.
6012          */
6013         switch (cmd) {
6014         case FS_IOC32_GETFLAGS:
6015                 cmd = FS_IOC_GETFLAGS;
6016                 break;
6017         case FS_IOC32_SETFLAGS:
6018                 cmd = FS_IOC_SETFLAGS;
6019                 break;
6020         case FS_IOC32_GETVERSION:
6021                 cmd = FS_IOC_GETVERSION;
6022                 break;
6023         }
6024 
6025         return btrfs_ioctl(file, cmd, (unsigned long) compat_ptr(arg));
6026 }
6027 #endif
6028 

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