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)
359 int err = 0, over = 0;
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
479 ubifs_err("cannot find next direntry, error %d", err);
481 kfree(file->private_data);
482 file->private_data = NULL;
483 /* 2 is a special value indicating that there are no more direntries */
488 static loff_t ubifs_dir_llseek(struct file *file, loff_t offset, int origin)
490 return generic_file_llseek(file, offset, origin);
493 /* Free saved readdir() state when the directory is closed */
494 static int ubifs_dir_release(struct inode *dir, struct file *file)
496 kfree(file->private_data);
497 file->private_data = NULL;
502 * lock_2_inodes - a wrapper for locking two UBIFS inodes.
503 * @inode1: first inode
504 * @inode2: second inode
506 * We do not implement any tricks to guarantee strict lock ordering, because
507 * VFS has already done it for us on the @i_mutex. So this is just a simple
510 static void lock_2_inodes(struct inode *inode1, struct inode *inode2)
512 mutex_lock_nested(&ubifs_inode(inode1)->ui_mutex, WB_MUTEX_1);
513 mutex_lock_nested(&ubifs_inode(inode2)->ui_mutex, WB_MUTEX_2);
517 * unlock_2_inodes - a wrapper for unlocking two UBIFS inodes.
518 * @inode1: first inode
519 * @inode2: second inode
521 static void unlock_2_inodes(struct inode *inode1, struct inode *inode2)
523 mutex_unlock(&ubifs_inode(inode2)->ui_mutex);
524 mutex_unlock(&ubifs_inode(inode1)->ui_mutex);
527 static int ubifs_link(struct dentry *old_dentry, struct inode *dir,
528 struct dentry *dentry)
530 struct ubifs_info *c = dir->i_sb->s_fs_info;
531 struct inode *inode = old_dentry->d_inode;
532 struct ubifs_inode *ui = ubifs_inode(inode);
533 struct ubifs_inode *dir_ui = ubifs_inode(dir);
534 int err, sz_change = CALC_DENT_SIZE(dentry->d_name.len);
535 struct ubifs_budget_req req = { .new_dent = 1, .dirtied_ino = 2,
536 .dirtied_ino_d = ALIGN(ui->data_len, 8) };
539 * Budget request settings: new direntry, changing the target inode,
540 * changing the parent inode.
543 dbg_gen("dent '%.*s' to ino %lu (nlink %d) in dir ino %lu",
544 dentry->d_name.len, dentry->d_name.name, inode->i_ino,
545 inode->i_nlink, dir->i_ino);
546 ubifs_assert(mutex_is_locked(&dir->i_mutex));
547 ubifs_assert(mutex_is_locked(&inode->i_mutex));
549 err = dbg_check_synced_i_size(c, inode);
553 err = ubifs_budget_space(c, &req);
557 lock_2_inodes(dir, inode);
560 inode->i_ctime = ubifs_current_time(inode);
561 dir->i_size += sz_change;
562 dir_ui->ui_size = dir->i_size;
563 dir->i_mtime = dir->i_ctime = inode->i_ctime;
564 err = ubifs_jnl_update(c, dir, &dentry->d_name, inode, 0, 0);
567 unlock_2_inodes(dir, inode);
569 ubifs_release_budget(c, &req);
570 d_instantiate(dentry, inode);
574 dir->i_size -= sz_change;
575 dir_ui->ui_size = dir->i_size;
577 unlock_2_inodes(dir, inode);
578 ubifs_release_budget(c, &req);
583 static int ubifs_unlink(struct inode *dir, struct dentry *dentry)
585 struct ubifs_info *c = dir->i_sb->s_fs_info;
586 struct inode *inode = dentry->d_inode;
587 struct ubifs_inode *dir_ui = ubifs_inode(dir);
588 int sz_change = CALC_DENT_SIZE(dentry->d_name.len);
589 int err, budgeted = 1;
590 struct ubifs_budget_req req = { .mod_dent = 1, .dirtied_ino = 2 };
593 * Budget request settings: deletion direntry, deletion inode (+1 for
594 * @dirtied_ino), changing the parent directory inode. If budgeting
595 * fails, go ahead anyway because we have extra space reserved for
599 dbg_gen("dent '%.*s' from ino %lu (nlink %d) in dir ino %lu",
600 dentry->d_name.len, dentry->d_name.name, inode->i_ino,
601 inode->i_nlink, dir->i_ino);
602 ubifs_assert(mutex_is_locked(&dir->i_mutex));
603 ubifs_assert(mutex_is_locked(&inode->i_mutex));
604 err = dbg_check_synced_i_size(c, inode);
608 err = ubifs_budget_space(c, &req);
615 lock_2_inodes(dir, inode);
616 inode->i_ctime = ubifs_current_time(dir);
618 dir->i_size -= sz_change;
619 dir_ui->ui_size = dir->i_size;
620 dir->i_mtime = dir->i_ctime = inode->i_ctime;
621 err = ubifs_jnl_update(c, dir, &dentry->d_name, inode, 1, 0);
624 unlock_2_inodes(dir, inode);
627 ubifs_release_budget(c, &req);
629 /* We've deleted something - clean the "no space" flags */
630 c->bi.nospace = c->bi.nospace_rp = 0;
636 dir->i_size += sz_change;
637 dir_ui->ui_size = dir->i_size;
639 unlock_2_inodes(dir, inode);
641 ubifs_release_budget(c, &req);
646 * check_dir_empty - check if a directory is empty or not.
647 * @c: UBIFS file-system description object
648 * @dir: VFS inode object of the directory to check
650 * This function checks if directory @dir is empty. Returns zero if the
651 * directory is empty, %-ENOTEMPTY if it is not, and other negative error codes
652 * in case of of errors.
654 static int check_dir_empty(struct ubifs_info *c, struct inode *dir)
656 struct qstr nm = { .name = NULL };
657 struct ubifs_dent_node *dent;
661 lowest_dent_key(c, &key, dir->i_ino);
662 dent = ubifs_tnc_next_ent(c, &key, &nm);
674 static int ubifs_rmdir(struct inode *dir, struct dentry *dentry)
676 struct ubifs_info *c = dir->i_sb->s_fs_info;
677 struct inode *inode = dentry->d_inode;
678 int sz_change = CALC_DENT_SIZE(dentry->d_name.len);
679 int err, budgeted = 1;
680 struct ubifs_inode *dir_ui = ubifs_inode(dir);
681 struct ubifs_budget_req req = { .mod_dent = 1, .dirtied_ino = 2 };
684 * Budget request settings: deletion direntry, deletion inode and
685 * changing the parent inode. If budgeting fails, go ahead anyway
686 * because we have extra space reserved for deletions.
689 dbg_gen("directory '%.*s', ino %lu in dir ino %lu", dentry->d_name.len,
690 dentry->d_name.name, inode->i_ino, dir->i_ino);
691 ubifs_assert(mutex_is_locked(&dir->i_mutex));
692 ubifs_assert(mutex_is_locked(&inode->i_mutex));
693 err = check_dir_empty(c, dentry->d_inode);
697 err = ubifs_budget_space(c, &req);
704 lock_2_inodes(dir, inode);
705 inode->i_ctime = ubifs_current_time(dir);
708 dir->i_size -= sz_change;
709 dir_ui->ui_size = dir->i_size;
710 dir->i_mtime = dir->i_ctime = inode->i_ctime;
711 err = ubifs_jnl_update(c, dir, &dentry->d_name, inode, 1, 0);
714 unlock_2_inodes(dir, inode);
717 ubifs_release_budget(c, &req);
719 /* We've deleted something - clean the "no space" flags */
720 c->bi.nospace = c->bi.nospace_rp = 0;
726 dir->i_size += sz_change;
727 dir_ui->ui_size = dir->i_size;
731 unlock_2_inodes(dir, inode);
733 ubifs_release_budget(c, &req);
737 static int ubifs_mkdir(struct inode *dir, struct dentry *dentry, int mode)
740 struct ubifs_inode *dir_ui = ubifs_inode(dir);
741 struct ubifs_info *c = dir->i_sb->s_fs_info;
742 int err, sz_change = CALC_DENT_SIZE(dentry->d_name.len);
743 struct ubifs_budget_req req = { .new_ino = 1, .new_dent = 1 };
746 * Budget request settings: new inode, new direntry and changing parent
750 dbg_gen("dent '%.*s', mode %#x in dir ino %lu",
751 dentry->d_name.len, dentry->d_name.name, mode, dir->i_ino);
753 err = ubifs_budget_space(c, &req);
757 inode = ubifs_new_inode(c, dir, S_IFDIR | mode);
759 err = PTR_ERR(inode);
763 mutex_lock(&dir_ui->ui_mutex);
764 insert_inode_hash(inode);
767 dir->i_size += sz_change;
768 dir_ui->ui_size = dir->i_size;
769 dir->i_mtime = dir->i_ctime = inode->i_ctime;
770 err = ubifs_jnl_update(c, dir, &dentry->d_name, inode, 0, 0);
772 ubifs_err("cannot create directory, error %d", err);
775 mutex_unlock(&dir_ui->ui_mutex);
777 ubifs_release_budget(c, &req);
778 d_instantiate(dentry, inode);
782 dir->i_size -= sz_change;
783 dir_ui->ui_size = dir->i_size;
785 mutex_unlock(&dir_ui->ui_mutex);
786 make_bad_inode(inode);
789 ubifs_release_budget(c, &req);
793 static int ubifs_mknod(struct inode *dir, struct dentry *dentry,
794 int mode, dev_t rdev)
797 struct ubifs_inode *ui;
798 struct ubifs_inode *dir_ui = ubifs_inode(dir);
799 struct ubifs_info *c = dir->i_sb->s_fs_info;
800 union ubifs_dev_desc *dev = NULL;
801 int sz_change = CALC_DENT_SIZE(dentry->d_name.len);
803 struct ubifs_budget_req req = { .new_ino = 1, .new_dent = 1,
804 .new_ino_d = ALIGN(devlen, 8),
808 * Budget request settings: new inode, new direntry and changing parent
812 dbg_gen("dent '%.*s' in dir ino %lu",
813 dentry->d_name.len, dentry->d_name.name, dir->i_ino);
815 if (!new_valid_dev(rdev))
818 if (S_ISBLK(mode) || S_ISCHR(mode)) {
819 dev = kmalloc(sizeof(union ubifs_dev_desc), GFP_NOFS);
822 devlen = ubifs_encode_dev(dev, rdev);
825 err = ubifs_budget_space(c, &req);
831 inode = ubifs_new_inode(c, dir, mode);
834 err = PTR_ERR(inode);
838 init_special_inode(inode, inode->i_mode, rdev);
839 inode->i_size = ubifs_inode(inode)->ui_size = devlen;
840 ui = ubifs_inode(inode);
842 ui->data_len = devlen;
844 mutex_lock(&dir_ui->ui_mutex);
845 dir->i_size += sz_change;
846 dir_ui->ui_size = dir->i_size;
847 dir->i_mtime = dir->i_ctime = inode->i_ctime;
848 err = ubifs_jnl_update(c, dir, &dentry->d_name, inode, 0, 0);
851 mutex_unlock(&dir_ui->ui_mutex);
853 ubifs_release_budget(c, &req);
854 insert_inode_hash(inode);
855 d_instantiate(dentry, inode);
859 dir->i_size -= sz_change;
860 dir_ui->ui_size = dir->i_size;
861 mutex_unlock(&dir_ui->ui_mutex);
862 make_bad_inode(inode);
865 ubifs_release_budget(c, &req);
869 static int ubifs_symlink(struct inode *dir, struct dentry *dentry,
873 struct ubifs_inode *ui;
874 struct ubifs_inode *dir_ui = ubifs_inode(dir);
875 struct ubifs_info *c = dir->i_sb->s_fs_info;
876 int err, len = strlen(symname);
877 int sz_change = CALC_DENT_SIZE(dentry->d_name.len);
878 struct ubifs_budget_req req = { .new_ino = 1, .new_dent = 1,
879 .new_ino_d = ALIGN(len, 8),
883 * Budget request settings: new inode, new direntry and changing parent
887 dbg_gen("dent '%.*s', target '%s' in dir ino %lu", dentry->d_name.len,
888 dentry->d_name.name, symname, dir->i_ino);
890 if (len > UBIFS_MAX_INO_DATA)
891 return -ENAMETOOLONG;
893 err = ubifs_budget_space(c, &req);
897 inode = ubifs_new_inode(c, dir, S_IFLNK | S_IRWXUGO);
899 err = PTR_ERR(inode);
903 ui = ubifs_inode(inode);
904 ui->data = kmalloc(len + 1, GFP_NOFS);
910 memcpy(ui->data, symname, len);
911 ((char *)ui->data)[len] = '\0';
913 * The terminating zero byte is not written to the flash media and it
914 * is put just to make later in-memory string processing simpler. Thus,
915 * data length is @len, not @len + %1.
918 inode->i_size = ubifs_inode(inode)->ui_size = len;
920 mutex_lock(&dir_ui->ui_mutex);
921 dir->i_size += sz_change;
922 dir_ui->ui_size = dir->i_size;
923 dir->i_mtime = dir->i_ctime = inode->i_ctime;
924 err = ubifs_jnl_update(c, dir, &dentry->d_name, inode, 0, 0);
927 mutex_unlock(&dir_ui->ui_mutex);
929 ubifs_release_budget(c, &req);
930 insert_inode_hash(inode);
931 d_instantiate(dentry, inode);
935 dir->i_size -= sz_change;
936 dir_ui->ui_size = dir->i_size;
937 mutex_unlock(&dir_ui->ui_mutex);
939 make_bad_inode(inode);
942 ubifs_release_budget(c, &req);
947 * lock_3_inodes - a wrapper for locking three UBIFS inodes.
948 * @inode1: first inode
949 * @inode2: second inode
950 * @inode3: third inode
952 * This function is used for 'ubifs_rename()' and @inode1 may be the same as
953 * @inode2 whereas @inode3 may be %NULL.
955 * We do not implement any tricks to guarantee strict lock ordering, because
956 * VFS has already done it for us on the @i_mutex. So this is just a simple
959 static void lock_3_inodes(struct inode *inode1, struct inode *inode2,
960 struct inode *inode3)
962 mutex_lock_nested(&ubifs_inode(inode1)->ui_mutex, WB_MUTEX_1);
963 if (inode2 != inode1)
964 mutex_lock_nested(&ubifs_inode(inode2)->ui_mutex, WB_MUTEX_2);
966 mutex_lock_nested(&ubifs_inode(inode3)->ui_mutex, WB_MUTEX_3);
970 * unlock_3_inodes - a wrapper for unlocking three UBIFS inodes for rename.
971 * @inode1: first inode
972 * @inode2: second inode
973 * @inode3: third inode
975 static void unlock_3_inodes(struct inode *inode1, struct inode *inode2,
976 struct inode *inode3)
979 mutex_unlock(&ubifs_inode(inode3)->ui_mutex);
980 if (inode1 != inode2)
981 mutex_unlock(&ubifs_inode(inode2)->ui_mutex);
982 mutex_unlock(&ubifs_inode(inode1)->ui_mutex);
985 static int ubifs_rename(struct inode *old_dir, struct dentry *old_dentry,
986 struct inode *new_dir, struct dentry *new_dentry)
988 struct ubifs_info *c = old_dir->i_sb->s_fs_info;
989 struct inode *old_inode = old_dentry->d_inode;
990 struct inode *new_inode = new_dentry->d_inode;
991 struct ubifs_inode *old_inode_ui = ubifs_inode(old_inode);
992 int err, release, sync = 0, move = (new_dir != old_dir);
993 int is_dir = S_ISDIR(old_inode->i_mode);
994 int unlink = !!new_inode;
995 int new_sz = CALC_DENT_SIZE(new_dentry->d_name.len);
996 int old_sz = CALC_DENT_SIZE(old_dentry->d_name.len);
997 struct ubifs_budget_req req = { .new_dent = 1, .mod_dent = 1,
999 struct ubifs_budget_req ino_req = { .dirtied_ino = 1,
1000 .dirtied_ino_d = ALIGN(old_inode_ui->data_len, 8) };
1001 struct timespec time;
1004 * Budget request settings: deletion direntry, new direntry, removing
1005 * the old inode, and changing old and new parent directory inodes.
1007 * However, this operation also marks the target inode as dirty and
1008 * does not write it, so we allocate budget for the target inode
1012 dbg_gen("dent '%.*s' ino %lu in dir ino %lu to dent '%.*s' in "
1013 "dir ino %lu", old_dentry->d_name.len, old_dentry->d_name.name,
1014 old_inode->i_ino, old_dir->i_ino, new_dentry->d_name.len,
1015 new_dentry->d_name.name, new_dir->i_ino);
1016 ubifs_assert(mutex_is_locked(&old_dir->i_mutex));
1017 ubifs_assert(mutex_is_locked(&new_dir->i_mutex));
1019 ubifs_assert(mutex_is_locked(&new_inode->i_mutex));
1022 if (unlink && is_dir) {
1023 err = check_dir_empty(c, new_inode);
1028 err = ubifs_budget_space(c, &req);
1031 err = ubifs_budget_space(c, &ino_req);
1033 ubifs_release_budget(c, &req);
1037 lock_3_inodes(old_dir, new_dir, new_inode);
1040 * Like most other Unix systems, set the @i_ctime for inodes on a
1043 time = ubifs_current_time(old_dir);
1044 old_inode->i_ctime = time;
1046 /* We must adjust parent link count when renaming directories */
1050 * @old_dir loses a link because we are moving
1051 * @old_inode to a different directory.
1053 drop_nlink(old_dir);
1055 * @new_dir only gains a link if we are not also
1056 * overwriting an existing directory.
1062 * @old_inode is not moving to a different directory,
1063 * but @old_dir still loses a link if we are
1064 * overwriting an existing directory.
1067 drop_nlink(old_dir);
1071 old_dir->i_size -= old_sz;
1072 ubifs_inode(old_dir)->ui_size = old_dir->i_size;
1073 old_dir->i_mtime = old_dir->i_ctime = time;
1074 new_dir->i_mtime = new_dir->i_ctime = time;
1077 * And finally, if we unlinked a direntry which happened to have the
1078 * same name as the moved direntry, we have to decrement @i_nlink of
1079 * the unlinked inode and change its ctime.
1083 * Directories cannot have hard-links, so if this is a
1084 * directory, decrement its @i_nlink twice because an empty
1085 * directory has @i_nlink 2.
1088 drop_nlink(new_inode);
1089 new_inode->i_ctime = time;
1090 drop_nlink(new_inode);
1092 new_dir->i_size += new_sz;
1093 ubifs_inode(new_dir)->ui_size = new_dir->i_size;
1097 * Do not ask 'ubifs_jnl_rename()' to flush write-buffer if @old_inode
1098 * is dirty, because this will be done later on at the end of
1101 if (IS_SYNC(old_inode)) {
1102 sync = IS_DIRSYNC(old_dir) || IS_DIRSYNC(new_dir);
1103 if (unlink && IS_SYNC(new_inode))
1106 err = ubifs_jnl_rename(c, old_dir, old_dentry, new_dir, new_dentry,
1111 unlock_3_inodes(old_dir, new_dir, new_inode);
1112 ubifs_release_budget(c, &req);
1114 mutex_lock(&old_inode_ui->ui_mutex);
1115 release = old_inode_ui->dirty;
1116 mark_inode_dirty_sync(old_inode);
1117 mutex_unlock(&old_inode_ui->ui_mutex);
1120 ubifs_release_budget(c, &ino_req);
1121 if (IS_SYNC(old_inode))
1122 err = old_inode->i_sb->s_op->write_inode(old_inode, NULL);
1128 inc_nlink(new_inode);
1129 inc_nlink(new_inode);
1131 new_dir->i_size -= new_sz;
1132 ubifs_inode(new_dir)->ui_size = new_dir->i_size;
1134 old_dir->i_size += old_sz;
1135 ubifs_inode(old_dir)->ui_size = old_dir->i_size;
1140 drop_nlink(new_dir);
1146 unlock_3_inodes(old_dir, new_dir, new_inode);
1147 ubifs_release_budget(c, &ino_req);
1148 ubifs_release_budget(c, &req);
1152 int ubifs_getattr(struct vfsmount *mnt, struct dentry *dentry,
1156 struct inode *inode = dentry->d_inode;
1157 struct ubifs_inode *ui = ubifs_inode(inode);
1159 mutex_lock(&ui->ui_mutex);
1160 stat->dev = inode->i_sb->s_dev;
1161 stat->ino = inode->i_ino;
1162 stat->mode = inode->i_mode;
1163 stat->nlink = inode->i_nlink;
1164 stat->uid = inode->i_uid;
1165 stat->gid = inode->i_gid;
1166 stat->rdev = inode->i_rdev;
1167 stat->atime = inode->i_atime;
1168 stat->mtime = inode->i_mtime;
1169 stat->ctime = inode->i_ctime;
1170 stat->blksize = UBIFS_BLOCK_SIZE;
1171 stat->size = ui->ui_size;
1174 * Unfortunately, the 'stat()' system call was designed for block
1175 * device based file systems, and it is not appropriate for UBIFS,
1176 * because UBIFS does not have notion of "block". For example, it is
1177 * difficult to tell how many block a directory takes - it actually
1178 * takes less than 300 bytes, but we have to round it to block size,
1179 * which introduces large mistake. This makes utilities like 'du' to
1180 * report completely senseless numbers. This is the reason why UBIFS
1181 * goes the same way as JFFS2 - it reports zero blocks for everything
1182 * but regular files, which makes more sense than reporting completely
1185 if (S_ISREG(inode->i_mode)) {
1186 size = ui->xattr_size;
1188 size = ALIGN(size, UBIFS_BLOCK_SIZE);
1190 * Note, user-space expects 512-byte blocks count irrespectively
1191 * of what was reported in @stat->size.
1193 stat->blocks = size >> 9;
1196 mutex_unlock(&ui->ui_mutex);
1200 const struct inode_operations ubifs_dir_inode_operations = {
1201 .lookup = ubifs_lookup,
1202 .create = ubifs_create,
1204 .symlink = ubifs_symlink,
1205 .unlink = ubifs_unlink,
1206 .mkdir = ubifs_mkdir,
1207 .rmdir = ubifs_rmdir,
1208 .mknod = ubifs_mknod,
1209 .rename = ubifs_rename,
1210 .setattr = ubifs_setattr,
1211 .getattr = ubifs_getattr,
1212 #ifdef CONFIG_UBIFS_FS_XATTR
1213 .setxattr = ubifs_setxattr,
1214 .getxattr = ubifs_getxattr,
1215 .listxattr = ubifs_listxattr,
1216 .removexattr = ubifs_removexattr,
1220 const struct file_operations ubifs_dir_operations = {
1221 .llseek = ubifs_dir_llseek,
1222 .release = ubifs_dir_release,
1223 .read = generic_read_dir,
1224 .readdir = ubifs_readdir,
1225 .fsync = ubifs_fsync,
1226 .unlocked_ioctl = ubifs_ioctl,
1227 #ifdef CONFIG_COMPAT
1228 .compat_ioctl = ubifs_compat_ioctl,