Version:  2.0.40 2.2.26 2.4.37 3.13 3.14 3.15 3.16 3.17 3.18 3.19 4.0 4.1 4.2 4.3 4.4 4.5 4.6 4.7 4.8 4.9 4.10

Linux/fs/ubifs/super.c

  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 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 #ifdef CONFIG_UBIFS_FS_ENCRYPTION
383         fscrypt_put_encryption_info(inode, NULL);
384 #endif
385 }
386 
387 static void ubifs_dirty_inode(struct inode *inode, int flags)
388 {
389         struct ubifs_inode *ui = ubifs_inode(inode);
390 
391         ubifs_assert(mutex_is_locked(&ui->ui_mutex));
392         if (!ui->dirty) {
393                 ui->dirty = 1;
394                 dbg_gen("inode %lu",  inode->i_ino);
395         }
396 }
397 
398 static int ubifs_statfs(struct dentry *dentry, struct kstatfs *buf)
399 {
400         struct ubifs_info *c = dentry->d_sb->s_fs_info;
401         unsigned long long free;
402         __le32 *uuid = (__le32 *)c->uuid;
403 
404         free = ubifs_get_free_space(c);
405         dbg_gen("free space %lld bytes (%lld blocks)",
406                 free, free >> UBIFS_BLOCK_SHIFT);
407 
408         buf->f_type = UBIFS_SUPER_MAGIC;
409         buf->f_bsize = UBIFS_BLOCK_SIZE;
410         buf->f_blocks = c->block_cnt;
411         buf->f_bfree = free >> UBIFS_BLOCK_SHIFT;
412         if (free > c->report_rp_size)
413                 buf->f_bavail = (free - c->report_rp_size) >> UBIFS_BLOCK_SHIFT;
414         else
415                 buf->f_bavail = 0;
416         buf->f_files = 0;
417         buf->f_ffree = 0;
418         buf->f_namelen = UBIFS_MAX_NLEN;
419         buf->f_fsid.val[0] = le32_to_cpu(uuid[0]) ^ le32_to_cpu(uuid[2]);
420         buf->f_fsid.val[1] = le32_to_cpu(uuid[1]) ^ le32_to_cpu(uuid[3]);
421         ubifs_assert(buf->f_bfree <= c->block_cnt);
422         return 0;
423 }
424 
425 static int ubifs_show_options(struct seq_file *s, struct dentry *root)
426 {
427         struct ubifs_info *c = root->d_sb->s_fs_info;
428 
429         if (c->mount_opts.unmount_mode == 2)
430                 seq_puts(s, ",fast_unmount");
431         else if (c->mount_opts.unmount_mode == 1)
432                 seq_puts(s, ",norm_unmount");
433 
434         if (c->mount_opts.bulk_read == 2)
435                 seq_puts(s, ",bulk_read");
436         else if (c->mount_opts.bulk_read == 1)
437                 seq_puts(s, ",no_bulk_read");
438 
439         if (c->mount_opts.chk_data_crc == 2)
440                 seq_puts(s, ",chk_data_crc");
441         else if (c->mount_opts.chk_data_crc == 1)
442                 seq_puts(s, ",no_chk_data_crc");
443 
444         if (c->mount_opts.override_compr) {
445                 seq_printf(s, ",compr=%s",
446                            ubifs_compr_name(c->mount_opts.compr_type));
447         }
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_err,
935 };
936 
937 static const match_table_t tokens = {
938         {Opt_fast_unmount, "fast_unmount"},
939         {Opt_norm_unmount, "norm_unmount"},
940         {Opt_bulk_read, "bulk_read"},
941         {Opt_no_bulk_read, "no_bulk_read"},
942         {Opt_chk_data_crc, "chk_data_crc"},
943         {Opt_no_chk_data_crc, "no_chk_data_crc"},
944         {Opt_override_compr, "compr=%s"},
945         {Opt_err, NULL},
946 };
947 
948 /**
949  * parse_standard_option - parse a standard mount option.
950  * @option: the option to parse
951  *
952  * Normally, standard mount options like "sync" are passed to file-systems as
953  * flags. However, when a "rootflags=" kernel boot parameter is used, they may
954  * be present in the options string. This function tries to deal with this
955  * situation and parse standard options. Returns 0 if the option was not
956  * recognized, and the corresponding integer flag if it was.
957  *
958  * UBIFS is only interested in the "sync" option, so do not check for anything
959  * else.
960  */
961 static int parse_standard_option(const char *option)
962 {
963 
964         pr_notice("UBIFS: parse %s\n", option);
965         if (!strcmp(option, "sync"))
966                 return MS_SYNCHRONOUS;
967         return 0;
968 }
969 
970 /**
971  * ubifs_parse_options - parse mount parameters.
972  * @c: UBIFS file-system description object
973  * @options: parameters to parse
974  * @is_remount: non-zero if this is FS re-mount
975  *
976  * This function parses UBIFS mount options and returns zero in case success
977  * and a negative error code in case of failure.
978  */
979 static int ubifs_parse_options(struct ubifs_info *c, char *options,
980                                int is_remount)
981 {
982         char *p;
983         substring_t args[MAX_OPT_ARGS];
984 
985         if (!options)
986                 return 0;
987 
988         while ((p = strsep(&options, ","))) {
989                 int token;
990 
991                 if (!*p)
992                         continue;
993 
994                 token = match_token(p, tokens, args);
995                 switch (token) {
996                 /*
997                  * %Opt_fast_unmount and %Opt_norm_unmount options are ignored.
998                  * We accept them in order to be backward-compatible. But this
999                  * should be removed at some point.
1000                  */
1001                 case Opt_fast_unmount:
1002                         c->mount_opts.unmount_mode = 2;
1003                         break;
1004                 case Opt_norm_unmount:
1005                         c->mount_opts.unmount_mode = 1;
1006                         break;
1007                 case Opt_bulk_read:
1008                         c->mount_opts.bulk_read = 2;
1009                         c->bulk_read = 1;
1010                         break;
1011                 case Opt_no_bulk_read:
1012                         c->mount_opts.bulk_read = 1;
1013                         c->bulk_read = 0;
1014                         break;
1015                 case Opt_chk_data_crc:
1016                         c->mount_opts.chk_data_crc = 2;
1017                         c->no_chk_data_crc = 0;
1018                         break;
1019                 case Opt_no_chk_data_crc:
1020                         c->mount_opts.chk_data_crc = 1;
1021                         c->no_chk_data_crc = 1;
1022                         break;
1023                 case Opt_override_compr:
1024                 {
1025                         char *name = match_strdup(&args[0]);
1026 
1027                         if (!name)
1028                                 return -ENOMEM;
1029                         if (!strcmp(name, "none"))
1030                                 c->mount_opts.compr_type = UBIFS_COMPR_NONE;
1031                         else if (!strcmp(name, "lzo"))
1032                                 c->mount_opts.compr_type = UBIFS_COMPR_LZO;
1033                         else if (!strcmp(name, "zlib"))
1034                                 c->mount_opts.compr_type = UBIFS_COMPR_ZLIB;
1035                         else {
1036                                 ubifs_err(c, "unknown compressor \"%s\"", name); //FIXME: is c ready?
1037                                 kfree(name);
1038                                 return -EINVAL;
1039                         }
1040                         kfree(name);
1041                         c->mount_opts.override_compr = 1;
1042                         c->default_compr = c->mount_opts.compr_type;
1043                         break;
1044                 }
1045                 default:
1046                 {
1047                         unsigned long flag;
1048                         struct super_block *sb = c->vfs_sb;
1049 
1050                         flag = parse_standard_option(p);
1051                         if (!flag) {
1052                                 ubifs_err(c, "unrecognized mount option \"%s\" or missing value",
1053                                           p);
1054                                 return -EINVAL;
1055                         }
1056                         sb->s_flags |= flag;
1057                         break;
1058                 }
1059                 }
1060         }
1061 
1062         return 0;
1063 }
1064 
1065 /**
1066  * destroy_journal - destroy journal data structures.
1067  * @c: UBIFS file-system description object
1068  *
1069  * This function destroys journal data structures including those that may have
1070  * been created by recovery functions.
1071  */
1072 static void destroy_journal(struct ubifs_info *c)
1073 {
1074         while (!list_empty(&c->unclean_leb_list)) {
1075                 struct ubifs_unclean_leb *ucleb;
1076 
1077                 ucleb = list_entry(c->unclean_leb_list.next,
1078                                    struct ubifs_unclean_leb, list);
1079                 list_del(&ucleb->list);
1080                 kfree(ucleb);
1081         }
1082         while (!list_empty(&c->old_buds)) {
1083                 struct ubifs_bud *bud;
1084 
1085                 bud = list_entry(c->old_buds.next, struct ubifs_bud, list);
1086                 list_del(&bud->list);
1087                 kfree(bud);
1088         }
1089         ubifs_destroy_idx_gc(c);
1090         ubifs_destroy_size_tree(c);
1091         ubifs_tnc_close(c);
1092         free_buds(c);
1093 }
1094 
1095 /**
1096  * bu_init - initialize bulk-read information.
1097  * @c: UBIFS file-system description object
1098  */
1099 static void bu_init(struct ubifs_info *c)
1100 {
1101         ubifs_assert(c->bulk_read == 1);
1102 
1103         if (c->bu.buf)
1104                 return; /* Already initialized */
1105 
1106 again:
1107         c->bu.buf = kmalloc(c->max_bu_buf_len, GFP_KERNEL | __GFP_NOWARN);
1108         if (!c->bu.buf) {
1109                 if (c->max_bu_buf_len > UBIFS_KMALLOC_OK) {
1110                         c->max_bu_buf_len = UBIFS_KMALLOC_OK;
1111                         goto again;
1112                 }
1113 
1114                 /* Just disable bulk-read */
1115                 ubifs_warn(c, "cannot allocate %d bytes of memory for bulk-read, disabling it",
1116                            c->max_bu_buf_len);
1117                 c->mount_opts.bulk_read = 1;
1118                 c->bulk_read = 0;
1119                 return;
1120         }
1121 }
1122 
1123 /**
1124  * check_free_space - check if there is enough free space to mount.
1125  * @c: UBIFS file-system description object
1126  *
1127  * This function makes sure UBIFS has enough free space to be mounted in
1128  * read/write mode. UBIFS must always have some free space to allow deletions.
1129  */
1130 static int check_free_space(struct ubifs_info *c)
1131 {
1132         ubifs_assert(c->dark_wm > 0);
1133         if (c->lst.total_free + c->lst.total_dirty < c->dark_wm) {
1134                 ubifs_err(c, "insufficient free space to mount in R/W mode");
1135                 ubifs_dump_budg(c, &c->bi);
1136                 ubifs_dump_lprops(c);
1137                 return -ENOSPC;
1138         }
1139         return 0;
1140 }
1141 
1142 /**
1143  * mount_ubifs - mount UBIFS file-system.
1144  * @c: UBIFS file-system description object
1145  *
1146  * This function mounts UBIFS file system. Returns zero in case of success and
1147  * a negative error code in case of failure.
1148  */
1149 static int mount_ubifs(struct ubifs_info *c)
1150 {
1151         int err;
1152         long long x, y;
1153         size_t sz;
1154 
1155         c->ro_mount = !!(c->vfs_sb->s_flags & MS_RDONLY);
1156         /* Suppress error messages while probing if MS_SILENT is set */
1157         c->probing = !!(c->vfs_sb->s_flags & MS_SILENT);
1158 
1159         err = init_constants_early(c);
1160         if (err)
1161                 return err;
1162 
1163         err = ubifs_debugging_init(c);
1164         if (err)
1165                 return err;
1166 
1167         err = check_volume_empty(c);
1168         if (err)
1169                 goto out_free;
1170 
1171         if (c->empty && (c->ro_mount || c->ro_media)) {
1172                 /*
1173                  * This UBI volume is empty, and read-only, or the file system
1174                  * is mounted read-only - we cannot format it.
1175                  */
1176                 ubifs_err(c, "can't format empty UBI volume: read-only %s",
1177                           c->ro_media ? "UBI volume" : "mount");
1178                 err = -EROFS;
1179                 goto out_free;
1180         }
1181 
1182         if (c->ro_media && !c->ro_mount) {
1183                 ubifs_err(c, "cannot mount read-write - read-only media");
1184                 err = -EROFS;
1185                 goto out_free;
1186         }
1187 
1188         /*
1189          * The requirement for the buffer is that it should fit indexing B-tree
1190          * height amount of integers. We assume the height if the TNC tree will
1191          * never exceed 64.
1192          */
1193         err = -ENOMEM;
1194         c->bottom_up_buf = kmalloc(BOTTOM_UP_HEIGHT * sizeof(int), GFP_KERNEL);
1195         if (!c->bottom_up_buf)
1196                 goto out_free;
1197 
1198         c->sbuf = vmalloc(c->leb_size);
1199         if (!c->sbuf)
1200                 goto out_free;
1201 
1202         if (!c->ro_mount) {
1203                 c->ileb_buf = vmalloc(c->leb_size);
1204                 if (!c->ileb_buf)
1205                         goto out_free;
1206         }
1207 
1208         if (c->bulk_read == 1)
1209                 bu_init(c);
1210 
1211         if (!c->ro_mount) {
1212                 c->write_reserve_buf = kmalloc(COMPRESSED_DATA_NODE_BUF_SZ + \
1213                                                UBIFS_CIPHER_BLOCK_SIZE,
1214                                                GFP_KERNEL);
1215                 if (!c->write_reserve_buf)
1216                         goto out_free;
1217         }
1218 
1219         c->mounting = 1;
1220 
1221         err = ubifs_read_superblock(c);
1222         if (err)
1223                 goto out_free;
1224 
1225         c->probing = 0;
1226 
1227         /*
1228          * Make sure the compressor which is set as default in the superblock
1229          * or overridden by mount options is actually compiled in.
1230          */
1231         if (!ubifs_compr_present(c->default_compr)) {
1232                 ubifs_err(c, "'compressor \"%s\" is not compiled in",
1233                           ubifs_compr_name(c->default_compr));
1234                 err = -ENOTSUPP;
1235                 goto out_free;
1236         }
1237 
1238         err = init_constants_sb(c);
1239         if (err)
1240                 goto out_free;
1241 
1242         sz = ALIGN(c->max_idx_node_sz, c->min_io_size);
1243         sz = ALIGN(sz + c->max_idx_node_sz, c->min_io_size);
1244         c->cbuf = kmalloc(sz, GFP_NOFS);
1245         if (!c->cbuf) {
1246                 err = -ENOMEM;
1247                 goto out_free;
1248         }
1249 
1250         err = alloc_wbufs(c);
1251         if (err)
1252                 goto out_cbuf;
1253 
1254         sprintf(c->bgt_name, BGT_NAME_PATTERN, c->vi.ubi_num, c->vi.vol_id);
1255         if (!c->ro_mount) {
1256                 /* Create background thread */
1257                 c->bgt = kthread_create(ubifs_bg_thread, c, "%s", c->bgt_name);
1258                 if (IS_ERR(c->bgt)) {
1259                         err = PTR_ERR(c->bgt);
1260                         c->bgt = NULL;
1261                         ubifs_err(c, "cannot spawn \"%s\", error %d",
1262                                   c->bgt_name, err);
1263                         goto out_wbufs;
1264                 }
1265                 wake_up_process(c->bgt);
1266         }
1267 
1268         err = ubifs_read_master(c);
1269         if (err)
1270                 goto out_master;
1271 
1272         init_constants_master(c);
1273 
1274         if ((c->mst_node->flags & cpu_to_le32(UBIFS_MST_DIRTY)) != 0) {
1275                 ubifs_msg(c, "recovery needed");
1276                 c->need_recovery = 1;
1277         }
1278 
1279         if (c->need_recovery && !c->ro_mount) {
1280                 err = ubifs_recover_inl_heads(c, c->sbuf);
1281                 if (err)
1282                         goto out_master;
1283         }
1284 
1285         err = ubifs_lpt_init(c, 1, !c->ro_mount);
1286         if (err)
1287                 goto out_master;
1288 
1289         if (!c->ro_mount && c->space_fixup) {
1290                 err = ubifs_fixup_free_space(c);
1291                 if (err)
1292                         goto out_lpt;
1293         }
1294 
1295         if (!c->ro_mount && !c->need_recovery) {
1296                 /*
1297                  * Set the "dirty" flag so that if we reboot uncleanly we
1298                  * will notice this immediately on the next mount.
1299                  */
1300                 c->mst_node->flags |= cpu_to_le32(UBIFS_MST_DIRTY);
1301                 err = ubifs_write_master(c);
1302                 if (err)
1303                         goto out_lpt;
1304         }
1305 
1306         err = dbg_check_idx_size(c, c->bi.old_idx_sz);
1307         if (err)
1308                 goto out_lpt;
1309 
1310         err = ubifs_replay_journal(c);
1311         if (err)
1312                 goto out_journal;
1313 
1314         /* Calculate 'min_idx_lebs' after journal replay */
1315         c->bi.min_idx_lebs = ubifs_calc_min_idx_lebs(c);
1316 
1317         err = ubifs_mount_orphans(c, c->need_recovery, c->ro_mount);
1318         if (err)
1319                 goto out_orphans;
1320 
1321         if (!c->ro_mount) {
1322                 int lnum;
1323 
1324                 err = check_free_space(c);
1325                 if (err)
1326                         goto out_orphans;
1327 
1328                 /* Check for enough log space */
1329                 lnum = c->lhead_lnum + 1;
1330                 if (lnum >= UBIFS_LOG_LNUM + c->log_lebs)
1331                         lnum = UBIFS_LOG_LNUM;
1332                 if (lnum == c->ltail_lnum) {
1333                         err = ubifs_consolidate_log(c);
1334                         if (err)
1335                                 goto out_orphans;
1336                 }
1337 
1338                 if (c->need_recovery) {
1339                         err = ubifs_recover_size(c);
1340                         if (err)
1341                                 goto out_orphans;
1342                         err = ubifs_rcvry_gc_commit(c);
1343                         if (err)
1344                                 goto out_orphans;
1345                 } else {
1346                         err = take_gc_lnum(c);
1347                         if (err)
1348                                 goto out_orphans;
1349 
1350                         /*
1351                          * GC LEB may contain garbage if there was an unclean
1352                          * reboot, and it should be un-mapped.
1353                          */
1354                         err = ubifs_leb_unmap(c, c->gc_lnum);
1355                         if (err)
1356                                 goto out_orphans;
1357                 }
1358 
1359                 err = dbg_check_lprops(c);
1360                 if (err)
1361                         goto out_orphans;
1362         } else if (c->need_recovery) {
1363                 err = ubifs_recover_size(c);
1364                 if (err)
1365                         goto out_orphans;
1366         } else {
1367                 /*
1368                  * Even if we mount read-only, we have to set space in GC LEB
1369                  * to proper value because this affects UBIFS free space
1370                  * reporting. We do not want to have a situation when
1371                  * re-mounting from R/O to R/W changes amount of free space.
1372                  */
1373                 err = take_gc_lnum(c);
1374                 if (err)
1375                         goto out_orphans;
1376         }
1377 
1378         spin_lock(&ubifs_infos_lock);
1379         list_add_tail(&c->infos_list, &ubifs_infos);
1380         spin_unlock(&ubifs_infos_lock);
1381 
1382         if (c->need_recovery) {
1383                 if (c->ro_mount)
1384                         ubifs_msg(c, "recovery deferred");
1385                 else {
1386                         c->need_recovery = 0;
1387                         ubifs_msg(c, "recovery completed");
1388                         /*
1389                          * GC LEB has to be empty and taken at this point. But
1390                          * the journal head LEBs may also be accounted as
1391                          * "empty taken" if they are empty.
1392                          */
1393                         ubifs_assert(c->lst.taken_empty_lebs > 0);
1394                 }
1395         } else
1396                 ubifs_assert(c->lst.taken_empty_lebs > 0);
1397 
1398         err = dbg_check_filesystem(c);
1399         if (err)
1400                 goto out_infos;
1401 
1402         err = dbg_debugfs_init_fs(c);
1403         if (err)
1404                 goto out_infos;
1405 
1406         c->mounting = 0;
1407 
1408         ubifs_msg(c, "UBIFS: mounted UBI device %d, volume %d, name \"%s\"%s",
1409                   c->vi.ubi_num, c->vi.vol_id, c->vi.name,
1410                   c->ro_mount ? ", R/O mode" : "");
1411         x = (long long)c->main_lebs * c->leb_size;
1412         y = (long long)c->log_lebs * c->leb_size + c->max_bud_bytes;
1413         ubifs_msg(c, "LEB size: %d bytes (%d KiB), min./max. I/O unit sizes: %d bytes/%d bytes",
1414                   c->leb_size, c->leb_size >> 10, c->min_io_size,
1415                   c->max_write_size);
1416         ubifs_msg(c, "FS size: %lld bytes (%lld MiB, %d LEBs), journal size %lld bytes (%lld MiB, %d LEBs)",
1417                   x, x >> 20, c->main_lebs,
1418                   y, y >> 20, c->log_lebs + c->max_bud_cnt);
1419         ubifs_msg(c, "reserved for root: %llu bytes (%llu KiB)",
1420                   c->report_rp_size, c->report_rp_size >> 10);
1421         ubifs_msg(c, "media format: w%d/r%d (latest is w%d/r%d), UUID %pUB%s",
1422                   c->fmt_version, c->ro_compat_version,
1423                   UBIFS_FORMAT_VERSION, UBIFS_RO_COMPAT_VERSION, c->uuid,
1424                   c->big_lpt ? ", big LPT model" : ", small LPT model");
1425 
1426         dbg_gen("default compressor:  %s", ubifs_compr_name(c->default_compr));
1427         dbg_gen("data journal heads:  %d",
1428                 c->jhead_cnt - NONDATA_JHEADS_CNT);
1429         dbg_gen("log LEBs:            %d (%d - %d)",
1430                 c->log_lebs, UBIFS_LOG_LNUM, c->log_last);
1431         dbg_gen("LPT area LEBs:       %d (%d - %d)",
1432                 c->lpt_lebs, c->lpt_first, c->lpt_last);
1433         dbg_gen("orphan area LEBs:    %d (%d - %d)",
1434                 c->orph_lebs, c->orph_first, c->orph_last);
1435         dbg_gen("main area LEBs:      %d (%d - %d)",
1436                 c->main_lebs, c->main_first, c->leb_cnt - 1);
1437         dbg_gen("index LEBs:          %d", c->lst.idx_lebs);
1438         dbg_gen("total index bytes:   %lld (%lld KiB, %lld MiB)",
1439                 c->bi.old_idx_sz, c->bi.old_idx_sz >> 10,
1440                 c->bi.old_idx_sz >> 20);
1441         dbg_gen("key hash type:       %d", c->key_hash_type);
1442         dbg_gen("tree fanout:         %d", c->fanout);
1443         dbg_gen("reserved GC LEB:     %d", c->gc_lnum);
1444         dbg_gen("max. znode size      %d", c->max_znode_sz);
1445         dbg_gen("max. index node size %d", c->max_idx_node_sz);
1446         dbg_gen("node sizes:          data %zu, inode %zu, dentry %zu",
1447                 UBIFS_DATA_NODE_SZ, UBIFS_INO_NODE_SZ, UBIFS_DENT_NODE_SZ);
1448         dbg_gen("node sizes:          trun %zu, sb %zu, master %zu",
1449                 UBIFS_TRUN_NODE_SZ, UBIFS_SB_NODE_SZ, UBIFS_MST_NODE_SZ);
1450         dbg_gen("node sizes:          ref %zu, cmt. start %zu, orph %zu",
1451                 UBIFS_REF_NODE_SZ, UBIFS_CS_NODE_SZ, UBIFS_ORPH_NODE_SZ);
1452         dbg_gen("max. node sizes:     data %zu, inode %zu dentry %zu, idx %d",
1453                 UBIFS_MAX_DATA_NODE_SZ, UBIFS_MAX_INO_NODE_SZ,
1454                 UBIFS_MAX_DENT_NODE_SZ, ubifs_idx_node_sz(c, c->fanout));
1455         dbg_gen("dead watermark:      %d", c->dead_wm);
1456         dbg_gen("dark watermark:      %d", c->dark_wm);
1457         dbg_gen("LEB overhead:        %d", c->leb_overhead);
1458         x = (long long)c->main_lebs * c->dark_wm;
1459         dbg_gen("max. dark space:     %lld (%lld KiB, %lld MiB)",
1460                 x, x >> 10, x >> 20);
1461         dbg_gen("maximum bud bytes:   %lld (%lld KiB, %lld MiB)",
1462                 c->max_bud_bytes, c->max_bud_bytes >> 10,
1463                 c->max_bud_bytes >> 20);
1464         dbg_gen("BG commit bud bytes: %lld (%lld KiB, %lld MiB)",
1465                 c->bg_bud_bytes, c->bg_bud_bytes >> 10,
1466                 c->bg_bud_bytes >> 20);
1467         dbg_gen("current bud bytes    %lld (%lld KiB, %lld MiB)",
1468                 c->bud_bytes, c->bud_bytes >> 10, c->bud_bytes >> 20);
1469         dbg_gen("max. seq. number:    %llu", c->max_sqnum);
1470         dbg_gen("commit number:       %llu", c->cmt_no);
1471 
1472         return 0;
1473 
1474 out_infos:
1475         spin_lock(&ubifs_infos_lock);
1476         list_del(&c->infos_list);
1477         spin_unlock(&ubifs_infos_lock);
1478 out_orphans:
1479         free_orphans(c);
1480 out_journal:
1481         destroy_journal(c);
1482 out_lpt:
1483         ubifs_lpt_free(c, 0);
1484 out_master:
1485         kfree(c->mst_node);
1486         kfree(c->rcvrd_mst_node);
1487         if (c->bgt)
1488                 kthread_stop(c->bgt);
1489 out_wbufs:
1490         free_wbufs(c);
1491 out_cbuf:
1492         kfree(c->cbuf);
1493 out_free:
1494         kfree(c->write_reserve_buf);
1495         kfree(c->bu.buf);
1496         vfree(c->ileb_buf);
1497         vfree(c->sbuf);
1498         kfree(c->bottom_up_buf);
1499         ubifs_debugging_exit(c);
1500         return err;
1501 }
1502 
1503 /**
1504  * ubifs_umount - un-mount UBIFS file-system.
1505  * @c: UBIFS file-system description object
1506  *
1507  * Note, this function is called to free allocated resourced when un-mounting,
1508  * as well as free resources when an error occurred while we were half way
1509  * through mounting (error path cleanup function). So it has to make sure the
1510  * resource was actually allocated before freeing it.
1511  */
1512 static void ubifs_umount(struct ubifs_info *c)
1513 {
1514         dbg_gen("un-mounting UBI device %d, volume %d", c->vi.ubi_num,
1515                 c->vi.vol_id);
1516 
1517         dbg_debugfs_exit_fs(c);
1518         spin_lock(&ubifs_infos_lock);
1519         list_del(&c->infos_list);
1520         spin_unlock(&ubifs_infos_lock);
1521 
1522         if (c->bgt)
1523                 kthread_stop(c->bgt);
1524 
1525         destroy_journal(c);
1526         free_wbufs(c);
1527         free_orphans(c);
1528         ubifs_lpt_free(c, 0);
1529 
1530         kfree(c->cbuf);
1531         kfree(c->rcvrd_mst_node);
1532         kfree(c->mst_node);
1533         kfree(c->write_reserve_buf);
1534         kfree(c->bu.buf);
1535         vfree(c->ileb_buf);
1536         vfree(c->sbuf);
1537         kfree(c->bottom_up_buf);
1538         ubifs_debugging_exit(c);
1539 }
1540 
1541 /**
1542  * ubifs_remount_rw - re-mount in read-write mode.
1543  * @c: UBIFS file-system description object
1544  *
1545  * UBIFS avoids allocating many unnecessary resources when mounted in read-only
1546  * mode. This function allocates the needed resources and re-mounts UBIFS in
1547  * read-write mode.
1548  */
1549 static int ubifs_remount_rw(struct ubifs_info *c)
1550 {
1551         int err, lnum;
1552 
1553         if (c->rw_incompat) {
1554                 ubifs_err(c, "the file-system is not R/W-compatible");
1555                 ubifs_msg(c, "on-flash format version is w%d/r%d, but software only supports up to version w%d/r%d",
1556                           c->fmt_version, c->ro_compat_version,
1557                           UBIFS_FORMAT_VERSION, UBIFS_RO_COMPAT_VERSION);
1558                 return -EROFS;
1559         }
1560 
1561         mutex_lock(&c->umount_mutex);
1562         dbg_save_space_info(c);
1563         c->remounting_rw = 1;
1564         c->ro_mount = 0;
1565 
1566         if (c->space_fixup) {
1567                 err = ubifs_fixup_free_space(c);
1568                 if (err)
1569                         goto out;
1570         }
1571 
1572         err = check_free_space(c);
1573         if (err)
1574                 goto out;
1575 
1576         if (c->old_leb_cnt != c->leb_cnt) {
1577                 struct ubifs_sb_node *sup;
1578 
1579                 sup = ubifs_read_sb_node(c);
1580                 if (IS_ERR(sup)) {
1581                         err = PTR_ERR(sup);
1582                         goto out;
1583                 }
1584                 sup->leb_cnt = cpu_to_le32(c->leb_cnt);
1585                 err = ubifs_write_sb_node(c, sup);
1586                 kfree(sup);
1587                 if (err)
1588                         goto out;
1589         }
1590 
1591         if (c->need_recovery) {
1592                 ubifs_msg(c, "completing deferred recovery");
1593                 err = ubifs_write_rcvrd_mst_node(c);
1594                 if (err)
1595                         goto out;
1596                 err = ubifs_recover_size(c);
1597                 if (err)
1598                         goto out;
1599                 err = ubifs_clean_lebs(c, c->sbuf);
1600                 if (err)
1601                         goto out;
1602                 err = ubifs_recover_inl_heads(c, c->sbuf);
1603                 if (err)
1604                         goto out;
1605         } else {
1606                 /* A readonly mount is not allowed to have orphans */
1607                 ubifs_assert(c->tot_orphans == 0);
1608                 err = ubifs_clear_orphans(c);
1609                 if (err)
1610                         goto out;
1611         }
1612 
1613         if (!(c->mst_node->flags & cpu_to_le32(UBIFS_MST_DIRTY))) {
1614                 c->mst_node->flags |= cpu_to_le32(UBIFS_MST_DIRTY);
1615                 err = ubifs_write_master(c);
1616                 if (err)
1617                         goto out;
1618         }
1619 
1620         c->ileb_buf = vmalloc(c->leb_size);
1621         if (!c->ileb_buf) {
1622                 err = -ENOMEM;
1623                 goto out;
1624         }
1625 
1626         c->write_reserve_buf = kmalloc(COMPRESSED_DATA_NODE_BUF_SZ + \
1627                                        UBIFS_CIPHER_BLOCK_SIZE, GFP_KERNEL);
1628         if (!c->write_reserve_buf) {
1629                 err = -ENOMEM;
1630                 goto out;
1631         }
1632 
1633         err = ubifs_lpt_init(c, 0, 1);
1634         if (err)
1635                 goto out;
1636 
1637         /* Create background thread */
1638         c->bgt = kthread_create(ubifs_bg_thread, c, "%s", c->bgt_name);
1639         if (IS_ERR(c->bgt)) {
1640                 err = PTR_ERR(c->bgt);
1641                 c->bgt = NULL;
1642                 ubifs_err(c, "cannot spawn \"%s\", error %d",
1643                           c->bgt_name, err);
1644                 goto out;
1645         }
1646         wake_up_process(c->bgt);
1647 
1648         c->orph_buf = vmalloc(c->leb_size);
1649         if (!c->orph_buf) {
1650                 err = -ENOMEM;
1651                 goto out;
1652         }
1653 
1654         /* Check for enough log space */
1655         lnum = c->lhead_lnum + 1;
1656         if (lnum >= UBIFS_LOG_LNUM + c->log_lebs)
1657                 lnum = UBIFS_LOG_LNUM;
1658         if (lnum == c->ltail_lnum) {
1659                 err = ubifs_consolidate_log(c);
1660                 if (err)
1661                         goto out;
1662         }
1663 
1664         if (c->need_recovery)
1665                 err = ubifs_rcvry_gc_commit(c);
1666         else
1667                 err = ubifs_leb_unmap(c, c->gc_lnum);
1668         if (err)
1669                 goto out;
1670 
1671         dbg_gen("re-mounted read-write");
1672         c->remounting_rw = 0;
1673 
1674         if (c->need_recovery) {
1675                 c->need_recovery = 0;
1676                 ubifs_msg(c, "deferred recovery completed");
1677         } else {
1678                 /*
1679                  * Do not run the debugging space check if the were doing
1680                  * recovery, because when we saved the information we had the
1681                  * file-system in a state where the TNC and lprops has been
1682                  * modified in memory, but all the I/O operations (including a
1683                  * commit) were deferred. So the file-system was in
1684                  * "non-committed" state. Now the file-system is in committed
1685                  * state, and of course the amount of free space will change
1686                  * because, for example, the old index size was imprecise.
1687                  */
1688                 err = dbg_check_space_info(c);
1689         }
1690 
1691         mutex_unlock(&c->umount_mutex);
1692         return err;
1693 
1694 out:
1695         c->ro_mount = 1;
1696         vfree(c->orph_buf);
1697         c->orph_buf = NULL;
1698         if (c->bgt) {
1699                 kthread_stop(c->bgt);
1700                 c->bgt = NULL;
1701         }
1702         free_wbufs(c);
1703         kfree(c->write_reserve_buf);
1704         c->write_reserve_buf = NULL;
1705         vfree(c->ileb_buf);
1706         c->ileb_buf = NULL;
1707         ubifs_lpt_free(c, 1);
1708         c->remounting_rw = 0;
1709         mutex_unlock(&c->umount_mutex);
1710         return err;
1711 }
1712 
1713 /**
1714  * ubifs_remount_ro - re-mount in read-only mode.
1715  * @c: UBIFS file-system description object
1716  *
1717  * We assume VFS has stopped writing. Possibly the background thread could be
1718  * running a commit, however kthread_stop will wait in that case.
1719  */
1720 static void ubifs_remount_ro(struct ubifs_info *c)
1721 {
1722         int i, err;
1723 
1724         ubifs_assert(!c->need_recovery);
1725         ubifs_assert(!c->ro_mount);
1726 
1727         mutex_lock(&c->umount_mutex);
1728         if (c->bgt) {
1729                 kthread_stop(c->bgt);
1730                 c->bgt = NULL;
1731         }
1732 
1733         dbg_save_space_info(c);
1734 
1735         for (i = 0; i < c->jhead_cnt; i++)
1736                 ubifs_wbuf_sync(&c->jheads[i].wbuf);
1737 
1738         c->mst_node->flags &= ~cpu_to_le32(UBIFS_MST_DIRTY);
1739         c->mst_node->flags |= cpu_to_le32(UBIFS_MST_NO_ORPHS);
1740         c->mst_node->gc_lnum = cpu_to_le32(c->gc_lnum);
1741         err = ubifs_write_master(c);
1742         if (err)
1743                 ubifs_ro_mode(c, err);
1744 
1745         vfree(c->orph_buf);
1746         c->orph_buf = NULL;
1747         kfree(c->write_reserve_buf);
1748         c->write_reserve_buf = NULL;
1749         vfree(c->ileb_buf);
1750         c->ileb_buf = NULL;
1751         ubifs_lpt_free(c, 1);
1752         c->ro_mount = 1;
1753         err = dbg_check_space_info(c);
1754         if (err)
1755                 ubifs_ro_mode(c, err);
1756         mutex_unlock(&c->umount_mutex);
1757 }
1758 
1759 static void ubifs_put_super(struct super_block *sb)
1760 {
1761         int i;
1762         struct ubifs_info *c = sb->s_fs_info;
1763 
1764         ubifs_msg(c, "un-mount UBI device %d", c->vi.ubi_num);
1765 
1766         /*
1767          * The following asserts are only valid if there has not been a failure
1768          * of the media. For example, there will be dirty inodes if we failed
1769          * to write them back because of I/O errors.
1770          */
1771         if (!c->ro_error) {
1772                 ubifs_assert(c->bi.idx_growth == 0);
1773                 ubifs_assert(c->bi.dd_growth == 0);
1774                 ubifs_assert(c->bi.data_growth == 0);
1775         }
1776 
1777         /*
1778          * The 'c->umount_lock' prevents races between UBIFS memory shrinker
1779          * and file system un-mount. Namely, it prevents the shrinker from
1780          * picking this superblock for shrinking - it will be just skipped if
1781          * the mutex is locked.
1782          */
1783         mutex_lock(&c->umount_mutex);
1784         if (!c->ro_mount) {
1785                 /*
1786                  * First of all kill the background thread to make sure it does
1787                  * not interfere with un-mounting and freeing resources.
1788                  */
1789                 if (c->bgt) {
1790                         kthread_stop(c->bgt);
1791                         c->bgt = NULL;
1792                 }
1793 
1794                 /*
1795                  * On fatal errors c->ro_error is set to 1, in which case we do
1796                  * not write the master node.
1797                  */
1798                 if (!c->ro_error) {
1799                         int err;
1800 
1801                         /* Synchronize write-buffers */
1802                         for (i = 0; i < c->jhead_cnt; i++)
1803                                 ubifs_wbuf_sync(&c->jheads[i].wbuf);
1804 
1805                         /*
1806                          * We are being cleanly unmounted which means the
1807                          * orphans were killed - indicate this in the master
1808                          * node. Also save the reserved GC LEB number.
1809                          */
1810                         c->mst_node->flags &= ~cpu_to_le32(UBIFS_MST_DIRTY);
1811                         c->mst_node->flags |= cpu_to_le32(UBIFS_MST_NO_ORPHS);
1812                         c->mst_node->gc_lnum = cpu_to_le32(c->gc_lnum);
1813                         err = ubifs_write_master(c);
1814                         if (err)
1815                                 /*
1816                                  * Recovery will attempt to fix the master area
1817                                  * next mount, so we just print a message and
1818                                  * continue to unmount normally.
1819                                  */
1820                                 ubifs_err(c, "failed to write master node, error %d",
1821                                           err);
1822                 } else {
1823                         for (i = 0; i < c->jhead_cnt; i++)
1824                                 /* Make sure write-buffer timers are canceled */
1825                                 hrtimer_cancel(&c->jheads[i].wbuf.timer);
1826                 }
1827         }
1828 
1829         ubifs_umount(c);
1830         bdi_destroy(&c->bdi);
1831         ubi_close_volume(c->ubi);
1832         mutex_unlock(&c->umount_mutex);
1833 }
1834 
1835 static int ubifs_remount_fs(struct super_block *sb, int *flags, char *data)
1836 {
1837         int err;
1838         struct ubifs_info *c = sb->s_fs_info;
1839 
1840         sync_filesystem(sb);
1841         dbg_gen("old flags %#lx, new flags %#x", sb->s_flags, *flags);
1842 
1843         err = ubifs_parse_options(c, data, 1);
1844         if (err) {
1845                 ubifs_err(c, "invalid or unknown remount parameter");
1846                 return err;
1847         }
1848 
1849         if (c->ro_mount && !(*flags & MS_RDONLY)) {
1850                 if (c->ro_error) {
1851                         ubifs_msg(c, "cannot re-mount R/W due to prior errors");
1852                         return -EROFS;
1853                 }
1854                 if (c->ro_media) {
1855                         ubifs_msg(c, "cannot re-mount R/W - UBI volume is R/O");
1856                         return -EROFS;
1857                 }
1858                 err = ubifs_remount_rw(c);
1859                 if (err)
1860                         return err;
1861         } else if (!c->ro_mount && (*flags & MS_RDONLY)) {
1862                 if (c->ro_error) {
1863                         ubifs_msg(c, "cannot re-mount R/O due to prior errors");
1864                         return -EROFS;
1865                 }
1866                 ubifs_remount_ro(c);
1867         }
1868 
1869         if (c->bulk_read == 1)
1870                 bu_init(c);
1871         else {
1872                 dbg_gen("disable bulk-read");
1873                 kfree(c->bu.buf);
1874                 c->bu.buf = NULL;
1875         }
1876 
1877         ubifs_assert(c->lst.taken_empty_lebs > 0);
1878         return 0;
1879 }
1880 
1881 const struct super_operations ubifs_super_operations = {
1882         .alloc_inode   = ubifs_alloc_inode,
1883         .destroy_inode = ubifs_destroy_inode,
1884         .put_super     = ubifs_put_super,
1885         .write_inode   = ubifs_write_inode,
1886         .evict_inode   = ubifs_evict_inode,
1887         .statfs        = ubifs_statfs,
1888         .dirty_inode   = ubifs_dirty_inode,
1889         .remount_fs    = ubifs_remount_fs,
1890         .show_options  = ubifs_show_options,
1891         .sync_fs       = ubifs_sync_fs,
1892 };
1893 
1894 /**
1895  * open_ubi - parse UBI device name string and open the UBI device.
1896  * @name: UBI volume name
1897  * @mode: UBI volume open mode
1898  *
1899  * The primary method of mounting UBIFS is by specifying the UBI volume
1900  * character device node path. However, UBIFS may also be mounted withoug any
1901  * character device node using one of the following methods:
1902  *
1903  * o ubiX_Y    - mount UBI device number X, volume Y;
1904  * o ubiY      - mount UBI device number 0, volume Y;
1905  * o ubiX:NAME - mount UBI device X, volume with name NAME;
1906  * o ubi:NAME  - mount UBI device 0, volume with name NAME.
1907  *
1908  * Alternative '!' separator may be used instead of ':' (because some shells
1909  * like busybox may interpret ':' as an NFS host name separator). This function
1910  * returns UBI volume description object in case of success and a negative
1911  * error code in case of failure.
1912  */
1913 static struct ubi_volume_desc *open_ubi(const char *name, int mode)
1914 {
1915         struct ubi_volume_desc *ubi;
1916         int dev, vol;
1917         char *endptr;
1918 
1919         /* First, try to open using the device node path method */
1920         ubi = ubi_open_volume_path(name, mode);
1921         if (!IS_ERR(ubi))
1922                 return ubi;
1923 
1924         /* Try the "nodev" method */
1925         if (name[0] != 'u' || name[1] != 'b' || name[2] != 'i')
1926                 return ERR_PTR(-EINVAL);
1927 
1928         /* ubi:NAME method */
1929         if ((name[3] == ':' || name[3] == '!') && name[4] != '\0')
1930                 return ubi_open_volume_nm(0, name + 4, mode);
1931 
1932         if (!isdigit(name[3]))
1933                 return ERR_PTR(-EINVAL);
1934 
1935         dev = simple_strtoul(name + 3, &endptr, 0);
1936 
1937         /* ubiY method */
1938         if (*endptr == '\0')
1939                 return ubi_open_volume(0, dev, mode);
1940 
1941         /* ubiX_Y method */
1942         if (*endptr == '_' && isdigit(endptr[1])) {
1943                 vol = simple_strtoul(endptr + 1, &endptr, 0);
1944                 if (*endptr != '\0')
1945                         return ERR_PTR(-EINVAL);
1946                 return ubi_open_volume(dev, vol, mode);
1947         }
1948 
1949         /* ubiX:NAME method */
1950         if ((*endptr == ':' || *endptr == '!') && endptr[1] != '\0')
1951                 return ubi_open_volume_nm(dev, ++endptr, mode);
1952 
1953         return ERR_PTR(-EINVAL);
1954 }
1955 
1956 static struct ubifs_info *alloc_ubifs_info(struct ubi_volume_desc *ubi)
1957 {
1958         struct ubifs_info *c;
1959 
1960         c = kzalloc(sizeof(struct ubifs_info), GFP_KERNEL);
1961         if (c) {
1962                 spin_lock_init(&c->cnt_lock);
1963                 spin_lock_init(&c->cs_lock);
1964                 spin_lock_init(&c->buds_lock);
1965                 spin_lock_init(&c->space_lock);
1966                 spin_lock_init(&c->orphan_lock);
1967                 init_rwsem(&c->commit_sem);
1968                 mutex_init(&c->lp_mutex);
1969                 mutex_init(&c->tnc_mutex);
1970                 mutex_init(&c->log_mutex);
1971                 mutex_init(&c->umount_mutex);
1972                 mutex_init(&c->bu_mutex);
1973                 mutex_init(&c->write_reserve_mutex);
1974                 init_waitqueue_head(&c->cmt_wq);
1975                 c->buds = RB_ROOT;
1976                 c->old_idx = RB_ROOT;
1977                 c->size_tree = RB_ROOT;
1978                 c->orph_tree = RB_ROOT;
1979                 INIT_LIST_HEAD(&c->infos_list);
1980                 INIT_LIST_HEAD(&c->idx_gc);
1981                 INIT_LIST_HEAD(&c->replay_list);
1982                 INIT_LIST_HEAD(&c->replay_buds);
1983                 INIT_LIST_HEAD(&c->uncat_list);
1984                 INIT_LIST_HEAD(&c->empty_list);
1985                 INIT_LIST_HEAD(&c->freeable_list);
1986                 INIT_LIST_HEAD(&c->frdi_idx_list);
1987                 INIT_LIST_HEAD(&c->unclean_leb_list);
1988                 INIT_LIST_HEAD(&c->old_buds);
1989                 INIT_LIST_HEAD(&c->orph_list);
1990                 INIT_LIST_HEAD(&c->orph_new);
1991                 c->no_chk_data_crc = 1;
1992 
1993                 c->highest_inum = UBIFS_FIRST_INO;
1994                 c->lhead_lnum = c->ltail_lnum = UBIFS_LOG_LNUM;
1995 
1996                 ubi_get_volume_info(ubi, &c->vi);
1997                 ubi_get_device_info(c->vi.ubi_num, &c->di);
1998         }
1999         return c;
2000 }
2001 
2002 #ifndef CONFIG_UBIFS_FS_ENCRYPTION
2003 struct fscrypt_operations ubifs_crypt_operations = {
2004         .is_encrypted           = __ubifs_crypt_is_encrypted,
2005 };
2006 #endif
2007 
2008 static int ubifs_fill_super(struct super_block *sb, void *data, int silent)
2009 {
2010         struct ubifs_info *c = sb->s_fs_info;
2011         struct inode *root;
2012         int err;
2013 
2014         c->vfs_sb = sb;
2015         /* Re-open the UBI device in read-write mode */
2016         c->ubi = ubi_open_volume(c->vi.ubi_num, c->vi.vol_id, UBI_READWRITE);
2017         if (IS_ERR(c->ubi)) {
2018                 err = PTR_ERR(c->ubi);
2019                 goto out;
2020         }
2021 
2022         /*
2023          * UBIFS provides 'backing_dev_info' in order to disable read-ahead. For
2024          * UBIFS, I/O is not deferred, it is done immediately in readpage,
2025          * which means the user would have to wait not just for their own I/O
2026          * but the read-ahead I/O as well i.e. completely pointless.
2027          *
2028          * Read-ahead will be disabled because @c->bdi.ra_pages is 0.
2029          */
2030         c->bdi.name = "ubifs",
2031         c->bdi.capabilities = 0;
2032         err  = bdi_init(&c->bdi);
2033         if (err)
2034                 goto out_close;
2035         err = bdi_register(&c->bdi, NULL, "ubifs_%d_%d",
2036                            c->vi.ubi_num, c->vi.vol_id);
2037         if (err)
2038                 goto out_bdi;
2039 
2040         err = ubifs_parse_options(c, data, 0);
2041         if (err)
2042                 goto out_bdi;
2043 
2044         sb->s_bdi = &c->bdi;
2045         sb->s_fs_info = c;
2046         sb->s_magic = UBIFS_SUPER_MAGIC;
2047         sb->s_blocksize = UBIFS_BLOCK_SIZE;
2048         sb->s_blocksize_bits = UBIFS_BLOCK_SHIFT;
2049         sb->s_maxbytes = c->max_inode_sz = key_max_inode_size(c);
2050         if (c->max_inode_sz > MAX_LFS_FILESIZE)
2051                 sb->s_maxbytes = c->max_inode_sz = MAX_LFS_FILESIZE;
2052         sb->s_op = &ubifs_super_operations;
2053         sb->s_xattr = ubifs_xattr_handlers;
2054         sb->s_cop = &ubifs_crypt_operations;
2055 
2056         mutex_lock(&c->umount_mutex);
2057         err = mount_ubifs(c);
2058         if (err) {
2059                 ubifs_assert(err < 0);
2060                 goto out_unlock;
2061         }
2062 
2063         /* Read the root inode */
2064         root = ubifs_iget(sb, UBIFS_ROOT_INO);
2065         if (IS_ERR(root)) {
2066                 err = PTR_ERR(root);
2067                 goto out_umount;
2068         }
2069 
2070         sb->s_root = d_make_root(root);
2071         if (!sb->s_root) {
2072                 err = -ENOMEM;
2073                 goto out_umount;
2074         }
2075 
2076         mutex_unlock(&c->umount_mutex);
2077         return 0;
2078 
2079 out_umount:
2080         ubifs_umount(c);
2081 out_unlock:
2082         mutex_unlock(&c->umount_mutex);
2083 out_bdi:
2084         bdi_destroy(&c->bdi);
2085 out_close:
2086         ubi_close_volume(c->ubi);
2087 out:
2088         return err;
2089 }
2090 
2091 static int sb_test(struct super_block *sb, void *data)
2092 {
2093         struct ubifs_info *c1 = data;
2094         struct ubifs_info *c = sb->s_fs_info;
2095 
2096         return c->vi.cdev == c1->vi.cdev;
2097 }
2098 
2099 static int sb_set(struct super_block *sb, void *data)
2100 {
2101         sb->s_fs_info = data;
2102         return set_anon_super(sb, NULL);
2103 }
2104 
2105 static struct dentry *ubifs_mount(struct file_system_type *fs_type, int flags,
2106                         const char *name, void *data)
2107 {
2108         struct ubi_volume_desc *ubi;
2109         struct ubifs_info *c;
2110         struct super_block *sb;
2111         int err;
2112 
2113         dbg_gen("name %s, flags %#x", name, flags);
2114 
2115         /*
2116          * Get UBI device number and volume ID. Mount it read-only so far
2117          * because this might be a new mount point, and UBI allows only one
2118          * read-write user at a time.
2119          */
2120         ubi = open_ubi(name, UBI_READONLY);
2121         if (IS_ERR(ubi)) {
2122                 if (!(flags & MS_SILENT))
2123                         pr_err("UBIFS error (pid: %d): cannot open \"%s\", error %d",
2124                                current->pid, name, (int)PTR_ERR(ubi));
2125                 return ERR_CAST(ubi);
2126         }
2127 
2128         c = alloc_ubifs_info(ubi);
2129         if (!c) {
2130                 err = -ENOMEM;
2131                 goto out_close;
2132         }
2133 
2134         dbg_gen("opened ubi%d_%d", c->vi.ubi_num, c->vi.vol_id);
2135 
2136         sb = sget(fs_type, sb_test, sb_set, flags, c);
2137         if (IS_ERR(sb)) {
2138                 err = PTR_ERR(sb);
2139                 kfree(c);
2140                 goto out_close;
2141         }
2142 
2143         if (sb->s_root) {
2144                 struct ubifs_info *c1 = sb->s_fs_info;
2145                 kfree(c);
2146                 /* A new mount point for already mounted UBIFS */
2147                 dbg_gen("this ubi volume is already mounted");
2148                 if (!!(flags & MS_RDONLY) != c1->ro_mount) {
2149                         err = -EBUSY;
2150                         goto out_deact;
2151                 }
2152         } else {
2153                 err = ubifs_fill_super(sb, data, flags & MS_SILENT ? 1 : 0);
2154                 if (err)
2155                         goto out_deact;
2156                 /* We do not support atime */
2157                 sb->s_flags |= MS_ACTIVE;
2158 #ifndef CONFIG_UBIFS_ATIME_SUPPORT
2159                 sb->s_flags |= MS_NOATIME;
2160 #else
2161                 ubifs_msg(c, "full atime support is enabled.");
2162 #endif
2163         }
2164 
2165         /* 'fill_super()' opens ubi again so we must close it here */
2166         ubi_close_volume(ubi);
2167 
2168         return dget(sb->s_root);
2169 
2170 out_deact:
2171         deactivate_locked_super(sb);
2172 out_close:
2173         ubi_close_volume(ubi);
2174         return ERR_PTR(err);
2175 }
2176 
2177 static void kill_ubifs_super(struct super_block *s)
2178 {
2179         struct ubifs_info *c = s->s_fs_info;
2180         kill_anon_super(s);
2181         kfree(c);
2182 }
2183 
2184 static struct file_system_type ubifs_fs_type = {
2185         .name    = "ubifs",
2186         .owner   = THIS_MODULE,
2187         .mount   = ubifs_mount,
2188         .kill_sb = kill_ubifs_super,
2189 };
2190 MODULE_ALIAS_FS("ubifs");
2191 
2192 /*
2193  * Inode slab cache constructor.
2194  */
2195 static void inode_slab_ctor(void *obj)
2196 {
2197         struct ubifs_inode *ui = obj;
2198         inode_init_once(&ui->vfs_inode);
2199 }
2200 
2201 static int __init ubifs_init(void)
2202 {
2203         int err;
2204 
2205         BUILD_BUG_ON(sizeof(struct ubifs_ch) != 24);
2206 
2207         /* Make sure node sizes are 8-byte aligned */
2208         BUILD_BUG_ON(UBIFS_CH_SZ        & 7);
2209         BUILD_BUG_ON(UBIFS_INO_NODE_SZ  & 7);
2210         BUILD_BUG_ON(UBIFS_DENT_NODE_SZ & 7);
2211         BUILD_BUG_ON(UBIFS_XENT_NODE_SZ & 7);
2212         BUILD_BUG_ON(UBIFS_DATA_NODE_SZ & 7);
2213         BUILD_BUG_ON(UBIFS_TRUN_NODE_SZ & 7);
2214         BUILD_BUG_ON(UBIFS_SB_NODE_SZ   & 7);
2215         BUILD_BUG_ON(UBIFS_MST_NODE_SZ  & 7);
2216         BUILD_BUG_ON(UBIFS_REF_NODE_SZ  & 7);
2217         BUILD_BUG_ON(UBIFS_CS_NODE_SZ   & 7);
2218         BUILD_BUG_ON(UBIFS_ORPH_NODE_SZ & 7);
2219 
2220         BUILD_BUG_ON(UBIFS_MAX_DENT_NODE_SZ & 7);
2221         BUILD_BUG_ON(UBIFS_MAX_XENT_NODE_SZ & 7);
2222         BUILD_BUG_ON(UBIFS_MAX_DATA_NODE_SZ & 7);
2223         BUILD_BUG_ON(UBIFS_MAX_INO_NODE_SZ  & 7);
2224         BUILD_BUG_ON(UBIFS_MAX_NODE_SZ      & 7);
2225         BUILD_BUG_ON(MIN_WRITE_SZ           & 7);
2226 
2227         /* Check min. node size */
2228         BUILD_BUG_ON(UBIFS_INO_NODE_SZ  < MIN_WRITE_SZ);
2229         BUILD_BUG_ON(UBIFS_DENT_NODE_SZ < MIN_WRITE_SZ);
2230         BUILD_BUG_ON(UBIFS_XENT_NODE_SZ < MIN_WRITE_SZ);
2231         BUILD_BUG_ON(UBIFS_TRUN_NODE_SZ < MIN_WRITE_SZ);
2232 
2233         BUILD_BUG_ON(UBIFS_MAX_DENT_NODE_SZ > UBIFS_MAX_NODE_SZ);
2234         BUILD_BUG_ON(UBIFS_MAX_XENT_NODE_SZ > UBIFS_MAX_NODE_SZ);
2235         BUILD_BUG_ON(UBIFS_MAX_DATA_NODE_SZ > UBIFS_MAX_NODE_SZ);
2236         BUILD_BUG_ON(UBIFS_MAX_INO_NODE_SZ  > UBIFS_MAX_NODE_SZ);
2237 
2238         /* Defined node sizes */
2239         BUILD_BUG_ON(UBIFS_SB_NODE_SZ  != 4096);
2240         BUILD_BUG_ON(UBIFS_MST_NODE_SZ != 512);
2241         BUILD_BUG_ON(UBIFS_INO_NODE_SZ != 160);
2242         BUILD_BUG_ON(UBIFS_REF_NODE_SZ != 64);
2243 
2244         /*
2245          * We use 2 bit wide bit-fields to store compression type, which should
2246          * be amended if more compressors are added. The bit-fields are:
2247          * @compr_type in 'struct ubifs_inode', @default_compr in
2248          * 'struct ubifs_info' and @compr_type in 'struct ubifs_mount_opts'.
2249          */
2250         BUILD_BUG_ON(UBIFS_COMPR_TYPES_CNT > 4);
2251 
2252         /*
2253          * We require that PAGE_SIZE is greater-than-or-equal-to
2254          * UBIFS_BLOCK_SIZE. It is assumed that both are powers of 2.
2255          */
2256         if (PAGE_SIZE < UBIFS_BLOCK_SIZE) {
2257                 pr_err("UBIFS error (pid %d): VFS page cache size is %u bytes, but UBIFS requires at least 4096 bytes",
2258                        current->pid, (unsigned int)PAGE_SIZE);
2259                 return -EINVAL;
2260         }
2261 
2262         ubifs_inode_slab = kmem_cache_create("ubifs_inode_slab",
2263                                 sizeof(struct ubifs_inode), 0,
2264                                 SLAB_MEM_SPREAD | SLAB_RECLAIM_ACCOUNT |
2265                                 SLAB_ACCOUNT, &inode_slab_ctor);
2266         if (!ubifs_inode_slab)
2267                 return -ENOMEM;
2268 
2269         err = register_shrinker(&ubifs_shrinker_info);
2270         if (err)
2271                 goto out_slab;
2272 
2273         err = ubifs_compressors_init();
2274         if (err)
2275                 goto out_shrinker;
2276 
2277         err = dbg_debugfs_init();
2278         if (err)
2279                 goto out_compr;
2280 
2281         err = register_filesystem(&ubifs_fs_type);
2282         if (err) {
2283                 pr_err("UBIFS error (pid %d): cannot register file system, error %d",
2284                        current->pid, err);
2285                 goto out_dbg;
2286         }
2287         return 0;
2288 
2289 out_dbg:
2290         dbg_debugfs_exit();
2291 out_compr:
2292         ubifs_compressors_exit();
2293 out_shrinker:
2294         unregister_shrinker(&ubifs_shrinker_info);
2295 out_slab:
2296         kmem_cache_destroy(ubifs_inode_slab);
2297         return err;
2298 }
2299 /* late_initcall to let compressors initialize first */
2300 late_initcall(ubifs_init);
2301 
2302 static void __exit ubifs_exit(void)
2303 {
2304         ubifs_assert(list_empty(&ubifs_infos));
2305         ubifs_assert(atomic_long_read(&ubifs_clean_zn_cnt) == 0);
2306 
2307         dbg_debugfs_exit();
2308         ubifs_compressors_exit();
2309         unregister_shrinker(&ubifs_shrinker_info);
2310 
2311         /*
2312          * Make sure all delayed rcu free inodes are flushed before we
2313          * destroy cache.
2314          */
2315         rcu_barrier();
2316         kmem_cache_destroy(ubifs_inode_slab);
2317         unregister_filesystem(&ubifs_fs_type);
2318 }
2319 module_exit(ubifs_exit);
2320 
2321 MODULE_LICENSE("GPL");
2322 MODULE_VERSION(__stringify(UBIFS_VERSION));
2323 MODULE_AUTHOR("Artem Bityutskiy, Adrian Hunter");
2324 MODULE_DESCRIPTION("UBIFS - UBI File System");
2325 

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