1 /* * This file is part of UBIFS.
3 * Copyright (C) 2006-2008 Nokia Corporation.
4 * Copyright (C) 2006, 2007 University of Szeged, Hungary
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.
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
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
19 * Authors: Artem Bityutskiy (Битюцкий Артём)
25 * This file implements directory operations.
27 * All FS operations in this file allocate budget before writing anything to the
28 * media. If they fail to allocate it, the error is returned. The only
29 * exceptions are 'ubifs_unlink()' and 'ubifs_rmdir()' which keep working even
30 * if they unable to allocate the budget, because deletion %-ENOSPC failure is
31 * not what users are usually ready to get. UBIFS budgeting subsystem has some
32 * space reserved for these purposes.
34 * All operations in this file write all inodes which they change straight
35 * away, instead of marking them dirty. For example, 'ubifs_link()' changes
36 * @i_size of the parent inode and writes the parent inode together with the
37 * target inode. This was done to simplify file-system recovery which would
38 * otherwise be very difficult to do. The only exception is rename which marks
39 * the re-named inode dirty (because its @i_ctime is updated) but does not
40 * write it, but just marks it as dirty.
46 * inherit_flags - inherit flags of the parent inode.
48 * @mode: new inode mode flags
50 * This is a helper function for 'ubifs_new_inode()' which inherits flag of the
51 * parent directory inode @dir. UBIFS inodes inherit the following flags:
52 * o %UBIFS_COMPR_FL, which is useful to switch compression on/of on
53 * sub-directory basis;
54 * o %UBIFS_SYNC_FL - useful for the same reasons;
55 * o %UBIFS_DIRSYNC_FL - similar, but relevant only to directories.
57 * This function returns the inherited flags.
59 static int inherit_flags(const struct inode *dir, int mode)
62 const struct ubifs_inode *ui = ubifs_inode(dir);
64 if (!S_ISDIR(dir->i_mode))
66 * The parent is not a directory, which means that an extended
67 * attribute inode is being created. No flags.
71 flags = ui->flags & (UBIFS_COMPR_FL | UBIFS_SYNC_FL | UBIFS_DIRSYNC_FL);
73 /* The "DIRSYNC" flag only applies to directories */
74 flags &= ~UBIFS_DIRSYNC_FL;
79 * ubifs_new_inode - allocate new UBIFS inode object.
80 * @c: UBIFS file-system description object
81 * @dir: parent directory inode
82 * @mode: inode mode flags
84 * This function finds an unused inode number, allocates new inode and
85 * initializes it. Returns new inode in case of success and an error code in
88 struct inode *ubifs_new_inode(struct ubifs_info *c, const struct inode *dir,
92 struct ubifs_inode *ui;
94 inode = new_inode(c->vfs_sb);
95 ui = ubifs_inode(inode);
97 return ERR_PTR(-ENOMEM);
100 * Set 'S_NOCMTIME' to prevent VFS form updating [mc]time of inodes and
101 * marking them dirty in file write path (see 'file_update_time()').
102 * UBIFS has to fully control "clean <-> dirty" transitions of inodes
103 * to make budgeting work.
105 inode->i_flags |= S_NOCMTIME;
107 inode_init_owner(inode, dir, mode);
108 inode->i_mtime = inode->i_atime = inode->i_ctime =
109 ubifs_current_time(inode);
110 inode->i_mapping->nrpages = 0;
111 /* Disable readahead */
112 inode->i_mapping->backing_dev_info = &c->bdi;
114 switch (mode & S_IFMT) {
116 inode->i_mapping->a_ops = &ubifs_file_address_operations;
117 inode->i_op = &ubifs_file_inode_operations;
118 inode->i_fop = &ubifs_file_operations;
121 inode->i_op = &ubifs_dir_inode_operations;
122 inode->i_fop = &ubifs_dir_operations;
123 inode->i_size = ui->ui_size = UBIFS_INO_NODE_SZ;
126 inode->i_op = &ubifs_symlink_inode_operations;
132 inode->i_op = &ubifs_file_inode_operations;
138 ui->flags = inherit_flags(dir, mode);
139 ubifs_set_inode_flags(inode);
141 ui->compr_type = c->default_compr;
143 ui->compr_type = UBIFS_COMPR_NONE;
144 ui->synced_i_size = 0;
146 spin_lock(&c->cnt_lock);
147 /* Inode number overflow is currently not supported */
148 if (c->highest_inum >= INUM_WARN_WATERMARK) {
149 if (c->highest_inum >= INUM_WATERMARK) {
150 spin_unlock(&c->cnt_lock);
151 ubifs_err("out of inode numbers");
152 make_bad_inode(inode);
154 return ERR_PTR(-EINVAL);
156 ubifs_warn("running out of inode numbers (current %lu, max %d)",
157 (unsigned long)c->highest_inum, INUM_WATERMARK);
160 inode->i_ino = ++c->highest_inum;
162 * The creation sequence number remains with this inode for its
163 * lifetime. All nodes for this inode have a greater sequence number,
164 * and so it is possible to distinguish obsolete nodes belonging to a
165 * previous incarnation of the same inode number - for example, for the
166 * purpose of rebuilding the index.
168 ui->creat_sqnum = ++c->max_sqnum;
169 spin_unlock(&c->cnt_lock);
173 #ifdef CONFIG_UBIFS_FS_DEBUG
175 static int dbg_check_name(const struct ubifs_info *c,
176 const struct ubifs_dent_node *dent,
177 const struct qstr *nm)
179 if (!dbg_is_chk_gen(c))
181 if (le16_to_cpu(dent->nlen) != nm->len)
183 if (memcmp(dent->name, nm->name, nm->len))
190 #define dbg_check_name(c, dent, nm) 0
194 static struct dentry *ubifs_lookup(struct inode *dir, struct dentry *dentry,
195 struct nameidata *nd)
199 struct inode *inode = NULL;
200 struct ubifs_dent_node *dent;
201 struct ubifs_info *c = dir->i_sb->s_fs_info;
203 dbg_gen("'%.*s' in dir ino %lu",
204 dentry->d_name.len, dentry->d_name.name, dir->i_ino);
206 if (dentry->d_name.len > UBIFS_MAX_NLEN)
207 return ERR_PTR(-ENAMETOOLONG);
209 dent = kmalloc(UBIFS_MAX_DENT_NODE_SZ, GFP_NOFS);
211 return ERR_PTR(-ENOMEM);
213 dent_key_init(c, &key, dir->i_ino, &dentry->d_name);
215 err = ubifs_tnc_lookup_nm(c, &key, dent, &dentry->d_name);
217 if (err == -ENOENT) {
218 dbg_gen("not found");
224 if (dbg_check_name(c, dent, &dentry->d_name)) {
229 inode = ubifs_iget(dir->i_sb, le64_to_cpu(dent->inum));
232 * This should not happen. Probably the file-system needs
235 err = PTR_ERR(inode);
236 ubifs_err("dead directory entry '%.*s', error %d",
237 dentry->d_name.len, dentry->d_name.name, err);
238 ubifs_ro_mode(c, err);
245 * Note, d_splice_alias() would be required instead if we supported
248 d_add(dentry, inode);
256 static int ubifs_create(struct inode *dir, struct dentry *dentry, int mode,
257 struct nameidata *nd)
260 struct ubifs_info *c = dir->i_sb->s_fs_info;
261 int err, sz_change = CALC_DENT_SIZE(dentry->d_name.len);
262 struct ubifs_budget_req req = { .new_ino = 1, .new_dent = 1,
264 struct ubifs_inode *dir_ui = ubifs_inode(dir);
267 * Budget request settings: new inode, new direntry, changing the
268 * parent directory inode.
271 dbg_gen("dent '%.*s', mode %#x in dir ino %lu",
272 dentry->d_name.len, dentry->d_name.name, mode, dir->i_ino);
274 err = ubifs_budget_space(c, &req);
278 inode = ubifs_new_inode(c, dir, mode);
280 err = PTR_ERR(inode);
284 mutex_lock(&dir_ui->ui_mutex);
285 dir->i_size += sz_change;
286 dir_ui->ui_size = dir->i_size;
287 dir->i_mtime = dir->i_ctime = inode->i_ctime;
288 err = ubifs_jnl_update(c, dir, &dentry->d_name, inode, 0, 0);
291 mutex_unlock(&dir_ui->ui_mutex);
293 ubifs_release_budget(c, &req);
294 insert_inode_hash(inode);
295 d_instantiate(dentry, inode);
299 dir->i_size -= sz_change;
300 dir_ui->ui_size = dir->i_size;
301 mutex_unlock(&dir_ui->ui_mutex);
302 make_bad_inode(inode);
305 ubifs_release_budget(c, &req);
306 ubifs_err("cannot create regular file, error %d", err);
311 * vfs_dent_type - get VFS directory entry type.
312 * @type: UBIFS directory entry type
314 * This function converts UBIFS directory entry type into VFS directory entry
317 static unsigned int vfs_dent_type(uint8_t type)
320 case UBIFS_ITYPE_REG:
322 case UBIFS_ITYPE_DIR:
324 case UBIFS_ITYPE_LNK:
326 case UBIFS_ITYPE_BLK:
328 case UBIFS_ITYPE_CHR:
330 case UBIFS_ITYPE_FIFO:
332 case UBIFS_ITYPE_SOCK:
341 * The classical Unix view for directory is that it is a linear array of
342 * (name, inode number) entries. Linux/VFS assumes this model as well.
343 * Particularly, 'readdir()' call wants us to return a directory entry offset
344 * which later may be used to continue 'readdir()'ing the directory or to
345 * 'seek()' to that specific direntry. Obviously UBIFS does not really fit this
346 * model because directory entries are identified by keys, which may collide.
348 * UBIFS uses directory entry hash value for directory offsets, so
349 * 'seekdir()'/'telldir()' may not always work because of possible key
350 * collisions. But UBIFS guarantees that consecutive 'readdir()' calls work
351 * properly by means of saving full directory entry name in the private field
352 * of the file description object.
354 * This means that UBIFS cannot support NFS which requires full
355 * 'seekdir()'/'telldir()' support.
357 static int ubifs_readdir(struct file *file, void *dirent, filldir_t filldir)
360 loff_t pos = file->f_pos;
363 struct ubifs_dent_node *dent;
364 struct inode *dir = file->f_path.dentry->d_inode;
365 struct ubifs_info *c = dir->i_sb->s_fs_info;
367 dbg_gen("dir ino %lu, f_pos %#llx", dir->i_ino, pos);
369 if (pos > UBIFS_S_KEY_HASH_MASK || pos == 2)
371 * The directory was seek'ed to a senseless position or there
372 * are no more entries.
376 if (file->f_version == 0) {
378 * The file was seek'ed, which means that @file->private_data
379 * is now invalid. This may also be just the first
380 * 'ubifs_readdir()' invocation, in which case
381 * @file->private_data is NULL, and the below code is
384 kfree(file->private_data);
385 file->private_data = NULL;
389 * 'generic_file_llseek()' unconditionally sets @file->f_version to
390 * zero, and we use this for detecting whether the file was seek'ed.
394 /* File positions 0 and 1 correspond to "." and ".." */
396 ubifs_assert(!file->private_data);
397 over = filldir(dirent, ".", 1, 0, dir->i_ino, DT_DIR);
400 file->f_pos = pos = 1;
404 ubifs_assert(!file->private_data);
405 over = filldir(dirent, "..", 2, 1,
406 parent_ino(file->f_path.dentry), DT_DIR);
410 /* Find the first entry in TNC and save it */
411 lowest_dent_key(c, &key, dir->i_ino);
413 dent = ubifs_tnc_next_ent(c, &key, &nm);
419 file->f_pos = pos = key_hash_flash(c, &dent->key);
420 file->private_data = dent;
423 dent = file->private_data;
426 * The directory was seek'ed to and is now readdir'ed.
427 * Find the entry corresponding to @pos or the closest one.
429 dent_key_init_hash(c, &key, dir->i_ino, pos);
431 dent = ubifs_tnc_next_ent(c, &key, &nm);
436 file->f_pos = pos = key_hash_flash(c, &dent->key);
437 file->private_data = dent;
441 dbg_gen("feed '%s', ino %llu, new f_pos %#x",
442 dent->name, (unsigned long long)le64_to_cpu(dent->inum),
443 key_hash_flash(c, &dent->key));
444 ubifs_assert(le64_to_cpu(dent->ch.sqnum) >
445 ubifs_inode(dir)->creat_sqnum);
447 nm.len = le16_to_cpu(dent->nlen);
448 over = filldir(dirent, dent->name, nm.len, pos,
449 le64_to_cpu(dent->inum),
450 vfs_dent_type(dent->type));
454 /* Switch to the next entry */
455 key_read(c, &dent->key, &key);
456 nm.name = dent->name;
457 dent = ubifs_tnc_next_ent(c, &key, &nm);
463 kfree(file->private_data);
464 file->f_pos = pos = key_hash_flash(c, &dent->key);
465 file->private_data = dent;
468 if (file->f_version == 0)
470 * The file was seek'ed meanwhile, lets return and start
471 * reading direntries from the new position on the next
478 if (err != -ENOENT) {
479 ubifs_err("cannot find next direntry, error %d", err);
483 kfree(file->private_data);
484 file->private_data = NULL;
485 /* 2 is a special value indicating that there are no more direntries */
490 static loff_t ubifs_dir_llseek(struct file *file, loff_t offset, int origin)
492 return generic_file_llseek(file, offset, origin);
495 /* Free saved readdir() state when the directory is closed */
496 static int ubifs_dir_release(struct inode *dir, struct file *file)
498 kfree(file->private_data);
499 file->private_data = NULL;
504 * lock_2_inodes - a wrapper for locking two UBIFS inodes.
505 * @inode1: first inode
506 * @inode2: second inode
508 * We do not implement any tricks to guarantee strict lock ordering, because
509 * VFS has already done it for us on the @i_mutex. So this is just a simple
512 static void lock_2_inodes(struct inode *inode1, struct inode *inode2)
514 mutex_lock_nested(&ubifs_inode(inode1)->ui_mutex, WB_MUTEX_1);
515 mutex_lock_nested(&ubifs_inode(inode2)->ui_mutex, WB_MUTEX_2);
519 * unlock_2_inodes - a wrapper for unlocking two UBIFS inodes.
520 * @inode1: first inode
521 * @inode2: second inode
523 static void unlock_2_inodes(struct inode *inode1, struct inode *inode2)
525 mutex_unlock(&ubifs_inode(inode2)->ui_mutex);
526 mutex_unlock(&ubifs_inode(inode1)->ui_mutex);
529 static int ubifs_link(struct dentry *old_dentry, struct inode *dir,
530 struct dentry *dentry)
532 struct ubifs_info *c = dir->i_sb->s_fs_info;
533 struct inode *inode = old_dentry->d_inode;
534 struct ubifs_inode *ui = ubifs_inode(inode);
535 struct ubifs_inode *dir_ui = ubifs_inode(dir);
536 int err, sz_change = CALC_DENT_SIZE(dentry->d_name.len);
537 struct ubifs_budget_req req = { .new_dent = 1, .dirtied_ino = 2,
538 .dirtied_ino_d = ALIGN(ui->data_len, 8) };
541 * Budget request settings: new direntry, changing the target inode,
542 * changing the parent inode.
545 dbg_gen("dent '%.*s' to ino %lu (nlink %d) in dir ino %lu",
546 dentry->d_name.len, dentry->d_name.name, inode->i_ino,
547 inode->i_nlink, dir->i_ino);
548 ubifs_assert(mutex_is_locked(&dir->i_mutex));
549 ubifs_assert(mutex_is_locked(&inode->i_mutex));
551 err = dbg_check_synced_i_size(c, inode);
555 err = ubifs_budget_space(c, &req);
559 lock_2_inodes(dir, inode);
562 inode->i_ctime = ubifs_current_time(inode);
563 dir->i_size += sz_change;
564 dir_ui->ui_size = dir->i_size;
565 dir->i_mtime = dir->i_ctime = inode->i_ctime;
566 err = ubifs_jnl_update(c, dir, &dentry->d_name, inode, 0, 0);
569 unlock_2_inodes(dir, inode);
571 ubifs_release_budget(c, &req);
572 d_instantiate(dentry, inode);
576 dir->i_size -= sz_change;
577 dir_ui->ui_size = dir->i_size;
579 unlock_2_inodes(dir, inode);
580 ubifs_release_budget(c, &req);
585 static int ubifs_unlink(struct inode *dir, struct dentry *dentry)
587 struct ubifs_info *c = dir->i_sb->s_fs_info;
588 struct inode *inode = dentry->d_inode;
589 struct ubifs_inode *dir_ui = ubifs_inode(dir);
590 int sz_change = CALC_DENT_SIZE(dentry->d_name.len);
591 int err, budgeted = 1;
592 struct ubifs_budget_req req = { .mod_dent = 1, .dirtied_ino = 2 };
595 * Budget request settings: deletion direntry, deletion inode (+1 for
596 * @dirtied_ino), changing the parent directory inode. If budgeting
597 * fails, go ahead anyway because we have extra space reserved for
601 dbg_gen("dent '%.*s' from ino %lu (nlink %d) in dir ino %lu",
602 dentry->d_name.len, dentry->d_name.name, inode->i_ino,
603 inode->i_nlink, dir->i_ino);
604 ubifs_assert(mutex_is_locked(&dir->i_mutex));
605 ubifs_assert(mutex_is_locked(&inode->i_mutex));
606 err = dbg_check_synced_i_size(c, inode);
610 err = ubifs_budget_space(c, &req);
617 lock_2_inodes(dir, inode);
618 inode->i_ctime = ubifs_current_time(dir);
620 dir->i_size -= sz_change;
621 dir_ui->ui_size = dir->i_size;
622 dir->i_mtime = dir->i_ctime = inode->i_ctime;
623 err = ubifs_jnl_update(c, dir, &dentry->d_name, inode, 1, 0);
626 unlock_2_inodes(dir, inode);
629 ubifs_release_budget(c, &req);
631 /* We've deleted something - clean the "no space" flags */
632 c->bi.nospace = c->bi.nospace_rp = 0;
638 dir->i_size += sz_change;
639 dir_ui->ui_size = dir->i_size;
641 unlock_2_inodes(dir, inode);
643 ubifs_release_budget(c, &req);
648 * check_dir_empty - check if a directory is empty or not.
649 * @c: UBIFS file-system description object
650 * @dir: VFS inode object of the directory to check
652 * This function checks if directory @dir is empty. Returns zero if the
653 * directory is empty, %-ENOTEMPTY if it is not, and other negative error codes
654 * in case of of errors.
656 static int check_dir_empty(struct ubifs_info *c, struct inode *dir)
658 struct qstr nm = { .name = NULL };
659 struct ubifs_dent_node *dent;
663 lowest_dent_key(c, &key, dir->i_ino);
664 dent = ubifs_tnc_next_ent(c, &key, &nm);
676 static int ubifs_rmdir(struct inode *dir, struct dentry *dentry)
678 struct ubifs_info *c = dir->i_sb->s_fs_info;
679 struct inode *inode = dentry->d_inode;
680 int sz_change = CALC_DENT_SIZE(dentry->d_name.len);
681 int err, budgeted = 1;
682 struct ubifs_inode *dir_ui = ubifs_inode(dir);
683 struct ubifs_budget_req req = { .mod_dent = 1, .dirtied_ino = 2 };
686 * Budget request settings: deletion direntry, deletion inode and
687 * changing the parent inode. If budgeting fails, go ahead anyway
688 * because we have extra space reserved for deletions.
691 dbg_gen("directory '%.*s', ino %lu in dir ino %lu", dentry->d_name.len,
692 dentry->d_name.name, inode->i_ino, dir->i_ino);
693 ubifs_assert(mutex_is_locked(&dir->i_mutex));
694 ubifs_assert(mutex_is_locked(&inode->i_mutex));
695 err = check_dir_empty(c, dentry->d_inode);
699 err = ubifs_budget_space(c, &req);
706 lock_2_inodes(dir, inode);
707 inode->i_ctime = ubifs_current_time(dir);
710 dir->i_size -= sz_change;
711 dir_ui->ui_size = dir->i_size;
712 dir->i_mtime = dir->i_ctime = inode->i_ctime;
713 err = ubifs_jnl_update(c, dir, &dentry->d_name, inode, 1, 0);
716 unlock_2_inodes(dir, inode);
719 ubifs_release_budget(c, &req);
721 /* We've deleted something - clean the "no space" flags */
722 c->bi.nospace = c->bi.nospace_rp = 0;
728 dir->i_size += sz_change;
729 dir_ui->ui_size = dir->i_size;
733 unlock_2_inodes(dir, inode);
735 ubifs_release_budget(c, &req);
739 static int ubifs_mkdir(struct inode *dir, struct dentry *dentry, int mode)
742 struct ubifs_inode *dir_ui = ubifs_inode(dir);
743 struct ubifs_info *c = dir->i_sb->s_fs_info;
744 int err, sz_change = CALC_DENT_SIZE(dentry->d_name.len);
745 struct ubifs_budget_req req = { .new_ino = 1, .new_dent = 1 };
748 * Budget request settings: new inode, new direntry and changing parent
752 dbg_gen("dent '%.*s', mode %#x in dir ino %lu",
753 dentry->d_name.len, dentry->d_name.name, mode, dir->i_ino);
755 err = ubifs_budget_space(c, &req);
759 inode = ubifs_new_inode(c, dir, S_IFDIR | mode);
761 err = PTR_ERR(inode);
765 mutex_lock(&dir_ui->ui_mutex);
766 insert_inode_hash(inode);
769 dir->i_size += sz_change;
770 dir_ui->ui_size = dir->i_size;
771 dir->i_mtime = dir->i_ctime = inode->i_ctime;
772 err = ubifs_jnl_update(c, dir, &dentry->d_name, inode, 0, 0);
774 ubifs_err("cannot create directory, error %d", err);
777 mutex_unlock(&dir_ui->ui_mutex);
779 ubifs_release_budget(c, &req);
780 d_instantiate(dentry, inode);
784 dir->i_size -= sz_change;
785 dir_ui->ui_size = dir->i_size;
787 mutex_unlock(&dir_ui->ui_mutex);
788 make_bad_inode(inode);
791 ubifs_release_budget(c, &req);
795 static int ubifs_mknod(struct inode *dir, struct dentry *dentry,
796 int mode, dev_t rdev)
799 struct ubifs_inode *ui;
800 struct ubifs_inode *dir_ui = ubifs_inode(dir);
801 struct ubifs_info *c = dir->i_sb->s_fs_info;
802 union ubifs_dev_desc *dev = NULL;
803 int sz_change = CALC_DENT_SIZE(dentry->d_name.len);
805 struct ubifs_budget_req req = { .new_ino = 1, .new_dent = 1,
806 .new_ino_d = ALIGN(devlen, 8),
810 * Budget request settings: new inode, new direntry and changing parent
814 dbg_gen("dent '%.*s' in dir ino %lu",
815 dentry->d_name.len, dentry->d_name.name, dir->i_ino);
817 if (!new_valid_dev(rdev))
820 if (S_ISBLK(mode) || S_ISCHR(mode)) {
821 dev = kmalloc(sizeof(union ubifs_dev_desc), GFP_NOFS);
824 devlen = ubifs_encode_dev(dev, rdev);
827 err = ubifs_budget_space(c, &req);
833 inode = ubifs_new_inode(c, dir, mode);
836 err = PTR_ERR(inode);
840 init_special_inode(inode, inode->i_mode, rdev);
841 inode->i_size = ubifs_inode(inode)->ui_size = devlen;
842 ui = ubifs_inode(inode);
844 ui->data_len = devlen;
846 mutex_lock(&dir_ui->ui_mutex);
847 dir->i_size += sz_change;
848 dir_ui->ui_size = dir->i_size;
849 dir->i_mtime = dir->i_ctime = inode->i_ctime;
850 err = ubifs_jnl_update(c, dir, &dentry->d_name, inode, 0, 0);
853 mutex_unlock(&dir_ui->ui_mutex);
855 ubifs_release_budget(c, &req);
856 insert_inode_hash(inode);
857 d_instantiate(dentry, inode);
861 dir->i_size -= sz_change;
862 dir_ui->ui_size = dir->i_size;
863 mutex_unlock(&dir_ui->ui_mutex);
864 make_bad_inode(inode);
867 ubifs_release_budget(c, &req);
871 static int ubifs_symlink(struct inode *dir, struct dentry *dentry,
875 struct ubifs_inode *ui;
876 struct ubifs_inode *dir_ui = ubifs_inode(dir);
877 struct ubifs_info *c = dir->i_sb->s_fs_info;
878 int err, len = strlen(symname);
879 int sz_change = CALC_DENT_SIZE(dentry->d_name.len);
880 struct ubifs_budget_req req = { .new_ino = 1, .new_dent = 1,
881 .new_ino_d = ALIGN(len, 8),
885 * Budget request settings: new inode, new direntry and changing parent
889 dbg_gen("dent '%.*s', target '%s' in dir ino %lu", dentry->d_name.len,
890 dentry->d_name.name, symname, dir->i_ino);
892 if (len > UBIFS_MAX_INO_DATA)
893 return -ENAMETOOLONG;
895 err = ubifs_budget_space(c, &req);
899 inode = ubifs_new_inode(c, dir, S_IFLNK | S_IRWXUGO);
901 err = PTR_ERR(inode);
905 ui = ubifs_inode(inode);
906 ui->data = kmalloc(len + 1, GFP_NOFS);
912 memcpy(ui->data, symname, len);
913 ((char *)ui->data)[len] = '\0';
915 * The terminating zero byte is not written to the flash media and it
916 * is put just to make later in-memory string processing simpler. Thus,
917 * data length is @len, not @len + %1.
920 inode->i_size = ubifs_inode(inode)->ui_size = len;
922 mutex_lock(&dir_ui->ui_mutex);
923 dir->i_size += sz_change;
924 dir_ui->ui_size = dir->i_size;
925 dir->i_mtime = dir->i_ctime = inode->i_ctime;
926 err = ubifs_jnl_update(c, dir, &dentry->d_name, inode, 0, 0);
929 mutex_unlock(&dir_ui->ui_mutex);
931 ubifs_release_budget(c, &req);
932 insert_inode_hash(inode);
933 d_instantiate(dentry, inode);
937 dir->i_size -= sz_change;
938 dir_ui->ui_size = dir->i_size;
939 mutex_unlock(&dir_ui->ui_mutex);
941 make_bad_inode(inode);
944 ubifs_release_budget(c, &req);
949 * lock_3_inodes - a wrapper for locking three UBIFS inodes.
950 * @inode1: first inode
951 * @inode2: second inode
952 * @inode3: third inode
954 * This function is used for 'ubifs_rename()' and @inode1 may be the same as
955 * @inode2 whereas @inode3 may be %NULL.
957 * We do not implement any tricks to guarantee strict lock ordering, because
958 * VFS has already done it for us on the @i_mutex. So this is just a simple
961 static void lock_3_inodes(struct inode *inode1, struct inode *inode2,
962 struct inode *inode3)
964 mutex_lock_nested(&ubifs_inode(inode1)->ui_mutex, WB_MUTEX_1);
965 if (inode2 != inode1)
966 mutex_lock_nested(&ubifs_inode(inode2)->ui_mutex, WB_MUTEX_2);
968 mutex_lock_nested(&ubifs_inode(inode3)->ui_mutex, WB_MUTEX_3);
972 * unlock_3_inodes - a wrapper for unlocking three UBIFS inodes for rename.
973 * @inode1: first inode
974 * @inode2: second inode
975 * @inode3: third inode
977 static void unlock_3_inodes(struct inode *inode1, struct inode *inode2,
978 struct inode *inode3)
981 mutex_unlock(&ubifs_inode(inode3)->ui_mutex);
982 if (inode1 != inode2)
983 mutex_unlock(&ubifs_inode(inode2)->ui_mutex);
984 mutex_unlock(&ubifs_inode(inode1)->ui_mutex);
987 static int ubifs_rename(struct inode *old_dir, struct dentry *old_dentry,
988 struct inode *new_dir, struct dentry *new_dentry)
990 struct ubifs_info *c = old_dir->i_sb->s_fs_info;
991 struct inode *old_inode = old_dentry->d_inode;
992 struct inode *new_inode = new_dentry->d_inode;
993 struct ubifs_inode *old_inode_ui = ubifs_inode(old_inode);
994 int err, release, sync = 0, move = (new_dir != old_dir);
995 int is_dir = S_ISDIR(old_inode->i_mode);
996 int unlink = !!new_inode;
997 int new_sz = CALC_DENT_SIZE(new_dentry->d_name.len);
998 int old_sz = CALC_DENT_SIZE(old_dentry->d_name.len);
999 struct ubifs_budget_req req = { .new_dent = 1, .mod_dent = 1,
1001 struct ubifs_budget_req ino_req = { .dirtied_ino = 1,
1002 .dirtied_ino_d = ALIGN(old_inode_ui->data_len, 8) };
1003 struct timespec time;
1006 * Budget request settings: deletion direntry, new direntry, removing
1007 * the old inode, and changing old and new parent directory inodes.
1009 * However, this operation also marks the target inode as dirty and
1010 * does not write it, so we allocate budget for the target inode
1014 dbg_gen("dent '%.*s' ino %lu in dir ino %lu to dent '%.*s' in "
1015 "dir ino %lu", old_dentry->d_name.len, old_dentry->d_name.name,
1016 old_inode->i_ino, old_dir->i_ino, new_dentry->d_name.len,
1017 new_dentry->d_name.name, new_dir->i_ino);
1018 ubifs_assert(mutex_is_locked(&old_dir->i_mutex));
1019 ubifs_assert(mutex_is_locked(&new_dir->i_mutex));
1021 ubifs_assert(mutex_is_locked(&new_inode->i_mutex));
1024 if (unlink && is_dir) {
1025 err = check_dir_empty(c, new_inode);
1030 err = ubifs_budget_space(c, &req);
1033 err = ubifs_budget_space(c, &ino_req);
1035 ubifs_release_budget(c, &req);
1039 lock_3_inodes(old_dir, new_dir, new_inode);
1042 * Like most other Unix systems, set the @i_ctime for inodes on a
1045 time = ubifs_current_time(old_dir);
1046 old_inode->i_ctime = time;
1048 /* We must adjust parent link count when renaming directories */
1052 * @old_dir loses a link because we are moving
1053 * @old_inode to a different directory.
1055 drop_nlink(old_dir);
1057 * @new_dir only gains a link if we are not also
1058 * overwriting an existing directory.
1064 * @old_inode is not moving to a different directory,
1065 * but @old_dir still loses a link if we are
1066 * overwriting an existing directory.
1069 drop_nlink(old_dir);
1073 old_dir->i_size -= old_sz;
1074 ubifs_inode(old_dir)->ui_size = old_dir->i_size;
1075 old_dir->i_mtime = old_dir->i_ctime = time;
1076 new_dir->i_mtime = new_dir->i_ctime = time;
1079 * And finally, if we unlinked a direntry which happened to have the
1080 * same name as the moved direntry, we have to decrement @i_nlink of
1081 * the unlinked inode and change its ctime.
1085 * Directories cannot have hard-links, so if this is a
1086 * directory, decrement its @i_nlink twice because an empty
1087 * directory has @i_nlink 2.
1090 drop_nlink(new_inode);
1091 new_inode->i_ctime = time;
1092 drop_nlink(new_inode);
1094 new_dir->i_size += new_sz;
1095 ubifs_inode(new_dir)->ui_size = new_dir->i_size;
1099 * Do not ask 'ubifs_jnl_rename()' to flush write-buffer if @old_inode
1100 * is dirty, because this will be done later on at the end of
1103 if (IS_SYNC(old_inode)) {
1104 sync = IS_DIRSYNC(old_dir) || IS_DIRSYNC(new_dir);
1105 if (unlink && IS_SYNC(new_inode))
1108 err = ubifs_jnl_rename(c, old_dir, old_dentry, new_dir, new_dentry,
1113 unlock_3_inodes(old_dir, new_dir, new_inode);
1114 ubifs_release_budget(c, &req);
1116 mutex_lock(&old_inode_ui->ui_mutex);
1117 release = old_inode_ui->dirty;
1118 mark_inode_dirty_sync(old_inode);
1119 mutex_unlock(&old_inode_ui->ui_mutex);
1122 ubifs_release_budget(c, &ino_req);
1123 if (IS_SYNC(old_inode))
1124 err = old_inode->i_sb->s_op->write_inode(old_inode, NULL);
1130 inc_nlink(new_inode);
1131 inc_nlink(new_inode);
1133 new_dir->i_size -= new_sz;
1134 ubifs_inode(new_dir)->ui_size = new_dir->i_size;
1136 old_dir->i_size += old_sz;
1137 ubifs_inode(old_dir)->ui_size = old_dir->i_size;
1142 drop_nlink(new_dir);
1148 unlock_3_inodes(old_dir, new_dir, new_inode);
1149 ubifs_release_budget(c, &ino_req);
1150 ubifs_release_budget(c, &req);
1154 int ubifs_getattr(struct vfsmount *mnt, struct dentry *dentry,
1158 struct inode *inode = dentry->d_inode;
1159 struct ubifs_inode *ui = ubifs_inode(inode);
1161 mutex_lock(&ui->ui_mutex);
1162 stat->dev = inode->i_sb->s_dev;
1163 stat->ino = inode->i_ino;
1164 stat->mode = inode->i_mode;
1165 stat->nlink = inode->i_nlink;
1166 stat->uid = inode->i_uid;
1167 stat->gid = inode->i_gid;
1168 stat->rdev = inode->i_rdev;
1169 stat->atime = inode->i_atime;
1170 stat->mtime = inode->i_mtime;
1171 stat->ctime = inode->i_ctime;
1172 stat->blksize = UBIFS_BLOCK_SIZE;
1173 stat->size = ui->ui_size;
1176 * Unfortunately, the 'stat()' system call was designed for block
1177 * device based file systems, and it is not appropriate for UBIFS,
1178 * because UBIFS does not have notion of "block". For example, it is
1179 * difficult to tell how many block a directory takes - it actually
1180 * takes less than 300 bytes, but we have to round it to block size,
1181 * which introduces large mistake. This makes utilities like 'du' to
1182 * report completely senseless numbers. This is the reason why UBIFS
1183 * goes the same way as JFFS2 - it reports zero blocks for everything
1184 * but regular files, which makes more sense than reporting completely
1187 if (S_ISREG(inode->i_mode)) {
1188 size = ui->xattr_size;
1190 size = ALIGN(size, UBIFS_BLOCK_SIZE);
1192 * Note, user-space expects 512-byte blocks count irrespectively
1193 * of what was reported in @stat->size.
1195 stat->blocks = size >> 9;
1198 mutex_unlock(&ui->ui_mutex);
1202 const struct inode_operations ubifs_dir_inode_operations = {
1203 .lookup = ubifs_lookup,
1204 .create = ubifs_create,
1206 .symlink = ubifs_symlink,
1207 .unlink = ubifs_unlink,
1208 .mkdir = ubifs_mkdir,
1209 .rmdir = ubifs_rmdir,
1210 .mknod = ubifs_mknod,
1211 .rename = ubifs_rename,
1212 .setattr = ubifs_setattr,
1213 .getattr = ubifs_getattr,
1214 #ifdef CONFIG_UBIFS_FS_XATTR
1215 .setxattr = ubifs_setxattr,
1216 .getxattr = ubifs_getxattr,
1217 .listxattr = ubifs_listxattr,
1218 .removexattr = ubifs_removexattr,
1222 const struct file_operations ubifs_dir_operations = {
1223 .llseek = ubifs_dir_llseek,
1224 .release = ubifs_dir_release,
1225 .read = generic_read_dir,
1226 .readdir = ubifs_readdir,
1227 .fsync = ubifs_fsync,
1228 .unlocked_ioctl = ubifs_ioctl,
1229 #ifdef CONFIG_COMPAT
1230 .compat_ioctl = ubifs_compat_ioctl,