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TOMOYO Linux Cross Reference
Linux/fs/ubifs/super.c

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  1 // SPDX-License-Identifier: GPL-2.0-only
  2 /*
  3  * This file is part of UBIFS.
  4  *
  5  * Copyright (C) 2006-2008 Nokia Corporation.
  6  *
  7  * Authors: Artem Bityutskiy (Битюцкий Артём)
  8  *          Adrian Hunter
  9  */
 10 
 11 /*
 12  * This file implements UBIFS initialization and VFS superblock operations. Some
 13  * initialization stuff which is rather large and complex is placed at
 14  * corresponding subsystems, but most of it is here.
 15  */
 16 
 17 #include <linux/init.h>
 18 #include <linux/slab.h>
 19 #include <linux/module.h>
 20 #include <linux/ctype.h>
 21 #include <linux/kthread.h>
 22 #include <linux/parser.h>
 23 #include <linux/seq_file.h>
 24 #include <linux/mount.h>
 25 #include <linux/math64.h>
 26 #include <linux/writeback.h>
 27 #include "ubifs.h"
 28 
 29 /*
 30  * Maximum amount of memory we may 'kmalloc()' without worrying that we are
 31  * allocating too much.
 32  */
 33 #define UBIFS_KMALLOC_OK (128*1024)
 34 
 35 /* Slab cache for UBIFS inodes */
 36 static struct kmem_cache *ubifs_inode_slab;
 37 
 38 /* UBIFS TNC shrinker description */
 39 static struct shrinker ubifs_shrinker_info = {
 40         .scan_objects = ubifs_shrink_scan,
 41         .count_objects = ubifs_shrink_count,
 42         .seeks = DEFAULT_SEEKS,
 43 };
 44 
 45 /**
 46  * validate_inode - validate inode.
 47  * @c: UBIFS file-system description object
 48  * @inode: the inode to validate
 49  *
 50  * This is a helper function for 'ubifs_iget()' which validates various fields
 51  * of a newly built inode to make sure they contain sane values and prevent
 52  * possible vulnerabilities. Returns zero if the inode is all right and
 53  * a non-zero error code if not.
 54  */
 55 static int validate_inode(struct ubifs_info *c, const struct inode *inode)
 56 {
 57         int err;
 58         const struct ubifs_inode *ui = ubifs_inode(inode);
 59 
 60         if (inode->i_size > c->max_inode_sz) {
 61                 ubifs_err(c, "inode is too large (%lld)",
 62                           (long long)inode->i_size);
 63                 return 1;
 64         }
 65 
 66         if (ui->compr_type >= UBIFS_COMPR_TYPES_CNT) {
 67                 ubifs_err(c, "unknown compression type %d", ui->compr_type);
 68                 return 2;
 69         }
 70 
 71         if (ui->xattr_names + ui->xattr_cnt > XATTR_LIST_MAX)
 72                 return 3;
 73 
 74         if (ui->data_len < 0 || ui->data_len > UBIFS_MAX_INO_DATA)
 75                 return 4;
 76 
 77         if (ui->xattr && !S_ISREG(inode->i_mode))
 78                 return 5;
 79 
 80         if (!ubifs_compr_present(c, ui->compr_type)) {
 81                 ubifs_warn(c, "inode %lu uses '%s' compression, but it was not compiled in",
 82                            inode->i_ino, ubifs_compr_name(c, ui->compr_type));
 83         }
 84 
 85         err = dbg_check_dir(c, inode);
 86         return err;
 87 }
 88 
 89 struct inode *ubifs_iget(struct super_block *sb, unsigned long inum)
 90 {
 91         int err;
 92         union ubifs_key key;
 93         struct ubifs_ino_node *ino;
 94         struct ubifs_info *c = sb->s_fs_info;
 95         struct inode *inode;
 96         struct ubifs_inode *ui;
 97 
 98         dbg_gen("inode %lu", inum);
 99 
100         inode = iget_locked(sb, inum);
101         if (!inode)
102                 return ERR_PTR(-ENOMEM);
103         if (!(inode->i_state & I_NEW))
104                 return inode;
105         ui = ubifs_inode(inode);
106 
107         ino = kmalloc(UBIFS_MAX_INO_NODE_SZ, GFP_NOFS);
108         if (!ino) {
109                 err = -ENOMEM;
110                 goto out;
111         }
112 
113         ino_key_init(c, &key, inode->i_ino);
114 
115         err = ubifs_tnc_lookup(c, &key, ino);
116         if (err)
117                 goto out_ino;
118 
119         inode->i_flags |= S_NOCMTIME;
120 
121         if (!IS_ENABLED(CONFIG_UBIFS_ATIME_SUPPORT))
122                 inode->i_flags |= S_NOATIME;
123 
124         set_nlink(inode, le32_to_cpu(ino->nlink));
125         i_uid_write(inode, le32_to_cpu(ino->uid));
126         i_gid_write(inode, le32_to_cpu(ino->gid));
127         inode->i_atime.tv_sec  = (int64_t)le64_to_cpu(ino->atime_sec);
128         inode->i_atime.tv_nsec = le32_to_cpu(ino->atime_nsec);
129         inode->i_mtime.tv_sec  = (int64_t)le64_to_cpu(ino->mtime_sec);
130         inode->i_mtime.tv_nsec = le32_to_cpu(ino->mtime_nsec);
131         inode->i_ctime.tv_sec  = (int64_t)le64_to_cpu(ino->ctime_sec);
132         inode->i_ctime.tv_nsec = le32_to_cpu(ino->ctime_nsec);
133         inode->i_mode = le32_to_cpu(ino->mode);
134         inode->i_size = le64_to_cpu(ino->size);
135 
136         ui->data_len    = le32_to_cpu(ino->data_len);
137         ui->flags       = le32_to_cpu(ino->flags);
138         ui->compr_type  = le16_to_cpu(ino->compr_type);
139         ui->creat_sqnum = le64_to_cpu(ino->creat_sqnum);
140         ui->xattr_cnt   = le32_to_cpu(ino->xattr_cnt);
141         ui->xattr_size  = le32_to_cpu(ino->xattr_size);
142         ui->xattr_names = le32_to_cpu(ino->xattr_names);
143         ui->synced_i_size = ui->ui_size = inode->i_size;
144 
145         ui->xattr = (ui->flags & UBIFS_XATTR_FL) ? 1 : 0;
146 
147         err = validate_inode(c, inode);
148         if (err)
149                 goto out_invalid;
150 
151         switch (inode->i_mode & S_IFMT) {
152         case S_IFREG:
153                 inode->i_mapping->a_ops = &ubifs_file_address_operations;
154                 inode->i_op = &ubifs_file_inode_operations;
155                 inode->i_fop = &ubifs_file_operations;
156                 if (ui->xattr) {
157                         ui->data = kmalloc(ui->data_len + 1, GFP_NOFS);
158                         if (!ui->data) {
159                                 err = -ENOMEM;
160                                 goto out_ino;
161                         }
162                         memcpy(ui->data, ino->data, ui->data_len);
163                         ((char *)ui->data)[ui->data_len] = '\0';
164                 } else if (ui->data_len != 0) {
165                         err = 10;
166                         goto out_invalid;
167                 }
168                 break;
169         case S_IFDIR:
170                 inode->i_op  = &ubifs_dir_inode_operations;
171                 inode->i_fop = &ubifs_dir_operations;
172                 if (ui->data_len != 0) {
173                         err = 11;
174                         goto out_invalid;
175                 }
176                 break;
177         case S_IFLNK:
178                 inode->i_op = &ubifs_symlink_inode_operations;
179                 if (ui->data_len <= 0 || ui->data_len > UBIFS_MAX_INO_DATA) {
180                         err = 12;
181                         goto out_invalid;
182                 }
183                 ui->data = kmalloc(ui->data_len + 1, GFP_NOFS);
184                 if (!ui->data) {
185                         err = -ENOMEM;
186                         goto out_ino;
187                 }
188                 memcpy(ui->data, ino->data, ui->data_len);
189                 ((char *)ui->data)[ui->data_len] = '\0';
190                 break;
191         case S_IFBLK:
192         case S_IFCHR:
193         {
194                 dev_t rdev;
195                 union ubifs_dev_desc *dev;
196 
197                 ui->data = kmalloc(sizeof(union ubifs_dev_desc), GFP_NOFS);
198                 if (!ui->data) {
199                         err = -ENOMEM;
200                         goto out_ino;
201                 }
202 
203                 dev = (union ubifs_dev_desc *)ino->data;
204                 if (ui->data_len == sizeof(dev->new))
205                         rdev = new_decode_dev(le32_to_cpu(dev->new));
206                 else if (ui->data_len == sizeof(dev->huge))
207                         rdev = huge_decode_dev(le64_to_cpu(dev->huge));
208                 else {
209                         err = 13;
210                         goto out_invalid;
211                 }
212                 memcpy(ui->data, ino->data, ui->data_len);
213                 inode->i_op = &ubifs_file_inode_operations;
214                 init_special_inode(inode, inode->i_mode, rdev);
215                 break;
216         }
217         case S_IFSOCK:
218         case S_IFIFO:
219                 inode->i_op = &ubifs_file_inode_operations;
220                 init_special_inode(inode, inode->i_mode, 0);
221                 if (ui->data_len != 0) {
222                         err = 14;
223                         goto out_invalid;
224                 }
225                 break;
226         default:
227                 err = 15;
228                 goto out_invalid;
229         }
230 
231         kfree(ino);
232         ubifs_set_inode_flags(inode);
233         unlock_new_inode(inode);
234         return inode;
235 
236 out_invalid:
237         ubifs_err(c, "inode %lu validation failed, error %d", inode->i_ino, err);
238         ubifs_dump_node(c, ino);
239         ubifs_dump_inode(c, inode);
240         err = -EINVAL;
241 out_ino:
242         kfree(ino);
243 out:
244         ubifs_err(c, "failed to read inode %lu, error %d", inode->i_ino, err);
245         iget_failed(inode);
246         return ERR_PTR(err);
247 }
248 
249 static struct inode *ubifs_alloc_inode(struct super_block *sb)
250 {
251         struct ubifs_inode *ui;
252 
253         ui = kmem_cache_alloc(ubifs_inode_slab, GFP_NOFS);
254         if (!ui)
255                 return NULL;
256 
257         memset((void *)ui + sizeof(struct inode), 0,
258                sizeof(struct ubifs_inode) - sizeof(struct inode));
259         mutex_init(&ui->ui_mutex);
260         spin_lock_init(&ui->ui_lock);
261         return &ui->vfs_inode;
262 };
263 
264 static void ubifs_free_inode(struct inode *inode)
265 {
266         struct ubifs_inode *ui = ubifs_inode(inode);
267 
268         kfree(ui->data);
269         fscrypt_free_inode(inode);
270 
271         kmem_cache_free(ubifs_inode_slab, ui);
272 }
273 
274 /*
275  * Note, Linux write-back code calls this without 'i_mutex'.
276  */
277 static int ubifs_write_inode(struct inode *inode, struct writeback_control *wbc)
278 {
279         int err = 0;
280         struct ubifs_info *c = inode->i_sb->s_fs_info;
281         struct ubifs_inode *ui = ubifs_inode(inode);
282 
283         ubifs_assert(c, !ui->xattr);
284         if (is_bad_inode(inode))
285                 return 0;
286 
287         mutex_lock(&ui->ui_mutex);
288         /*
289          * Due to races between write-back forced by budgeting
290          * (see 'sync_some_inodes()') and background write-back, the inode may
291          * have already been synchronized, do not do this again. This might
292          * also happen if it was synchronized in an VFS operation, e.g.
293          * 'ubifs_link()'.
294          */
295         if (!ui->dirty) {
296                 mutex_unlock(&ui->ui_mutex);
297                 return 0;
298         }
299 
300         /*
301          * As an optimization, do not write orphan inodes to the media just
302          * because this is not needed.
303          */
304         dbg_gen("inode %lu, mode %#x, nlink %u",
305                 inode->i_ino, (int)inode->i_mode, inode->i_nlink);
306         if (inode->i_nlink) {
307                 err = ubifs_jnl_write_inode(c, inode);
308                 if (err)
309                         ubifs_err(c, "can't write inode %lu, error %d",
310                                   inode->i_ino, err);
311                 else
312                         err = dbg_check_inode_size(c, inode, ui->ui_size);
313         }
314 
315         ui->dirty = 0;
316         mutex_unlock(&ui->ui_mutex);
317         ubifs_release_dirty_inode_budget(c, ui);
318         return err;
319 }
320 
321 static int ubifs_drop_inode(struct inode *inode)
322 {
323         int drop = generic_drop_inode(inode);
324 
325         if (!drop)
326                 drop = fscrypt_drop_inode(inode);
327 
328         return drop;
329 }
330 
331 static void ubifs_evict_inode(struct inode *inode)
332 {
333         int err;
334         struct ubifs_info *c = inode->i_sb->s_fs_info;
335         struct ubifs_inode *ui = ubifs_inode(inode);
336 
337         if (ui->xattr)
338                 /*
339                  * Extended attribute inode deletions are fully handled in
340                  * 'ubifs_removexattr()'. These inodes are special and have
341                  * limited usage, so there is nothing to do here.
342                  */
343                 goto out;
344 
345         dbg_gen("inode %lu, mode %#x", inode->i_ino, (int)inode->i_mode);
346         ubifs_assert(c, !atomic_read(&inode->i_count));
347 
348         truncate_inode_pages_final(&inode->i_data);
349 
350         if (inode->i_nlink)
351                 goto done;
352 
353         if (is_bad_inode(inode))
354                 goto out;
355 
356         ui->ui_size = inode->i_size = 0;
357         err = ubifs_jnl_delete_inode(c, inode);
358         if (err)
359                 /*
360                  * Worst case we have a lost orphan inode wasting space, so a
361                  * simple error message is OK here.
362                  */
363                 ubifs_err(c, "can't delete inode %lu, error %d",
364                           inode->i_ino, err);
365 
366 out:
367         if (ui->dirty)
368                 ubifs_release_dirty_inode_budget(c, ui);
369         else {
370                 /* We've deleted something - clean the "no space" flags */
371                 c->bi.nospace = c->bi.nospace_rp = 0;
372                 smp_wmb();
373         }
374 done:
375         clear_inode(inode);
376         fscrypt_put_encryption_info(inode);
377 }
378 
379 static void ubifs_dirty_inode(struct inode *inode, int flags)
380 {
381         struct ubifs_info *c = inode->i_sb->s_fs_info;
382         struct ubifs_inode *ui = ubifs_inode(inode);
383 
384         ubifs_assert(c, mutex_is_locked(&ui->ui_mutex));
385         if (!ui->dirty) {
386                 ui->dirty = 1;
387                 dbg_gen("inode %lu",  inode->i_ino);
388         }
389 }
390 
391 static int ubifs_statfs(struct dentry *dentry, struct kstatfs *buf)
392 {
393         struct ubifs_info *c = dentry->d_sb->s_fs_info;
394         unsigned long long free;
395         __le32 *uuid = (__le32 *)c->uuid;
396 
397         free = ubifs_get_free_space(c);
398         dbg_gen("free space %lld bytes (%lld blocks)",
399                 free, free >> UBIFS_BLOCK_SHIFT);
400 
401         buf->f_type = UBIFS_SUPER_MAGIC;
402         buf->f_bsize = UBIFS_BLOCK_SIZE;
403         buf->f_blocks = c->block_cnt;
404         buf->f_bfree = free >> UBIFS_BLOCK_SHIFT;
405         if (free > c->report_rp_size)
406                 buf->f_bavail = (free - c->report_rp_size) >> UBIFS_BLOCK_SHIFT;
407         else
408                 buf->f_bavail = 0;
409         buf->f_files = 0;
410         buf->f_ffree = 0;
411         buf->f_namelen = UBIFS_MAX_NLEN;
412         buf->f_fsid.val[0] = le32_to_cpu(uuid[0]) ^ le32_to_cpu(uuid[2]);
413         buf->f_fsid.val[1] = le32_to_cpu(uuid[1]) ^ le32_to_cpu(uuid[3]);
414         ubifs_assert(c, buf->f_bfree <= c->block_cnt);
415         return 0;
416 }
417 
418 static int ubifs_show_options(struct seq_file *s, struct dentry *root)
419 {
420         struct ubifs_info *c = root->d_sb->s_fs_info;
421 
422         if (c->mount_opts.unmount_mode == 2)
423                 seq_puts(s, ",fast_unmount");
424         else if (c->mount_opts.unmount_mode == 1)
425                 seq_puts(s, ",norm_unmount");
426 
427         if (c->mount_opts.bulk_read == 2)
428                 seq_puts(s, ",bulk_read");
429         else if (c->mount_opts.bulk_read == 1)
430                 seq_puts(s, ",no_bulk_read");
431 
432         if (c->mount_opts.chk_data_crc == 2)
433                 seq_puts(s, ",chk_data_crc");
434         else if (c->mount_opts.chk_data_crc == 1)
435                 seq_puts(s, ",no_chk_data_crc");
436 
437         if (c->mount_opts.override_compr) {
438                 seq_printf(s, ",compr=%s",
439                            ubifs_compr_name(c, c->mount_opts.compr_type));
440         }
441 
442         seq_printf(s, ",assert=%s", ubifs_assert_action_name(c));
443         seq_printf(s, ",ubi=%d,vol=%d", c->vi.ubi_num, c->vi.vol_id);
444 
445         return 0;
446 }
447 
448 static int ubifs_sync_fs(struct super_block *sb, int wait)
449 {
450         int i, err;
451         struct ubifs_info *c = sb->s_fs_info;
452 
453         /*
454          * Zero @wait is just an advisory thing to help the file system shove
455          * lots of data into the queues, and there will be the second
456          * '->sync_fs()' call, with non-zero @wait.
457          */
458         if (!wait)
459                 return 0;
460 
461         /*
462          * Synchronize write buffers, because 'ubifs_run_commit()' does not
463          * do this if it waits for an already running commit.
464          */
465         for (i = 0; i < c->jhead_cnt; i++) {
466                 err = ubifs_wbuf_sync(&c->jheads[i].wbuf);
467                 if (err)
468                         return err;
469         }
470 
471         /*
472          * Strictly speaking, it is not necessary to commit the journal here,
473          * synchronizing write-buffers would be enough. But committing makes
474          * UBIFS free space predictions much more accurate, so we want to let
475          * the user be able to get more accurate results of 'statfs()' after
476          * they synchronize the file system.
477          */
478         err = ubifs_run_commit(c);
479         if (err)
480                 return err;
481 
482         return ubi_sync(c->vi.ubi_num);
483 }
484 
485 /**
486  * init_constants_early - initialize UBIFS constants.
487  * @c: UBIFS file-system description object
488  *
489  * This function initialize UBIFS constants which do not need the superblock to
490  * be read. It also checks that the UBI volume satisfies basic UBIFS
491  * requirements. Returns zero in case of success and a negative error code in
492  * case of failure.
493  */
494 static int init_constants_early(struct ubifs_info *c)
495 {
496         if (c->vi.corrupted) {
497                 ubifs_warn(c, "UBI volume is corrupted - read-only mode");
498                 c->ro_media = 1;
499         }
500 
501         if (c->di.ro_mode) {
502                 ubifs_msg(c, "read-only UBI device");
503                 c->ro_media = 1;
504         }
505 
506         if (c->vi.vol_type == UBI_STATIC_VOLUME) {
507                 ubifs_msg(c, "static UBI volume - read-only mode");
508                 c->ro_media = 1;
509         }
510 
511         c->leb_cnt = c->vi.size;
512         c->leb_size = c->vi.usable_leb_size;
513         c->leb_start = c->di.leb_start;
514         c->half_leb_size = c->leb_size / 2;
515         c->min_io_size = c->di.min_io_size;
516         c->min_io_shift = fls(c->min_io_size) - 1;
517         c->max_write_size = c->di.max_write_size;
518         c->max_write_shift = fls(c->max_write_size) - 1;
519 
520         if (c->leb_size < UBIFS_MIN_LEB_SZ) {
521                 ubifs_errc(c, "too small LEBs (%d bytes), min. is %d bytes",
522                            c->leb_size, UBIFS_MIN_LEB_SZ);
523                 return -EINVAL;
524         }
525 
526         if (c->leb_cnt < UBIFS_MIN_LEB_CNT) {
527                 ubifs_errc(c, "too few LEBs (%d), min. is %d",
528                            c->leb_cnt, UBIFS_MIN_LEB_CNT);
529                 return -EINVAL;
530         }
531 
532         if (!is_power_of_2(c->min_io_size)) {
533                 ubifs_errc(c, "bad min. I/O size %d", c->min_io_size);
534                 return -EINVAL;
535         }
536 
537         /*
538          * Maximum write size has to be greater or equivalent to min. I/O
539          * size, and be multiple of min. I/O size.
540          */
541         if (c->max_write_size < c->min_io_size ||
542             c->max_write_size % c->min_io_size ||
543             !is_power_of_2(c->max_write_size)) {
544                 ubifs_errc(c, "bad write buffer size %d for %d min. I/O unit",
545                            c->max_write_size, c->min_io_size);
546                 return -EINVAL;
547         }
548 
549         /*
550          * UBIFS aligns all node to 8-byte boundary, so to make function in
551          * io.c simpler, assume minimum I/O unit size to be 8 bytes if it is
552          * less than 8.
553          */
554         if (c->min_io_size < 8) {
555                 c->min_io_size = 8;
556                 c->min_io_shift = 3;
557                 if (c->max_write_size < c->min_io_size) {
558                         c->max_write_size = c->min_io_size;
559                         c->max_write_shift = c->min_io_shift;
560                 }
561         }
562 
563         c->ref_node_alsz = ALIGN(UBIFS_REF_NODE_SZ, c->min_io_size);
564         c->mst_node_alsz = ALIGN(UBIFS_MST_NODE_SZ, c->min_io_size);
565 
566         /*
567          * Initialize node length ranges which are mostly needed for node
568          * length validation.
569          */
570         c->ranges[UBIFS_PAD_NODE].len  = UBIFS_PAD_NODE_SZ;
571         c->ranges[UBIFS_SB_NODE].len   = UBIFS_SB_NODE_SZ;
572         c->ranges[UBIFS_MST_NODE].len  = UBIFS_MST_NODE_SZ;
573         c->ranges[UBIFS_REF_NODE].len  = UBIFS_REF_NODE_SZ;
574         c->ranges[UBIFS_TRUN_NODE].len = UBIFS_TRUN_NODE_SZ;
575         c->ranges[UBIFS_CS_NODE].len   = UBIFS_CS_NODE_SZ;
576         c->ranges[UBIFS_AUTH_NODE].min_len = UBIFS_AUTH_NODE_SZ;
577         c->ranges[UBIFS_AUTH_NODE].max_len = UBIFS_AUTH_NODE_SZ +
578                                 UBIFS_MAX_HMAC_LEN;
579         c->ranges[UBIFS_SIG_NODE].min_len = UBIFS_SIG_NODE_SZ;
580         c->ranges[UBIFS_SIG_NODE].max_len = c->leb_size - UBIFS_SB_NODE_SZ;
581 
582         c->ranges[UBIFS_INO_NODE].min_len  = UBIFS_INO_NODE_SZ;
583         c->ranges[UBIFS_INO_NODE].max_len  = UBIFS_MAX_INO_NODE_SZ;
584         c->ranges[UBIFS_ORPH_NODE].min_len =
585                                 UBIFS_ORPH_NODE_SZ + sizeof(__le64);
586         c->ranges[UBIFS_ORPH_NODE].max_len = c->leb_size;
587         c->ranges[UBIFS_DENT_NODE].min_len = UBIFS_DENT_NODE_SZ;
588         c->ranges[UBIFS_DENT_NODE].max_len = UBIFS_MAX_DENT_NODE_SZ;
589         c->ranges[UBIFS_XENT_NODE].min_len = UBIFS_XENT_NODE_SZ;
590         c->ranges[UBIFS_XENT_NODE].max_len = UBIFS_MAX_XENT_NODE_SZ;
591         c->ranges[UBIFS_DATA_NODE].min_len = UBIFS_DATA_NODE_SZ;
592         c->ranges[UBIFS_DATA_NODE].max_len = UBIFS_MAX_DATA_NODE_SZ;
593         /*
594          * Minimum indexing node size is amended later when superblock is
595          * read and the key length is known.
596          */
597         c->ranges[UBIFS_IDX_NODE].min_len = UBIFS_IDX_NODE_SZ + UBIFS_BRANCH_SZ;
598         /*
599          * Maximum indexing node size is amended later when superblock is
600          * read and the fanout is known.
601          */
602         c->ranges[UBIFS_IDX_NODE].max_len = INT_MAX;
603 
604         /*
605          * Initialize dead and dark LEB space watermarks. See gc.c for comments
606          * about these values.
607          */
608         c->dead_wm = ALIGN(MIN_WRITE_SZ, c->min_io_size);
609         c->dark_wm = ALIGN(UBIFS_MAX_NODE_SZ, c->min_io_size);
610 
611         /*
612          * Calculate how many bytes would be wasted at the end of LEB if it was
613          * fully filled with data nodes of maximum size. This is used in
614          * calculations when reporting free space.
615          */
616         c->leb_overhead = c->leb_size % UBIFS_MAX_DATA_NODE_SZ;
617 
618         /* Buffer size for bulk-reads */
619         c->max_bu_buf_len = UBIFS_MAX_BULK_READ * UBIFS_MAX_DATA_NODE_SZ;
620         if (c->max_bu_buf_len > c->leb_size)
621                 c->max_bu_buf_len = c->leb_size;
622 
623         /* Log is ready, preserve one LEB for commits. */
624         c->min_log_bytes = c->leb_size;
625 
626         return 0;
627 }
628 
629 /**
630  * bud_wbuf_callback - bud LEB write-buffer synchronization call-back.
631  * @c: UBIFS file-system description object
632  * @lnum: LEB the write-buffer was synchronized to
633  * @free: how many free bytes left in this LEB
634  * @pad: how many bytes were padded
635  *
636  * This is a callback function which is called by the I/O unit when the
637  * write-buffer is synchronized. We need this to correctly maintain space
638  * accounting in bud logical eraseblocks. This function returns zero in case of
639  * success and a negative error code in case of failure.
640  *
641  * This function actually belongs to the journal, but we keep it here because
642  * we want to keep it static.
643  */
644 static int bud_wbuf_callback(struct ubifs_info *c, int lnum, int free, int pad)
645 {
646         return ubifs_update_one_lp(c, lnum, free, pad, 0, 0);
647 }
648 
649 /*
650  * init_constants_sb - initialize UBIFS constants.
651  * @c: UBIFS file-system description object
652  *
653  * This is a helper function which initializes various UBIFS constants after
654  * the superblock has been read. It also checks various UBIFS parameters and
655  * makes sure they are all right. Returns zero in case of success and a
656  * negative error code in case of failure.
657  */
658 static int init_constants_sb(struct ubifs_info *c)
659 {
660         int tmp, err;
661         long long tmp64;
662 
663         c->main_bytes = (long long)c->main_lebs * c->leb_size;
664         c->max_znode_sz = sizeof(struct ubifs_znode) +
665                                 c->fanout * sizeof(struct ubifs_zbranch);
666 
667         tmp = ubifs_idx_node_sz(c, 1);
668         c->ranges[UBIFS_IDX_NODE].min_len = tmp;
669         c->min_idx_node_sz = ALIGN(tmp, 8);
670 
671         tmp = ubifs_idx_node_sz(c, c->fanout);
672         c->ranges[UBIFS_IDX_NODE].max_len = tmp;
673         c->max_idx_node_sz = ALIGN(tmp, 8);
674 
675         /* Make sure LEB size is large enough to fit full commit */
676         tmp = UBIFS_CS_NODE_SZ + UBIFS_REF_NODE_SZ * c->jhead_cnt;
677         tmp = ALIGN(tmp, c->min_io_size);
678         if (tmp > c->leb_size) {
679                 ubifs_err(c, "too small LEB size %d, at least %d needed",
680                           c->leb_size, tmp);
681                 return -EINVAL;
682         }
683 
684         /*
685          * Make sure that the log is large enough to fit reference nodes for
686          * all buds plus one reserved LEB.
687          */
688         tmp64 = c->max_bud_bytes + c->leb_size - 1;
689         c->max_bud_cnt = div_u64(tmp64, c->leb_size);
690         tmp = (c->ref_node_alsz * c->max_bud_cnt + c->leb_size - 1);
691         tmp /= c->leb_size;
692         tmp += 1;
693         if (c->log_lebs < tmp) {
694                 ubifs_err(c, "too small log %d LEBs, required min. %d LEBs",
695                           c->log_lebs, tmp);
696                 return -EINVAL;
697         }
698 
699         /*
700          * When budgeting we assume worst-case scenarios when the pages are not
701          * be compressed and direntries are of the maximum size.
702          *
703          * Note, data, which may be stored in inodes is budgeted separately, so
704          * it is not included into 'c->bi.inode_budget'.
705          */
706         c->bi.page_budget = UBIFS_MAX_DATA_NODE_SZ * UBIFS_BLOCKS_PER_PAGE;
707         c->bi.inode_budget = UBIFS_INO_NODE_SZ;
708         c->bi.dent_budget = UBIFS_MAX_DENT_NODE_SZ;
709 
710         /*
711          * When the amount of flash space used by buds becomes
712          * 'c->max_bud_bytes', UBIFS just blocks all writers and starts commit.
713          * The writers are unblocked when the commit is finished. To avoid
714          * writers to be blocked UBIFS initiates background commit in advance,
715          * when number of bud bytes becomes above the limit defined below.
716          */
717         c->bg_bud_bytes = (c->max_bud_bytes * 13) >> 4;
718 
719         /*
720          * Ensure minimum journal size. All the bytes in the journal heads are
721          * considered to be used, when calculating the current journal usage.
722          * Consequently, if the journal is too small, UBIFS will treat it as
723          * always full.
724          */
725         tmp64 = (long long)(c->jhead_cnt + 1) * c->leb_size + 1;
726         if (c->bg_bud_bytes < tmp64)
727                 c->bg_bud_bytes = tmp64;
728         if (c->max_bud_bytes < tmp64 + c->leb_size)
729                 c->max_bud_bytes = tmp64 + c->leb_size;
730 
731         err = ubifs_calc_lpt_geom(c);
732         if (err)
733                 return err;
734 
735         /* Initialize effective LEB size used in budgeting calculations */
736         c->idx_leb_size = c->leb_size - c->max_idx_node_sz;
737         return 0;
738 }
739 
740 /*
741  * init_constants_master - initialize UBIFS constants.
742  * @c: UBIFS file-system description object
743  *
744  * This is a helper function which initializes various UBIFS constants after
745  * the master node has been read. It also checks various UBIFS parameters and
746  * makes sure they are all right.
747  */
748 static void init_constants_master(struct ubifs_info *c)
749 {
750         long long tmp64;
751 
752         c->bi.min_idx_lebs = ubifs_calc_min_idx_lebs(c);
753         c->report_rp_size = ubifs_reported_space(c, c->rp_size);
754 
755         /*
756          * Calculate total amount of FS blocks. This number is not used
757          * internally because it does not make much sense for UBIFS, but it is
758          * necessary to report something for the 'statfs()' call.
759          *
760          * Subtract the LEB reserved for GC, the LEB which is reserved for
761          * deletions, minimum LEBs for the index, and assume only one journal
762          * head is available.
763          */
764         tmp64 = c->main_lebs - 1 - 1 - MIN_INDEX_LEBS - c->jhead_cnt + 1;
765         tmp64 *= (long long)c->leb_size - c->leb_overhead;
766         tmp64 = ubifs_reported_space(c, tmp64);
767         c->block_cnt = tmp64 >> UBIFS_BLOCK_SHIFT;
768 }
769 
770 /**
771  * take_gc_lnum - reserve GC LEB.
772  * @c: UBIFS file-system description object
773  *
774  * This function ensures that the LEB reserved for garbage collection is marked
775  * as "taken" in lprops. We also have to set free space to LEB size and dirty
776  * space to zero, because lprops may contain out-of-date information if the
777  * file-system was un-mounted before it has been committed. This function
778  * returns zero in case of success and a negative error code in case of
779  * failure.
780  */
781 static int take_gc_lnum(struct ubifs_info *c)
782 {
783         int err;
784 
785         if (c->gc_lnum == -1) {
786                 ubifs_err(c, "no LEB for GC");
787                 return -EINVAL;
788         }
789 
790         /* And we have to tell lprops that this LEB is taken */
791         err = ubifs_change_one_lp(c, c->gc_lnum, c->leb_size, 0,
792                                   LPROPS_TAKEN, 0, 0);
793         return err;
794 }
795 
796 /**
797  * alloc_wbufs - allocate write-buffers.
798  * @c: UBIFS file-system description object
799  *
800  * This helper function allocates and initializes UBIFS write-buffers. Returns
801  * zero in case of success and %-ENOMEM in case of failure.
802  */
803 static int alloc_wbufs(struct ubifs_info *c)
804 {
805         int i, err;
806 
807         c->jheads = kcalloc(c->jhead_cnt, sizeof(struct ubifs_jhead),
808                             GFP_KERNEL);
809         if (!c->jheads)
810                 return -ENOMEM;
811 
812         /* Initialize journal heads */
813         for (i = 0; i < c->jhead_cnt; i++) {
814                 INIT_LIST_HEAD(&c->jheads[i].buds_list);
815                 err = ubifs_wbuf_init(c, &c->jheads[i].wbuf);
816                 if (err)
817                         return err;
818 
819                 c->jheads[i].wbuf.sync_callback = &bud_wbuf_callback;
820                 c->jheads[i].wbuf.jhead = i;
821                 c->jheads[i].grouped = 1;
822                 c->jheads[i].log_hash = ubifs_hash_get_desc(c);
823                 if (IS_ERR(c->jheads[i].log_hash))
824                         goto out;
825         }
826 
827         /*
828          * Garbage Collector head does not need to be synchronized by timer.
829          * Also GC head nodes are not grouped.
830          */
831         c->jheads[GCHD].wbuf.no_timer = 1;
832         c->jheads[GCHD].grouped = 0;
833 
834         return 0;
835 
836 out:
837         while (i--)
838                 kfree(c->jheads[i].log_hash);
839 
840         return err;
841 }
842 
843 /**
844  * free_wbufs - free write-buffers.
845  * @c: UBIFS file-system description object
846  */
847 static void free_wbufs(struct ubifs_info *c)
848 {
849         int i;
850 
851         if (c->jheads) {
852                 for (i = 0; i < c->jhead_cnt; i++) {
853                         kfree(c->jheads[i].wbuf.buf);
854                         kfree(c->jheads[i].wbuf.inodes);
855                         kfree(c->jheads[i].log_hash);
856                 }
857                 kfree(c->jheads);
858                 c->jheads = NULL;
859         }
860 }
861 
862 /**
863  * free_orphans - free orphans.
864  * @c: UBIFS file-system description object
865  */
866 static void free_orphans(struct ubifs_info *c)
867 {
868         struct ubifs_orphan *orph;
869 
870         while (c->orph_dnext) {
871                 orph = c->orph_dnext;
872                 c->orph_dnext = orph->dnext;
873                 list_del(&orph->list);
874                 kfree(orph);
875         }
876 
877         while (!list_empty(&c->orph_list)) {
878                 orph = list_entry(c->orph_list.next, struct ubifs_orphan, list);
879                 list_del(&orph->list);
880                 kfree(orph);
881                 ubifs_err(c, "orphan list not empty at unmount");
882         }
883 
884         vfree(c->orph_buf);
885         c->orph_buf = NULL;
886 }
887 
888 /**
889  * free_buds - free per-bud objects.
890  * @c: UBIFS file-system description object
891  */
892 static void free_buds(struct ubifs_info *c)
893 {
894         struct ubifs_bud *bud, *n;
895 
896         rbtree_postorder_for_each_entry_safe(bud, n, &c->buds, rb)
897                 kfree(bud);
898 }
899 
900 /**
901  * check_volume_empty - check if the UBI volume is empty.
902  * @c: UBIFS file-system description object
903  *
904  * This function checks if the UBIFS volume is empty by looking if its LEBs are
905  * mapped or not. The result of checking is stored in the @c->empty variable.
906  * Returns zero in case of success and a negative error code in case of
907  * failure.
908  */
909 static int check_volume_empty(struct ubifs_info *c)
910 {
911         int lnum, err;
912 
913         c->empty = 1;
914         for (lnum = 0; lnum < c->leb_cnt; lnum++) {
915                 err = ubifs_is_mapped(c, lnum);
916                 if (unlikely(err < 0))
917                         return err;
918                 if (err == 1) {
919                         c->empty = 0;
920                         break;
921                 }
922 
923                 cond_resched();
924         }
925 
926         return 0;
927 }
928 
929 /*
930  * UBIFS mount options.
931  *
932  * Opt_fast_unmount: do not run a journal commit before un-mounting
933  * Opt_norm_unmount: run a journal commit before un-mounting
934  * Opt_bulk_read: enable bulk-reads
935  * Opt_no_bulk_read: disable bulk-reads
936  * Opt_chk_data_crc: check CRCs when reading data nodes
937  * Opt_no_chk_data_crc: do not check CRCs when reading data nodes
938  * Opt_override_compr: override default compressor
939  * Opt_assert: set ubifs_assert() action
940  * Opt_auth_key: The key name used for authentication
941  * Opt_auth_hash_name: The hash type used for authentication
942  * Opt_err: just end of array marker
943  */
944 enum {
945         Opt_fast_unmount,
946         Opt_norm_unmount,
947         Opt_bulk_read,
948         Opt_no_bulk_read,
949         Opt_chk_data_crc,
950         Opt_no_chk_data_crc,
951         Opt_override_compr,
952         Opt_assert,
953         Opt_auth_key,
954         Opt_auth_hash_name,
955         Opt_ignore,
956         Opt_err,
957 };
958 
959 static const match_table_t tokens = {
960         {Opt_fast_unmount, "fast_unmount"},
961         {Opt_norm_unmount, "norm_unmount"},
962         {Opt_bulk_read, "bulk_read"},
963         {Opt_no_bulk_read, "no_bulk_read"},
964         {Opt_chk_data_crc, "chk_data_crc"},
965         {Opt_no_chk_data_crc, "no_chk_data_crc"},
966         {Opt_override_compr, "compr=%s"},
967         {Opt_auth_key, "auth_key=%s"},
968         {Opt_auth_hash_name, "auth_hash_name=%s"},
969         {Opt_ignore, "ubi=%s"},
970         {Opt_ignore, "vol=%s"},
971         {Opt_assert, "assert=%s"},
972         {Opt_err, NULL},
973 };
974 
975 /**
976  * parse_standard_option - parse a standard mount option.
977  * @option: the option to parse
978  *
979  * Normally, standard mount options like "sync" are passed to file-systems as
980  * flags. However, when a "rootflags=" kernel boot parameter is used, they may
981  * be present in the options string. This function tries to deal with this
982  * situation and parse standard options. Returns 0 if the option was not
983  * recognized, and the corresponding integer flag if it was.
984  *
985  * UBIFS is only interested in the "sync" option, so do not check for anything
986  * else.
987  */
988 static int parse_standard_option(const char *option)
989 {
990 
991         pr_notice("UBIFS: parse %s\n", option);
992         if (!strcmp(option, "sync"))
993                 return SB_SYNCHRONOUS;
994         return 0;
995 }
996 
997 /**
998  * ubifs_parse_options - parse mount parameters.
999  * @c: UBIFS file-system description object
1000  * @options: parameters to parse
1001  * @is_remount: non-zero if this is FS re-mount
1002  *
1003  * This function parses UBIFS mount options and returns zero in case success
1004  * and a negative error code in case of failure.
1005  */
1006 static int ubifs_parse_options(struct ubifs_info *c, char *options,
1007                                int is_remount)
1008 {
1009         char *p;
1010         substring_t args[MAX_OPT_ARGS];
1011 
1012         if (!options)
1013                 return 0;
1014 
1015         while ((p = strsep(&options, ","))) {
1016                 int token;
1017 
1018                 if (!*p)
1019                         continue;
1020 
1021                 token = match_token(p, tokens, args);
1022                 switch (token) {
1023                 /*
1024                  * %Opt_fast_unmount and %Opt_norm_unmount options are ignored.
1025                  * We accept them in order to be backward-compatible. But this
1026                  * should be removed at some point.
1027                  */
1028                 case Opt_fast_unmount:
1029                         c->mount_opts.unmount_mode = 2;
1030                         break;
1031                 case Opt_norm_unmount:
1032                         c->mount_opts.unmount_mode = 1;
1033                         break;
1034                 case Opt_bulk_read:
1035                         c->mount_opts.bulk_read = 2;
1036                         c->bulk_read = 1;
1037                         break;
1038                 case Opt_no_bulk_read:
1039                         c->mount_opts.bulk_read = 1;
1040                         c->bulk_read = 0;
1041                         break;
1042                 case Opt_chk_data_crc:
1043                         c->mount_opts.chk_data_crc = 2;
1044                         c->no_chk_data_crc = 0;
1045                         break;
1046                 case Opt_no_chk_data_crc:
1047                         c->mount_opts.chk_data_crc = 1;
1048                         c->no_chk_data_crc = 1;
1049                         break;
1050                 case Opt_override_compr:
1051                 {
1052                         char *name = match_strdup(&args[0]);
1053 
1054                         if (!name)
1055                                 return -ENOMEM;
1056                         if (!strcmp(name, "none"))
1057                                 c->mount_opts.compr_type = UBIFS_COMPR_NONE;
1058                         else if (!strcmp(name, "lzo"))
1059                                 c->mount_opts.compr_type = UBIFS_COMPR_LZO;
1060                         else if (!strcmp(name, "zlib"))
1061                                 c->mount_opts.compr_type = UBIFS_COMPR_ZLIB;
1062                         else if (!strcmp(name, "zstd"))
1063                                 c->mount_opts.compr_type = UBIFS_COMPR_ZSTD;
1064                         else {
1065                                 ubifs_err(c, "unknown compressor \"%s\"", name); //FIXME: is c ready?
1066                                 kfree(name);
1067                                 return -EINVAL;
1068                         }
1069                         kfree(name);
1070                         c->mount_opts.override_compr = 1;
1071                         c->default_compr = c->mount_opts.compr_type;
1072                         break;
1073                 }
1074                 case Opt_assert:
1075                 {
1076                         char *act = match_strdup(&args[0]);
1077 
1078                         if (!act)
1079                                 return -ENOMEM;
1080                         if (!strcmp(act, "report"))
1081                                 c->assert_action = ASSACT_REPORT;
1082                         else if (!strcmp(act, "read-only"))
1083                                 c->assert_action = ASSACT_RO;
1084                         else if (!strcmp(act, "panic"))
1085                                 c->assert_action = ASSACT_PANIC;
1086                         else {
1087                                 ubifs_err(c, "unknown assert action \"%s\"", act);
1088                                 kfree(act);
1089                                 return -EINVAL;
1090                         }
1091                         kfree(act);
1092                         break;
1093                 }
1094                 case Opt_auth_key:
1095                         c->auth_key_name = kstrdup(args[0].from, GFP_KERNEL);
1096                         if (!c->auth_key_name)
1097                                 return -ENOMEM;
1098                         break;
1099                 case Opt_auth_hash_name:
1100                         c->auth_hash_name = kstrdup(args[0].from, GFP_KERNEL);
1101                         if (!c->auth_hash_name)
1102                                 return -ENOMEM;
1103                         break;
1104                 case Opt_ignore:
1105                         break;
1106                 default:
1107                 {
1108                         unsigned long flag;
1109                         struct super_block *sb = c->vfs_sb;
1110 
1111                         flag = parse_standard_option(p);
1112                         if (!flag) {
1113                                 ubifs_err(c, "unrecognized mount option \"%s\" or missing value",
1114                                           p);
1115                                 return -EINVAL;
1116                         }
1117                         sb->s_flags |= flag;
1118                         break;
1119                 }
1120                 }
1121         }
1122 
1123         return 0;
1124 }
1125 
1126 /**
1127  * destroy_journal - destroy journal data structures.
1128  * @c: UBIFS file-system description object
1129  *
1130  * This function destroys journal data structures including those that may have
1131  * been created by recovery functions.
1132  */
1133 static void destroy_journal(struct ubifs_info *c)
1134 {
1135         while (!list_empty(&c->unclean_leb_list)) {
1136                 struct ubifs_unclean_leb *ucleb;
1137 
1138                 ucleb = list_entry(c->unclean_leb_list.next,
1139                                    struct ubifs_unclean_leb, list);
1140                 list_del(&ucleb->list);
1141                 kfree(ucleb);
1142         }
1143         while (!list_empty(&c->old_buds)) {
1144                 struct ubifs_bud *bud;
1145 
1146                 bud = list_entry(c->old_buds.next, struct ubifs_bud, list);
1147                 list_del(&bud->list);
1148                 kfree(bud);
1149         }
1150         ubifs_destroy_idx_gc(c);
1151         ubifs_destroy_size_tree(c);
1152         ubifs_tnc_close(c);
1153         free_buds(c);
1154 }
1155 
1156 /**
1157  * bu_init - initialize bulk-read information.
1158  * @c: UBIFS file-system description object
1159  */
1160 static void bu_init(struct ubifs_info *c)
1161 {
1162         ubifs_assert(c, c->bulk_read == 1);
1163 
1164         if (c->bu.buf)
1165                 return; /* Already initialized */
1166 
1167 again:
1168         c->bu.buf = kmalloc(c->max_bu_buf_len, GFP_KERNEL | __GFP_NOWARN);
1169         if (!c->bu.buf) {
1170                 if (c->max_bu_buf_len > UBIFS_KMALLOC_OK) {
1171                         c->max_bu_buf_len = UBIFS_KMALLOC_OK;
1172                         goto again;
1173                 }
1174 
1175                 /* Just disable bulk-read */
1176                 ubifs_warn(c, "cannot allocate %d bytes of memory for bulk-read, disabling it",
1177                            c->max_bu_buf_len);
1178                 c->mount_opts.bulk_read = 1;
1179                 c->bulk_read = 0;
1180                 return;
1181         }
1182 }
1183 
1184 /**
1185  * check_free_space - check if there is enough free space to mount.
1186  * @c: UBIFS file-system description object
1187  *
1188  * This function makes sure UBIFS has enough free space to be mounted in
1189  * read/write mode. UBIFS must always have some free space to allow deletions.
1190  */
1191 static int check_free_space(struct ubifs_info *c)
1192 {
1193         ubifs_assert(c, c->dark_wm > 0);
1194         if (c->lst.total_free + c->lst.total_dirty < c->dark_wm) {
1195                 ubifs_err(c, "insufficient free space to mount in R/W mode");
1196                 ubifs_dump_budg(c, &c->bi);
1197                 ubifs_dump_lprops(c);
1198                 return -ENOSPC;
1199         }
1200         return 0;
1201 }
1202 
1203 /**
1204  * mount_ubifs - mount UBIFS file-system.
1205  * @c: UBIFS file-system description object
1206  *
1207  * This function mounts UBIFS file system. Returns zero in case of success and
1208  * a negative error code in case of failure.
1209  */
1210 static int mount_ubifs(struct ubifs_info *c)
1211 {
1212         int err;
1213         long long x, y;
1214         size_t sz;
1215 
1216         c->ro_mount = !!sb_rdonly(c->vfs_sb);
1217         /* Suppress error messages while probing if SB_SILENT is set */
1218         c->probing = !!(c->vfs_sb->s_flags & SB_SILENT);
1219 
1220         err = init_constants_early(c);
1221         if (err)
1222                 return err;
1223 
1224         err = ubifs_debugging_init(c);
1225         if (err)
1226                 return err;
1227 
1228         err = check_volume_empty(c);
1229         if (err)
1230                 goto out_free;
1231 
1232         if (c->empty && (c->ro_mount || c->ro_media)) {
1233                 /*
1234                  * This UBI volume is empty, and read-only, or the file system
1235                  * is mounted read-only - we cannot format it.
1236                  */
1237                 ubifs_err(c, "can't format empty UBI volume: read-only %s",
1238                           c->ro_media ? "UBI volume" : "mount");
1239                 err = -EROFS;
1240                 goto out_free;
1241         }
1242 
1243         if (c->ro_media && !c->ro_mount) {
1244                 ubifs_err(c, "cannot mount read-write - read-only media");
1245                 err = -EROFS;
1246                 goto out_free;
1247         }
1248 
1249         /*
1250          * The requirement for the buffer is that it should fit indexing B-tree
1251          * height amount of integers. We assume the height if the TNC tree will
1252          * never exceed 64.
1253          */
1254         err = -ENOMEM;
1255         c->bottom_up_buf = kmalloc_array(BOTTOM_UP_HEIGHT, sizeof(int),
1256                                          GFP_KERNEL);
1257         if (!c->bottom_up_buf)
1258                 goto out_free;
1259 
1260         c->sbuf = vmalloc(c->leb_size);
1261         if (!c->sbuf)
1262                 goto out_free;
1263 
1264         if (!c->ro_mount) {
1265                 c->ileb_buf = vmalloc(c->leb_size);
1266                 if (!c->ileb_buf)
1267                         goto out_free;
1268         }
1269 
1270         if (c->bulk_read == 1)
1271                 bu_init(c);
1272 
1273         if (!c->ro_mount) {
1274                 c->write_reserve_buf = kmalloc(COMPRESSED_DATA_NODE_BUF_SZ + \
1275                                                UBIFS_CIPHER_BLOCK_SIZE,
1276                                                GFP_KERNEL);
1277                 if (!c->write_reserve_buf)
1278                         goto out_free;
1279         }
1280 
1281         c->mounting = 1;
1282 
1283         if (c->auth_key_name) {
1284                 if (IS_ENABLED(CONFIG_UBIFS_FS_AUTHENTICATION)) {
1285                         err = ubifs_init_authentication(c);
1286                         if (err)
1287                                 goto out_free;
1288                 } else {
1289                         ubifs_err(c, "auth_key_name, but UBIFS is built without"
1290                                   " authentication support");
1291                         err = -EINVAL;
1292                         goto out_free;
1293                 }
1294         }
1295 
1296         err = ubifs_read_superblock(c);
1297         if (err)
1298                 goto out_free;
1299 
1300         c->probing = 0;
1301 
1302         /*
1303          * Make sure the compressor which is set as default in the superblock
1304          * or overridden by mount options is actually compiled in.
1305          */
1306         if (!ubifs_compr_present(c, c->default_compr)) {
1307                 ubifs_err(c, "'compressor \"%s\" is not compiled in",
1308                           ubifs_compr_name(c, c->default_compr));
1309                 err = -ENOTSUPP;
1310                 goto out_free;
1311         }
1312 
1313         err = init_constants_sb(c);
1314         if (err)
1315                 goto out_free;
1316 
1317         sz = ALIGN(c->max_idx_node_sz, c->min_io_size) * 2;
1318         c->cbuf = kmalloc(sz, GFP_NOFS);
1319         if (!c->cbuf) {
1320                 err = -ENOMEM;
1321                 goto out_free;
1322         }
1323 
1324         err = alloc_wbufs(c);
1325         if (err)
1326                 goto out_cbuf;
1327 
1328         sprintf(c->bgt_name, BGT_NAME_PATTERN, c->vi.ubi_num, c->vi.vol_id);
1329         if (!c->ro_mount) {
1330                 /* Create background thread */
1331                 c->bgt = kthread_create(ubifs_bg_thread, c, "%s", c->bgt_name);
1332                 if (IS_ERR(c->bgt)) {
1333                         err = PTR_ERR(c->bgt);
1334                         c->bgt = NULL;
1335                         ubifs_err(c, "cannot spawn \"%s\", error %d",
1336                                   c->bgt_name, err);
1337                         goto out_wbufs;
1338                 }
1339                 wake_up_process(c->bgt);
1340         }
1341 
1342         err = ubifs_read_master(c);
1343         if (err)
1344                 goto out_master;
1345 
1346         init_constants_master(c);
1347 
1348         if ((c->mst_node->flags & cpu_to_le32(UBIFS_MST_DIRTY)) != 0) {
1349                 ubifs_msg(c, "recovery needed");
1350                 c->need_recovery = 1;
1351         }
1352 
1353         if (c->need_recovery && !c->ro_mount) {
1354                 err = ubifs_recover_inl_heads(c, c->sbuf);
1355                 if (err)
1356                         goto out_master;
1357         }
1358 
1359         err = ubifs_lpt_init(c, 1, !c->ro_mount);
1360         if (err)
1361                 goto out_master;
1362 
1363         if (!c->ro_mount && c->space_fixup) {
1364                 err = ubifs_fixup_free_space(c);
1365                 if (err)
1366                         goto out_lpt;
1367         }
1368 
1369         if (!c->ro_mount && !c->need_recovery) {
1370                 /*
1371                  * Set the "dirty" flag so that if we reboot uncleanly we
1372                  * will notice this immediately on the next mount.
1373                  */
1374                 c->mst_node->flags |= cpu_to_le32(UBIFS_MST_DIRTY);
1375                 err = ubifs_write_master(c);
1376                 if (err)
1377                         goto out_lpt;
1378         }
1379 
1380         /*
1381          * Handle offline signed images: Now that the master node is
1382          * written and its validation no longer depends on the hash
1383          * in the superblock, we can update the offline signed
1384          * superblock with a HMAC version,
1385          */
1386         if (ubifs_authenticated(c) && ubifs_hmac_zero(c, c->sup_node->hmac)) {
1387                 err = ubifs_hmac_wkm(c, c->sup_node->hmac_wkm);
1388                 if (err)
1389                         goto out_lpt;
1390                 c->superblock_need_write = 1;
1391         }
1392 
1393         if (!c->ro_mount && c->superblock_need_write) {
1394                 err = ubifs_write_sb_node(c, c->sup_node);
1395                 if (err)
1396                         goto out_lpt;
1397                 c->superblock_need_write = 0;
1398         }
1399 
1400         err = dbg_check_idx_size(c, c->bi.old_idx_sz);
1401         if (err)
1402                 goto out_lpt;
1403 
1404         err = ubifs_replay_journal(c);
1405         if (err)
1406                 goto out_journal;
1407 
1408         /* Calculate 'min_idx_lebs' after journal replay */
1409         c->bi.min_idx_lebs = ubifs_calc_min_idx_lebs(c);
1410 
1411         err = ubifs_mount_orphans(c, c->need_recovery, c->ro_mount);
1412         if (err)
1413                 goto out_orphans;
1414 
1415         if (!c->ro_mount) {
1416                 int lnum;
1417 
1418                 err = check_free_space(c);
1419                 if (err)
1420                         goto out_orphans;
1421 
1422                 /* Check for enough log space */
1423                 lnum = c->lhead_lnum + 1;
1424                 if (lnum >= UBIFS_LOG_LNUM + c->log_lebs)
1425                         lnum = UBIFS_LOG_LNUM;
1426                 if (lnum == c->ltail_lnum) {
1427                         err = ubifs_consolidate_log(c);
1428                         if (err)
1429                                 goto out_orphans;
1430                 }
1431 
1432                 if (c->need_recovery) {
1433                         if (!ubifs_authenticated(c)) {
1434                                 err = ubifs_recover_size(c, true);
1435                                 if (err)
1436                                         goto out_orphans;
1437                         }
1438 
1439                         err = ubifs_rcvry_gc_commit(c);
1440                         if (err)
1441                                 goto out_orphans;
1442 
1443                         if (ubifs_authenticated(c)) {
1444                                 err = ubifs_recover_size(c, false);
1445                                 if (err)
1446                                         goto out_orphans;
1447                         }
1448                 } else {
1449                         err = take_gc_lnum(c);
1450                         if (err)
1451                                 goto out_orphans;
1452 
1453                         /*
1454                          * GC LEB may contain garbage if there was an unclean
1455                          * reboot, and it should be un-mapped.
1456                          */
1457                         err = ubifs_leb_unmap(c, c->gc_lnum);
1458                         if (err)
1459                                 goto out_orphans;
1460                 }
1461 
1462                 err = dbg_check_lprops(c);
1463                 if (err)
1464                         goto out_orphans;
1465         } else if (c->need_recovery) {
1466                 err = ubifs_recover_size(c, false);
1467                 if (err)
1468                         goto out_orphans;
1469         } else {
1470                 /*
1471                  * Even if we mount read-only, we have to set space in GC LEB
1472                  * to proper value because this affects UBIFS free space
1473                  * reporting. We do not want to have a situation when
1474                  * re-mounting from R/O to R/W changes amount of free space.
1475                  */
1476                 err = take_gc_lnum(c);
1477                 if (err)
1478                         goto out_orphans;
1479         }
1480 
1481         spin_lock(&ubifs_infos_lock);
1482         list_add_tail(&c->infos_list, &ubifs_infos);
1483         spin_unlock(&ubifs_infos_lock);
1484 
1485         if (c->need_recovery) {
1486                 if (c->ro_mount)
1487                         ubifs_msg(c, "recovery deferred");
1488                 else {
1489                         c->need_recovery = 0;
1490                         ubifs_msg(c, "recovery completed");
1491                         /*
1492                          * GC LEB has to be empty and taken at this point. But
1493                          * the journal head LEBs may also be accounted as
1494                          * "empty taken" if they are empty.
1495                          */
1496                         ubifs_assert(c, c->lst.taken_empty_lebs > 0);
1497                 }
1498         } else
1499                 ubifs_assert(c, c->lst.taken_empty_lebs > 0);
1500 
1501         err = dbg_check_filesystem(c);
1502         if (err)
1503                 goto out_infos;
1504 
1505         dbg_debugfs_init_fs(c);
1506 
1507         c->mounting = 0;
1508 
1509         ubifs_msg(c, "UBIFS: mounted UBI device %d, volume %d, name \"%s\"%s",
1510                   c->vi.ubi_num, c->vi.vol_id, c->vi.name,
1511                   c->ro_mount ? ", R/O mode" : "");
1512         x = (long long)c->main_lebs * c->leb_size;
1513         y = (long long)c->log_lebs * c->leb_size + c->max_bud_bytes;
1514         ubifs_msg(c, "LEB size: %d bytes (%d KiB), min./max. I/O unit sizes: %d bytes/%d bytes",
1515                   c->leb_size, c->leb_size >> 10, c->min_io_size,
1516                   c->max_write_size);
1517         ubifs_msg(c, "FS size: %lld bytes (%lld MiB, %d LEBs), journal size %lld bytes (%lld MiB, %d LEBs)",
1518                   x, x >> 20, c->main_lebs,
1519                   y, y >> 20, c->log_lebs + c->max_bud_cnt);
1520         ubifs_msg(c, "reserved for root: %llu bytes (%llu KiB)",
1521                   c->report_rp_size, c->report_rp_size >> 10);
1522         ubifs_msg(c, "media format: w%d/r%d (latest is w%d/r%d), UUID %pUB%s",
1523                   c->fmt_version, c->ro_compat_version,
1524                   UBIFS_FORMAT_VERSION, UBIFS_RO_COMPAT_VERSION, c->uuid,
1525                   c->big_lpt ? ", big LPT model" : ", small LPT model");
1526 
1527         dbg_gen("default compressor:  %s", ubifs_compr_name(c, c->default_compr));
1528         dbg_gen("data journal heads:  %d",
1529                 c->jhead_cnt - NONDATA_JHEADS_CNT);
1530         dbg_gen("log LEBs:            %d (%d - %d)",
1531                 c->log_lebs, UBIFS_LOG_LNUM, c->log_last);
1532         dbg_gen("LPT area LEBs:       %d (%d - %d)",
1533                 c->lpt_lebs, c->lpt_first, c->lpt_last);
1534         dbg_gen("orphan area LEBs:    %d (%d - %d)",
1535                 c->orph_lebs, c->orph_first, c->orph_last);
1536         dbg_gen("main area LEBs:      %d (%d - %d)",
1537                 c->main_lebs, c->main_first, c->leb_cnt - 1);
1538         dbg_gen("index LEBs:          %d", c->lst.idx_lebs);
1539         dbg_gen("total index bytes:   %lld (%lld KiB, %lld MiB)",
1540                 c->bi.old_idx_sz, c->bi.old_idx_sz >> 10,
1541                 c->bi.old_idx_sz >> 20);
1542         dbg_gen("key hash type:       %d", c->key_hash_type);
1543         dbg_gen("tree fanout:         %d", c->fanout);
1544         dbg_gen("reserved GC LEB:     %d", c->gc_lnum);
1545         dbg_gen("max. znode size      %d", c->max_znode_sz);
1546         dbg_gen("max. index node size %d", c->max_idx_node_sz);
1547         dbg_gen("node sizes:          data %zu, inode %zu, dentry %zu",
1548                 UBIFS_DATA_NODE_SZ, UBIFS_INO_NODE_SZ, UBIFS_DENT_NODE_SZ);
1549         dbg_gen("node sizes:          trun %zu, sb %zu, master %zu",
1550                 UBIFS_TRUN_NODE_SZ, UBIFS_SB_NODE_SZ, UBIFS_MST_NODE_SZ);
1551         dbg_gen("node sizes:          ref %zu, cmt. start %zu, orph %zu",
1552                 UBIFS_REF_NODE_SZ, UBIFS_CS_NODE_SZ, UBIFS_ORPH_NODE_SZ);
1553         dbg_gen("max. node sizes:     data %zu, inode %zu dentry %zu, idx %d",
1554                 UBIFS_MAX_DATA_NODE_SZ, UBIFS_MAX_INO_NODE_SZ,
1555                 UBIFS_MAX_DENT_NODE_SZ, ubifs_idx_node_sz(c, c->fanout));
1556         dbg_gen("dead watermark:      %d", c->dead_wm);
1557         dbg_gen("dark watermark:      %d", c->dark_wm);
1558         dbg_gen("LEB overhead:        %d", c->leb_overhead);
1559         x = (long long)c->main_lebs * c->dark_wm;
1560         dbg_gen("max. dark space:     %lld (%lld KiB, %lld MiB)",
1561                 x, x >> 10, x >> 20);
1562         dbg_gen("maximum bud bytes:   %lld (%lld KiB, %lld MiB)",
1563                 c->max_bud_bytes, c->max_bud_bytes >> 10,
1564                 c->max_bud_bytes >> 20);
1565         dbg_gen("BG commit bud bytes: %lld (%lld KiB, %lld MiB)",
1566                 c->bg_bud_bytes, c->bg_bud_bytes >> 10,
1567                 c->bg_bud_bytes >> 20);
1568         dbg_gen("current bud bytes    %lld (%lld KiB, %lld MiB)",
1569                 c->bud_bytes, c->bud_bytes >> 10, c->bud_bytes >> 20);
1570         dbg_gen("max. seq. number:    %llu", c->max_sqnum);
1571         dbg_gen("commit number:       %llu", c->cmt_no);
1572         dbg_gen("max. xattrs per inode: %d", ubifs_xattr_max_cnt(c));
1573         dbg_gen("max orphans:           %d", c->max_orphans);
1574 
1575         return 0;
1576 
1577 out_infos:
1578         spin_lock(&ubifs_infos_lock);
1579         list_del(&c->infos_list);
1580         spin_unlock(&ubifs_infos_lock);
1581 out_orphans:
1582         free_orphans(c);
1583 out_journal:
1584         destroy_journal(c);
1585 out_lpt:
1586         ubifs_lpt_free(c, 0);
1587 out_master:
1588         kfree(c->mst_node);
1589         kfree(c->rcvrd_mst_node);
1590         if (c->bgt)
1591                 kthread_stop(c->bgt);
1592 out_wbufs:
1593         free_wbufs(c);
1594 out_cbuf:
1595         kfree(c->cbuf);
1596 out_free:
1597         kfree(c->write_reserve_buf);
1598         kfree(c->bu.buf);
1599         vfree(c->ileb_buf);
1600         vfree(c->sbuf);
1601         kfree(c->bottom_up_buf);
1602         kfree(c->sup_node);
1603         ubifs_debugging_exit(c);
1604         return err;
1605 }
1606 
1607 /**
1608  * ubifs_umount - un-mount UBIFS file-system.
1609  * @c: UBIFS file-system description object
1610  *
1611  * Note, this function is called to free allocated resourced when un-mounting,
1612  * as well as free resources when an error occurred while we were half way
1613  * through mounting (error path cleanup function). So it has to make sure the
1614  * resource was actually allocated before freeing it.
1615  */
1616 static void ubifs_umount(struct ubifs_info *c)
1617 {
1618         dbg_gen("un-mounting UBI device %d, volume %d", c->vi.ubi_num,
1619                 c->vi.vol_id);
1620 
1621         dbg_debugfs_exit_fs(c);
1622         spin_lock(&ubifs_infos_lock);
1623         list_del(&c->infos_list);
1624         spin_unlock(&ubifs_infos_lock);
1625 
1626         if (c->bgt)
1627                 kthread_stop(c->bgt);
1628 
1629         destroy_journal(c);
1630         free_wbufs(c);
1631         free_orphans(c);
1632         ubifs_lpt_free(c, 0);
1633         ubifs_exit_authentication(c);
1634 
1635         kfree(c->auth_key_name);
1636         kfree(c->auth_hash_name);
1637         kfree(c->cbuf);
1638         kfree(c->rcvrd_mst_node);
1639         kfree(c->mst_node);
1640         kfree(c->write_reserve_buf);
1641         kfree(c->bu.buf);
1642         vfree(c->ileb_buf);
1643         vfree(c->sbuf);
1644         kfree(c->bottom_up_buf);
1645         kfree(c->sup_node);
1646         ubifs_debugging_exit(c);
1647 }
1648 
1649 /**
1650  * ubifs_remount_rw - re-mount in read-write mode.
1651  * @c: UBIFS file-system description object
1652  *
1653  * UBIFS avoids allocating many unnecessary resources when mounted in read-only
1654  * mode. This function allocates the needed resources and re-mounts UBIFS in
1655  * read-write mode.
1656  */
1657 static int ubifs_remount_rw(struct ubifs_info *c)
1658 {
1659         int err, lnum;
1660 
1661         if (c->rw_incompat) {
1662                 ubifs_err(c, "the file-system is not R/W-compatible");
1663                 ubifs_msg(c, "on-flash format version is w%d/r%d, but software only supports up to version w%d/r%d",
1664                           c->fmt_version, c->ro_compat_version,
1665                           UBIFS_FORMAT_VERSION, UBIFS_RO_COMPAT_VERSION);
1666                 return -EROFS;
1667         }
1668 
1669         mutex_lock(&c->umount_mutex);
1670         dbg_save_space_info(c);
1671         c->remounting_rw = 1;
1672         c->ro_mount = 0;
1673 
1674         if (c->space_fixup) {
1675                 err = ubifs_fixup_free_space(c);
1676                 if (err)
1677                         goto out;
1678         }
1679 
1680         err = check_free_space(c);
1681         if (err)
1682                 goto out;
1683 
1684         if (c->need_recovery) {
1685                 ubifs_msg(c, "completing deferred recovery");
1686                 err = ubifs_write_rcvrd_mst_node(c);
1687                 if (err)
1688                         goto out;
1689                 if (!ubifs_authenticated(c)) {
1690                         err = ubifs_recover_size(c, true);
1691                         if (err)
1692                                 goto out;
1693                 }
1694                 err = ubifs_clean_lebs(c, c->sbuf);
1695                 if (err)
1696                         goto out;
1697                 err = ubifs_recover_inl_heads(c, c->sbuf);
1698                 if (err)
1699                         goto out;
1700         } else {
1701                 /* A readonly mount is not allowed to have orphans */
1702                 ubifs_assert(c, c->tot_orphans == 0);
1703                 err = ubifs_clear_orphans(c);
1704                 if (err)
1705                         goto out;
1706         }
1707 
1708         if (!(c->mst_node->flags & cpu_to_le32(UBIFS_MST_DIRTY))) {
1709                 c->mst_node->flags |= cpu_to_le32(UBIFS_MST_DIRTY);
1710                 err = ubifs_write_master(c);
1711                 if (err)
1712                         goto out;
1713         }
1714 
1715         if (c->superblock_need_write) {
1716                 struct ubifs_sb_node *sup = c->sup_node;
1717 
1718                 err = ubifs_write_sb_node(c, sup);
1719                 if (err)
1720                         goto out;
1721 
1722                 c->superblock_need_write = 0;
1723         }
1724 
1725         c->ileb_buf = vmalloc(c->leb_size);
1726         if (!c->ileb_buf) {
1727                 err = -ENOMEM;
1728                 goto out;
1729         }
1730 
1731         c->write_reserve_buf = kmalloc(COMPRESSED_DATA_NODE_BUF_SZ + \
1732                                        UBIFS_CIPHER_BLOCK_SIZE, GFP_KERNEL);
1733         if (!c->write_reserve_buf) {
1734                 err = -ENOMEM;
1735                 goto out;
1736         }
1737 
1738         err = ubifs_lpt_init(c, 0, 1);
1739         if (err)
1740                 goto out;
1741 
1742         /* Create background thread */
1743         c->bgt = kthread_create(ubifs_bg_thread, c, "%s", c->bgt_name);
1744         if (IS_ERR(c->bgt)) {
1745                 err = PTR_ERR(c->bgt);
1746                 c->bgt = NULL;
1747                 ubifs_err(c, "cannot spawn \"%s\", error %d",
1748                           c->bgt_name, err);
1749                 goto out;
1750         }
1751         wake_up_process(c->bgt);
1752 
1753         c->orph_buf = vmalloc(c->leb_size);
1754         if (!c->orph_buf) {
1755                 err = -ENOMEM;
1756                 goto out;
1757         }
1758 
1759         /* Check for enough log space */
1760         lnum = c->lhead_lnum + 1;
1761         if (lnum >= UBIFS_LOG_LNUM + c->log_lebs)
1762                 lnum = UBIFS_LOG_LNUM;
1763         if (lnum == c->ltail_lnum) {
1764                 err = ubifs_consolidate_log(c);
1765                 if (err)
1766                         goto out;
1767         }
1768 
1769         if (c->need_recovery) {
1770                 err = ubifs_rcvry_gc_commit(c);
1771                 if (err)
1772                         goto out;
1773 
1774                 if (ubifs_authenticated(c)) {
1775                         err = ubifs_recover_size(c, false);
1776                         if (err)
1777                                 goto out;
1778                 }
1779         } else {
1780                 err = ubifs_leb_unmap(c, c->gc_lnum);
1781         }
1782         if (err)
1783                 goto out;
1784 
1785         dbg_gen("re-mounted read-write");
1786         c->remounting_rw = 0;
1787 
1788         if (c->need_recovery) {
1789                 c->need_recovery = 0;
1790                 ubifs_msg(c, "deferred recovery completed");
1791         } else {
1792                 /*
1793                  * Do not run the debugging space check if the were doing
1794                  * recovery, because when we saved the information we had the
1795                  * file-system in a state where the TNC and lprops has been
1796                  * modified in memory, but all the I/O operations (including a
1797                  * commit) were deferred. So the file-system was in
1798                  * "non-committed" state. Now the file-system is in committed
1799                  * state, and of course the amount of free space will change
1800                  * because, for example, the old index size was imprecise.
1801                  */
1802                 err = dbg_check_space_info(c);
1803         }
1804 
1805         mutex_unlock(&c->umount_mutex);
1806         return err;
1807 
1808 out:
1809         c->ro_mount = 1;
1810         vfree(c->orph_buf);
1811         c->orph_buf = NULL;
1812         if (c->bgt) {
1813                 kthread_stop(c->bgt);
1814                 c->bgt = NULL;
1815         }
1816         free_wbufs(c);
1817         kfree(c->write_reserve_buf);
1818         c->write_reserve_buf = NULL;
1819         vfree(c->ileb_buf);
1820         c->ileb_buf = NULL;
1821         ubifs_lpt_free(c, 1);
1822         c->remounting_rw = 0;
1823         mutex_unlock(&c->umount_mutex);
1824         return err;
1825 }
1826 
1827 /**
1828  * ubifs_remount_ro - re-mount in read-only mode.
1829  * @c: UBIFS file-system description object
1830  *
1831  * We assume VFS has stopped writing. Possibly the background thread could be
1832  * running a commit, however kthread_stop will wait in that case.
1833  */
1834 static void ubifs_remount_ro(struct ubifs_info *c)
1835 {
1836         int i, err;
1837 
1838         ubifs_assert(c, !c->need_recovery);
1839         ubifs_assert(c, !c->ro_mount);
1840 
1841         mutex_lock(&c->umount_mutex);
1842         if (c->bgt) {
1843                 kthread_stop(c->bgt);
1844                 c->bgt = NULL;
1845         }
1846 
1847         dbg_save_space_info(c);
1848 
1849         for (i = 0; i < c->jhead_cnt; i++) {
1850                 err = ubifs_wbuf_sync(&c->jheads[i].wbuf);
1851                 if (err)
1852                         ubifs_ro_mode(c, err);
1853         }
1854 
1855         c->mst_node->flags &= ~cpu_to_le32(UBIFS_MST_DIRTY);
1856         c->mst_node->flags |= cpu_to_le32(UBIFS_MST_NO_ORPHS);
1857         c->mst_node->gc_lnum = cpu_to_le32(c->gc_lnum);
1858         err = ubifs_write_master(c);
1859         if (err)
1860                 ubifs_ro_mode(c, err);
1861 
1862         vfree(c->orph_buf);
1863         c->orph_buf = NULL;
1864         kfree(c->write_reserve_buf);
1865         c->write_reserve_buf = NULL;
1866         vfree(c->ileb_buf);
1867         c->ileb_buf = NULL;
1868         ubifs_lpt_free(c, 1);
1869         c->ro_mount = 1;
1870         err = dbg_check_space_info(c);
1871         if (err)
1872                 ubifs_ro_mode(c, err);
1873         mutex_unlock(&c->umount_mutex);
1874 }
1875 
1876 static void ubifs_put_super(struct super_block *sb)
1877 {
1878         int i;
1879         struct ubifs_info *c = sb->s_fs_info;
1880 
1881         ubifs_msg(c, "un-mount UBI device %d", c->vi.ubi_num);
1882 
1883         /*
1884          * The following asserts are only valid if there has not been a failure
1885          * of the media. For example, there will be dirty inodes if we failed
1886          * to write them back because of I/O errors.
1887          */
1888         if (!c->ro_error) {
1889                 ubifs_assert(c, c->bi.idx_growth == 0);
1890                 ubifs_assert(c, c->bi.dd_growth == 0);
1891                 ubifs_assert(c, c->bi.data_growth == 0);
1892         }
1893 
1894         /*
1895          * The 'c->umount_lock' prevents races between UBIFS memory shrinker
1896          * and file system un-mount. Namely, it prevents the shrinker from
1897          * picking this superblock for shrinking - it will be just skipped if
1898          * the mutex is locked.
1899          */
1900         mutex_lock(&c->umount_mutex);
1901         if (!c->ro_mount) {
1902                 /*
1903                  * First of all kill the background thread to make sure it does
1904                  * not interfere with un-mounting and freeing resources.
1905                  */
1906                 if (c->bgt) {
1907                         kthread_stop(c->bgt);
1908                         c->bgt = NULL;
1909                 }
1910 
1911                 /*
1912                  * On fatal errors c->ro_error is set to 1, in which case we do
1913                  * not write the master node.
1914                  */
1915                 if (!c->ro_error) {
1916                         int err;
1917 
1918                         /* Synchronize write-buffers */
1919                         for (i = 0; i < c->jhead_cnt; i++) {
1920                                 err = ubifs_wbuf_sync(&c->jheads[i].wbuf);
1921                                 if (err)
1922                                         ubifs_ro_mode(c, err);
1923                         }
1924 
1925                         /*
1926                          * We are being cleanly unmounted which means the
1927                          * orphans were killed - indicate this in the master
1928                          * node. Also save the reserved GC LEB number.
1929                          */
1930                         c->mst_node->flags &= ~cpu_to_le32(UBIFS_MST_DIRTY);
1931                         c->mst_node->flags |= cpu_to_le32(UBIFS_MST_NO_ORPHS);
1932                         c->mst_node->gc_lnum = cpu_to_le32(c->gc_lnum);
1933                         err = ubifs_write_master(c);
1934                         if (err)
1935                                 /*
1936                                  * Recovery will attempt to fix the master area
1937                                  * next mount, so we just print a message and
1938                                  * continue to unmount normally.
1939                                  */
1940                                 ubifs_err(c, "failed to write master node, error %d",
1941                                           err);
1942                 } else {
1943                         for (i = 0; i < c->jhead_cnt; i++)
1944                                 /* Make sure write-buffer timers are canceled */
1945                                 hrtimer_cancel(&c->jheads[i].wbuf.timer);
1946                 }
1947         }
1948 
1949         ubifs_umount(c);
1950         ubi_close_volume(c->ubi);
1951         mutex_unlock(&c->umount_mutex);
1952 }
1953 
1954 static int ubifs_remount_fs(struct super_block *sb, int *flags, char *data)
1955 {
1956         int err;
1957         struct ubifs_info *c = sb->s_fs_info;
1958 
1959         sync_filesystem(sb);
1960         dbg_gen("old flags %#lx, new flags %#x", sb->s_flags, *flags);
1961 
1962         err = ubifs_parse_options(c, data, 1);
1963         if (err) {
1964                 ubifs_err(c, "invalid or unknown remount parameter");
1965                 return err;
1966         }
1967 
1968         if (c->ro_mount && !(*flags & SB_RDONLY)) {
1969                 if (c->ro_error) {
1970                         ubifs_msg(c, "cannot re-mount R/W due to prior errors");
1971                         return -EROFS;
1972                 }
1973                 if (c->ro_media) {
1974                         ubifs_msg(c, "cannot re-mount R/W - UBI volume is R/O");
1975                         return -EROFS;
1976                 }
1977                 err = ubifs_remount_rw(c);
1978                 if (err)
1979                         return err;
1980         } else if (!c->ro_mount && (*flags & SB_RDONLY)) {
1981                 if (c->ro_error) {
1982                         ubifs_msg(c, "cannot re-mount R/O due to prior errors");
1983                         return -EROFS;
1984                 }
1985                 ubifs_remount_ro(c);
1986         }
1987 
1988         if (c->bulk_read == 1)
1989                 bu_init(c);
1990         else {
1991                 dbg_gen("disable bulk-read");
1992                 mutex_lock(&c->bu_mutex);
1993                 kfree(c->bu.buf);
1994                 c->bu.buf = NULL;
1995                 mutex_unlock(&c->bu_mutex);
1996         }
1997 
1998         if (!c->need_recovery)
1999                 ubifs_assert(c, c->lst.taken_empty_lebs > 0);
2000 
2001         return 0;
2002 }
2003 
2004 const struct super_operations ubifs_super_operations = {
2005         .alloc_inode   = ubifs_alloc_inode,
2006         .free_inode    = ubifs_free_inode,
2007         .put_super     = ubifs_put_super,
2008         .write_inode   = ubifs_write_inode,
2009         .drop_inode    = ubifs_drop_inode,
2010         .evict_inode   = ubifs_evict_inode,
2011         .statfs        = ubifs_statfs,
2012         .dirty_inode   = ubifs_dirty_inode,
2013         .remount_fs    = ubifs_remount_fs,
2014         .show_options  = ubifs_show_options,
2015         .sync_fs       = ubifs_sync_fs,
2016 };
2017 
2018 /**
2019  * open_ubi - parse UBI device name string and open the UBI device.
2020  * @name: UBI volume name
2021  * @mode: UBI volume open mode
2022  *
2023  * The primary method of mounting UBIFS is by specifying the UBI volume
2024  * character device node path. However, UBIFS may also be mounted withoug any
2025  * character device node using one of the following methods:
2026  *
2027  * o ubiX_Y    - mount UBI device number X, volume Y;
2028  * o ubiY      - mount UBI device number 0, volume Y;
2029  * o ubiX:NAME - mount UBI device X, volume with name NAME;
2030  * o ubi:NAME  - mount UBI device 0, volume with name NAME.
2031  *
2032  * Alternative '!' separator may be used instead of ':' (because some shells
2033  * like busybox may interpret ':' as an NFS host name separator). This function
2034  * returns UBI volume description object in case of success and a negative
2035  * error code in case of failure.
2036  */
2037 static struct ubi_volume_desc *open_ubi(const char *name, int mode)
2038 {
2039         struct ubi_volume_desc *ubi;
2040         int dev, vol;
2041         char *endptr;
2042 
2043         if (!name || !*name)
2044                 return ERR_PTR(-EINVAL);
2045 
2046         /* First, try to open using the device node path method */
2047         ubi = ubi_open_volume_path(name, mode);
2048         if (!IS_ERR(ubi))
2049                 return ubi;
2050 
2051         /* Try the "nodev" method */
2052         if (name[0] != 'u' || name[1] != 'b' || name[2] != 'i')
2053                 return ERR_PTR(-EINVAL);
2054 
2055         /* ubi:NAME method */
2056         if ((name[3] == ':' || name[3] == '!') && name[4] != '\0')
2057                 return ubi_open_volume_nm(0, name + 4, mode);
2058 
2059         if (!isdigit(name[3]))
2060                 return ERR_PTR(-EINVAL);
2061 
2062         dev = simple_strtoul(name + 3, &endptr, 0);
2063 
2064         /* ubiY method */
2065         if (*endptr == '\0')
2066                 return ubi_open_volume(0, dev, mode);
2067 
2068         /* ubiX_Y method */
2069         if (*endptr == '_' && isdigit(endptr[1])) {
2070                 vol = simple_strtoul(endptr + 1, &endptr, 0);
2071                 if (*endptr != '\0')
2072                         return ERR_PTR(-EINVAL);
2073                 return ubi_open_volume(dev, vol, mode);
2074         }
2075 
2076         /* ubiX:NAME method */
2077         if ((*endptr == ':' || *endptr == '!') && endptr[1] != '\0')
2078                 return ubi_open_volume_nm(dev, ++endptr, mode);
2079 
2080         return ERR_PTR(-EINVAL);
2081 }
2082 
2083 static struct ubifs_info *alloc_ubifs_info(struct ubi_volume_desc *ubi)
2084 {
2085         struct ubifs_info *c;
2086 
2087         c = kzalloc(sizeof(struct ubifs_info), GFP_KERNEL);
2088         if (c) {
2089                 spin_lock_init(&c->cnt_lock);
2090                 spin_lock_init(&c->cs_lock);
2091                 spin_lock_init(&c->buds_lock);
2092                 spin_lock_init(&c->space_lock);
2093                 spin_lock_init(&c->orphan_lock);
2094                 init_rwsem(&c->commit_sem);
2095                 mutex_init(&c->lp_mutex);
2096                 mutex_init(&c->tnc_mutex);
2097                 mutex_init(&c->log_mutex);
2098                 mutex_init(&c->umount_mutex);
2099                 mutex_init(&c->bu_mutex);
2100                 mutex_init(&c->write_reserve_mutex);
2101                 init_waitqueue_head(&c->cmt_wq);
2102                 c->buds = RB_ROOT;
2103                 c->old_idx = RB_ROOT;
2104                 c->size_tree = RB_ROOT;
2105                 c->orph_tree = RB_ROOT;
2106                 INIT_LIST_HEAD(&c->infos_list);
2107                 INIT_LIST_HEAD(&c->idx_gc);
2108                 INIT_LIST_HEAD(&c->replay_list);
2109                 INIT_LIST_HEAD(&c->replay_buds);
2110                 INIT_LIST_HEAD(&c->uncat_list);
2111                 INIT_LIST_HEAD(&c->empty_list);
2112                 INIT_LIST_HEAD(&c->freeable_list);
2113                 INIT_LIST_HEAD(&c->frdi_idx_list);
2114                 INIT_LIST_HEAD(&c->unclean_leb_list);
2115                 INIT_LIST_HEAD(&c->old_buds);
2116                 INIT_LIST_HEAD(&c->orph_list);
2117                 INIT_LIST_HEAD(&c->orph_new);
2118                 c->no_chk_data_crc = 1;
2119                 c->assert_action = ASSACT_RO;
2120 
2121                 c->highest_inum = UBIFS_FIRST_INO;
2122                 c->lhead_lnum = c->ltail_lnum = UBIFS_LOG_LNUM;
2123 
2124                 ubi_get_volume_info(ubi, &c->vi);
2125                 ubi_get_device_info(c->vi.ubi_num, &c->di);
2126         }
2127         return c;
2128 }
2129 
2130 static int ubifs_fill_super(struct super_block *sb, void *data, int silent)
2131 {
2132         struct ubifs_info *c = sb->s_fs_info;
2133         struct inode *root;
2134         int err;
2135 
2136         c->vfs_sb = sb;
2137         /* Re-open the UBI device in read-write mode */
2138         c->ubi = ubi_open_volume(c->vi.ubi_num, c->vi.vol_id, UBI_READWRITE);
2139         if (IS_ERR(c->ubi)) {
2140                 err = PTR_ERR(c->ubi);
2141                 goto out;
2142         }
2143 
2144         err = ubifs_parse_options(c, data, 0);
2145         if (err)
2146                 goto out_close;
2147 
2148         /*
2149          * UBIFS provides 'backing_dev_info' in order to disable read-ahead. For
2150          * UBIFS, I/O is not deferred, it is done immediately in readpage,
2151          * which means the user would have to wait not just for their own I/O
2152          * but the read-ahead I/O as well i.e. completely pointless.
2153          *
2154          * Read-ahead will be disabled because @sb->s_bdi->ra_pages is 0. Also
2155          * @sb->s_bdi->capabilities are initialized to 0 so there won't be any
2156          * writeback happening.
2157          */
2158         err = super_setup_bdi_name(sb, "ubifs_%d_%d", c->vi.ubi_num,
2159                                    c->vi.vol_id);
2160         if (err)
2161                 goto out_close;
2162 
2163         sb->s_fs_info = c;
2164         sb->s_magic = UBIFS_SUPER_MAGIC;
2165         sb->s_blocksize = UBIFS_BLOCK_SIZE;
2166         sb->s_blocksize_bits = UBIFS_BLOCK_SHIFT;
2167         sb->s_maxbytes = c->max_inode_sz = key_max_inode_size(c);
2168         if (c->max_inode_sz > MAX_LFS_FILESIZE)
2169                 sb->s_maxbytes = c->max_inode_sz = MAX_LFS_FILESIZE;
2170         sb->s_op = &ubifs_super_operations;
2171 #ifdef CONFIG_UBIFS_FS_XATTR
2172         sb->s_xattr = ubifs_xattr_handlers;
2173 #endif
2174         fscrypt_set_ops(sb, &ubifs_crypt_operations);
2175 
2176         mutex_lock(&c->umount_mutex);
2177         err = mount_ubifs(c);
2178         if (err) {
2179                 ubifs_assert(c, err < 0);
2180                 goto out_unlock;
2181         }
2182 
2183         /* Read the root inode */
2184         root = ubifs_iget(sb, UBIFS_ROOT_INO);
2185         if (IS_ERR(root)) {
2186                 err = PTR_ERR(root);
2187                 goto out_umount;
2188         }
2189 
2190         sb->s_root = d_make_root(root);
2191         if (!sb->s_root) {
2192                 err = -ENOMEM;
2193                 goto out_umount;
2194         }
2195 
2196         mutex_unlock(&c->umount_mutex);
2197         return 0;
2198 
2199 out_umount:
2200         ubifs_umount(c);
2201 out_unlock:
2202         mutex_unlock(&c->umount_mutex);
2203 out_close:
2204         ubi_close_volume(c->ubi);
2205 out:
2206         return err;
2207 }
2208 
2209 static int sb_test(struct super_block *sb, void *data)
2210 {
2211         struct ubifs_info *c1 = data;
2212         struct ubifs_info *c = sb->s_fs_info;
2213 
2214         return c->vi.cdev == c1->vi.cdev;
2215 }
2216 
2217 static int sb_set(struct super_block *sb, void *data)
2218 {
2219         sb->s_fs_info = data;
2220         return set_anon_super(sb, NULL);
2221 }
2222 
2223 static struct dentry *ubifs_mount(struct file_system_type *fs_type, int flags,
2224                         const char *name, void *data)
2225 {
2226         struct ubi_volume_desc *ubi;
2227         struct ubifs_info *c;
2228         struct super_block *sb;
2229         int err;
2230 
2231         dbg_gen("name %s, flags %#x", name, flags);
2232 
2233         /*
2234          * Get UBI device number and volume ID. Mount it read-only so far
2235          * because this might be a new mount point, and UBI allows only one
2236          * read-write user at a time.
2237          */
2238         ubi = open_ubi(name, UBI_READONLY);
2239         if (IS_ERR(ubi)) {
2240                 if (!(flags & SB_SILENT))
2241                         pr_err("UBIFS error (pid: %d): cannot open \"%s\", error %d",
2242                                current->pid, name, (int)PTR_ERR(ubi));
2243                 return ERR_CAST(ubi);
2244         }
2245 
2246         c = alloc_ubifs_info(ubi);
2247         if (!c) {
2248                 err = -ENOMEM;
2249                 goto out_close;
2250         }
2251 
2252         dbg_gen("opened ubi%d_%d", c->vi.ubi_num, c->vi.vol_id);
2253 
2254         sb = sget(fs_type, sb_test, sb_set, flags, c);
2255         if (IS_ERR(sb)) {
2256                 err = PTR_ERR(sb);
2257                 kfree(c);
2258                 goto out_close;
2259         }
2260 
2261         if (sb->s_root) {
2262                 struct ubifs_info *c1 = sb->s_fs_info;
2263                 kfree(c);
2264                 /* A new mount point for already mounted UBIFS */
2265                 dbg_gen("this ubi volume is already mounted");
2266                 if (!!(flags & SB_RDONLY) != c1->ro_mount) {
2267                         err = -EBUSY;
2268                         goto out_deact;
2269                 }
2270         } else {
2271                 err = ubifs_fill_super(sb, data, flags & SB_SILENT ? 1 : 0);
2272                 if (err)
2273                         goto out_deact;
2274                 /* We do not support atime */
2275                 sb->s_flags |= SB_ACTIVE;
2276                 if (IS_ENABLED(CONFIG_UBIFS_ATIME_SUPPORT))
2277                         ubifs_msg(c, "full atime support is enabled.");
2278                 else
2279                         sb->s_flags |= SB_NOATIME;
2280         }
2281 
2282         /* 'fill_super()' opens ubi again so we must close it here */
2283         ubi_close_volume(ubi);
2284 
2285         return dget(sb->s_root);
2286 
2287 out_deact:
2288         deactivate_locked_super(sb);
2289 out_close:
2290         ubi_close_volume(ubi);
2291         return ERR_PTR(err);
2292 }
2293 
2294 static void kill_ubifs_super(struct super_block *s)
2295 {
2296         struct ubifs_info *c = s->s_fs_info;
2297         kill_anon_super(s);
2298         kfree(c);
2299 }
2300 
2301 static struct file_system_type ubifs_fs_type = {
2302         .name    = "ubifs",
2303         .owner   = THIS_MODULE,
2304         .mount   = ubifs_mount,
2305         .kill_sb = kill_ubifs_super,
2306 };
2307 MODULE_ALIAS_FS("ubifs");
2308 
2309 /*
2310  * Inode slab cache constructor.
2311  */
2312 static void inode_slab_ctor(void *obj)
2313 {
2314         struct ubifs_inode *ui = obj;
2315         inode_init_once(&ui->vfs_inode);
2316 }
2317 
2318 static int __init ubifs_init(void)
2319 {
2320         int err;
2321 
2322         BUILD_BUG_ON(sizeof(struct ubifs_ch) != 24);
2323 
2324         /* Make sure node sizes are 8-byte aligned */
2325         BUILD_BUG_ON(UBIFS_CH_SZ        & 7);
2326         BUILD_BUG_ON(UBIFS_INO_NODE_SZ  & 7);
2327         BUILD_BUG_ON(UBIFS_DENT_NODE_SZ & 7);
2328         BUILD_BUG_ON(UBIFS_XENT_NODE_SZ & 7);
2329         BUILD_BUG_ON(UBIFS_DATA_NODE_SZ & 7);
2330         BUILD_BUG_ON(UBIFS_TRUN_NODE_SZ & 7);
2331         BUILD_BUG_ON(UBIFS_SB_NODE_SZ   & 7);
2332         BUILD_BUG_ON(UBIFS_MST_NODE_SZ  & 7);
2333         BUILD_BUG_ON(UBIFS_REF_NODE_SZ  & 7);
2334         BUILD_BUG_ON(UBIFS_CS_NODE_SZ   & 7);
2335         BUILD_BUG_ON(UBIFS_ORPH_NODE_SZ & 7);
2336 
2337         BUILD_BUG_ON(UBIFS_MAX_DENT_NODE_SZ & 7);
2338         BUILD_BUG_ON(UBIFS_MAX_XENT_NODE_SZ & 7);
2339         BUILD_BUG_ON(UBIFS_MAX_DATA_NODE_SZ & 7);
2340         BUILD_BUG_ON(UBIFS_MAX_INO_NODE_SZ  & 7);
2341         BUILD_BUG_ON(UBIFS_MAX_NODE_SZ      & 7);
2342         BUILD_BUG_ON(MIN_WRITE_SZ           & 7);
2343 
2344         /* Check min. node size */
2345         BUILD_BUG_ON(UBIFS_INO_NODE_SZ  < MIN_WRITE_SZ);
2346         BUILD_BUG_ON(UBIFS_DENT_NODE_SZ < MIN_WRITE_SZ);
2347         BUILD_BUG_ON(UBIFS_XENT_NODE_SZ < MIN_WRITE_SZ);
2348         BUILD_BUG_ON(UBIFS_TRUN_NODE_SZ < MIN_WRITE_SZ);
2349 
2350         BUILD_BUG_ON(UBIFS_MAX_DENT_NODE_SZ > UBIFS_MAX_NODE_SZ);
2351         BUILD_BUG_ON(UBIFS_MAX_XENT_NODE_SZ > UBIFS_MAX_NODE_SZ);
2352         BUILD_BUG_ON(UBIFS_MAX_DATA_NODE_SZ > UBIFS_MAX_NODE_SZ);
2353         BUILD_BUG_ON(UBIFS_MAX_INO_NODE_SZ  > UBIFS_MAX_NODE_SZ);
2354 
2355         /* Defined node sizes */
2356         BUILD_BUG_ON(UBIFS_SB_NODE_SZ  != 4096);
2357         BUILD_BUG_ON(UBIFS_MST_NODE_SZ != 512);
2358         BUILD_BUG_ON(UBIFS_INO_NODE_SZ != 160);
2359         BUILD_BUG_ON(UBIFS_REF_NODE_SZ != 64);
2360 
2361         /*
2362          * We use 2 bit wide bit-fields to store compression type, which should
2363          * be amended if more compressors are added. The bit-fields are:
2364          * @compr_type in 'struct ubifs_inode', @default_compr in
2365          * 'struct ubifs_info' and @compr_type in 'struct ubifs_mount_opts'.
2366          */
2367         BUILD_BUG_ON(UBIFS_COMPR_TYPES_CNT > 4);
2368 
2369         /*
2370          * We require that PAGE_SIZE is greater-than-or-equal-to
2371          * UBIFS_BLOCK_SIZE. It is assumed that both are powers of 2.
2372          */
2373         if (PAGE_SIZE < UBIFS_BLOCK_SIZE) {
2374                 pr_err("UBIFS error (pid %d): VFS page cache size is %u bytes, but UBIFS requires at least 4096 bytes",
2375                        current->pid, (unsigned int)PAGE_SIZE);
2376                 return -EINVAL;
2377         }
2378 
2379         ubifs_inode_slab = kmem_cache_create("ubifs_inode_slab",
2380                                 sizeof(struct ubifs_inode), 0,
2381                                 SLAB_MEM_SPREAD | SLAB_RECLAIM_ACCOUNT |
2382                                 SLAB_ACCOUNT, &inode_slab_ctor);
2383         if (!ubifs_inode_slab)
2384                 return -ENOMEM;
2385 
2386         err = register_shrinker(&ubifs_shrinker_info);
2387         if (err)
2388                 goto out_slab;
2389 
2390         err = ubifs_compressors_init();
2391         if (err)
2392                 goto out_shrinker;
2393 
2394         dbg_debugfs_init();
2395 
2396         err = register_filesystem(&ubifs_fs_type);
2397         if (err) {
2398                 pr_err("UBIFS error (pid %d): cannot register file system, error %d",
2399                        current->pid, err);
2400                 goto out_dbg;
2401         }
2402         return 0;
2403 
2404 out_dbg:
2405         dbg_debugfs_exit();
2406         ubifs_compressors_exit();
2407 out_shrinker:
2408         unregister_shrinker(&ubifs_shrinker_info);
2409 out_slab:
2410         kmem_cache_destroy(ubifs_inode_slab);
2411         return err;
2412 }
2413 /* late_initcall to let compressors initialize first */
2414 late_initcall(ubifs_init);
2415 
2416 static void __exit ubifs_exit(void)
2417 {
2418         WARN_ON(!list_empty(&ubifs_infos));
2419         WARN_ON(atomic_long_read(&ubifs_clean_zn_cnt) != 0);
2420 
2421         dbg_debugfs_exit();
2422         ubifs_compressors_exit();
2423         unregister_shrinker(&ubifs_shrinker_info);
2424 
2425         /*
2426          * Make sure all delayed rcu free inodes are flushed before we
2427          * destroy cache.
2428          */
2429         rcu_barrier();
2430         kmem_cache_destroy(ubifs_inode_slab);
2431         unregister_filesystem(&ubifs_fs_type);
2432 }
2433 module_exit(ubifs_exit);
2434 
2435 MODULE_LICENSE("GPL");
2436 MODULE_VERSION(__stringify(UBIFS_VERSION));
2437 MODULE_AUTHOR("Artem Bityutskiy, Adrian Hunter");
2438 MODULE_DESCRIPTION("UBIFS - UBI File System");
2439 

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