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, umode_t 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 static int dbg_check_name(const struct ubifs_info *c,
174 const struct ubifs_dent_node *dent,
175 const struct qstr *nm)
177 if (!dbg_is_chk_gen(c))
179 if (le16_to_cpu(dent->nlen) != nm->len)
181 if (memcmp(dent->name, nm->name, nm->len))
186 static struct dentry *ubifs_lookup(struct inode *dir, struct dentry *dentry,
191 struct inode *inode = NULL;
192 struct ubifs_dent_node *dent;
193 struct ubifs_info *c = dir->i_sb->s_fs_info;
195 dbg_gen("'%.*s' in dir ino %lu",
196 dentry->d_name.len, dentry->d_name.name, dir->i_ino);
198 if (dentry->d_name.len > UBIFS_MAX_NLEN)
199 return ERR_PTR(-ENAMETOOLONG);
201 dent = kmalloc(UBIFS_MAX_DENT_NODE_SZ, GFP_NOFS);
203 return ERR_PTR(-ENOMEM);
205 dent_key_init(c, &key, dir->i_ino, &dentry->d_name);
207 err = ubifs_tnc_lookup_nm(c, &key, dent, &dentry->d_name);
209 if (err == -ENOENT) {
210 dbg_gen("not found");
216 if (dbg_check_name(c, dent, &dentry->d_name)) {
221 inode = ubifs_iget(dir->i_sb, le64_to_cpu(dent->inum));
224 * This should not happen. Probably the file-system needs
227 err = PTR_ERR(inode);
228 ubifs_err("dead directory entry '%.*s', error %d",
229 dentry->d_name.len, dentry->d_name.name, err);
230 ubifs_ro_mode(c, err);
237 * Note, d_splice_alias() would be required instead if we supported
240 d_add(dentry, inode);
248 static int ubifs_create(struct inode *dir, struct dentry *dentry, umode_t mode,
252 struct ubifs_info *c = dir->i_sb->s_fs_info;
253 int err, sz_change = CALC_DENT_SIZE(dentry->d_name.len);
254 struct ubifs_budget_req req = { .new_ino = 1, .new_dent = 1,
256 struct ubifs_inode *dir_ui = ubifs_inode(dir);
259 * Budget request settings: new inode, new direntry, changing the
260 * parent directory inode.
263 dbg_gen("dent '%.*s', mode %#hx in dir ino %lu",
264 dentry->d_name.len, dentry->d_name.name, mode, dir->i_ino);
266 err = ubifs_budget_space(c, &req);
270 inode = ubifs_new_inode(c, dir, mode);
272 err = PTR_ERR(inode);
276 mutex_lock(&dir_ui->ui_mutex);
277 dir->i_size += sz_change;
278 dir_ui->ui_size = dir->i_size;
279 dir->i_mtime = dir->i_ctime = inode->i_ctime;
280 err = ubifs_jnl_update(c, dir, &dentry->d_name, inode, 0, 0);
283 mutex_unlock(&dir_ui->ui_mutex);
285 ubifs_release_budget(c, &req);
286 insert_inode_hash(inode);
287 d_instantiate(dentry, inode);
291 dir->i_size -= sz_change;
292 dir_ui->ui_size = dir->i_size;
293 mutex_unlock(&dir_ui->ui_mutex);
294 make_bad_inode(inode);
297 ubifs_release_budget(c, &req);
298 ubifs_err("cannot create regular file, error %d", err);
303 * vfs_dent_type - get VFS directory entry type.
304 * @type: UBIFS directory entry type
306 * This function converts UBIFS directory entry type into VFS directory entry
309 static unsigned int vfs_dent_type(uint8_t type)
312 case UBIFS_ITYPE_REG:
314 case UBIFS_ITYPE_DIR:
316 case UBIFS_ITYPE_LNK:
318 case UBIFS_ITYPE_BLK:
320 case UBIFS_ITYPE_CHR:
322 case UBIFS_ITYPE_FIFO:
324 case UBIFS_ITYPE_SOCK:
333 * The classical Unix view for directory is that it is a linear array of
334 * (name, inode number) entries. Linux/VFS assumes this model as well.
335 * Particularly, 'readdir()' call wants us to return a directory entry offset
336 * which later may be used to continue 'readdir()'ing the directory or to
337 * 'seek()' to that specific direntry. Obviously UBIFS does not really fit this
338 * model because directory entries are identified by keys, which may collide.
340 * UBIFS uses directory entry hash value for directory offsets, so
341 * 'seekdir()'/'telldir()' may not always work because of possible key
342 * collisions. But UBIFS guarantees that consecutive 'readdir()' calls work
343 * properly by means of saving full directory entry name in the private field
344 * of the file description object.
346 * This means that UBIFS cannot support NFS which requires full
347 * 'seekdir()'/'telldir()' support.
349 static int ubifs_readdir(struct file *file, void *dirent, filldir_t filldir)
352 loff_t pos = file->f_pos;
355 struct ubifs_dent_node *dent;
356 struct inode *dir = file_inode(file);
357 struct ubifs_info *c = dir->i_sb->s_fs_info;
359 dbg_gen("dir ino %lu, f_pos %#llx", dir->i_ino, pos);
361 if (pos > UBIFS_S_KEY_HASH_MASK || pos == 2)
363 * The directory was seek'ed to a senseless position or there
364 * are no more entries.
368 if (file->f_version == 0) {
370 * The file was seek'ed, which means that @file->private_data
371 * is now invalid. This may also be just the first
372 * 'ubifs_readdir()' invocation, in which case
373 * @file->private_data is NULL, and the below code is
376 kfree(file->private_data);
377 file->private_data = NULL;
381 * 'generic_file_llseek()' unconditionally sets @file->f_version to
382 * zero, and we use this for detecting whether the file was seek'ed.
386 /* File positions 0 and 1 correspond to "." and ".." */
388 ubifs_assert(!file->private_data);
389 over = filldir(dirent, ".", 1, 0, dir->i_ino, DT_DIR);
392 file->f_pos = pos = 1;
396 ubifs_assert(!file->private_data);
397 over = filldir(dirent, "..", 2, 1,
398 parent_ino(file->f_path.dentry), DT_DIR);
402 /* Find the first entry in TNC and save it */
403 lowest_dent_key(c, &key, dir->i_ino);
405 dent = ubifs_tnc_next_ent(c, &key, &nm);
411 file->f_pos = pos = key_hash_flash(c, &dent->key);
412 file->private_data = dent;
415 dent = file->private_data;
418 * The directory was seek'ed to and is now readdir'ed.
419 * Find the entry corresponding to @pos or the closest one.
421 dent_key_init_hash(c, &key, dir->i_ino, pos);
423 dent = ubifs_tnc_next_ent(c, &key, &nm);
428 file->f_pos = pos = key_hash_flash(c, &dent->key);
429 file->private_data = dent;
433 dbg_gen("feed '%s', ino %llu, new f_pos %#x",
434 dent->name, (unsigned long long)le64_to_cpu(dent->inum),
435 key_hash_flash(c, &dent->key));
436 ubifs_assert(le64_to_cpu(dent->ch.sqnum) >
437 ubifs_inode(dir)->creat_sqnum);
439 nm.len = le16_to_cpu(dent->nlen);
440 over = filldir(dirent, dent->name, nm.len, pos,
441 le64_to_cpu(dent->inum),
442 vfs_dent_type(dent->type));
446 /* Switch to the next entry */
447 key_read(c, &dent->key, &key);
448 nm.name = dent->name;
449 dent = ubifs_tnc_next_ent(c, &key, &nm);
455 kfree(file->private_data);
456 file->f_pos = pos = key_hash_flash(c, &dent->key);
457 file->private_data = dent;
460 if (file->f_version == 0)
462 * The file was seek'ed meanwhile, lets return and start
463 * reading direntries from the new position on the next
470 if (err != -ENOENT) {
471 ubifs_err("cannot find next direntry, error %d", err);
475 kfree(file->private_data);
476 file->private_data = NULL;
477 /* 2 is a special value indicating that there are no more direntries */
482 static loff_t ubifs_dir_llseek(struct file *file, loff_t offset, int whence)
484 return generic_file_llseek(file, offset, whence);
487 /* Free saved readdir() state when the directory is closed */
488 static int ubifs_dir_release(struct inode *dir, struct file *file)
490 kfree(file->private_data);
491 file->private_data = NULL;
496 * lock_2_inodes - a wrapper for locking two UBIFS inodes.
497 * @inode1: first inode
498 * @inode2: second inode
500 * We do not implement any tricks to guarantee strict lock ordering, because
501 * VFS has already done it for us on the @i_mutex. So this is just a simple
504 static void lock_2_inodes(struct inode *inode1, struct inode *inode2)
506 mutex_lock_nested(&ubifs_inode(inode1)->ui_mutex, WB_MUTEX_1);
507 mutex_lock_nested(&ubifs_inode(inode2)->ui_mutex, WB_MUTEX_2);
511 * unlock_2_inodes - a wrapper for unlocking two UBIFS inodes.
512 * @inode1: first inode
513 * @inode2: second inode
515 static void unlock_2_inodes(struct inode *inode1, struct inode *inode2)
517 mutex_unlock(&ubifs_inode(inode2)->ui_mutex);
518 mutex_unlock(&ubifs_inode(inode1)->ui_mutex);
521 static int ubifs_link(struct dentry *old_dentry, struct inode *dir,
522 struct dentry *dentry)
524 struct ubifs_info *c = dir->i_sb->s_fs_info;
525 struct inode *inode = old_dentry->d_inode;
526 struct ubifs_inode *ui = ubifs_inode(inode);
527 struct ubifs_inode *dir_ui = ubifs_inode(dir);
528 int err, sz_change = CALC_DENT_SIZE(dentry->d_name.len);
529 struct ubifs_budget_req req = { .new_dent = 1, .dirtied_ino = 2,
530 .dirtied_ino_d = ALIGN(ui->data_len, 8) };
533 * Budget request settings: new direntry, changing the target inode,
534 * changing the parent inode.
537 dbg_gen("dent '%.*s' to ino %lu (nlink %d) in dir ino %lu",
538 dentry->d_name.len, dentry->d_name.name, inode->i_ino,
539 inode->i_nlink, dir->i_ino);
540 ubifs_assert(mutex_is_locked(&dir->i_mutex));
541 ubifs_assert(mutex_is_locked(&inode->i_mutex));
543 err = dbg_check_synced_i_size(c, inode);
547 err = ubifs_budget_space(c, &req);
551 lock_2_inodes(dir, inode);
554 inode->i_ctime = ubifs_current_time(inode);
555 dir->i_size += sz_change;
556 dir_ui->ui_size = dir->i_size;
557 dir->i_mtime = dir->i_ctime = inode->i_ctime;
558 err = ubifs_jnl_update(c, dir, &dentry->d_name, inode, 0, 0);
561 unlock_2_inodes(dir, inode);
563 ubifs_release_budget(c, &req);
564 d_instantiate(dentry, inode);
568 dir->i_size -= sz_change;
569 dir_ui->ui_size = dir->i_size;
571 unlock_2_inodes(dir, inode);
572 ubifs_release_budget(c, &req);
577 static int ubifs_unlink(struct inode *dir, struct dentry *dentry)
579 struct ubifs_info *c = dir->i_sb->s_fs_info;
580 struct inode *inode = dentry->d_inode;
581 struct ubifs_inode *dir_ui = ubifs_inode(dir);
582 int sz_change = CALC_DENT_SIZE(dentry->d_name.len);
583 int err, budgeted = 1;
584 struct ubifs_budget_req req = { .mod_dent = 1, .dirtied_ino = 2 };
585 unsigned int saved_nlink = inode->i_nlink;
588 * Budget request settings: deletion direntry, deletion inode (+1 for
589 * @dirtied_ino), changing the parent directory inode. If budgeting
590 * fails, go ahead anyway because we have extra space reserved for
594 dbg_gen("dent '%.*s' from ino %lu (nlink %d) in dir ino %lu",
595 dentry->d_name.len, dentry->d_name.name, inode->i_ino,
596 inode->i_nlink, dir->i_ino);
597 ubifs_assert(mutex_is_locked(&dir->i_mutex));
598 ubifs_assert(mutex_is_locked(&inode->i_mutex));
599 err = dbg_check_synced_i_size(c, inode);
603 err = ubifs_budget_space(c, &req);
610 lock_2_inodes(dir, inode);
611 inode->i_ctime = ubifs_current_time(dir);
613 dir->i_size -= sz_change;
614 dir_ui->ui_size = dir->i_size;
615 dir->i_mtime = dir->i_ctime = inode->i_ctime;
616 err = ubifs_jnl_update(c, dir, &dentry->d_name, inode, 1, 0);
619 unlock_2_inodes(dir, inode);
622 ubifs_release_budget(c, &req);
624 /* We've deleted something - clean the "no space" flags */
625 c->bi.nospace = c->bi.nospace_rp = 0;
631 dir->i_size += sz_change;
632 dir_ui->ui_size = dir->i_size;
633 set_nlink(inode, saved_nlink);
634 unlock_2_inodes(dir, inode);
636 ubifs_release_budget(c, &req);
641 * check_dir_empty - check if a directory is empty or not.
642 * @c: UBIFS file-system description object
643 * @dir: VFS inode object of the directory to check
645 * This function checks if directory @dir is empty. Returns zero if the
646 * directory is empty, %-ENOTEMPTY if it is not, and other negative error codes
647 * in case of of errors.
649 static int check_dir_empty(struct ubifs_info *c, struct inode *dir)
651 struct qstr nm = { .name = NULL };
652 struct ubifs_dent_node *dent;
656 lowest_dent_key(c, &key, dir->i_ino);
657 dent = ubifs_tnc_next_ent(c, &key, &nm);
669 static int ubifs_rmdir(struct inode *dir, struct dentry *dentry)
671 struct ubifs_info *c = dir->i_sb->s_fs_info;
672 struct inode *inode = dentry->d_inode;
673 int sz_change = CALC_DENT_SIZE(dentry->d_name.len);
674 int err, budgeted = 1;
675 struct ubifs_inode *dir_ui = ubifs_inode(dir);
676 struct ubifs_budget_req req = { .mod_dent = 1, .dirtied_ino = 2 };
679 * Budget request settings: deletion direntry, deletion inode and
680 * changing the parent inode. If budgeting fails, go ahead anyway
681 * because we have extra space reserved for deletions.
684 dbg_gen("directory '%.*s', ino %lu in dir ino %lu", dentry->d_name.len,
685 dentry->d_name.name, inode->i_ino, dir->i_ino);
686 ubifs_assert(mutex_is_locked(&dir->i_mutex));
687 ubifs_assert(mutex_is_locked(&inode->i_mutex));
688 err = check_dir_empty(c, dentry->d_inode);
692 err = ubifs_budget_space(c, &req);
699 lock_2_inodes(dir, inode);
700 inode->i_ctime = ubifs_current_time(dir);
703 dir->i_size -= sz_change;
704 dir_ui->ui_size = dir->i_size;
705 dir->i_mtime = dir->i_ctime = inode->i_ctime;
706 err = ubifs_jnl_update(c, dir, &dentry->d_name, inode, 1, 0);
709 unlock_2_inodes(dir, inode);
712 ubifs_release_budget(c, &req);
714 /* We've deleted something - clean the "no space" flags */
715 c->bi.nospace = c->bi.nospace_rp = 0;
721 dir->i_size += sz_change;
722 dir_ui->ui_size = dir->i_size;
725 unlock_2_inodes(dir, inode);
727 ubifs_release_budget(c, &req);
731 static int ubifs_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode)
734 struct ubifs_inode *dir_ui = ubifs_inode(dir);
735 struct ubifs_info *c = dir->i_sb->s_fs_info;
736 int err, sz_change = CALC_DENT_SIZE(dentry->d_name.len);
737 struct ubifs_budget_req req = { .new_ino = 1, .new_dent = 1 };
740 * Budget request settings: new inode, new direntry and changing parent
744 dbg_gen("dent '%.*s', mode %#hx in dir ino %lu",
745 dentry->d_name.len, dentry->d_name.name, mode, dir->i_ino);
747 err = ubifs_budget_space(c, &req);
751 inode = ubifs_new_inode(c, dir, S_IFDIR | mode);
753 err = PTR_ERR(inode);
757 mutex_lock(&dir_ui->ui_mutex);
758 insert_inode_hash(inode);
761 dir->i_size += sz_change;
762 dir_ui->ui_size = dir->i_size;
763 dir->i_mtime = dir->i_ctime = inode->i_ctime;
764 err = ubifs_jnl_update(c, dir, &dentry->d_name, inode, 0, 0);
766 ubifs_err("cannot create directory, error %d", err);
769 mutex_unlock(&dir_ui->ui_mutex);
771 ubifs_release_budget(c, &req);
772 d_instantiate(dentry, inode);
776 dir->i_size -= sz_change;
777 dir_ui->ui_size = dir->i_size;
779 mutex_unlock(&dir_ui->ui_mutex);
780 make_bad_inode(inode);
783 ubifs_release_budget(c, &req);
787 static int ubifs_mknod(struct inode *dir, struct dentry *dentry,
788 umode_t mode, dev_t rdev)
791 struct ubifs_inode *ui;
792 struct ubifs_inode *dir_ui = ubifs_inode(dir);
793 struct ubifs_info *c = dir->i_sb->s_fs_info;
794 union ubifs_dev_desc *dev = NULL;
795 int sz_change = CALC_DENT_SIZE(dentry->d_name.len);
797 struct ubifs_budget_req req = { .new_ino = 1, .new_dent = 1,
798 .new_ino_d = ALIGN(devlen, 8),
802 * Budget request settings: new inode, new direntry and changing parent
806 dbg_gen("dent '%.*s' in dir ino %lu",
807 dentry->d_name.len, dentry->d_name.name, dir->i_ino);
809 if (!new_valid_dev(rdev))
812 if (S_ISBLK(mode) || S_ISCHR(mode)) {
813 dev = kmalloc(sizeof(union ubifs_dev_desc), GFP_NOFS);
816 devlen = ubifs_encode_dev(dev, rdev);
819 err = ubifs_budget_space(c, &req);
825 inode = ubifs_new_inode(c, dir, mode);
828 err = PTR_ERR(inode);
832 init_special_inode(inode, inode->i_mode, rdev);
833 inode->i_size = ubifs_inode(inode)->ui_size = devlen;
834 ui = ubifs_inode(inode);
836 ui->data_len = devlen;
838 mutex_lock(&dir_ui->ui_mutex);
839 dir->i_size += sz_change;
840 dir_ui->ui_size = dir->i_size;
841 dir->i_mtime = dir->i_ctime = inode->i_ctime;
842 err = ubifs_jnl_update(c, dir, &dentry->d_name, inode, 0, 0);
845 mutex_unlock(&dir_ui->ui_mutex);
847 ubifs_release_budget(c, &req);
848 insert_inode_hash(inode);
849 d_instantiate(dentry, inode);
853 dir->i_size -= sz_change;
854 dir_ui->ui_size = dir->i_size;
855 mutex_unlock(&dir_ui->ui_mutex);
856 make_bad_inode(inode);
859 ubifs_release_budget(c, &req);
863 static int ubifs_symlink(struct inode *dir, struct dentry *dentry,
867 struct ubifs_inode *ui;
868 struct ubifs_inode *dir_ui = ubifs_inode(dir);
869 struct ubifs_info *c = dir->i_sb->s_fs_info;
870 int err, len = strlen(symname);
871 int sz_change = CALC_DENT_SIZE(dentry->d_name.len);
872 struct ubifs_budget_req req = { .new_ino = 1, .new_dent = 1,
873 .new_ino_d = ALIGN(len, 8),
877 * Budget request settings: new inode, new direntry and changing parent
881 dbg_gen("dent '%.*s', target '%s' in dir ino %lu", dentry->d_name.len,
882 dentry->d_name.name, symname, dir->i_ino);
884 if (len > UBIFS_MAX_INO_DATA)
885 return -ENAMETOOLONG;
887 err = ubifs_budget_space(c, &req);
891 inode = ubifs_new_inode(c, dir, S_IFLNK | S_IRWXUGO);
893 err = PTR_ERR(inode);
897 ui = ubifs_inode(inode);
898 ui->data = kmalloc(len + 1, GFP_NOFS);
904 memcpy(ui->data, symname, len);
905 ((char *)ui->data)[len] = '\0';
907 * The terminating zero byte is not written to the flash media and it
908 * is put just to make later in-memory string processing simpler. Thus,
909 * data length is @len, not @len + %1.
912 inode->i_size = ubifs_inode(inode)->ui_size = len;
914 mutex_lock(&dir_ui->ui_mutex);
915 dir->i_size += sz_change;
916 dir_ui->ui_size = dir->i_size;
917 dir->i_mtime = dir->i_ctime = inode->i_ctime;
918 err = ubifs_jnl_update(c, dir, &dentry->d_name, inode, 0, 0);
921 mutex_unlock(&dir_ui->ui_mutex);
923 ubifs_release_budget(c, &req);
924 insert_inode_hash(inode);
925 d_instantiate(dentry, inode);
929 dir->i_size -= sz_change;
930 dir_ui->ui_size = dir->i_size;
931 mutex_unlock(&dir_ui->ui_mutex);
933 make_bad_inode(inode);
936 ubifs_release_budget(c, &req);
941 * lock_3_inodes - a wrapper for locking three UBIFS inodes.
942 * @inode1: first inode
943 * @inode2: second inode
944 * @inode3: third inode
946 * This function is used for 'ubifs_rename()' and @inode1 may be the same as
947 * @inode2 whereas @inode3 may be %NULL.
949 * We do not implement any tricks to guarantee strict lock ordering, because
950 * VFS has already done it for us on the @i_mutex. So this is just a simple
953 static void lock_3_inodes(struct inode *inode1, struct inode *inode2,
954 struct inode *inode3)
956 mutex_lock_nested(&ubifs_inode(inode1)->ui_mutex, WB_MUTEX_1);
957 if (inode2 != inode1)
958 mutex_lock_nested(&ubifs_inode(inode2)->ui_mutex, WB_MUTEX_2);
960 mutex_lock_nested(&ubifs_inode(inode3)->ui_mutex, WB_MUTEX_3);
964 * unlock_3_inodes - a wrapper for unlocking three UBIFS inodes for rename.
965 * @inode1: first inode
966 * @inode2: second inode
967 * @inode3: third inode
969 static void unlock_3_inodes(struct inode *inode1, struct inode *inode2,
970 struct inode *inode3)
973 mutex_unlock(&ubifs_inode(inode3)->ui_mutex);
974 if (inode1 != inode2)
975 mutex_unlock(&ubifs_inode(inode2)->ui_mutex);
976 mutex_unlock(&ubifs_inode(inode1)->ui_mutex);
979 static int ubifs_rename(struct inode *old_dir, struct dentry *old_dentry,
980 struct inode *new_dir, struct dentry *new_dentry)
982 struct ubifs_info *c = old_dir->i_sb->s_fs_info;
983 struct inode *old_inode = old_dentry->d_inode;
984 struct inode *new_inode = new_dentry->d_inode;
985 struct ubifs_inode *old_inode_ui = ubifs_inode(old_inode);
986 int err, release, sync = 0, move = (new_dir != old_dir);
987 int is_dir = S_ISDIR(old_inode->i_mode);
988 int unlink = !!new_inode;
989 int new_sz = CALC_DENT_SIZE(new_dentry->d_name.len);
990 int old_sz = CALC_DENT_SIZE(old_dentry->d_name.len);
991 struct ubifs_budget_req req = { .new_dent = 1, .mod_dent = 1,
993 struct ubifs_budget_req ino_req = { .dirtied_ino = 1,
994 .dirtied_ino_d = ALIGN(old_inode_ui->data_len, 8) };
995 struct timespec time;
996 unsigned int uninitialized_var(saved_nlink);
999 * Budget request settings: deletion direntry, new direntry, removing
1000 * the old inode, and changing old and new parent directory inodes.
1002 * However, this operation also marks the target inode as dirty and
1003 * does not write it, so we allocate budget for the target inode
1007 dbg_gen("dent '%.*s' ino %lu in dir ino %lu to dent '%.*s' in dir ino %lu",
1008 old_dentry->d_name.len, old_dentry->d_name.name,
1009 old_inode->i_ino, old_dir->i_ino, new_dentry->d_name.len,
1010 new_dentry->d_name.name, new_dir->i_ino);
1011 ubifs_assert(mutex_is_locked(&old_dir->i_mutex));
1012 ubifs_assert(mutex_is_locked(&new_dir->i_mutex));
1014 ubifs_assert(mutex_is_locked(&new_inode->i_mutex));
1017 if (unlink && is_dir) {
1018 err = check_dir_empty(c, new_inode);
1023 err = ubifs_budget_space(c, &req);
1026 err = ubifs_budget_space(c, &ino_req);
1028 ubifs_release_budget(c, &req);
1032 lock_3_inodes(old_dir, new_dir, new_inode);
1035 * Like most other Unix systems, set the @i_ctime for inodes on a
1038 time = ubifs_current_time(old_dir);
1039 old_inode->i_ctime = time;
1041 /* We must adjust parent link count when renaming directories */
1045 * @old_dir loses a link because we are moving
1046 * @old_inode to a different directory.
1048 drop_nlink(old_dir);
1050 * @new_dir only gains a link if we are not also
1051 * overwriting an existing directory.
1057 * @old_inode is not moving to a different directory,
1058 * but @old_dir still loses a link if we are
1059 * overwriting an existing directory.
1062 drop_nlink(old_dir);
1066 old_dir->i_size -= old_sz;
1067 ubifs_inode(old_dir)->ui_size = old_dir->i_size;
1068 old_dir->i_mtime = old_dir->i_ctime = time;
1069 new_dir->i_mtime = new_dir->i_ctime = time;
1072 * And finally, if we unlinked a direntry which happened to have the
1073 * same name as the moved direntry, we have to decrement @i_nlink of
1074 * the unlinked inode and change its ctime.
1078 * Directories cannot have hard-links, so if this is a
1079 * directory, just clear @i_nlink.
1081 saved_nlink = new_inode->i_nlink;
1083 clear_nlink(new_inode);
1085 drop_nlink(new_inode);
1086 new_inode->i_ctime = time;
1088 new_dir->i_size += new_sz;
1089 ubifs_inode(new_dir)->ui_size = new_dir->i_size;
1093 * Do not ask 'ubifs_jnl_rename()' to flush write-buffer if @old_inode
1094 * is dirty, because this will be done later on at the end of
1097 if (IS_SYNC(old_inode)) {
1098 sync = IS_DIRSYNC(old_dir) || IS_DIRSYNC(new_dir);
1099 if (unlink && IS_SYNC(new_inode))
1102 err = ubifs_jnl_rename(c, old_dir, old_dentry, new_dir, new_dentry,
1107 unlock_3_inodes(old_dir, new_dir, new_inode);
1108 ubifs_release_budget(c, &req);
1110 mutex_lock(&old_inode_ui->ui_mutex);
1111 release = old_inode_ui->dirty;
1112 mark_inode_dirty_sync(old_inode);
1113 mutex_unlock(&old_inode_ui->ui_mutex);
1116 ubifs_release_budget(c, &ino_req);
1117 if (IS_SYNC(old_inode))
1118 err = old_inode->i_sb->s_op->write_inode(old_inode, NULL);
1123 set_nlink(new_inode, saved_nlink);
1125 new_dir->i_size -= new_sz;
1126 ubifs_inode(new_dir)->ui_size = new_dir->i_size;
1128 old_dir->i_size += old_sz;
1129 ubifs_inode(old_dir)->ui_size = old_dir->i_size;
1134 drop_nlink(new_dir);
1140 unlock_3_inodes(old_dir, new_dir, new_inode);
1141 ubifs_release_budget(c, &ino_req);
1142 ubifs_release_budget(c, &req);
1146 int ubifs_getattr(struct vfsmount *mnt, struct dentry *dentry,
1150 struct inode *inode = dentry->d_inode;
1151 struct ubifs_inode *ui = ubifs_inode(inode);
1153 mutex_lock(&ui->ui_mutex);
1154 generic_fillattr(inode, stat);
1155 stat->blksize = UBIFS_BLOCK_SIZE;
1156 stat->size = ui->ui_size;
1159 * Unfortunately, the 'stat()' system call was designed for block
1160 * device based file systems, and it is not appropriate for UBIFS,
1161 * because UBIFS does not have notion of "block". For example, it is
1162 * difficult to tell how many block a directory takes - it actually
1163 * takes less than 300 bytes, but we have to round it to block size,
1164 * which introduces large mistake. This makes utilities like 'du' to
1165 * report completely senseless numbers. This is the reason why UBIFS
1166 * goes the same way as JFFS2 - it reports zero blocks for everything
1167 * but regular files, which makes more sense than reporting completely
1170 if (S_ISREG(inode->i_mode)) {
1171 size = ui->xattr_size;
1173 size = ALIGN(size, UBIFS_BLOCK_SIZE);
1175 * Note, user-space expects 512-byte blocks count irrespectively
1176 * of what was reported in @stat->size.
1178 stat->blocks = size >> 9;
1181 mutex_unlock(&ui->ui_mutex);
1185 const struct inode_operations ubifs_dir_inode_operations = {
1186 .lookup = ubifs_lookup,
1187 .create = ubifs_create,
1189 .symlink = ubifs_symlink,
1190 .unlink = ubifs_unlink,
1191 .mkdir = ubifs_mkdir,
1192 .rmdir = ubifs_rmdir,
1193 .mknod = ubifs_mknod,
1194 .rename = ubifs_rename,
1195 .setattr = ubifs_setattr,
1196 .getattr = ubifs_getattr,
1197 .setxattr = ubifs_setxattr,
1198 .getxattr = ubifs_getxattr,
1199 .listxattr = ubifs_listxattr,
1200 .removexattr = ubifs_removexattr,
1203 const struct file_operations ubifs_dir_operations = {
1204 .llseek = ubifs_dir_llseek,
1205 .release = ubifs_dir_release,
1206 .read = generic_read_dir,
1207 .readdir = ubifs_readdir,
1208 .fsync = ubifs_fsync,
1209 .unlocked_ioctl = ubifs_ioctl,
1210 #ifdef CONFIG_COMPAT
1211 .compat_ioctl = ubifs_compat_ioctl,