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

Version: ~ [ linux-5.5-rc6 ] ~ [ linux-5.4.11 ] ~ [ linux-5.3.18 ] ~ [ linux-5.2.21 ] ~ [ linux-5.1.21 ] ~ [ linux-5.0.21 ] ~ [ linux-4.20.17 ] ~ [ linux-4.19.95 ] ~ [ linux-4.18.20 ] ~ [ linux-4.17.19 ] ~ [ linux-4.16.18 ] ~ [ linux-4.15.18 ] ~ [ linux-4.14.164 ] ~ [ linux-4.13.16 ] ~ [ linux-4.12.14 ] ~ [ linux-4.11.12 ] ~ [ linux-4.10.17 ] ~ [ linux-4.9.209 ] ~ [ linux-4.8.17 ] ~ [ linux-4.7.10 ] ~ [ linux-4.6.7 ] ~ [ linux-4.5.7 ] ~ [ linux-4.4.209 ] ~ [ linux-4.3.6 ] ~ [ linux-4.2.8 ] ~ [ linux-4.1.52 ] ~ [ linux-4.0.9 ] ~ [ linux-3.19.8 ] ~ [ linux-3.18.140 ] ~ [ linux-3.17.8 ] ~ [ linux-3.16.81 ] ~ [ linux-3.15.10 ] ~ [ linux-3.14.79 ] ~ [ linux-3.13.11 ] ~ [ linux-3.12.74 ] ~ [ linux-3.11.10 ] ~ [ linux-3.10.108 ] ~ [ linux-3.9.11 ] ~ [ linux-3.8.13 ] ~ [ linux-3.7.10 ] ~ [ linux-3.6.11 ] ~ [ linux-3.5.7 ] ~ [ linux-3.4.113 ] ~ [ linux-3.3.8 ] ~ [ linux-3.2.102 ] ~ [ linux-3.1.10 ] ~ [ linux-3.0.101 ] ~ [ linux-2.6.32.71 ] ~ [ linux-2.6.0 ] ~ [ linux-2.4.37.11 ] ~ [ unix-v6-master ] ~ [ ccs-tools-1.8.5 ] ~ [ policy-sample ] ~
Architecture: ~ [ i386 ] ~ [ alpha ] ~ [ m68k ] ~ [ mips ] ~ [ ppc ] ~ [ sparc ] ~ [ sparc64 ] ~

  1 /*
  2  * This file is part of UBIFS.
  3  *
  4  * Copyright (C) 2006-2008 Nokia Corporation.
  5  *
  6  * This program is free software; you can redistribute it and/or modify it
  7  * under the terms of the GNU General Public License version 2 as published by
  8  * the Free Software Foundation.
  9  *
 10  * This program is distributed in the hope that it will be useful, but WITHOUT
 11  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 12  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
 13  * more details.
 14  *
 15  * You should have received a copy of the GNU General Public License along with
 16  * this program; if not, write to the Free Software Foundation, Inc., 51
 17  * Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
 18  *
 19  * Authors: Artem Bityutskiy (Битюцкий Артём)
 20  *          Adrian Hunter
 21  */
 22 
 23 /*
 24  * This file implements UBIFS initialization and VFS superblock operations. Some
 25  * initialization stuff which is rather large and complex is placed at
 26  * corresponding subsystems, but most of it is here.
 27  */
 28 
 29 #include <linux/init.h>
 30 #include <linux/slab.h>
 31 #include <linux/module.h>
 32 #include <linux/ctype.h>
 33 #include <linux/kthread.h>
 34 #include <linux/parser.h>
 35 #include <linux/seq_file.h>
 36 #include <linux/mount.h>
 37 #include <linux/math64.h>
 38 #include <linux/writeback.h>
 39 #include "ubifs.h"
 40 
 41 /*
 42  * Maximum amount of memory we may 'kmalloc()' without worrying that we are
 43  * allocating too much.
 44  */
 45 #define UBIFS_KMALLOC_OK (128*1024)
 46 
 47 /* Slab cache for UBIFS inodes */
 48 static struct kmem_cache *ubifs_inode_slab;
 49 
 50 /* UBIFS TNC shrinker description */
 51 static struct shrinker ubifs_shrinker_info = {
 52         .scan_objects = ubifs_shrink_scan,
 53         .count_objects = ubifs_shrink_count,
 54         .seeks = DEFAULT_SEEKS,
 55 };
 56 
 57 /**
 58  * validate_inode - validate inode.
 59  * @c: UBIFS file-system description object
 60  * @inode: the inode to validate
 61  *
 62  * This is a helper function for 'ubifs_iget()' which validates various fields
 63  * of a newly built inode to make sure they contain sane values and prevent
 64  * possible vulnerabilities. Returns zero if the inode is all right and
 65  * a non-zero error code if not.
 66  */
 67 static int validate_inode(struct ubifs_info *c, const struct inode *inode)
 68 {
 69         int err;
 70         const struct ubifs_inode *ui = ubifs_inode(inode);
 71 
 72         if (inode->i_size > c->max_inode_sz) {
 73                 ubifs_err(c, "inode is too large (%lld)",
 74                           (long long)inode->i_size);
 75                 return 1;
 76         }
 77 
 78         if (ui->compr_type >= UBIFS_COMPR_TYPES_CNT) {
 79                 ubifs_err(c, "unknown compression type %d", ui->compr_type);
 80                 return 2;
 81         }
 82 
 83         if (ui->xattr_names + ui->xattr_cnt > XATTR_LIST_MAX)
 84                 return 3;
 85 
 86         if (ui->data_len < 0 || ui->data_len > UBIFS_MAX_INO_DATA)
 87                 return 4;
 88 
 89         if (ui->xattr && !S_ISREG(inode->i_mode))
 90                 return 5;
 91 
 92         if (!ubifs_compr_present(ui->compr_type)) {
 93                 ubifs_warn(c, "inode %lu uses '%s' compression, but it was not compiled in",
 94                            inode->i_ino, ubifs_compr_name(ui->compr_type));
 95         }
 96 
 97         err = dbg_check_dir(c, inode);
 98         return err;
 99 }
100 
101 struct inode *ubifs_iget(struct super_block *sb, unsigned long inum)
102 {
103         int err;
104         union ubifs_key key;
105         struct ubifs_ino_node *ino;
106         struct ubifs_info *c = sb->s_fs_info;
107         struct inode *inode;
108         struct ubifs_inode *ui;
109 
110         dbg_gen("inode %lu", inum);
111 
112         inode = iget_locked(sb, inum);
113         if (!inode)
114                 return ERR_PTR(-ENOMEM);
115         if (!(inode->i_state & I_NEW))
116                 return inode;
117         ui = ubifs_inode(inode);
118 
119         ino = kmalloc(UBIFS_MAX_INO_NODE_SZ, GFP_NOFS);
120         if (!ino) {
121                 err = -ENOMEM;
122                 goto out;
123         }
124 
125         ino_key_init(c, &key, inode->i_ino);
126 
127         err = ubifs_tnc_lookup(c, &key, ino);
128         if (err)
129                 goto out_ino;
130 
131         inode->i_flags |= S_NOCMTIME;
132 #ifndef CONFIG_UBIFS_ATIME_SUPPORT
133         inode->i_flags |= S_NOATIME;
134 #endif
135         set_nlink(inode, le32_to_cpu(ino->nlink));
136         i_uid_write(inode, le32_to_cpu(ino->uid));
137         i_gid_write(inode, le32_to_cpu(ino->gid));
138         inode->i_atime.tv_sec  = (int64_t)le64_to_cpu(ino->atime_sec);
139         inode->i_atime.tv_nsec = le32_to_cpu(ino->atime_nsec);
140         inode->i_mtime.tv_sec  = (int64_t)le64_to_cpu(ino->mtime_sec);
141         inode->i_mtime.tv_nsec = le32_to_cpu(ino->mtime_nsec);
142         inode->i_ctime.tv_sec  = (int64_t)le64_to_cpu(ino->ctime_sec);
143         inode->i_ctime.tv_nsec = le32_to_cpu(ino->ctime_nsec);
144         inode->i_mode = le32_to_cpu(ino->mode);
145         inode->i_size = le64_to_cpu(ino->size);
146 
147         ui->data_len    = le32_to_cpu(ino->data_len);
148         ui->flags       = le32_to_cpu(ino->flags);
149         ui->compr_type  = le16_to_cpu(ino->compr_type);
150         ui->creat_sqnum = le64_to_cpu(ino->creat_sqnum);
151         ui->xattr_cnt   = le32_to_cpu(ino->xattr_cnt);
152         ui->xattr_size  = le32_to_cpu(ino->xattr_size);
153         ui->xattr_names = le32_to_cpu(ino->xattr_names);
154         ui->synced_i_size = ui->ui_size = inode->i_size;
155 
156         ui->xattr = (ui->flags & UBIFS_XATTR_FL) ? 1 : 0;
157 
158         err = validate_inode(c, inode);
159         if (err)
160                 goto out_invalid;
161 
162         switch (inode->i_mode & S_IFMT) {
163         case S_IFREG:
164                 inode->i_mapping->a_ops = &ubifs_file_address_operations;
165                 inode->i_op = &ubifs_file_inode_operations;
166                 inode->i_fop = &ubifs_file_operations;
167                 if (ui->xattr) {
168                         ui->data = kmalloc(ui->data_len + 1, GFP_NOFS);
169                         if (!ui->data) {
170                                 err = -ENOMEM;
171                                 goto out_ino;
172                         }
173                         memcpy(ui->data, ino->data, ui->data_len);
174                         ((char *)ui->data)[ui->data_len] = '\0';
175                 } else if (ui->data_len != 0) {
176                         err = 10;
177                         goto out_invalid;
178                 }
179                 break;
180         case S_IFDIR:
181                 inode->i_op  = &ubifs_dir_inode_operations;
182                 inode->i_fop = &ubifs_dir_operations;
183                 if (ui->data_len != 0) {
184                         err = 11;
185                         goto out_invalid;
186                 }
187                 break;
188         case S_IFLNK:
189                 inode->i_op = &ubifs_symlink_inode_operations;
190                 if (ui->data_len <= 0 || ui->data_len > UBIFS_MAX_INO_DATA) {
191                         err = 12;
192                         goto out_invalid;
193                 }
194                 ui->data = kmalloc(ui->data_len + 1, GFP_NOFS);
195                 if (!ui->data) {
196                         err = -ENOMEM;
197                         goto out_ino;
198                 }
199                 memcpy(ui->data, ino->data, ui->data_len);
200                 ((char *)ui->data)[ui->data_len] = '\0';
201                 break;
202         case S_IFBLK:
203         case S_IFCHR:
204         {
205                 dev_t rdev;
206                 union ubifs_dev_desc *dev;
207 
208                 ui->data = kmalloc(sizeof(union ubifs_dev_desc), GFP_NOFS);
209                 if (!ui->data) {
210                         err = -ENOMEM;
211                         goto out_ino;
212                 }
213 
214                 dev = (union ubifs_dev_desc *)ino->data;
215                 if (ui->data_len == sizeof(dev->new))
216                         rdev = new_decode_dev(le32_to_cpu(dev->new));
217                 else if (ui->data_len == sizeof(dev->huge))
218                         rdev = huge_decode_dev(le64_to_cpu(dev->huge));
219                 else {
220                         err = 13;
221                         goto out_invalid;
222                 }
223                 memcpy(ui->data, ino->data, ui->data_len);
224                 inode->i_op = &ubifs_file_inode_operations;
225                 init_special_inode(inode, inode->i_mode, rdev);
226                 break;
227         }
228         case S_IFSOCK:
229         case S_IFIFO:
230                 inode->i_op = &ubifs_file_inode_operations;
231                 init_special_inode(inode, inode->i_mode, 0);
232                 if (ui->data_len != 0) {
233                         err = 14;
234                         goto out_invalid;
235                 }
236                 break;
237         default:
238                 err = 15;
239                 goto out_invalid;
240         }
241 
242         kfree(ino);
243         ubifs_set_inode_flags(inode);
244         unlock_new_inode(inode);
245         return inode;
246 
247 out_invalid:
248         ubifs_err(c, "inode %lu validation failed, error %d", inode->i_ino, err);
249         ubifs_dump_node(c, ino);
250         ubifs_dump_inode(c, inode);
251         err = -EINVAL;
252 out_ino:
253         kfree(ino);
254 out:
255         ubifs_err(c, "failed to read inode %lu, error %d", inode->i_ino, err);
256         iget_failed(inode);
257         return ERR_PTR(err);
258 }
259 
260 static struct inode *ubifs_alloc_inode(struct super_block *sb)
261 {
262         struct ubifs_inode *ui;
263 
264         ui = kmem_cache_alloc(ubifs_inode_slab, GFP_NOFS);
265         if (!ui)
266                 return NULL;
267 
268         memset((void *)ui + sizeof(struct inode), 0,
269                sizeof(struct ubifs_inode) - sizeof(struct inode));
270         mutex_init(&ui->ui_mutex);
271         spin_lock_init(&ui->ui_lock);
272         return &ui->vfs_inode;
273 };
274 
275 static void ubifs_i_callback(struct rcu_head *head)
276 {
277         struct inode *inode = container_of(head, struct inode, i_rcu);
278         struct ubifs_inode *ui = ubifs_inode(inode);
279         kmem_cache_free(ubifs_inode_slab, ui);
280 }
281 
282 static void ubifs_destroy_inode(struct inode *inode)
283 {
284         struct ubifs_inode *ui = ubifs_inode(inode);
285 
286         kfree(ui->data);
287         call_rcu(&inode->i_rcu, ubifs_i_callback);
288 }
289 
290 /*
291  * Note, Linux write-back code calls this without 'i_mutex'.
292  */
293 static int ubifs_write_inode(struct inode *inode, struct writeback_control *wbc)
294 {
295         int err = 0;
296         struct ubifs_info *c = inode->i_sb->s_fs_info;
297         struct ubifs_inode *ui = ubifs_inode(inode);
298 
299         ubifs_assert(!ui->xattr);
300         if (is_bad_inode(inode))
301                 return 0;
302 
303         mutex_lock(&ui->ui_mutex);
304         /*
305          * Due to races between write-back forced by budgeting
306          * (see 'sync_some_inodes()') and background write-back, the inode may
307          * have already been synchronized, do not do this again. This might
308          * also happen if it was synchronized in an VFS operation, e.g.
309          * 'ubifs_link()'.
310          */
311         if (!ui->dirty) {
312                 mutex_unlock(&ui->ui_mutex);
313                 return 0;
314         }
315 
316         /*
317          * As an optimization, do not write orphan inodes to the media just
318          * because this is not needed.
319          */
320         dbg_gen("inode %lu, mode %#x, nlink %u",
321                 inode->i_ino, (int)inode->i_mode, inode->i_nlink);
322         if (inode->i_nlink) {
323                 err = ubifs_jnl_write_inode(c, inode);
324                 if (err)
325                         ubifs_err(c, "can't write inode %lu, error %d",
326                                   inode->i_ino, err);
327                 else
328                         err = dbg_check_inode_size(c, inode, ui->ui_size);
329         }
330 
331         ui->dirty = 0;
332         mutex_unlock(&ui->ui_mutex);
333         ubifs_release_dirty_inode_budget(c, ui);
334         return err;
335 }
336 
337 static void ubifs_evict_inode(struct inode *inode)
338 {
339         int err;
340         struct ubifs_info *c = inode->i_sb->s_fs_info;
341         struct ubifs_inode *ui = ubifs_inode(inode);
342 
343         if (ui->xattr)
344                 /*
345                  * Extended attribute inode deletions are fully handled in
346                  * 'ubifs_removexattr()'. These inodes are special and have
347                  * limited usage, so there is nothing to do here.
348                  */
349                 goto out;
350 
351         dbg_gen("inode %lu, mode %#x", inode->i_ino, (int)inode->i_mode);
352         ubifs_assert(!atomic_read(&inode->i_count));
353 
354         truncate_inode_pages_final(&inode->i_data);
355 
356         if (inode->i_nlink)
357                 goto done;
358 
359         if (is_bad_inode(inode))
360                 goto out;
361 
362         ui->ui_size = inode->i_size = 0;
363         err = ubifs_jnl_delete_inode(c, inode);
364         if (err)
365                 /*
366                  * Worst case we have a lost orphan inode wasting space, so a
367                  * simple error message is OK here.
368                  */
369                 ubifs_err(c, "can't delete inode %lu, error %d",
370                           inode->i_ino, err);
371 
372 out:
373         if (ui->dirty)
374                 ubifs_release_dirty_inode_budget(c, ui);
375         else {
376                 /* We've deleted something - clean the "no space" flags */
377                 c->bi.nospace = c->bi.nospace_rp = 0;
378                 smp_wmb();
379         }
380 done:
381         clear_inode(inode);
382         fscrypt_put_encryption_info(inode);
383 }
384 
385 static void ubifs_dirty_inode(struct inode *inode, int flags)
386 {
387         struct ubifs_inode *ui = ubifs_inode(inode);
388 
389         ubifs_assert(mutex_is_locked(&ui->ui_mutex));
390         if (!ui->dirty) {
391                 ui->dirty = 1;
392                 dbg_gen("inode %lu",  inode->i_ino);
393         }
394 }
395 
396 static int ubifs_statfs(struct dentry *dentry, struct kstatfs *buf)
397 {
398         struct ubifs_info *c = dentry->d_sb->s_fs_info;
399         unsigned long long free;
400         __le32 *uuid = (__le32 *)c->uuid;
401 
402         free = ubifs_get_free_space(c);
403         dbg_gen("free space %lld bytes (%lld blocks)",
404                 free, free >> UBIFS_BLOCK_SHIFT);
405 
406         buf->f_type = UBIFS_SUPER_MAGIC;
407         buf->f_bsize = UBIFS_BLOCK_SIZE;
408         buf->f_blocks = c->block_cnt;
409         buf->f_bfree = free >> UBIFS_BLOCK_SHIFT;
410         if (free > c->report_rp_size)
411                 buf->f_bavail = (free - c->report_rp_size) >> UBIFS_BLOCK_SHIFT;
412         else
413                 buf->f_bavail = 0;
414         buf->f_files = 0;
415         buf->f_ffree = 0;
416         buf->f_namelen = UBIFS_MAX_NLEN;
417         buf->f_fsid.val[0] = le32_to_cpu(uuid[0]) ^ le32_to_cpu(uuid[2]);
418         buf->f_fsid.val[1] = le32_to_cpu(uuid[1]) ^ le32_to_cpu(uuid[3]);
419         ubifs_assert(buf->f_bfree <= c->block_cnt);
420         return 0;
421 }
422 
423 static int ubifs_show_options(struct seq_file *s, struct dentry *root)
424 {
425         struct ubifs_info *c = root->d_sb->s_fs_info;
426 
427         if (c->mount_opts.unmount_mode == 2)
428                 seq_puts(s, ",fast_unmount");
429         else if (c->mount_opts.unmount_mode == 1)
430                 seq_puts(s, ",norm_unmount");
431 
432         if (c->mount_opts.bulk_read == 2)
433                 seq_puts(s, ",bulk_read");
434         else if (c->mount_opts.bulk_read == 1)
435                 seq_puts(s, ",no_bulk_read");
436 
437         if (c->mount_opts.chk_data_crc == 2)
438                 seq_puts(s, ",chk_data_crc");
439         else if (c->mount_opts.chk_data_crc == 1)
440                 seq_puts(s, ",no_chk_data_crc");
441 
442         if (c->mount_opts.override_compr) {
443                 seq_printf(s, ",compr=%s",
444                            ubifs_compr_name(c->mount_opts.compr_type));
445         }
446 
447         seq_printf(s, ",ubi=%d,vol=%d", c->vi.ubi_num, c->vi.vol_id);
448 
449         return 0;
450 }
451 
452 static int ubifs_sync_fs(struct super_block *sb, int wait)
453 {
454         int i, err;
455         struct ubifs_info *c = sb->s_fs_info;
456 
457         /*
458          * Zero @wait is just an advisory thing to help the file system shove
459          * lots of data into the queues, and there will be the second
460          * '->sync_fs()' call, with non-zero @wait.
461          */
462         if (!wait)
463                 return 0;
464 
465         /*
466          * Synchronize write buffers, because 'ubifs_run_commit()' does not
467          * do this if it waits for an already running commit.
468          */
469         for (i = 0; i < c->jhead_cnt; i++) {
470                 err = ubifs_wbuf_sync(&c->jheads[i].wbuf);
471                 if (err)
472                         return err;
473         }
474 
475         /*
476          * Strictly speaking, it is not necessary to commit the journal here,
477          * synchronizing write-buffers would be enough. But committing makes
478          * UBIFS free space predictions much more accurate, so we want to let
479          * the user be able to get more accurate results of 'statfs()' after
480          * they synchronize the file system.
481          */
482         err = ubifs_run_commit(c);
483         if (err)
484                 return err;
485 
486         return ubi_sync(c->vi.ubi_num);
487 }
488 
489 /**
490  * init_constants_early - initialize UBIFS constants.
491  * @c: UBIFS file-system description object
492  *
493  * This function initialize UBIFS constants which do not need the superblock to
494  * be read. It also checks that the UBI volume satisfies basic UBIFS
495  * requirements. Returns zero in case of success and a negative error code in
496  * case of failure.
497  */
498 static int init_constants_early(struct ubifs_info *c)
499 {
500         if (c->vi.corrupted) {
501                 ubifs_warn(c, "UBI volume is corrupted - read-only mode");
502                 c->ro_media = 1;
503         }
504 
505         if (c->di.ro_mode) {
506                 ubifs_msg(c, "read-only UBI device");
507                 c->ro_media = 1;
508         }
509 
510         if (c->vi.vol_type == UBI_STATIC_VOLUME) {
511                 ubifs_msg(c, "static UBI volume - read-only mode");
512                 c->ro_media = 1;
513         }
514 
515         c->leb_cnt = c->vi.size;
516         c->leb_size = c->vi.usable_leb_size;
517         c->leb_start = c->di.leb_start;
518         c->half_leb_size = c->leb_size / 2;
519         c->min_io_size = c->di.min_io_size;
520         c->min_io_shift = fls(c->min_io_size) - 1;
521         c->max_write_size = c->di.max_write_size;
522         c->max_write_shift = fls(c->max_write_size) - 1;
523 
524         if (c->leb_size < UBIFS_MIN_LEB_SZ) {
525                 ubifs_errc(c, "too small LEBs (%d bytes), min. is %d bytes",
526                            c->leb_size, UBIFS_MIN_LEB_SZ);
527                 return -EINVAL;
528         }
529 
530         if (c->leb_cnt < UBIFS_MIN_LEB_CNT) {
531                 ubifs_errc(c, "too few LEBs (%d), min. is %d",
532                            c->leb_cnt, UBIFS_MIN_LEB_CNT);
533                 return -EINVAL;
534         }
535 
536         if (!is_power_of_2(c->min_io_size)) {
537                 ubifs_errc(c, "bad min. I/O size %d", c->min_io_size);
538                 return -EINVAL;
539         }
540 
541         /*
542          * Maximum write size has to be greater or equivalent to min. I/O
543          * size, and be multiple of min. I/O size.
544          */
545         if (c->max_write_size < c->min_io_size ||
546             c->max_write_size % c->min_io_size ||
547             !is_power_of_2(c->max_write_size)) {
548                 ubifs_errc(c, "bad write buffer size %d for %d min. I/O unit",
549                            c->max_write_size, c->min_io_size);
550                 return -EINVAL;
551         }
552 
553         /*
554          * UBIFS aligns all node to 8-byte boundary, so to make function in
555          * io.c simpler, assume minimum I/O unit size to be 8 bytes if it is
556          * less than 8.
557          */
558         if (c->min_io_size < 8) {
559                 c->min_io_size = 8;
560                 c->min_io_shift = 3;
561                 if (c->max_write_size < c->min_io_size) {
562                         c->max_write_size = c->min_io_size;
563                         c->max_write_shift = c->min_io_shift;
564                 }
565         }
566 
567         c->ref_node_alsz = ALIGN(UBIFS_REF_NODE_SZ, c->min_io_size);
568         c->mst_node_alsz = ALIGN(UBIFS_MST_NODE_SZ, c->min_io_size);
569 
570         /*
571          * Initialize node length ranges which are mostly needed for node
572          * length validation.
573          */
574         c->ranges[UBIFS_PAD_NODE].len  = UBIFS_PAD_NODE_SZ;
575         c->ranges[UBIFS_SB_NODE].len   = UBIFS_SB_NODE_SZ;
576         c->ranges[UBIFS_MST_NODE].len  = UBIFS_MST_NODE_SZ;
577         c->ranges[UBIFS_REF_NODE].len  = UBIFS_REF_NODE_SZ;
578         c->ranges[UBIFS_TRUN_NODE].len = UBIFS_TRUN_NODE_SZ;
579         c->ranges[UBIFS_CS_NODE].len   = UBIFS_CS_NODE_SZ;
580 
581         c->ranges[UBIFS_INO_NODE].min_len  = UBIFS_INO_NODE_SZ;
582         c->ranges[UBIFS_INO_NODE].max_len  = UBIFS_MAX_INO_NODE_SZ;
583         c->ranges[UBIFS_ORPH_NODE].min_len =
584                                 UBIFS_ORPH_NODE_SZ + sizeof(__le64);
585         c->ranges[UBIFS_ORPH_NODE].max_len = c->leb_size;
586         c->ranges[UBIFS_DENT_NODE].min_len = UBIFS_DENT_NODE_SZ;
587         c->ranges[UBIFS_DENT_NODE].max_len = UBIFS_MAX_DENT_NODE_SZ;
588         c->ranges[UBIFS_XENT_NODE].min_len = UBIFS_XENT_NODE_SZ;
589         c->ranges[UBIFS_XENT_NODE].max_len = UBIFS_MAX_XENT_NODE_SZ;
590         c->ranges[UBIFS_DATA_NODE].min_len = UBIFS_DATA_NODE_SZ;
591         c->ranges[UBIFS_DATA_NODE].max_len = UBIFS_MAX_DATA_NODE_SZ;
592         /*
593          * Minimum indexing node size is amended later when superblock is
594          * read and the key length is known.
595          */
596         c->ranges[UBIFS_IDX_NODE].min_len = UBIFS_IDX_NODE_SZ + UBIFS_BRANCH_SZ;
597         /*
598          * Maximum indexing node size is amended later when superblock is
599          * read and the fanout is known.
600          */
601         c->ranges[UBIFS_IDX_NODE].max_len = INT_MAX;
602 
603         /*
604          * Initialize dead and dark LEB space watermarks. See gc.c for comments
605          * about these values.
606          */
607         c->dead_wm = ALIGN(MIN_WRITE_SZ, c->min_io_size);
608         c->dark_wm = ALIGN(UBIFS_MAX_NODE_SZ, c->min_io_size);
609 
610         /*
611          * Calculate how many bytes would be wasted at the end of LEB if it was
612          * fully filled with data nodes of maximum size. This is used in
613          * calculations when reporting free space.
614          */
615         c->leb_overhead = c->leb_size % UBIFS_MAX_DATA_NODE_SZ;
616 
617         /* Buffer size for bulk-reads */
618         c->max_bu_buf_len = UBIFS_MAX_BULK_READ * UBIFS_MAX_DATA_NODE_SZ;
619         if (c->max_bu_buf_len > c->leb_size)
620                 c->max_bu_buf_len = c->leb_size;
621         return 0;
622 }
623 
624 /**
625  * bud_wbuf_callback - bud LEB write-buffer synchronization call-back.
626  * @c: UBIFS file-system description object
627  * @lnum: LEB the write-buffer was synchronized to
628  * @free: how many free bytes left in this LEB
629  * @pad: how many bytes were padded
630  *
631  * This is a callback function which is called by the I/O unit when the
632  * write-buffer is synchronized. We need this to correctly maintain space
633  * accounting in bud logical eraseblocks. This function returns zero in case of
634  * success and a negative error code in case of failure.
635  *
636  * This function actually belongs to the journal, but we keep it here because
637  * we want to keep it static.
638  */
639 static int bud_wbuf_callback(struct ubifs_info *c, int lnum, int free, int pad)
640 {
641         return ubifs_update_one_lp(c, lnum, free, pad, 0, 0);
642 }
643 
644 /*
645  * init_constants_sb - initialize UBIFS constants.
646  * @c: UBIFS file-system description object
647  *
648  * This is a helper function which initializes various UBIFS constants after
649  * the superblock has been read. It also checks various UBIFS parameters and
650  * makes sure they are all right. Returns zero in case of success and a
651  * negative error code in case of failure.
652  */
653 static int init_constants_sb(struct ubifs_info *c)
654 {
655         int tmp, err;
656         long long tmp64;
657 
658         c->main_bytes = (long long)c->main_lebs * c->leb_size;
659         c->max_znode_sz = sizeof(struct ubifs_znode) +
660                                 c->fanout * sizeof(struct ubifs_zbranch);
661 
662         tmp = ubifs_idx_node_sz(c, 1);
663         c->ranges[UBIFS_IDX_NODE].min_len = tmp;
664         c->min_idx_node_sz = ALIGN(tmp, 8);
665 
666         tmp = ubifs_idx_node_sz(c, c->fanout);
667         c->ranges[UBIFS_IDX_NODE].max_len = tmp;
668         c->max_idx_node_sz = ALIGN(tmp, 8);
669 
670         /* Make sure LEB size is large enough to fit full commit */
671         tmp = UBIFS_CS_NODE_SZ + UBIFS_REF_NODE_SZ * c->jhead_cnt;
672         tmp = ALIGN(tmp, c->min_io_size);
673         if (tmp > c->leb_size) {
674                 ubifs_err(c, "too small LEB size %d, at least %d needed",
675                           c->leb_size, tmp);
676                 return -EINVAL;
677         }
678 
679         /*
680          * Make sure that the log is large enough to fit reference nodes for
681          * all buds plus one reserved LEB.
682          */
683         tmp64 = c->max_bud_bytes + c->leb_size - 1;
684         c->max_bud_cnt = div_u64(tmp64, c->leb_size);
685         tmp = (c->ref_node_alsz * c->max_bud_cnt + c->leb_size - 1);
686         tmp /= c->leb_size;
687         tmp += 1;
688         if (c->log_lebs < tmp) {
689                 ubifs_err(c, "too small log %d LEBs, required min. %d LEBs",
690                           c->log_lebs, tmp);
691                 return -EINVAL;
692         }
693 
694         /*
695          * When budgeting we assume worst-case scenarios when the pages are not
696          * be compressed and direntries are of the maximum size.
697          *
698          * Note, data, which may be stored in inodes is budgeted separately, so
699          * it is not included into 'c->bi.inode_budget'.
700          */
701         c->bi.page_budget = UBIFS_MAX_DATA_NODE_SZ * UBIFS_BLOCKS_PER_PAGE;
702         c->bi.inode_budget = UBIFS_INO_NODE_SZ;
703         c->bi.dent_budget = UBIFS_MAX_DENT_NODE_SZ;
704 
705         /*
706          * When the amount of flash space used by buds becomes
707          * 'c->max_bud_bytes', UBIFS just blocks all writers and starts commit.
708          * The writers are unblocked when the commit is finished. To avoid
709          * writers to be blocked UBIFS initiates background commit in advance,
710          * when number of bud bytes becomes above the limit defined below.
711          */
712         c->bg_bud_bytes = (c->max_bud_bytes * 13) >> 4;
713 
714         /*
715          * Ensure minimum journal size. All the bytes in the journal heads are
716          * considered to be used, when calculating the current journal usage.
717          * Consequently, if the journal is too small, UBIFS will treat it as
718          * always full.
719          */
720         tmp64 = (long long)(c->jhead_cnt + 1) * c->leb_size + 1;
721         if (c->bg_bud_bytes < tmp64)
722                 c->bg_bud_bytes = tmp64;
723         if (c->max_bud_bytes < tmp64 + c->leb_size)
724                 c->max_bud_bytes = tmp64 + c->leb_size;
725 
726         err = ubifs_calc_lpt_geom(c);
727         if (err)
728                 return err;
729 
730         /* Initialize effective LEB size used in budgeting calculations */
731         c->idx_leb_size = c->leb_size - c->max_idx_node_sz;
732         return 0;
733 }
734 
735 /*
736  * init_constants_master - initialize UBIFS constants.
737  * @c: UBIFS file-system description object
738  *
739  * This is a helper function which initializes various UBIFS constants after
740  * the master node has been read. It also checks various UBIFS parameters and
741  * makes sure they are all right.
742  */
743 static void init_constants_master(struct ubifs_info *c)
744 {
745         long long tmp64;
746 
747         c->bi.min_idx_lebs = ubifs_calc_min_idx_lebs(c);
748         c->report_rp_size = ubifs_reported_space(c, c->rp_size);
749 
750         /*
751          * Calculate total amount of FS blocks. This number is not used
752          * internally because it does not make much sense for UBIFS, but it is
753          * necessary to report something for the 'statfs()' call.
754          *
755          * Subtract the LEB reserved for GC, the LEB which is reserved for
756          * deletions, minimum LEBs for the index, and assume only one journal
757          * head is available.
758          */
759         tmp64 = c->main_lebs - 1 - 1 - MIN_INDEX_LEBS - c->jhead_cnt + 1;
760         tmp64 *= (long long)c->leb_size - c->leb_overhead;
761         tmp64 = ubifs_reported_space(c, tmp64);
762         c->block_cnt = tmp64 >> UBIFS_BLOCK_SHIFT;
763 }
764 
765 /**
766  * take_gc_lnum - reserve GC LEB.
767  * @c: UBIFS file-system description object
768  *
769  * This function ensures that the LEB reserved for garbage collection is marked
770  * as "taken" in lprops. We also have to set free space to LEB size and dirty
771  * space to zero, because lprops may contain out-of-date information if the
772  * file-system was un-mounted before it has been committed. This function
773  * returns zero in case of success and a negative error code in case of
774  * failure.
775  */
776 static int take_gc_lnum(struct ubifs_info *c)
777 {
778         int err;
779 
780         if (c->gc_lnum == -1) {
781                 ubifs_err(c, "no LEB for GC");
782                 return -EINVAL;
783         }
784 
785         /* And we have to tell lprops that this LEB is taken */
786         err = ubifs_change_one_lp(c, c->gc_lnum, c->leb_size, 0,
787                                   LPROPS_TAKEN, 0, 0);
788         return err;
789 }
790 
791 /**
792  * alloc_wbufs - allocate write-buffers.
793  * @c: UBIFS file-system description object
794  *
795  * This helper function allocates and initializes UBIFS write-buffers. Returns
796  * zero in case of success and %-ENOMEM in case of failure.
797  */
798 static int alloc_wbufs(struct ubifs_info *c)
799 {
800         int i, err;
801 
802         c->jheads = kcalloc(c->jhead_cnt, sizeof(struct ubifs_jhead),
803                             GFP_KERNEL);
804         if (!c->jheads)
805                 return -ENOMEM;
806 
807         /* Initialize journal heads */
808         for (i = 0; i < c->jhead_cnt; i++) {
809                 INIT_LIST_HEAD(&c->jheads[i].buds_list);
810                 err = ubifs_wbuf_init(c, &c->jheads[i].wbuf);
811                 if (err)
812                         return err;
813 
814                 c->jheads[i].wbuf.sync_callback = &bud_wbuf_callback;
815                 c->jheads[i].wbuf.jhead = i;
816                 c->jheads[i].grouped = 1;
817         }
818 
819         /*
820          * Garbage Collector head does not need to be synchronized by timer.
821          * Also GC head nodes are not grouped.
822          */
823         c->jheads[GCHD].wbuf.no_timer = 1;
824         c->jheads[GCHD].grouped = 0;
825 
826         return 0;
827 }
828 
829 /**
830  * free_wbufs - free write-buffers.
831  * @c: UBIFS file-system description object
832  */
833 static void free_wbufs(struct ubifs_info *c)
834 {
835         int i;
836 
837         if (c->jheads) {
838                 for (i = 0; i < c->jhead_cnt; i++) {
839                         kfree(c->jheads[i].wbuf.buf);
840                         kfree(c->jheads[i].wbuf.inodes);
841                 }
842                 kfree(c->jheads);
843                 c->jheads = NULL;
844         }
845 }
846 
847 /**
848  * free_orphans - free orphans.
849  * @c: UBIFS file-system description object
850  */
851 static void free_orphans(struct ubifs_info *c)
852 {
853         struct ubifs_orphan *orph;
854 
855         while (c->orph_dnext) {
856                 orph = c->orph_dnext;
857                 c->orph_dnext = orph->dnext;
858                 list_del(&orph->list);
859                 kfree(orph);
860         }
861 
862         while (!list_empty(&c->orph_list)) {
863                 orph = list_entry(c->orph_list.next, struct ubifs_orphan, list);
864                 list_del(&orph->list);
865                 kfree(orph);
866                 ubifs_err(c, "orphan list not empty at unmount");
867         }
868 
869         vfree(c->orph_buf);
870         c->orph_buf = NULL;
871 }
872 
873 /**
874  * free_buds - free per-bud objects.
875  * @c: UBIFS file-system description object
876  */
877 static void free_buds(struct ubifs_info *c)
878 {
879         struct ubifs_bud *bud, *n;
880 
881         rbtree_postorder_for_each_entry_safe(bud, n, &c->buds, rb)
882                 kfree(bud);
883 }
884 
885 /**
886  * check_volume_empty - check if the UBI volume is empty.
887  * @c: UBIFS file-system description object
888  *
889  * This function checks if the UBIFS volume is empty by looking if its LEBs are
890  * mapped or not. The result of checking is stored in the @c->empty variable.
891  * Returns zero in case of success and a negative error code in case of
892  * failure.
893  */
894 static int check_volume_empty(struct ubifs_info *c)
895 {
896         int lnum, err;
897 
898         c->empty = 1;
899         for (lnum = 0; lnum < c->leb_cnt; lnum++) {
900                 err = ubifs_is_mapped(c, lnum);
901                 if (unlikely(err < 0))
902                         return err;
903                 if (err == 1) {
904                         c->empty = 0;
905                         break;
906                 }
907 
908                 cond_resched();
909         }
910 
911         return 0;
912 }
913 
914 /*
915  * UBIFS mount options.
916  *
917  * Opt_fast_unmount: do not run a journal commit before un-mounting
918  * Opt_norm_unmount: run a journal commit before un-mounting
919  * Opt_bulk_read: enable bulk-reads
920  * Opt_no_bulk_read: disable bulk-reads
921  * Opt_chk_data_crc: check CRCs when reading data nodes
922  * Opt_no_chk_data_crc: do not check CRCs when reading data nodes
923  * Opt_override_compr: override default compressor
924  * Opt_err: just end of array marker
925  */
926 enum {
927         Opt_fast_unmount,
928         Opt_norm_unmount,
929         Opt_bulk_read,
930         Opt_no_bulk_read,
931         Opt_chk_data_crc,
932         Opt_no_chk_data_crc,
933         Opt_override_compr,
934         Opt_ignore,
935         Opt_err,
936 };
937 
938 static const match_table_t tokens = {
939         {Opt_fast_unmount, "fast_unmount"},
940         {Opt_norm_unmount, "norm_unmount"},
941         {Opt_bulk_read, "bulk_read"},
942         {Opt_no_bulk_read, "no_bulk_read"},
943         {Opt_chk_data_crc, "chk_data_crc"},
944         {Opt_no_chk_data_crc, "no_chk_data_crc"},
945         {Opt_override_compr, "compr=%s"},
946         {Opt_ignore, "ubi=%s"},
947         {Opt_ignore, "vol=%s"},
948         {Opt_err, NULL},
949 };
950 
951 /**
952  * parse_standard_option - parse a standard mount option.
953  * @option: the option to parse
954  *
955  * Normally, standard mount options like "sync" are passed to file-systems as
956  * flags. However, when a "rootflags=" kernel boot parameter is used, they may
957  * be present in the options string. This function tries to deal with this
958  * situation and parse standard options. Returns 0 if the option was not
959  * recognized, and the corresponding integer flag if it was.
960  *
961  * UBIFS is only interested in the "sync" option, so do not check for anything
962  * else.
963  */
964 static int parse_standard_option(const char *option)
965 {
966 
967         pr_notice("UBIFS: parse %s\n", option);
968         if (!strcmp(option, "sync"))
969                 return SB_SYNCHRONOUS;
970         return 0;
971 }
972 
973 /**
974  * ubifs_parse_options - parse mount parameters.
975  * @c: UBIFS file-system description object
976  * @options: parameters to parse
977  * @is_remount: non-zero if this is FS re-mount
978  *
979  * This function parses UBIFS mount options and returns zero in case success
980  * and a negative error code in case of failure.
981  */
982 static int ubifs_parse_options(struct ubifs_info *c, char *options,
983                                int is_remount)
984 {
985         char *p;
986         substring_t args[MAX_OPT_ARGS];
987 
988         if (!options)
989                 return 0;
990 
991         while ((p = strsep(&options, ","))) {
992                 int token;
993 
994                 if (!*p)
995                         continue;
996 
997                 token = match_token(p, tokens, args);
998                 switch (token) {
999                 /*
1000                  * %Opt_fast_unmount and %Opt_norm_unmount options are ignored.
1001                  * We accept them in order to be backward-compatible. But this
1002                  * should be removed at some point.
1003                  */
1004                 case Opt_fast_unmount:
1005                         c->mount_opts.unmount_mode = 2;
1006                         break;
1007                 case Opt_norm_unmount:
1008                         c->mount_opts.unmount_mode = 1;
1009                         break;
1010                 case Opt_bulk_read:
1011                         c->mount_opts.bulk_read = 2;
1012                         c->bulk_read = 1;
1013                         break;
1014                 case Opt_no_bulk_read:
1015                         c->mount_opts.bulk_read = 1;
1016                         c->bulk_read = 0;
1017                         break;
1018                 case Opt_chk_data_crc:
1019                         c->mount_opts.chk_data_crc = 2;
1020                         c->no_chk_data_crc = 0;
1021                         break;
1022                 case Opt_no_chk_data_crc:
1023                         c->mount_opts.chk_data_crc = 1;
1024                         c->no_chk_data_crc = 1;
1025                         break;
1026                 case Opt_override_compr:
1027                 {
1028                         char *name = match_strdup(&args[0]);
1029 
1030                         if (!name)
1031                                 return -ENOMEM;
1032                         if (!strcmp(name, "none"))
1033                                 c->mount_opts.compr_type = UBIFS_COMPR_NONE;
1034                         else if (!strcmp(name, "lzo"))
1035                                 c->mount_opts.compr_type = UBIFS_COMPR_LZO;
1036                         else if (!strcmp(name, "zlib"))
1037                                 c->mount_opts.compr_type = UBIFS_COMPR_ZLIB;
1038                         else {
1039                                 ubifs_err(c, "unknown compressor \"%s\"", name); //FIXME: is c ready?
1040                                 kfree(name);
1041                                 return -EINVAL;
1042                         }
1043                         kfree(name);
1044                         c->mount_opts.override_compr = 1;
1045                         c->default_compr = c->mount_opts.compr_type;
1046                         break;
1047                 }
1048                 case Opt_ignore:
1049                         break;
1050                 default:
1051                 {
1052                         unsigned long flag;
1053                         struct super_block *sb = c->vfs_sb;
1054 
1055                         flag = parse_standard_option(p);
1056                         if (!flag) {
1057                                 ubifs_err(c, "unrecognized mount option \"%s\" or missing value",
1058                                           p);
1059                                 return -EINVAL;
1060                         }
1061                         sb->s_flags |= flag;
1062                         break;
1063                 }
1064                 }
1065         }
1066 
1067         return 0;
1068 }
1069 
1070 /**
1071  * destroy_journal - destroy journal data structures.
1072  * @c: UBIFS file-system description object
1073  *
1074  * This function destroys journal data structures including those that may have
1075  * been created by recovery functions.
1076  */
1077 static void destroy_journal(struct ubifs_info *c)
1078 {
1079         while (!list_empty(&c->unclean_leb_list)) {
1080                 struct ubifs_unclean_leb *ucleb;
1081 
1082                 ucleb = list_entry(c->unclean_leb_list.next,
1083                                    struct ubifs_unclean_leb, list);
1084                 list_del(&ucleb->list);
1085                 kfree(ucleb);
1086         }
1087         while (!list_empty(&c->old_buds)) {
1088                 struct ubifs_bud *bud;
1089 
1090                 bud = list_entry(c->old_buds.next, struct ubifs_bud, list);
1091                 list_del(&bud->list);
1092                 kfree(bud);
1093         }
1094         ubifs_destroy_idx_gc(c);
1095         ubifs_destroy_size_tree(c);
1096         ubifs_tnc_close(c);
1097         free_buds(c);
1098 }
1099 
1100 /**
1101  * bu_init - initialize bulk-read information.
1102  * @c: UBIFS file-system description object
1103  */
1104 static void bu_init(struct ubifs_info *c)
1105 {
1106         ubifs_assert(c->bulk_read == 1);
1107 
1108         if (c->bu.buf)
1109                 return; /* Already initialized */
1110 
1111 again:
1112         c->bu.buf = kmalloc(c->max_bu_buf_len, GFP_KERNEL | __GFP_NOWARN);
1113         if (!c->bu.buf) {
1114                 if (c->max_bu_buf_len > UBIFS_KMALLOC_OK) {
1115                         c->max_bu_buf_len = UBIFS_KMALLOC_OK;
1116                         goto again;
1117                 }
1118 
1119                 /* Just disable bulk-read */
1120                 ubifs_warn(c, "cannot allocate %d bytes of memory for bulk-read, disabling it",
1121                            c->max_bu_buf_len);
1122                 c->mount_opts.bulk_read = 1;
1123                 c->bulk_read = 0;
1124                 return;
1125         }
1126 }
1127 
1128 /**
1129  * check_free_space - check if there is enough free space to mount.
1130  * @c: UBIFS file-system description object
1131  *
1132  * This function makes sure UBIFS has enough free space to be mounted in
1133  * read/write mode. UBIFS must always have some free space to allow deletions.
1134  */
1135 static int check_free_space(struct ubifs_info *c)
1136 {
1137         ubifs_assert(c->dark_wm > 0);
1138         if (c->lst.total_free + c->lst.total_dirty < c->dark_wm) {
1139                 ubifs_err(c, "insufficient free space to mount in R/W mode");
1140                 ubifs_dump_budg(c, &c->bi);
1141                 ubifs_dump_lprops(c);
1142                 return -ENOSPC;
1143         }
1144         return 0;
1145 }
1146 
1147 /**
1148  * mount_ubifs - mount UBIFS file-system.
1149  * @c: UBIFS file-system description object
1150  *
1151  * This function mounts UBIFS file system. Returns zero in case of success and
1152  * a negative error code in case of failure.
1153  */
1154 static int mount_ubifs(struct ubifs_info *c)
1155 {
1156         int err;
1157         long long x, y;
1158         size_t sz;
1159 
1160         c->ro_mount = !!sb_rdonly(c->vfs_sb);
1161         /* Suppress error messages while probing if SB_SILENT is set */
1162         c->probing = !!(c->vfs_sb->s_flags & SB_SILENT);
1163 
1164         err = init_constants_early(c);
1165         if (err)
1166                 return err;
1167 
1168         err = ubifs_debugging_init(c);
1169         if (err)
1170                 return err;
1171 
1172         err = check_volume_empty(c);
1173         if (err)
1174                 goto out_free;
1175 
1176         if (c->empty && (c->ro_mount || c->ro_media)) {
1177                 /*
1178                  * This UBI volume is empty, and read-only, or the file system
1179                  * is mounted read-only - we cannot format it.
1180                  */
1181                 ubifs_err(c, "can't format empty UBI volume: read-only %s",
1182                           c->ro_media ? "UBI volume" : "mount");
1183                 err = -EROFS;
1184                 goto out_free;
1185         }
1186 
1187         if (c->ro_media && !c->ro_mount) {
1188                 ubifs_err(c, "cannot mount read-write - read-only media");
1189                 err = -EROFS;
1190                 goto out_free;
1191         }
1192 
1193         /*
1194          * The requirement for the buffer is that it should fit indexing B-tree
1195          * height amount of integers. We assume the height if the TNC tree will
1196          * never exceed 64.
1197          */
1198         err = -ENOMEM;
1199         c->bottom_up_buf = kmalloc(BOTTOM_UP_HEIGHT * sizeof(int), GFP_KERNEL);
1200         if (!c->bottom_up_buf)
1201                 goto out_free;
1202 
1203         c->sbuf = vmalloc(c->leb_size);
1204         if (!c->sbuf)
1205                 goto out_free;
1206 
1207         if (!c->ro_mount) {
1208                 c->ileb_buf = vmalloc(c->leb_size);
1209                 if (!c->ileb_buf)
1210                         goto out_free;
1211         }
1212 
1213         if (c->bulk_read == 1)
1214                 bu_init(c);
1215 
1216         if (!c->ro_mount) {
1217                 c->write_reserve_buf = kmalloc(COMPRESSED_DATA_NODE_BUF_SZ + \
1218                                                UBIFS_CIPHER_BLOCK_SIZE,
1219                                                GFP_KERNEL);
1220                 if (!c->write_reserve_buf)
1221                         goto out_free;
1222         }
1223 
1224         c->mounting = 1;
1225 
1226         err = ubifs_read_superblock(c);
1227         if (err)
1228                 goto out_free;
1229 
1230         c->probing = 0;
1231 
1232         /*
1233          * Make sure the compressor which is set as default in the superblock
1234          * or overridden by mount options is actually compiled in.
1235          */
1236         if (!ubifs_compr_present(c->default_compr)) {
1237                 ubifs_err(c, "'compressor \"%s\" is not compiled in",
1238                           ubifs_compr_name(c->default_compr));
1239                 err = -ENOTSUPP;
1240                 goto out_free;
1241         }
1242 
1243         err = init_constants_sb(c);
1244         if (err)
1245                 goto out_free;
1246 
1247         sz = ALIGN(c->max_idx_node_sz, c->min_io_size);
1248         sz = ALIGN(sz + c->max_idx_node_sz, c->min_io_size);
1249         c->cbuf = kmalloc(sz, GFP_NOFS);
1250         if (!c->cbuf) {
1251                 err = -ENOMEM;
1252                 goto out_free;
1253         }
1254 
1255         err = alloc_wbufs(c);
1256         if (err)
1257                 goto out_cbuf;
1258 
1259         sprintf(c->bgt_name, BGT_NAME_PATTERN, c->vi.ubi_num, c->vi.vol_id);
1260         if (!c->ro_mount) {
1261                 /* Create background thread */
1262                 c->bgt = kthread_create(ubifs_bg_thread, c, "%s", c->bgt_name);
1263                 if (IS_ERR(c->bgt)) {
1264                         err = PTR_ERR(c->bgt);
1265                         c->bgt = NULL;
1266                         ubifs_err(c, "cannot spawn \"%s\", error %d",
1267                                   c->bgt_name, err);
1268                         goto out_wbufs;
1269                 }
1270                 wake_up_process(c->bgt);
1271         }
1272 
1273         err = ubifs_read_master(c);
1274         if (err)
1275                 goto out_master;
1276 
1277         init_constants_master(c);
1278 
1279         if ((c->mst_node->flags & cpu_to_le32(UBIFS_MST_DIRTY)) != 0) {
1280                 ubifs_msg(c, "recovery needed");
1281                 c->need_recovery = 1;
1282         }
1283 
1284         if (c->need_recovery && !c->ro_mount) {
1285                 err = ubifs_recover_inl_heads(c, c->sbuf);
1286                 if (err)
1287                         goto out_master;
1288         }
1289 
1290         err = ubifs_lpt_init(c, 1, !c->ro_mount);
1291         if (err)
1292                 goto out_master;
1293 
1294         if (!c->ro_mount && c->space_fixup) {
1295                 err = ubifs_fixup_free_space(c);
1296                 if (err)
1297                         goto out_lpt;
1298         }
1299 
1300         if (!c->ro_mount && !c->need_recovery) {
1301                 /*
1302                  * Set the "dirty" flag so that if we reboot uncleanly we
1303                  * will notice this immediately on the next mount.
1304                  */
1305                 c->mst_node->flags |= cpu_to_le32(UBIFS_MST_DIRTY);
1306                 err = ubifs_write_master(c);
1307                 if (err)
1308                         goto out_lpt;
1309         }
1310 
1311         err = dbg_check_idx_size(c, c->bi.old_idx_sz);
1312         if (err)
1313                 goto out_lpt;
1314 
1315         err = ubifs_replay_journal(c);
1316         if (err)
1317                 goto out_journal;
1318 
1319         /* Calculate 'min_idx_lebs' after journal replay */
1320         c->bi.min_idx_lebs = ubifs_calc_min_idx_lebs(c);
1321 
1322         err = ubifs_mount_orphans(c, c->need_recovery, c->ro_mount);
1323         if (err)
1324                 goto out_orphans;
1325 
1326         if (!c->ro_mount) {
1327                 int lnum;
1328 
1329                 err = check_free_space(c);
1330                 if (err)
1331                         goto out_orphans;
1332 
1333                 /* Check for enough log space */
1334                 lnum = c->lhead_lnum + 1;
1335                 if (lnum >= UBIFS_LOG_LNUM + c->log_lebs)
1336                         lnum = UBIFS_LOG_LNUM;
1337                 if (lnum == c->ltail_lnum) {
1338                         err = ubifs_consolidate_log(c);
1339                         if (err)
1340                                 goto out_orphans;
1341                 }
1342 
1343                 if (c->need_recovery) {
1344                         err = ubifs_recover_size(c);
1345                         if (err)
1346                                 goto out_orphans;
1347                         err = ubifs_rcvry_gc_commit(c);
1348                         if (err)
1349                                 goto out_orphans;
1350                 } else {
1351                         err = take_gc_lnum(c);
1352                         if (err)
1353                                 goto out_orphans;
1354 
1355                         /*
1356                          * GC LEB may contain garbage if there was an unclean
1357                          * reboot, and it should be un-mapped.
1358                          */
1359                         err = ubifs_leb_unmap(c, c->gc_lnum);
1360                         if (err)
1361                                 goto out_orphans;
1362                 }
1363 
1364                 err = dbg_check_lprops(c);
1365                 if (err)
1366                         goto out_orphans;
1367         } else if (c->need_recovery) {
1368                 err = ubifs_recover_size(c);
1369                 if (err)
1370                         goto out_orphans;
1371         } else {
1372                 /*
1373                  * Even if we mount read-only, we have to set space in GC LEB
1374                  * to proper value because this affects UBIFS free space
1375                  * reporting. We do not want to have a situation when
1376                  * re-mounting from R/O to R/W changes amount of free space.
1377                  */
1378                 err = take_gc_lnum(c);
1379                 if (err)
1380                         goto out_orphans;
1381         }
1382 
1383         spin_lock(&ubifs_infos_lock);
1384         list_add_tail(&c->infos_list, &ubifs_infos);
1385         spin_unlock(&ubifs_infos_lock);
1386 
1387         if (c->need_recovery) {
1388                 if (c->ro_mount)
1389                         ubifs_msg(c, "recovery deferred");
1390                 else {
1391                         c->need_recovery = 0;
1392                         ubifs_msg(c, "recovery completed");
1393                         /*
1394                          * GC LEB has to be empty and taken at this point. But
1395                          * the journal head LEBs may also be accounted as
1396                          * "empty taken" if they are empty.
1397                          */
1398                         ubifs_assert(c->lst.taken_empty_lebs > 0);
1399                 }
1400         } else
1401                 ubifs_assert(c->lst.taken_empty_lebs > 0);
1402 
1403         err = dbg_check_filesystem(c);
1404         if (err)
1405                 goto out_infos;
1406 
1407         err = dbg_debugfs_init_fs(c);
1408         if (err)
1409                 goto out_infos;
1410 
1411         c->mounting = 0;
1412 
1413         ubifs_msg(c, "UBIFS: mounted UBI device %d, volume %d, name \"%s\"%s",
1414                   c->vi.ubi_num, c->vi.vol_id, c->vi.name,
1415                   c->ro_mount ? ", R/O mode" : "");
1416         x = (long long)c->main_lebs * c->leb_size;
1417         y = (long long)c->log_lebs * c->leb_size + c->max_bud_bytes;
1418         ubifs_msg(c, "LEB size: %d bytes (%d KiB), min./max. I/O unit sizes: %d bytes/%d bytes",
1419                   c->leb_size, c->leb_size >> 10, c->min_io_size,
1420                   c->max_write_size);
1421         ubifs_msg(c, "FS size: %lld bytes (%lld MiB, %d LEBs), journal size %lld bytes (%lld MiB, %d LEBs)",
1422                   x, x >> 20, c->main_lebs,
1423                   y, y >> 20, c->log_lebs + c->max_bud_cnt);
1424         ubifs_msg(c, "reserved for root: %llu bytes (%llu KiB)",
1425                   c->report_rp_size, c->report_rp_size >> 10);
1426         ubifs_msg(c, "media format: w%d/r%d (latest is w%d/r%d), UUID %pUB%s",
1427                   c->fmt_version, c->ro_compat_version,
1428                   UBIFS_FORMAT_VERSION, UBIFS_RO_COMPAT_VERSION, c->uuid,
1429                   c->big_lpt ? ", big LPT model" : ", small LPT model");
1430 
1431         dbg_gen("default compressor:  %s", ubifs_compr_name(c->default_compr));
1432         dbg_gen("data journal heads:  %d",
1433                 c->jhead_cnt - NONDATA_JHEADS_CNT);
1434         dbg_gen("log LEBs:            %d (%d - %d)",
1435                 c->log_lebs, UBIFS_LOG_LNUM, c->log_last);
1436         dbg_gen("LPT area LEBs:       %d (%d - %d)",
1437                 c->lpt_lebs, c->lpt_first, c->lpt_last);
1438         dbg_gen("orphan area LEBs:    %d (%d - %d)",
1439                 c->orph_lebs, c->orph_first, c->orph_last);
1440         dbg_gen("main area LEBs:      %d (%d - %d)",
1441                 c->main_lebs, c->main_first, c->leb_cnt - 1);
1442         dbg_gen("index LEBs:          %d", c->lst.idx_lebs);
1443         dbg_gen("total index bytes:   %lld (%lld KiB, %lld MiB)",
1444                 c->bi.old_idx_sz, c->bi.old_idx_sz >> 10,
1445                 c->bi.old_idx_sz >> 20);
1446         dbg_gen("key hash type:       %d", c->key_hash_type);
1447         dbg_gen("tree fanout:         %d", c->fanout);
1448         dbg_gen("reserved GC LEB:     %d", c->gc_lnum);
1449         dbg_gen("max. znode size      %d", c->max_znode_sz);
1450         dbg_gen("max. index node size %d", c->max_idx_node_sz);
1451         dbg_gen("node sizes:          data %zu, inode %zu, dentry %zu",
1452                 UBIFS_DATA_NODE_SZ, UBIFS_INO_NODE_SZ, UBIFS_DENT_NODE_SZ);
1453         dbg_gen("node sizes:          trun %zu, sb %zu, master %zu",
1454                 UBIFS_TRUN_NODE_SZ, UBIFS_SB_NODE_SZ, UBIFS_MST_NODE_SZ);
1455         dbg_gen("node sizes:          ref %zu, cmt. start %zu, orph %zu",
1456                 UBIFS_REF_NODE_SZ, UBIFS_CS_NODE_SZ, UBIFS_ORPH_NODE_SZ);
1457         dbg_gen("max. node sizes:     data %zu, inode %zu dentry %zu, idx %d",
1458                 UBIFS_MAX_DATA_NODE_SZ, UBIFS_MAX_INO_NODE_SZ,
1459                 UBIFS_MAX_DENT_NODE_SZ, ubifs_idx_node_sz(c, c->fanout));
1460         dbg_gen("dead watermark:      %d", c->dead_wm);
1461         dbg_gen("dark watermark:      %d", c->dark_wm);
1462         dbg_gen("LEB overhead:        %d", c->leb_overhead);
1463         x = (long long)c->main_lebs * c->dark_wm;
1464         dbg_gen("max. dark space:     %lld (%lld KiB, %lld MiB)",
1465                 x, x >> 10, x >> 20);
1466         dbg_gen("maximum bud bytes:   %lld (%lld KiB, %lld MiB)",
1467                 c->max_bud_bytes, c->max_bud_bytes >> 10,
1468                 c->max_bud_bytes >> 20);
1469         dbg_gen("BG commit bud bytes: %lld (%lld KiB, %lld MiB)",
1470                 c->bg_bud_bytes, c->bg_bud_bytes >> 10,
1471                 c->bg_bud_bytes >> 20);
1472         dbg_gen("current bud bytes    %lld (%lld KiB, %lld MiB)",
1473                 c->bud_bytes, c->bud_bytes >> 10, c->bud_bytes >> 20);
1474         dbg_gen("max. seq. number:    %llu", c->max_sqnum);
1475         dbg_gen("commit number:       %llu", c->cmt_no);
1476 
1477         return 0;
1478 
1479 out_infos:
1480         spin_lock(&ubifs_infos_lock);
1481         list_del(&c->infos_list);
1482         spin_unlock(&ubifs_infos_lock);
1483 out_orphans:
1484         free_orphans(c);
1485 out_journal:
1486         destroy_journal(c);
1487 out_lpt:
1488         ubifs_lpt_free(c, 0);
1489 out_master:
1490         kfree(c->mst_node);
1491         kfree(c->rcvrd_mst_node);
1492         if (c->bgt)
1493                 kthread_stop(c->bgt);
1494 out_wbufs:
1495         free_wbufs(c);
1496 out_cbuf:
1497         kfree(c->cbuf);
1498 out_free:
1499         kfree(c->write_reserve_buf);
1500         kfree(c->bu.buf);
1501         vfree(c->ileb_buf);
1502         vfree(c->sbuf);
1503         kfree(c->bottom_up_buf);
1504         ubifs_debugging_exit(c);
1505         return err;
1506 }
1507 
1508 /**
1509  * ubifs_umount - un-mount UBIFS file-system.
1510  * @c: UBIFS file-system description object
1511  *
1512  * Note, this function is called to free allocated resourced when un-mounting,
1513  * as well as free resources when an error occurred while we were half way
1514  * through mounting (error path cleanup function). So it has to make sure the
1515  * resource was actually allocated before freeing it.
1516  */
1517 static void ubifs_umount(struct ubifs_info *c)
1518 {
1519         dbg_gen("un-mounting UBI device %d, volume %d", c->vi.ubi_num,
1520                 c->vi.vol_id);
1521 
1522         dbg_debugfs_exit_fs(c);
1523         spin_lock(&ubifs_infos_lock);
1524         list_del(&c->infos_list);
1525         spin_unlock(&ubifs_infos_lock);
1526 
1527         if (c->bgt)
1528                 kthread_stop(c->bgt);
1529 
1530         destroy_journal(c);
1531         free_wbufs(c);
1532         free_orphans(c);
1533         ubifs_lpt_free(c, 0);
1534 
1535         kfree(c->cbuf);
1536         kfree(c->rcvrd_mst_node);
1537         kfree(c->mst_node);
1538         kfree(c->write_reserve_buf);
1539         kfree(c->bu.buf);
1540         vfree(c->ileb_buf);
1541         vfree(c->sbuf);
1542         kfree(c->bottom_up_buf);
1543         ubifs_debugging_exit(c);
1544 }
1545 
1546 /**
1547  * ubifs_remount_rw - re-mount in read-write mode.
1548  * @c: UBIFS file-system description object
1549  *
1550  * UBIFS avoids allocating many unnecessary resources when mounted in read-only
1551  * mode. This function allocates the needed resources and re-mounts UBIFS in
1552  * read-write mode.
1553  */
1554 static int ubifs_remount_rw(struct ubifs_info *c)
1555 {
1556         int err, lnum;
1557 
1558         if (c->rw_incompat) {
1559                 ubifs_err(c, "the file-system is not R/W-compatible");
1560                 ubifs_msg(c, "on-flash format version is w%d/r%d, but software only supports up to version w%d/r%d",
1561                           c->fmt_version, c->ro_compat_version,
1562                           UBIFS_FORMAT_VERSION, UBIFS_RO_COMPAT_VERSION);
1563                 return -EROFS;
1564         }
1565 
1566         mutex_lock(&c->umount_mutex);
1567         dbg_save_space_info(c);
1568         c->remounting_rw = 1;
1569         c->ro_mount = 0;
1570 
1571         if (c->space_fixup) {
1572                 err = ubifs_fixup_free_space(c);
1573                 if (err)
1574                         goto out;
1575         }
1576 
1577         err = check_free_space(c);
1578         if (err)
1579                 goto out;
1580 
1581         if (c->old_leb_cnt != c->leb_cnt) {
1582                 struct ubifs_sb_node *sup;
1583 
1584                 sup = ubifs_read_sb_node(c);
1585                 if (IS_ERR(sup)) {
1586                         err = PTR_ERR(sup);
1587                         goto out;
1588                 }
1589                 sup->leb_cnt = cpu_to_le32(c->leb_cnt);
1590                 err = ubifs_write_sb_node(c, sup);
1591                 kfree(sup);
1592                 if (err)
1593                         goto out;
1594         }
1595 
1596         if (c->need_recovery) {
1597                 ubifs_msg(c, "completing deferred recovery");
1598                 err = ubifs_write_rcvrd_mst_node(c);
1599                 if (err)
1600                         goto out;
1601                 err = ubifs_recover_size(c);
1602                 if (err)
1603                         goto out;
1604                 err = ubifs_clean_lebs(c, c->sbuf);
1605                 if (err)
1606                         goto out;
1607                 err = ubifs_recover_inl_heads(c, c->sbuf);
1608                 if (err)
1609                         goto out;
1610         } else {
1611                 /* A readonly mount is not allowed to have orphans */
1612                 ubifs_assert(c->tot_orphans == 0);
1613                 err = ubifs_clear_orphans(c);
1614                 if (err)
1615                         goto out;
1616         }
1617 
1618         if (!(c->mst_node->flags & cpu_to_le32(UBIFS_MST_DIRTY))) {
1619                 c->mst_node->flags |= cpu_to_le32(UBIFS_MST_DIRTY);
1620                 err = ubifs_write_master(c);
1621                 if (err)
1622                         goto out;
1623         }
1624 
1625         c->ileb_buf = vmalloc(c->leb_size);
1626         if (!c->ileb_buf) {
1627                 err = -ENOMEM;
1628                 goto out;
1629         }
1630 
1631         c->write_reserve_buf = kmalloc(COMPRESSED_DATA_NODE_BUF_SZ + \
1632                                        UBIFS_CIPHER_BLOCK_SIZE, GFP_KERNEL);
1633         if (!c->write_reserve_buf) {
1634                 err = -ENOMEM;
1635                 goto out;
1636         }
1637 
1638         err = ubifs_lpt_init(c, 0, 1);
1639         if (err)
1640                 goto out;
1641 
1642         /* Create background thread */
1643         c->bgt = kthread_create(ubifs_bg_thread, c, "%s", c->bgt_name);
1644         if (IS_ERR(c->bgt)) {
1645                 err = PTR_ERR(c->bgt);
1646                 c->bgt = NULL;
1647                 ubifs_err(c, "cannot spawn \"%s\", error %d",
1648                           c->bgt_name, err);
1649                 goto out;
1650         }
1651         wake_up_process(c->bgt);
1652 
1653         c->orph_buf = vmalloc(c->leb_size);
1654         if (!c->orph_buf) {
1655                 err = -ENOMEM;
1656                 goto out;
1657         }
1658 
1659         /* Check for enough log space */
1660         lnum = c->lhead_lnum + 1;
1661         if (lnum >= UBIFS_LOG_LNUM + c->log_lebs)
1662                 lnum = UBIFS_LOG_LNUM;
1663         if (lnum == c->ltail_lnum) {
1664                 err = ubifs_consolidate_log(c);
1665                 if (err)
1666                         goto out;
1667         }
1668 
1669         if (c->need_recovery)
1670                 err = ubifs_rcvry_gc_commit(c);
1671         else
1672                 err = ubifs_leb_unmap(c, c->gc_lnum);
1673         if (err)
1674                 goto out;
1675 
1676         dbg_gen("re-mounted read-write");
1677         c->remounting_rw = 0;
1678 
1679         if (c->need_recovery) {
1680                 c->need_recovery = 0;
1681                 ubifs_msg(c, "deferred recovery completed");
1682         } else {
1683                 /*
1684                  * Do not run the debugging space check if the were doing
1685                  * recovery, because when we saved the information we had the
1686                  * file-system in a state where the TNC and lprops has been
1687                  * modified in memory, but all the I/O operations (including a
1688                  * commit) were deferred. So the file-system was in
1689                  * "non-committed" state. Now the file-system is in committed
1690                  * state, and of course the amount of free space will change
1691                  * because, for example, the old index size was imprecise.
1692                  */
1693                 err = dbg_check_space_info(c);
1694         }
1695 
1696         mutex_unlock(&c->umount_mutex);
1697         return err;
1698 
1699 out:
1700         c->ro_mount = 1;
1701         vfree(c->orph_buf);
1702         c->orph_buf = NULL;
1703         if (c->bgt) {
1704                 kthread_stop(c->bgt);
1705                 c->bgt = NULL;
1706         }
1707         free_wbufs(c);
1708         kfree(c->write_reserve_buf);
1709         c->write_reserve_buf = NULL;
1710         vfree(c->ileb_buf);
1711         c->ileb_buf = NULL;
1712         ubifs_lpt_free(c, 1);
1713         c->remounting_rw = 0;
1714         mutex_unlock(&c->umount_mutex);
1715         return err;
1716 }
1717 
1718 /**
1719  * ubifs_remount_ro - re-mount in read-only mode.
1720  * @c: UBIFS file-system description object
1721  *
1722  * We assume VFS has stopped writing. Possibly the background thread could be
1723  * running a commit, however kthread_stop will wait in that case.
1724  */
1725 static void ubifs_remount_ro(struct ubifs_info *c)
1726 {
1727         int i, err;
1728 
1729         ubifs_assert(!c->need_recovery);
1730         ubifs_assert(!c->ro_mount);
1731 
1732         mutex_lock(&c->umount_mutex);
1733         if (c->bgt) {
1734                 kthread_stop(c->bgt);
1735                 c->bgt = NULL;
1736         }
1737 
1738         dbg_save_space_info(c);
1739 
1740         for (i = 0; i < c->jhead_cnt; i++) {
1741                 err = ubifs_wbuf_sync(&c->jheads[i].wbuf);
1742                 if (err)
1743                         ubifs_ro_mode(c, err);
1744         }
1745 
1746         c->mst_node->flags &= ~cpu_to_le32(UBIFS_MST_DIRTY);
1747         c->mst_node->flags |= cpu_to_le32(UBIFS_MST_NO_ORPHS);
1748         c->mst_node->gc_lnum = cpu_to_le32(c->gc_lnum);
1749         err = ubifs_write_master(c);
1750         if (err)
1751                 ubifs_ro_mode(c, err);
1752 
1753         vfree(c->orph_buf);
1754         c->orph_buf = NULL;
1755         kfree(c->write_reserve_buf);
1756         c->write_reserve_buf = NULL;
1757         vfree(c->ileb_buf);
1758         c->ileb_buf = NULL;
1759         ubifs_lpt_free(c, 1);
1760         c->ro_mount = 1;
1761         err = dbg_check_space_info(c);
1762         if (err)
1763                 ubifs_ro_mode(c, err);
1764         mutex_unlock(&c->umount_mutex);
1765 }
1766 
1767 static void ubifs_put_super(struct super_block *sb)
1768 {
1769         int i;
1770         struct ubifs_info *c = sb->s_fs_info;
1771 
1772         ubifs_msg(c, "un-mount UBI device %d", c->vi.ubi_num);
1773 
1774         /*
1775          * The following asserts are only valid if there has not been a failure
1776          * of the media. For example, there will be dirty inodes if we failed
1777          * to write them back because of I/O errors.
1778          */
1779         if (!c->ro_error) {
1780                 ubifs_assert(c->bi.idx_growth == 0);
1781                 ubifs_assert(c->bi.dd_growth == 0);
1782                 ubifs_assert(c->bi.data_growth == 0);
1783         }
1784 
1785         /*
1786          * The 'c->umount_lock' prevents races between UBIFS memory shrinker
1787          * and file system un-mount. Namely, it prevents the shrinker from
1788          * picking this superblock for shrinking - it will be just skipped if
1789          * the mutex is locked.
1790          */
1791         mutex_lock(&c->umount_mutex);
1792         if (!c->ro_mount) {
1793                 /*
1794                  * First of all kill the background thread to make sure it does
1795                  * not interfere with un-mounting and freeing resources.
1796                  */
1797                 if (c->bgt) {
1798                         kthread_stop(c->bgt);
1799                         c->bgt = NULL;
1800                 }
1801 
1802                 /*
1803                  * On fatal errors c->ro_error is set to 1, in which case we do
1804                  * not write the master node.
1805                  */
1806                 if (!c->ro_error) {
1807                         int err;
1808 
1809                         /* Synchronize write-buffers */
1810                         for (i = 0; i < c->jhead_cnt; i++) {
1811                                 err = ubifs_wbuf_sync(&c->jheads[i].wbuf);
1812                                 if (err)
1813                                         ubifs_ro_mode(c, err);
1814                         }
1815 
1816                         /*
1817                          * We are being cleanly unmounted which means the
1818                          * orphans were killed - indicate this in the master
1819                          * node. Also save the reserved GC LEB number.
1820                          */
1821                         c->mst_node->flags &= ~cpu_to_le32(UBIFS_MST_DIRTY);
1822                         c->mst_node->flags |= cpu_to_le32(UBIFS_MST_NO_ORPHS);
1823                         c->mst_node->gc_lnum = cpu_to_le32(c->gc_lnum);
1824                         err = ubifs_write_master(c);
1825                         if (err)
1826                                 /*
1827                                  * Recovery will attempt to fix the master area
1828                                  * next mount, so we just print a message and
1829                                  * continue to unmount normally.
1830                                  */
1831                                 ubifs_err(c, "failed to write master node, error %d",
1832                                           err);
1833                 } else {
1834                         for (i = 0; i < c->jhead_cnt; i++)
1835                                 /* Make sure write-buffer timers are canceled */
1836                                 hrtimer_cancel(&c->jheads[i].wbuf.timer);
1837                 }
1838         }
1839 
1840         ubifs_umount(c);
1841         ubi_close_volume(c->ubi);
1842         mutex_unlock(&c->umount_mutex);
1843 }
1844 
1845 static int ubifs_remount_fs(struct super_block *sb, int *flags, char *data)
1846 {
1847         int err;
1848         struct ubifs_info *c = sb->s_fs_info;
1849 
1850         sync_filesystem(sb);
1851         dbg_gen("old flags %#lx, new flags %#x", sb->s_flags, *flags);
1852 
1853         err = ubifs_parse_options(c, data, 1);
1854         if (err) {
1855                 ubifs_err(c, "invalid or unknown remount parameter");
1856                 return err;
1857         }
1858 
1859         if (c->ro_mount && !(*flags & SB_RDONLY)) {
1860                 if (c->ro_error) {
1861                         ubifs_msg(c, "cannot re-mount R/W due to prior errors");
1862                         return -EROFS;
1863                 }
1864                 if (c->ro_media) {
1865                         ubifs_msg(c, "cannot re-mount R/W - UBI volume is R/O");
1866                         return -EROFS;
1867                 }
1868                 err = ubifs_remount_rw(c);
1869                 if (err)
1870                         return err;
1871         } else if (!c->ro_mount && (*flags & SB_RDONLY)) {
1872                 if (c->ro_error) {
1873                         ubifs_msg(c, "cannot re-mount R/O due to prior errors");
1874                         return -EROFS;
1875                 }
1876                 ubifs_remount_ro(c);
1877         }
1878 
1879         if (c->bulk_read == 1)
1880                 bu_init(c);
1881         else {
1882                 dbg_gen("disable bulk-read");
1883                 mutex_lock(&c->bu_mutex);
1884                 kfree(c->bu.buf);
1885                 c->bu.buf = NULL;
1886                 mutex_unlock(&c->bu_mutex);
1887         }
1888 
1889         ubifs_assert(c->lst.taken_empty_lebs > 0);
1890         return 0;
1891 }
1892 
1893 const struct super_operations ubifs_super_operations = {
1894         .alloc_inode   = ubifs_alloc_inode,
1895         .destroy_inode = ubifs_destroy_inode,
1896         .put_super     = ubifs_put_super,
1897         .write_inode   = ubifs_write_inode,
1898         .evict_inode   = ubifs_evict_inode,
1899         .statfs        = ubifs_statfs,
1900         .dirty_inode   = ubifs_dirty_inode,
1901         .remount_fs    = ubifs_remount_fs,
1902         .show_options  = ubifs_show_options,
1903         .sync_fs       = ubifs_sync_fs,
1904 };
1905 
1906 /**
1907  * open_ubi - parse UBI device name string and open the UBI device.
1908  * @name: UBI volume name
1909  * @mode: UBI volume open mode
1910  *
1911  * The primary method of mounting UBIFS is by specifying the UBI volume
1912  * character device node path. However, UBIFS may also be mounted withoug any
1913  * character device node using one of the following methods:
1914  *
1915  * o ubiX_Y    - mount UBI device number X, volume Y;
1916  * o ubiY      - mount UBI device number 0, volume Y;
1917  * o ubiX:NAME - mount UBI device X, volume with name NAME;
1918  * o ubi:NAME  - mount UBI device 0, volume with name NAME.
1919  *
1920  * Alternative '!' separator may be used instead of ':' (because some shells
1921  * like busybox may interpret ':' as an NFS host name separator). This function
1922  * returns UBI volume description object in case of success and a negative
1923  * error code in case of failure.
1924  */
1925 static struct ubi_volume_desc *open_ubi(const char *name, int mode)
1926 {
1927         struct ubi_volume_desc *ubi;
1928         int dev, vol;
1929         char *endptr;
1930 
1931         /* First, try to open using the device node path method */
1932         ubi = ubi_open_volume_path(name, mode);
1933         if (!IS_ERR(ubi))
1934                 return ubi;
1935 
1936         /* Try the "nodev" method */
1937         if (name[0] != 'u' || name[1] != 'b' || name[2] != 'i')
1938                 return ERR_PTR(-EINVAL);
1939 
1940         /* ubi:NAME method */
1941         if ((name[3] == ':' || name[3] == '!') && name[4] != '\0')
1942                 return ubi_open_volume_nm(0, name + 4, mode);
1943 
1944         if (!isdigit(name[3]))
1945                 return ERR_PTR(-EINVAL);
1946 
1947         dev = simple_strtoul(name + 3, &endptr, 0);
1948 
1949         /* ubiY method */
1950         if (*endptr == '\0')
1951                 return ubi_open_volume(0, dev, mode);
1952 
1953         /* ubiX_Y method */
1954         if (*endptr == '_' && isdigit(endptr[1])) {
1955                 vol = simple_strtoul(endptr + 1, &endptr, 0);
1956                 if (*endptr != '\0')
1957                         return ERR_PTR(-EINVAL);
1958                 return ubi_open_volume(dev, vol, mode);
1959         }
1960 
1961         /* ubiX:NAME method */
1962         if ((*endptr == ':' || *endptr == '!') && endptr[1] != '\0')
1963                 return ubi_open_volume_nm(dev, ++endptr, mode);
1964 
1965         return ERR_PTR(-EINVAL);
1966 }
1967 
1968 static struct ubifs_info *alloc_ubifs_info(struct ubi_volume_desc *ubi)
1969 {
1970         struct ubifs_info *c;
1971 
1972         c = kzalloc(sizeof(struct ubifs_info), GFP_KERNEL);
1973         if (c) {
1974                 spin_lock_init(&c->cnt_lock);
1975                 spin_lock_init(&c->cs_lock);
1976                 spin_lock_init(&c->buds_lock);
1977                 spin_lock_init(&c->space_lock);
1978                 spin_lock_init(&c->orphan_lock);
1979                 init_rwsem(&c->commit_sem);
1980                 mutex_init(&c->lp_mutex);
1981                 mutex_init(&c->tnc_mutex);
1982                 mutex_init(&c->log_mutex);
1983                 mutex_init(&c->umount_mutex);
1984                 mutex_init(&c->bu_mutex);
1985                 mutex_init(&c->write_reserve_mutex);
1986                 init_waitqueue_head(&c->cmt_wq);
1987                 c->buds = RB_ROOT;
1988                 c->old_idx = RB_ROOT;
1989                 c->size_tree = RB_ROOT;
1990                 c->orph_tree = RB_ROOT;
1991                 INIT_LIST_HEAD(&c->infos_list);
1992                 INIT_LIST_HEAD(&c->idx_gc);
1993                 INIT_LIST_HEAD(&c->replay_list);
1994                 INIT_LIST_HEAD(&c->replay_buds);
1995                 INIT_LIST_HEAD(&c->uncat_list);
1996                 INIT_LIST_HEAD(&c->empty_list);
1997                 INIT_LIST_HEAD(&c->freeable_list);
1998                 INIT_LIST_HEAD(&c->frdi_idx_list);
1999                 INIT_LIST_HEAD(&c->unclean_leb_list);
2000                 INIT_LIST_HEAD(&c->old_buds);
2001                 INIT_LIST_HEAD(&c->orph_list);
2002                 INIT_LIST_HEAD(&c->orph_new);
2003                 c->no_chk_data_crc = 1;
2004 
2005                 c->highest_inum = UBIFS_FIRST_INO;
2006                 c->lhead_lnum = c->ltail_lnum = UBIFS_LOG_LNUM;
2007 
2008                 ubi_get_volume_info(ubi, &c->vi);
2009                 ubi_get_device_info(c->vi.ubi_num, &c->di);
2010         }
2011         return c;
2012 }
2013 
2014 static int ubifs_fill_super(struct super_block *sb, void *data, int silent)
2015 {
2016         struct ubifs_info *c = sb->s_fs_info;
2017         struct inode *root;
2018         int err;
2019 
2020         c->vfs_sb = sb;
2021         /* Re-open the UBI device in read-write mode */
2022         c->ubi = ubi_open_volume(c->vi.ubi_num, c->vi.vol_id, UBI_READWRITE);
2023         if (IS_ERR(c->ubi)) {
2024                 err = PTR_ERR(c->ubi);
2025                 goto out;
2026         }
2027 
2028         err = ubifs_parse_options(c, data, 0);
2029         if (err)
2030                 goto out_close;
2031 
2032         /*
2033          * UBIFS provides 'backing_dev_info' in order to disable read-ahead. For
2034          * UBIFS, I/O is not deferred, it is done immediately in readpage,
2035          * which means the user would have to wait not just for their own I/O
2036          * but the read-ahead I/O as well i.e. completely pointless.
2037          *
2038          * Read-ahead will be disabled because @sb->s_bdi->ra_pages is 0. Also
2039          * @sb->s_bdi->capabilities are initialized to 0 so there won't be any
2040          * writeback happening.
2041          */
2042         err = super_setup_bdi_name(sb, "ubifs_%d_%d", c->vi.ubi_num,
2043                                    c->vi.vol_id);
2044         if (err)
2045                 goto out_close;
2046 
2047         sb->s_fs_info = c;
2048         sb->s_magic = UBIFS_SUPER_MAGIC;
2049         sb->s_blocksize = UBIFS_BLOCK_SIZE;
2050         sb->s_blocksize_bits = UBIFS_BLOCK_SHIFT;
2051         sb->s_maxbytes = c->max_inode_sz = key_max_inode_size(c);
2052         if (c->max_inode_sz > MAX_LFS_FILESIZE)
2053                 sb->s_maxbytes = c->max_inode_sz = MAX_LFS_FILESIZE;
2054         sb->s_op = &ubifs_super_operations;
2055         sb->s_xattr = ubifs_xattr_handlers;
2056 #ifdef CONFIG_UBIFS_FS_ENCRYPTION
2057         sb->s_cop = &ubifs_crypt_operations;
2058 #endif
2059 
2060         mutex_lock(&c->umount_mutex);
2061         err = mount_ubifs(c);
2062         if (err) {
2063                 ubifs_assert(err < 0);
2064                 goto out_unlock;
2065         }
2066 
2067         /* Read the root inode */
2068         root = ubifs_iget(sb, UBIFS_ROOT_INO);
2069         if (IS_ERR(root)) {
2070                 err = PTR_ERR(root);
2071                 goto out_umount;
2072         }
2073 
2074         sb->s_root = d_make_root(root);
2075         if (!sb->s_root) {
2076                 err = -ENOMEM;
2077                 goto out_umount;
2078         }
2079 
2080         mutex_unlock(&c->umount_mutex);
2081         return 0;
2082 
2083 out_umount:
2084         ubifs_umount(c);
2085 out_unlock:
2086         mutex_unlock(&c->umount_mutex);
2087 out_close:
2088         ubi_close_volume(c->ubi);
2089 out:
2090         return err;
2091 }
2092 
2093 static int sb_test(struct super_block *sb, void *data)
2094 {
2095         struct ubifs_info *c1 = data;
2096         struct ubifs_info *c = sb->s_fs_info;
2097 
2098         return c->vi.cdev == c1->vi.cdev;
2099 }
2100 
2101 static int sb_set(struct super_block *sb, void *data)
2102 {
2103         sb->s_fs_info = data;
2104         return set_anon_super(sb, NULL);
2105 }
2106 
2107 static struct dentry *ubifs_mount(struct file_system_type *fs_type, int flags,
2108                         const char *name, void *data)
2109 {
2110         struct ubi_volume_desc *ubi;
2111         struct ubifs_info *c;
2112         struct super_block *sb;
2113         int err;
2114 
2115         dbg_gen("name %s, flags %#x", name, flags);
2116 
2117         /*
2118          * Get UBI device number and volume ID. Mount it read-only so far
2119          * because this might be a new mount point, and UBI allows only one
2120          * read-write user at a time.
2121          */
2122         ubi = open_ubi(name, UBI_READONLY);
2123         if (IS_ERR(ubi)) {
2124                 if (!(flags & SB_SILENT))
2125                         pr_err("UBIFS error (pid: %d): cannot open \"%s\", error %d",
2126                                current->pid, name, (int)PTR_ERR(ubi));
2127                 return ERR_CAST(ubi);
2128         }
2129 
2130         c = alloc_ubifs_info(ubi);
2131         if (!c) {
2132                 err = -ENOMEM;
2133                 goto out_close;
2134         }
2135 
2136         dbg_gen("opened ubi%d_%d", c->vi.ubi_num, c->vi.vol_id);
2137 
2138         sb = sget(fs_type, sb_test, sb_set, flags, c);
2139         if (IS_ERR(sb)) {
2140                 err = PTR_ERR(sb);
2141                 kfree(c);
2142                 goto out_close;
2143         }
2144 
2145         if (sb->s_root) {
2146                 struct ubifs_info *c1 = sb->s_fs_info;
2147                 kfree(c);
2148                 /* A new mount point for already mounted UBIFS */
2149                 dbg_gen("this ubi volume is already mounted");
2150                 if (!!(flags & SB_RDONLY) != c1->ro_mount) {
2151                         err = -EBUSY;
2152                         goto out_deact;
2153                 }
2154         } else {
2155                 err = ubifs_fill_super(sb, data, flags & SB_SILENT ? 1 : 0);
2156                 if (err)
2157                         goto out_deact;
2158                 /* We do not support atime */
2159                 sb->s_flags |= SB_ACTIVE;
2160 #ifndef CONFIG_UBIFS_ATIME_SUPPORT
2161                 sb->s_flags |= SB_NOATIME;
2162 #else
2163                 ubifs_msg(c, "full atime support is enabled.");
2164 #endif
2165         }
2166 
2167         /* 'fill_super()' opens ubi again so we must close it here */
2168         ubi_close_volume(ubi);
2169 
2170         return dget(sb->s_root);
2171 
2172 out_deact:
2173         deactivate_locked_super(sb);
2174 out_close:
2175         ubi_close_volume(ubi);
2176         return ERR_PTR(err);
2177 }
2178 
2179 static void kill_ubifs_super(struct super_block *s)
2180 {
2181         struct ubifs_info *c = s->s_fs_info;
2182         kill_anon_super(s);
2183         kfree(c);
2184 }
2185 
2186 static struct file_system_type ubifs_fs_type = {
2187         .name    = "ubifs",
2188         .owner   = THIS_MODULE,
2189         .mount   = ubifs_mount,
2190         .kill_sb = kill_ubifs_super,
2191 };
2192 MODULE_ALIAS_FS("ubifs");
2193 
2194 /*
2195  * Inode slab cache constructor.
2196  */
2197 static void inode_slab_ctor(void *obj)
2198 {
2199         struct ubifs_inode *ui = obj;
2200         inode_init_once(&ui->vfs_inode);
2201 }
2202 
2203 static int __init ubifs_init(void)
2204 {
2205         int err;
2206 
2207         BUILD_BUG_ON(sizeof(struct ubifs_ch) != 24);
2208 
2209         /* Make sure node sizes are 8-byte aligned */
2210         BUILD_BUG_ON(UBIFS_CH_SZ        & 7);
2211         BUILD_BUG_ON(UBIFS_INO_NODE_SZ  & 7);
2212         BUILD_BUG_ON(UBIFS_DENT_NODE_SZ & 7);
2213         BUILD_BUG_ON(UBIFS_XENT_NODE_SZ & 7);
2214         BUILD_BUG_ON(UBIFS_DATA_NODE_SZ & 7);
2215         BUILD_BUG_ON(UBIFS_TRUN_NODE_SZ & 7);
2216         BUILD_BUG_ON(UBIFS_SB_NODE_SZ   & 7);
2217         BUILD_BUG_ON(UBIFS_MST_NODE_SZ  & 7);
2218         BUILD_BUG_ON(UBIFS_REF_NODE_SZ  & 7);
2219         BUILD_BUG_ON(UBIFS_CS_NODE_SZ   & 7);
2220         BUILD_BUG_ON(UBIFS_ORPH_NODE_SZ & 7);
2221 
2222         BUILD_BUG_ON(UBIFS_MAX_DENT_NODE_SZ & 7);
2223         BUILD_BUG_ON(UBIFS_MAX_XENT_NODE_SZ & 7);
2224         BUILD_BUG_ON(UBIFS_MAX_DATA_NODE_SZ & 7);
2225         BUILD_BUG_ON(UBIFS_MAX_INO_NODE_SZ  & 7);
2226         BUILD_BUG_ON(UBIFS_MAX_NODE_SZ      & 7);
2227         BUILD_BUG_ON(MIN_WRITE_SZ           & 7);
2228 
2229         /* Check min. node size */
2230         BUILD_BUG_ON(UBIFS_INO_NODE_SZ  < MIN_WRITE_SZ);
2231         BUILD_BUG_ON(UBIFS_DENT_NODE_SZ < MIN_WRITE_SZ);
2232         BUILD_BUG_ON(UBIFS_XENT_NODE_SZ < MIN_WRITE_SZ);
2233         BUILD_BUG_ON(UBIFS_TRUN_NODE_SZ < MIN_WRITE_SZ);
2234 
2235         BUILD_BUG_ON(UBIFS_MAX_DENT_NODE_SZ > UBIFS_MAX_NODE_SZ);
2236         BUILD_BUG_ON(UBIFS_MAX_XENT_NODE_SZ > UBIFS_MAX_NODE_SZ);
2237         BUILD_BUG_ON(UBIFS_MAX_DATA_NODE_SZ > UBIFS_MAX_NODE_SZ);
2238         BUILD_BUG_ON(UBIFS_MAX_INO_NODE_SZ  > UBIFS_MAX_NODE_SZ);
2239 
2240         /* Defined node sizes */
2241         BUILD_BUG_ON(UBIFS_SB_NODE_SZ  != 4096);
2242         BUILD_BUG_ON(UBIFS_MST_NODE_SZ != 512);
2243         BUILD_BUG_ON(UBIFS_INO_NODE_SZ != 160);
2244         BUILD_BUG_ON(UBIFS_REF_NODE_SZ != 64);
2245 
2246         /*
2247          * We use 2 bit wide bit-fields to store compression type, which should
2248          * be amended if more compressors are added. The bit-fields are:
2249          * @compr_type in 'struct ubifs_inode', @default_compr in
2250          * 'struct ubifs_info' and @compr_type in 'struct ubifs_mount_opts'.
2251          */
2252         BUILD_BUG_ON(UBIFS_COMPR_TYPES_CNT > 4);
2253 
2254         /*
2255          * We require that PAGE_SIZE is greater-than-or-equal-to
2256          * UBIFS_BLOCK_SIZE. It is assumed that both are powers of 2.
2257          */
2258         if (PAGE_SIZE < UBIFS_BLOCK_SIZE) {
2259                 pr_err("UBIFS error (pid %d): VFS page cache size is %u bytes, but UBIFS requires at least 4096 bytes",
2260                        current->pid, (unsigned int)PAGE_SIZE);
2261                 return -EINVAL;
2262         }
2263 
2264         ubifs_inode_slab = kmem_cache_create("ubifs_inode_slab",
2265                                 sizeof(struct ubifs_inode), 0,
2266                                 SLAB_MEM_SPREAD | SLAB_RECLAIM_ACCOUNT |
2267                                 SLAB_ACCOUNT, &inode_slab_ctor);
2268         if (!ubifs_inode_slab)
2269                 return -ENOMEM;
2270 
2271         err = register_shrinker(&ubifs_shrinker_info);
2272         if (err)
2273                 goto out_slab;
2274 
2275         err = ubifs_compressors_init();
2276         if (err)
2277                 goto out_shrinker;
2278 
2279         err = dbg_debugfs_init();
2280         if (err)
2281                 goto out_compr;
2282 
2283         err = register_filesystem(&ubifs_fs_type);
2284         if (err) {
2285                 pr_err("UBIFS error (pid %d): cannot register file system, error %d",
2286                        current->pid, err);
2287                 goto out_dbg;
2288         }
2289         return 0;
2290 
2291 out_dbg:
2292         dbg_debugfs_exit();
2293 out_compr:
2294         ubifs_compressors_exit();
2295 out_shrinker:
2296         unregister_shrinker(&ubifs_shrinker_info);
2297 out_slab:
2298         kmem_cache_destroy(ubifs_inode_slab);
2299         return err;
2300 }
2301 /* late_initcall to let compressors initialize first */
2302 late_initcall(ubifs_init);
2303 
2304 static void __exit ubifs_exit(void)
2305 {
2306         ubifs_assert(list_empty(&ubifs_infos));
2307         ubifs_assert(atomic_long_read(&ubifs_clean_zn_cnt) == 0);
2308 
2309         dbg_debugfs_exit();
2310         ubifs_compressors_exit();
2311         unregister_shrinker(&ubifs_shrinker_info);
2312 
2313         /*
2314          * Make sure all delayed rcu free inodes are flushed before we
2315          * destroy cache.
2316          */
2317         rcu_barrier();
2318         kmem_cache_destroy(ubifs_inode_slab);
2319         unregister_filesystem(&ubifs_fs_type);
2320 }
2321 module_exit(ubifs_exit);
2322 
2323 MODULE_LICENSE("GPL");
2324 MODULE_VERSION(__stringify(UBIFS_VERSION));
2325 MODULE_AUTHOR("Artem Bityutskiy, Adrian Hunter");
2326 MODULE_DESCRIPTION("UBIFS - UBI File System");
2327 

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