Linux 2.6.32.17
[linux-2.6/linux-acpi-2.6/ibm-acpi-2.6.git] / fs / ubifs / dir.c
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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
13 * more details.
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)
20 * Adrian Hunter
21 * Zoltan Sogor
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.
43 #include "ubifs.h"
45 /**
46 * inherit_flags - inherit flags of the parent inode.
47 * @dir: 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)
61 int flags;
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.
69 return 0;
71 flags = ui->flags & (UBIFS_COMPR_FL | UBIFS_SYNC_FL | UBIFS_DIRSYNC_FL);
72 if (!S_ISDIR(mode))
73 /* The "DIRSYNC" flag only applies to directories */
74 flags &= ~UBIFS_DIRSYNC_FL;
75 return flags;
78 /**
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
86 * case of failure.
88 struct inode *ubifs_new_inode(struct ubifs_info *c, const struct inode *dir,
89 int mode)
91 struct inode *inode;
92 struct ubifs_inode *ui;
94 inode = new_inode(c->vfs_sb);
95 ui = ubifs_inode(inode);
96 if (!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->i_uid = current_fsuid();
108 if (dir->i_mode & S_ISGID) {
109 inode->i_gid = dir->i_gid;
110 if (S_ISDIR(mode))
111 mode |= S_ISGID;
112 } else
113 inode->i_gid = current_fsgid();
114 inode->i_mode = mode;
115 inode->i_mtime = inode->i_atime = inode->i_ctime =
116 ubifs_current_time(inode);
117 inode->i_mapping->nrpages = 0;
118 /* Disable readahead */
119 inode->i_mapping->backing_dev_info = &c->bdi;
121 switch (mode & S_IFMT) {
122 case S_IFREG:
123 inode->i_mapping->a_ops = &ubifs_file_address_operations;
124 inode->i_op = &ubifs_file_inode_operations;
125 inode->i_fop = &ubifs_file_operations;
126 break;
127 case S_IFDIR:
128 inode->i_op = &ubifs_dir_inode_operations;
129 inode->i_fop = &ubifs_dir_operations;
130 inode->i_size = ui->ui_size = UBIFS_INO_NODE_SZ;
131 break;
132 case S_IFLNK:
133 inode->i_op = &ubifs_symlink_inode_operations;
134 break;
135 case S_IFSOCK:
136 case S_IFIFO:
137 case S_IFBLK:
138 case S_IFCHR:
139 inode->i_op = &ubifs_file_inode_operations;
140 break;
141 default:
142 BUG();
145 ui->flags = inherit_flags(dir, mode);
146 ubifs_set_inode_flags(inode);
147 if (S_ISREG(mode))
148 ui->compr_type = c->default_compr;
149 else
150 ui->compr_type = UBIFS_COMPR_NONE;
151 ui->synced_i_size = 0;
153 spin_lock(&c->cnt_lock);
154 /* Inode number overflow is currently not supported */
155 if (c->highest_inum >= INUM_WARN_WATERMARK) {
156 if (c->highest_inum >= INUM_WATERMARK) {
157 spin_unlock(&c->cnt_lock);
158 ubifs_err("out of inode numbers");
159 make_bad_inode(inode);
160 iput(inode);
161 return ERR_PTR(-EINVAL);
163 ubifs_warn("running out of inode numbers (current %lu, max %d)",
164 (unsigned long)c->highest_inum, INUM_WATERMARK);
167 inode->i_ino = ++c->highest_inum;
169 * The creation sequence number remains with this inode for its
170 * lifetime. All nodes for this inode have a greater sequence number,
171 * and so it is possible to distinguish obsolete nodes belonging to a
172 * previous incarnation of the same inode number - for example, for the
173 * purpose of rebuilding the index.
175 ui->creat_sqnum = ++c->max_sqnum;
176 spin_unlock(&c->cnt_lock);
177 return inode;
180 #ifdef CONFIG_UBIFS_FS_DEBUG
182 static int dbg_check_name(struct ubifs_dent_node *dent, struct qstr *nm)
184 if (!(ubifs_chk_flags & UBIFS_CHK_GEN))
185 return 0;
186 if (le16_to_cpu(dent->nlen) != nm->len)
187 return -EINVAL;
188 if (memcmp(dent->name, nm->name, nm->len))
189 return -EINVAL;
190 return 0;
193 #else
195 #define dbg_check_name(dent, nm) 0
197 #endif
199 static struct dentry *ubifs_lookup(struct inode *dir, struct dentry *dentry,
200 struct nameidata *nd)
202 int err;
203 union ubifs_key key;
204 struct inode *inode = NULL;
205 struct ubifs_dent_node *dent;
206 struct ubifs_info *c = dir->i_sb->s_fs_info;
208 dbg_gen("'%.*s' in dir ino %lu",
209 dentry->d_name.len, dentry->d_name.name, dir->i_ino);
211 if (dentry->d_name.len > UBIFS_MAX_NLEN)
212 return ERR_PTR(-ENAMETOOLONG);
214 dent = kmalloc(UBIFS_MAX_DENT_NODE_SZ, GFP_NOFS);
215 if (!dent)
216 return ERR_PTR(-ENOMEM);
218 dent_key_init(c, &key, dir->i_ino, &dentry->d_name);
220 err = ubifs_tnc_lookup_nm(c, &key, dent, &dentry->d_name);
221 if (err) {
222 if (err == -ENOENT) {
223 dbg_gen("not found");
224 goto done;
226 goto out;
229 if (dbg_check_name(dent, &dentry->d_name)) {
230 err = -EINVAL;
231 goto out;
234 inode = ubifs_iget(dir->i_sb, le64_to_cpu(dent->inum));
235 if (IS_ERR(inode)) {
237 * This should not happen. Probably the file-system needs
238 * checking.
240 err = PTR_ERR(inode);
241 ubifs_err("dead directory entry '%.*s', error %d",
242 dentry->d_name.len, dentry->d_name.name, err);
243 ubifs_ro_mode(c, err);
244 goto out;
247 done:
248 kfree(dent);
250 * Note, d_splice_alias() would be required instead if we supported
251 * NFS.
253 d_add(dentry, inode);
254 return NULL;
256 out:
257 kfree(dent);
258 return ERR_PTR(err);
261 static int ubifs_create(struct inode *dir, struct dentry *dentry, int mode,
262 struct nameidata *nd)
264 struct inode *inode;
265 struct ubifs_info *c = dir->i_sb->s_fs_info;
266 int err, sz_change = CALC_DENT_SIZE(dentry->d_name.len);
267 struct ubifs_budget_req req = { .new_ino = 1, .new_dent = 1,
268 .dirtied_ino = 1 };
269 struct ubifs_inode *dir_ui = ubifs_inode(dir);
272 * Budget request settings: new inode, new direntry, changing the
273 * parent directory inode.
276 dbg_gen("dent '%.*s', mode %#x in dir ino %lu",
277 dentry->d_name.len, dentry->d_name.name, mode, dir->i_ino);
279 err = ubifs_budget_space(c, &req);
280 if (err)
281 return err;
283 inode = ubifs_new_inode(c, dir, mode);
284 if (IS_ERR(inode)) {
285 err = PTR_ERR(inode);
286 goto out_budg;
289 mutex_lock(&dir_ui->ui_mutex);
290 dir->i_size += sz_change;
291 dir_ui->ui_size = dir->i_size;
292 dir->i_mtime = dir->i_ctime = inode->i_ctime;
293 err = ubifs_jnl_update(c, dir, &dentry->d_name, inode, 0, 0);
294 if (err)
295 goto out_cancel;
296 mutex_unlock(&dir_ui->ui_mutex);
298 ubifs_release_budget(c, &req);
299 insert_inode_hash(inode);
300 d_instantiate(dentry, inode);
301 return 0;
303 out_cancel:
304 dir->i_size -= sz_change;
305 dir_ui->ui_size = dir->i_size;
306 mutex_unlock(&dir_ui->ui_mutex);
307 make_bad_inode(inode);
308 iput(inode);
309 out_budg:
310 ubifs_release_budget(c, &req);
311 ubifs_err("cannot create regular file, error %d", err);
312 return err;
316 * vfs_dent_type - get VFS directory entry type.
317 * @type: UBIFS directory entry type
319 * This function converts UBIFS directory entry type into VFS directory entry
320 * type.
322 static unsigned int vfs_dent_type(uint8_t type)
324 switch (type) {
325 case UBIFS_ITYPE_REG:
326 return DT_REG;
327 case UBIFS_ITYPE_DIR:
328 return DT_DIR;
329 case UBIFS_ITYPE_LNK:
330 return DT_LNK;
331 case UBIFS_ITYPE_BLK:
332 return DT_BLK;
333 case UBIFS_ITYPE_CHR:
334 return DT_CHR;
335 case UBIFS_ITYPE_FIFO:
336 return DT_FIFO;
337 case UBIFS_ITYPE_SOCK:
338 return DT_SOCK;
339 default:
340 BUG();
342 return 0;
346 * The classical Unix view for directory is that it is a linear array of
347 * (name, inode number) entries. Linux/VFS assumes this model as well.
348 * Particularly, 'readdir()' call wants us to return a directory entry offset
349 * which later may be used to continue 'readdir()'ing the directory or to
350 * 'seek()' to that specific direntry. Obviously UBIFS does not really fit this
351 * model because directory entries are identified by keys, which may collide.
353 * UBIFS uses directory entry hash value for directory offsets, so
354 * 'seekdir()'/'telldir()' may not always work because of possible key
355 * collisions. But UBIFS guarantees that consecutive 'readdir()' calls work
356 * properly by means of saving full directory entry name in the private field
357 * of the file description object.
359 * This means that UBIFS cannot support NFS which requires full
360 * 'seekdir()'/'telldir()' support.
362 static int ubifs_readdir(struct file *file, void *dirent, filldir_t filldir)
364 int err, over = 0;
365 struct qstr nm;
366 union ubifs_key key;
367 struct ubifs_dent_node *dent;
368 struct inode *dir = file->f_path.dentry->d_inode;
369 struct ubifs_info *c = dir->i_sb->s_fs_info;
371 dbg_gen("dir ino %lu, f_pos %#llx", dir->i_ino, file->f_pos);
373 if (file->f_pos > UBIFS_S_KEY_HASH_MASK || file->f_pos == 2)
375 * The directory was seek'ed to a senseless position or there
376 * are no more entries.
378 return 0;
380 /* File positions 0 and 1 correspond to "." and ".." */
381 if (file->f_pos == 0) {
382 ubifs_assert(!file->private_data);
383 over = filldir(dirent, ".", 1, 0, dir->i_ino, DT_DIR);
384 if (over)
385 return 0;
386 file->f_pos = 1;
389 if (file->f_pos == 1) {
390 ubifs_assert(!file->private_data);
391 over = filldir(dirent, "..", 2, 1,
392 parent_ino(file->f_path.dentry), DT_DIR);
393 if (over)
394 return 0;
396 /* Find the first entry in TNC and save it */
397 lowest_dent_key(c, &key, dir->i_ino);
398 nm.name = NULL;
399 dent = ubifs_tnc_next_ent(c, &key, &nm);
400 if (IS_ERR(dent)) {
401 err = PTR_ERR(dent);
402 goto out;
405 file->f_pos = key_hash_flash(c, &dent->key);
406 file->private_data = dent;
409 dent = file->private_data;
410 if (!dent) {
412 * The directory was seek'ed to and is now readdir'ed.
413 * Find the entry corresponding to @file->f_pos or the
414 * closest one.
416 dent_key_init_hash(c, &key, dir->i_ino, file->f_pos);
417 nm.name = NULL;
418 dent = ubifs_tnc_next_ent(c, &key, &nm);
419 if (IS_ERR(dent)) {
420 err = PTR_ERR(dent);
421 goto out;
423 file->f_pos = key_hash_flash(c, &dent->key);
424 file->private_data = dent;
427 while (1) {
428 dbg_gen("feed '%s', ino %llu, new f_pos %#x",
429 dent->name, (unsigned long long)le64_to_cpu(dent->inum),
430 key_hash_flash(c, &dent->key));
431 ubifs_assert(le64_to_cpu(dent->ch.sqnum) >
432 ubifs_inode(dir)->creat_sqnum);
434 nm.len = le16_to_cpu(dent->nlen);
435 over = filldir(dirent, dent->name, nm.len, file->f_pos,
436 le64_to_cpu(dent->inum),
437 vfs_dent_type(dent->type));
438 if (over)
439 return 0;
441 /* Switch to the next entry */
442 key_read(c, &dent->key, &key);
443 nm.name = dent->name;
444 dent = ubifs_tnc_next_ent(c, &key, &nm);
445 if (IS_ERR(dent)) {
446 err = PTR_ERR(dent);
447 goto out;
450 kfree(file->private_data);
451 file->f_pos = key_hash_flash(c, &dent->key);
452 file->private_data = dent;
453 cond_resched();
456 out:
457 if (err != -ENOENT) {
458 ubifs_err("cannot find next direntry, error %d", err);
459 return err;
462 kfree(file->private_data);
463 file->private_data = NULL;
464 file->f_pos = 2;
465 return 0;
468 /* If a directory is seeked, we have to free saved readdir() state */
469 static loff_t ubifs_dir_llseek(struct file *file, loff_t offset, int origin)
471 kfree(file->private_data);
472 file->private_data = NULL;
473 return generic_file_llseek(file, offset, origin);
476 /* Free saved readdir() state when the directory is closed */
477 static int ubifs_dir_release(struct inode *dir, struct file *file)
479 kfree(file->private_data);
480 file->private_data = NULL;
481 return 0;
485 * lock_2_inodes - a wrapper for locking two UBIFS inodes.
486 * @inode1: first inode
487 * @inode2: second inode
489 * We do not implement any tricks to guarantee strict lock ordering, because
490 * VFS has already done it for us on the @i_mutex. So this is just a simple
491 * wrapper function.
493 static void lock_2_inodes(struct inode *inode1, struct inode *inode2)
495 mutex_lock_nested(&ubifs_inode(inode1)->ui_mutex, WB_MUTEX_1);
496 mutex_lock_nested(&ubifs_inode(inode2)->ui_mutex, WB_MUTEX_2);
500 * unlock_2_inodes - a wrapper for unlocking two UBIFS inodes.
501 * @inode1: first inode
502 * @inode2: second inode
504 static void unlock_2_inodes(struct inode *inode1, struct inode *inode2)
506 mutex_unlock(&ubifs_inode(inode2)->ui_mutex);
507 mutex_unlock(&ubifs_inode(inode1)->ui_mutex);
510 static int ubifs_link(struct dentry *old_dentry, struct inode *dir,
511 struct dentry *dentry)
513 struct ubifs_info *c = dir->i_sb->s_fs_info;
514 struct inode *inode = old_dentry->d_inode;
515 struct ubifs_inode *ui = ubifs_inode(inode);
516 struct ubifs_inode *dir_ui = ubifs_inode(dir);
517 int err, sz_change = CALC_DENT_SIZE(dentry->d_name.len);
518 struct ubifs_budget_req req = { .new_dent = 1, .dirtied_ino = 2,
519 .dirtied_ino_d = ALIGN(ui->data_len, 8) };
522 * Budget request settings: new direntry, changing the target inode,
523 * changing the parent inode.
526 dbg_gen("dent '%.*s' to ino %lu (nlink %d) in dir ino %lu",
527 dentry->d_name.len, dentry->d_name.name, inode->i_ino,
528 inode->i_nlink, dir->i_ino);
529 ubifs_assert(mutex_is_locked(&dir->i_mutex));
530 ubifs_assert(mutex_is_locked(&inode->i_mutex));
533 * Return -ENOENT if we've raced with unlink and i_nlink is 0. Doing
534 * otherwise has the potential to corrupt the orphan inode list.
536 * Indeed, consider a scenario when 'vfs_link(dirA/fileA)' and
537 * 'vfs_unlink(dirA/fileA, dirB/fileB)' race. 'vfs_link()' does not
538 * lock 'dirA->i_mutex', so this is possible. Both of the functions
539 * lock 'fileA->i_mutex' though. Suppose 'vfs_unlink()' wins, and takes
540 * 'fileA->i_mutex' mutex first. Suppose 'fileA->i_nlink' is 1. In this
541 * case 'ubifs_unlink()' will drop the last reference, and put 'inodeA'
542 * to the list of orphans. After this, 'vfs_link()' will link
543 * 'dirB/fileB' to 'inodeA'. This is a problem because, for example,
544 * the subsequent 'vfs_unlink(dirB/fileB)' will add the same inode
545 * to the list of orphans.
547 if (inode->i_nlink == 0)
548 return -ENOENT;
550 err = dbg_check_synced_i_size(inode);
551 if (err)
552 return err;
554 err = ubifs_budget_space(c, &req);
555 if (err)
556 return err;
558 lock_2_inodes(dir, inode);
559 inc_nlink(inode);
560 atomic_inc(&inode->i_count);
561 inode->i_ctime = ubifs_current_time(inode);
562 dir->i_size += sz_change;
563 dir_ui->ui_size = dir->i_size;
564 dir->i_mtime = dir->i_ctime = inode->i_ctime;
565 err = ubifs_jnl_update(c, dir, &dentry->d_name, inode, 0, 0);
566 if (err)
567 goto out_cancel;
568 unlock_2_inodes(dir, inode);
570 ubifs_release_budget(c, &req);
571 d_instantiate(dentry, inode);
572 return 0;
574 out_cancel:
575 dir->i_size -= sz_change;
576 dir_ui->ui_size = dir->i_size;
577 drop_nlink(inode);
578 unlock_2_inodes(dir, inode);
579 ubifs_release_budget(c, &req);
580 iput(inode);
581 return err;
584 static int ubifs_unlink(struct inode *dir, struct dentry *dentry)
586 struct ubifs_info *c = dir->i_sb->s_fs_info;
587 struct inode *inode = dentry->d_inode;
588 struct ubifs_inode *dir_ui = ubifs_inode(dir);
589 int sz_change = CALC_DENT_SIZE(dentry->d_name.len);
590 int err, budgeted = 1;
591 struct ubifs_budget_req req = { .mod_dent = 1, .dirtied_ino = 2 };
594 * Budget request settings: deletion direntry, deletion inode (+1 for
595 * @dirtied_ino), changing the parent directory inode. If budgeting
596 * fails, go ahead anyway because we have extra space reserved for
597 * deletions.
600 dbg_gen("dent '%.*s' from ino %lu (nlink %d) in dir ino %lu",
601 dentry->d_name.len, dentry->d_name.name, inode->i_ino,
602 inode->i_nlink, dir->i_ino);
603 ubifs_assert(mutex_is_locked(&dir->i_mutex));
604 ubifs_assert(mutex_is_locked(&inode->i_mutex));
605 err = dbg_check_synced_i_size(inode);
606 if (err)
607 return err;
609 err = ubifs_budget_space(c, &req);
610 if (err) {
611 if (err != -ENOSPC)
612 return err;
613 budgeted = 0;
616 lock_2_inodes(dir, inode);
617 inode->i_ctime = ubifs_current_time(dir);
618 drop_nlink(inode);
619 dir->i_size -= sz_change;
620 dir_ui->ui_size = dir->i_size;
621 dir->i_mtime = dir->i_ctime = inode->i_ctime;
622 err = ubifs_jnl_update(c, dir, &dentry->d_name, inode, 1, 0);
623 if (err)
624 goto out_cancel;
625 unlock_2_inodes(dir, inode);
627 if (budgeted)
628 ubifs_release_budget(c, &req);
629 else {
630 /* We've deleted something - clean the "no space" flags */
631 c->nospace = c->nospace_rp = 0;
632 smp_wmb();
634 return 0;
636 out_cancel:
637 dir->i_size += sz_change;
638 dir_ui->ui_size = dir->i_size;
639 inc_nlink(inode);
640 unlock_2_inodes(dir, inode);
641 if (budgeted)
642 ubifs_release_budget(c, &req);
643 return err;
647 * check_dir_empty - check if a directory is empty or not.
648 * @c: UBIFS file-system description object
649 * @dir: VFS inode object of the directory to check
651 * This function checks if directory @dir is empty. Returns zero if the
652 * directory is empty, %-ENOTEMPTY if it is not, and other negative error codes
653 * in case of of errors.
655 static int check_dir_empty(struct ubifs_info *c, struct inode *dir)
657 struct qstr nm = { .name = NULL };
658 struct ubifs_dent_node *dent;
659 union ubifs_key key;
660 int err;
662 lowest_dent_key(c, &key, dir->i_ino);
663 dent = ubifs_tnc_next_ent(c, &key, &nm);
664 if (IS_ERR(dent)) {
665 err = PTR_ERR(dent);
666 if (err == -ENOENT)
667 err = 0;
668 } else {
669 kfree(dent);
670 err = -ENOTEMPTY;
672 return err;
675 static int ubifs_rmdir(struct inode *dir, struct dentry *dentry)
677 struct ubifs_info *c = dir->i_sb->s_fs_info;
678 struct inode *inode = dentry->d_inode;
679 int sz_change = CALC_DENT_SIZE(dentry->d_name.len);
680 int err, budgeted = 1;
681 struct ubifs_inode *dir_ui = ubifs_inode(dir);
682 struct ubifs_budget_req req = { .mod_dent = 1, .dirtied_ino = 2 };
685 * Budget request settings: deletion direntry, deletion inode and
686 * changing the parent inode. If budgeting fails, go ahead anyway
687 * because we have extra space reserved for deletions.
690 dbg_gen("directory '%.*s', ino %lu in dir ino %lu", dentry->d_name.len,
691 dentry->d_name.name, inode->i_ino, dir->i_ino);
692 ubifs_assert(mutex_is_locked(&dir->i_mutex));
693 ubifs_assert(mutex_is_locked(&inode->i_mutex));
694 err = check_dir_empty(c, dentry->d_inode);
695 if (err)
696 return err;
698 err = ubifs_budget_space(c, &req);
699 if (err) {
700 if (err != -ENOSPC)
701 return err;
702 budgeted = 0;
705 lock_2_inodes(dir, inode);
706 inode->i_ctime = ubifs_current_time(dir);
707 clear_nlink(inode);
708 drop_nlink(dir);
709 dir->i_size -= sz_change;
710 dir_ui->ui_size = dir->i_size;
711 dir->i_mtime = dir->i_ctime = inode->i_ctime;
712 err = ubifs_jnl_update(c, dir, &dentry->d_name, inode, 1, 0);
713 if (err)
714 goto out_cancel;
715 unlock_2_inodes(dir, inode);
717 if (budgeted)
718 ubifs_release_budget(c, &req);
719 else {
720 /* We've deleted something - clean the "no space" flags */
721 c->nospace = c->nospace_rp = 0;
722 smp_wmb();
724 return 0;
726 out_cancel:
727 dir->i_size += sz_change;
728 dir_ui->ui_size = dir->i_size;
729 inc_nlink(dir);
730 inc_nlink(inode);
731 inc_nlink(inode);
732 unlock_2_inodes(dir, inode);
733 if (budgeted)
734 ubifs_release_budget(c, &req);
735 return err;
738 static int ubifs_mkdir(struct inode *dir, struct dentry *dentry, int mode)
740 struct inode *inode;
741 struct ubifs_inode *dir_ui = ubifs_inode(dir);
742 struct ubifs_info *c = dir->i_sb->s_fs_info;
743 int err, sz_change = CALC_DENT_SIZE(dentry->d_name.len);
744 struct ubifs_budget_req req = { .new_ino = 1, .new_dent = 1 };
747 * Budget request settings: new inode, new direntry and changing parent
748 * directory inode.
751 dbg_gen("dent '%.*s', mode %#x in dir ino %lu",
752 dentry->d_name.len, dentry->d_name.name, mode, dir->i_ino);
754 err = ubifs_budget_space(c, &req);
755 if (err)
756 return err;
758 inode = ubifs_new_inode(c, dir, S_IFDIR | mode);
759 if (IS_ERR(inode)) {
760 err = PTR_ERR(inode);
761 goto out_budg;
764 mutex_lock(&dir_ui->ui_mutex);
765 insert_inode_hash(inode);
766 inc_nlink(inode);
767 inc_nlink(dir);
768 dir->i_size += sz_change;
769 dir_ui->ui_size = dir->i_size;
770 dir->i_mtime = dir->i_ctime = inode->i_ctime;
771 err = ubifs_jnl_update(c, dir, &dentry->d_name, inode, 0, 0);
772 if (err) {
773 ubifs_err("cannot create directory, error %d", err);
774 goto out_cancel;
776 mutex_unlock(&dir_ui->ui_mutex);
778 ubifs_release_budget(c, &req);
779 d_instantiate(dentry, inode);
780 return 0;
782 out_cancel:
783 dir->i_size -= sz_change;
784 dir_ui->ui_size = dir->i_size;
785 drop_nlink(dir);
786 mutex_unlock(&dir_ui->ui_mutex);
787 make_bad_inode(inode);
788 iput(inode);
789 out_budg:
790 ubifs_release_budget(c, &req);
791 return err;
794 static int ubifs_mknod(struct inode *dir, struct dentry *dentry,
795 int mode, dev_t rdev)
797 struct inode *inode;
798 struct ubifs_inode *ui;
799 struct ubifs_inode *dir_ui = ubifs_inode(dir);
800 struct ubifs_info *c = dir->i_sb->s_fs_info;
801 union ubifs_dev_desc *dev = NULL;
802 int sz_change = CALC_DENT_SIZE(dentry->d_name.len);
803 int err, devlen = 0;
804 struct ubifs_budget_req req = { .new_ino = 1, .new_dent = 1,
805 .new_ino_d = ALIGN(devlen, 8),
806 .dirtied_ino = 1 };
809 * Budget request settings: new inode, new direntry and changing parent
810 * directory inode.
813 dbg_gen("dent '%.*s' in dir ino %lu",
814 dentry->d_name.len, dentry->d_name.name, dir->i_ino);
816 if (!new_valid_dev(rdev))
817 return -EINVAL;
819 if (S_ISBLK(mode) || S_ISCHR(mode)) {
820 dev = kmalloc(sizeof(union ubifs_dev_desc), GFP_NOFS);
821 if (!dev)
822 return -ENOMEM;
823 devlen = ubifs_encode_dev(dev, rdev);
826 err = ubifs_budget_space(c, &req);
827 if (err) {
828 kfree(dev);
829 return err;
832 inode = ubifs_new_inode(c, dir, mode);
833 if (IS_ERR(inode)) {
834 kfree(dev);
835 err = PTR_ERR(inode);
836 goto out_budg;
839 init_special_inode(inode, inode->i_mode, rdev);
840 inode->i_size = ubifs_inode(inode)->ui_size = devlen;
841 ui = ubifs_inode(inode);
842 ui->data = dev;
843 ui->data_len = devlen;
845 mutex_lock(&dir_ui->ui_mutex);
846 dir->i_size += sz_change;
847 dir_ui->ui_size = dir->i_size;
848 dir->i_mtime = dir->i_ctime = inode->i_ctime;
849 err = ubifs_jnl_update(c, dir, &dentry->d_name, inode, 0, 0);
850 if (err)
851 goto out_cancel;
852 mutex_unlock(&dir_ui->ui_mutex);
854 ubifs_release_budget(c, &req);
855 insert_inode_hash(inode);
856 d_instantiate(dentry, inode);
857 return 0;
859 out_cancel:
860 dir->i_size -= sz_change;
861 dir_ui->ui_size = dir->i_size;
862 mutex_unlock(&dir_ui->ui_mutex);
863 make_bad_inode(inode);
864 iput(inode);
865 out_budg:
866 ubifs_release_budget(c, &req);
867 return err;
870 static int ubifs_symlink(struct inode *dir, struct dentry *dentry,
871 const char *symname)
873 struct inode *inode;
874 struct ubifs_inode *ui;
875 struct ubifs_inode *dir_ui = ubifs_inode(dir);
876 struct ubifs_info *c = dir->i_sb->s_fs_info;
877 int err, len = strlen(symname);
878 int sz_change = CALC_DENT_SIZE(dentry->d_name.len);
879 struct ubifs_budget_req req = { .new_ino = 1, .new_dent = 1,
880 .new_ino_d = ALIGN(len, 8),
881 .dirtied_ino = 1 };
884 * Budget request settings: new inode, new direntry and changing parent
885 * directory inode.
888 dbg_gen("dent '%.*s', target '%s' in dir ino %lu", dentry->d_name.len,
889 dentry->d_name.name, symname, dir->i_ino);
891 if (len > UBIFS_MAX_INO_DATA)
892 return -ENAMETOOLONG;
894 err = ubifs_budget_space(c, &req);
895 if (err)
896 return err;
898 inode = ubifs_new_inode(c, dir, S_IFLNK | S_IRWXUGO);
899 if (IS_ERR(inode)) {
900 err = PTR_ERR(inode);
901 goto out_budg;
904 ui = ubifs_inode(inode);
905 ui->data = kmalloc(len + 1, GFP_NOFS);
906 if (!ui->data) {
907 err = -ENOMEM;
908 goto out_inode;
911 memcpy(ui->data, symname, len);
912 ((char *)ui->data)[len] = '\0';
914 * The terminating zero byte is not written to the flash media and it
915 * is put just to make later in-memory string processing simpler. Thus,
916 * data length is @len, not @len + %1.
918 ui->data_len = len;
919 inode->i_size = ubifs_inode(inode)->ui_size = len;
921 mutex_lock(&dir_ui->ui_mutex);
922 dir->i_size += sz_change;
923 dir_ui->ui_size = dir->i_size;
924 dir->i_mtime = dir->i_ctime = inode->i_ctime;
925 err = ubifs_jnl_update(c, dir, &dentry->d_name, inode, 0, 0);
926 if (err)
927 goto out_cancel;
928 mutex_unlock(&dir_ui->ui_mutex);
930 ubifs_release_budget(c, &req);
931 insert_inode_hash(inode);
932 d_instantiate(dentry, inode);
933 return 0;
935 out_cancel:
936 dir->i_size -= sz_change;
937 dir_ui->ui_size = dir->i_size;
938 mutex_unlock(&dir_ui->ui_mutex);
939 out_inode:
940 make_bad_inode(inode);
941 iput(inode);
942 out_budg:
943 ubifs_release_budget(c, &req);
944 return err;
948 * lock_3_inodes - a wrapper for locking three UBIFS inodes.
949 * @inode1: first inode
950 * @inode2: second inode
951 * @inode3: third inode
953 * This function is used for 'ubifs_rename()' and @inode1 may be the same as
954 * @inode2 whereas @inode3 may be %NULL.
956 * We do not implement any tricks to guarantee strict lock ordering, because
957 * VFS has already done it for us on the @i_mutex. So this is just a simple
958 * wrapper function.
960 static void lock_3_inodes(struct inode *inode1, struct inode *inode2,
961 struct inode *inode3)
963 mutex_lock_nested(&ubifs_inode(inode1)->ui_mutex, WB_MUTEX_1);
964 if (inode2 != inode1)
965 mutex_lock_nested(&ubifs_inode(inode2)->ui_mutex, WB_MUTEX_2);
966 if (inode3)
967 mutex_lock_nested(&ubifs_inode(inode3)->ui_mutex, WB_MUTEX_3);
971 * unlock_3_inodes - a wrapper for unlocking three UBIFS inodes for rename.
972 * @inode1: first inode
973 * @inode2: second inode
974 * @inode3: third inode
976 static void unlock_3_inodes(struct inode *inode1, struct inode *inode2,
977 struct inode *inode3)
979 if (inode3)
980 mutex_unlock(&ubifs_inode(inode3)->ui_mutex);
981 if (inode1 != inode2)
982 mutex_unlock(&ubifs_inode(inode2)->ui_mutex);
983 mutex_unlock(&ubifs_inode(inode1)->ui_mutex);
986 static int ubifs_rename(struct inode *old_dir, struct dentry *old_dentry,
987 struct inode *new_dir, struct dentry *new_dentry)
989 struct ubifs_info *c = old_dir->i_sb->s_fs_info;
990 struct inode *old_inode = old_dentry->d_inode;
991 struct inode *new_inode = new_dentry->d_inode;
992 struct ubifs_inode *old_inode_ui = ubifs_inode(old_inode);
993 int err, release, sync = 0, move = (new_dir != old_dir);
994 int is_dir = S_ISDIR(old_inode->i_mode);
995 int unlink = !!new_inode;
996 int new_sz = CALC_DENT_SIZE(new_dentry->d_name.len);
997 int old_sz = CALC_DENT_SIZE(old_dentry->d_name.len);
998 struct ubifs_budget_req req = { .new_dent = 1, .mod_dent = 1,
999 .dirtied_ino = 3 };
1000 struct ubifs_budget_req ino_req = { .dirtied_ino = 1,
1001 .dirtied_ino_d = ALIGN(old_inode_ui->data_len, 8) };
1002 struct timespec time;
1005 * Budget request settings: deletion direntry, new direntry, removing
1006 * the old inode, and changing old and new parent directory inodes.
1008 * However, this operation also marks the target inode as dirty and
1009 * does not write it, so we allocate budget for the target inode
1010 * separately.
1013 dbg_gen("dent '%.*s' ino %lu in dir ino %lu to dent '%.*s' in "
1014 "dir ino %lu", old_dentry->d_name.len, old_dentry->d_name.name,
1015 old_inode->i_ino, old_dir->i_ino, new_dentry->d_name.len,
1016 new_dentry->d_name.name, new_dir->i_ino);
1017 ubifs_assert(mutex_is_locked(&old_dir->i_mutex));
1018 ubifs_assert(mutex_is_locked(&new_dir->i_mutex));
1019 if (unlink)
1020 ubifs_assert(mutex_is_locked(&new_inode->i_mutex));
1023 if (unlink && is_dir) {
1024 err = check_dir_empty(c, new_inode);
1025 if (err)
1026 return err;
1029 err = ubifs_budget_space(c, &req);
1030 if (err)
1031 return err;
1032 err = ubifs_budget_space(c, &ino_req);
1033 if (err) {
1034 ubifs_release_budget(c, &req);
1035 return err;
1038 lock_3_inodes(old_dir, new_dir, new_inode);
1041 * Like most other Unix systems, set the @i_ctime for inodes on a
1042 * rename.
1044 time = ubifs_current_time(old_dir);
1045 old_inode->i_ctime = time;
1047 /* We must adjust parent link count when renaming directories */
1048 if (is_dir) {
1049 if (move) {
1051 * @old_dir loses a link because we are moving
1052 * @old_inode to a different directory.
1054 drop_nlink(old_dir);
1056 * @new_dir only gains a link if we are not also
1057 * overwriting an existing directory.
1059 if (!unlink)
1060 inc_nlink(new_dir);
1061 } else {
1063 * @old_inode is not moving to a different directory,
1064 * but @old_dir still loses a link if we are
1065 * overwriting an existing directory.
1067 if (unlink)
1068 drop_nlink(old_dir);
1072 old_dir->i_size -= old_sz;
1073 ubifs_inode(old_dir)->ui_size = old_dir->i_size;
1074 old_dir->i_mtime = old_dir->i_ctime = time;
1075 new_dir->i_mtime = new_dir->i_ctime = time;
1078 * And finally, if we unlinked a direntry which happened to have the
1079 * same name as the moved direntry, we have to decrement @i_nlink of
1080 * the unlinked inode and change its ctime.
1082 if (unlink) {
1084 * Directories cannot have hard-links, so if this is a
1085 * directory, decrement its @i_nlink twice because an empty
1086 * directory has @i_nlink 2.
1088 if (is_dir)
1089 drop_nlink(new_inode);
1090 new_inode->i_ctime = time;
1091 drop_nlink(new_inode);
1092 } else {
1093 new_dir->i_size += new_sz;
1094 ubifs_inode(new_dir)->ui_size = new_dir->i_size;
1098 * Do not ask 'ubifs_jnl_rename()' to flush write-buffer if @old_inode
1099 * is dirty, because this will be done later on at the end of
1100 * 'ubifs_rename()'.
1102 if (IS_SYNC(old_inode)) {
1103 sync = IS_DIRSYNC(old_dir) || IS_DIRSYNC(new_dir);
1104 if (unlink && IS_SYNC(new_inode))
1105 sync = 1;
1107 err = ubifs_jnl_rename(c, old_dir, old_dentry, new_dir, new_dentry,
1108 sync);
1109 if (err)
1110 goto out_cancel;
1112 unlock_3_inodes(old_dir, new_dir, new_inode);
1113 ubifs_release_budget(c, &req);
1115 mutex_lock(&old_inode_ui->ui_mutex);
1116 release = old_inode_ui->dirty;
1117 mark_inode_dirty_sync(old_inode);
1118 mutex_unlock(&old_inode_ui->ui_mutex);
1120 if (release)
1121 ubifs_release_budget(c, &ino_req);
1122 if (IS_SYNC(old_inode))
1123 err = old_inode->i_sb->s_op->write_inode(old_inode, 1);
1124 return err;
1126 out_cancel:
1127 if (unlink) {
1128 if (is_dir)
1129 inc_nlink(new_inode);
1130 inc_nlink(new_inode);
1131 } else {
1132 new_dir->i_size -= new_sz;
1133 ubifs_inode(new_dir)->ui_size = new_dir->i_size;
1135 old_dir->i_size += old_sz;
1136 ubifs_inode(old_dir)->ui_size = old_dir->i_size;
1137 if (is_dir) {
1138 if (move) {
1139 inc_nlink(old_dir);
1140 if (!unlink)
1141 drop_nlink(new_dir);
1142 } else {
1143 if (unlink)
1144 inc_nlink(old_dir);
1147 unlock_3_inodes(old_dir, new_dir, new_inode);
1148 ubifs_release_budget(c, &ino_req);
1149 ubifs_release_budget(c, &req);
1150 return err;
1153 int ubifs_getattr(struct vfsmount *mnt, struct dentry *dentry,
1154 struct kstat *stat)
1156 loff_t size;
1157 struct inode *inode = dentry->d_inode;
1158 struct ubifs_inode *ui = ubifs_inode(inode);
1160 mutex_lock(&ui->ui_mutex);
1161 stat->dev = inode->i_sb->s_dev;
1162 stat->ino = inode->i_ino;
1163 stat->mode = inode->i_mode;
1164 stat->nlink = inode->i_nlink;
1165 stat->uid = inode->i_uid;
1166 stat->gid = inode->i_gid;
1167 stat->rdev = inode->i_rdev;
1168 stat->atime = inode->i_atime;
1169 stat->mtime = inode->i_mtime;
1170 stat->ctime = inode->i_ctime;
1171 stat->blksize = UBIFS_BLOCK_SIZE;
1172 stat->size = ui->ui_size;
1175 * Unfortunately, the 'stat()' system call was designed for block
1176 * device based file systems, and it is not appropriate for UBIFS,
1177 * because UBIFS does not have notion of "block". For example, it is
1178 * difficult to tell how many block a directory takes - it actually
1179 * takes less than 300 bytes, but we have to round it to block size,
1180 * which introduces large mistake. This makes utilities like 'du' to
1181 * report completely senseless numbers. This is the reason why UBIFS
1182 * goes the same way as JFFS2 - it reports zero blocks for everything
1183 * but regular files, which makes more sense than reporting completely
1184 * wrong sizes.
1186 if (S_ISREG(inode->i_mode)) {
1187 size = ui->xattr_size;
1188 size += stat->size;
1189 size = ALIGN(size, UBIFS_BLOCK_SIZE);
1191 * Note, user-space expects 512-byte blocks count irrespectively
1192 * of what was reported in @stat->size.
1194 stat->blocks = size >> 9;
1195 } else
1196 stat->blocks = 0;
1197 mutex_unlock(&ui->ui_mutex);
1198 return 0;
1201 const struct inode_operations ubifs_dir_inode_operations = {
1202 .lookup = ubifs_lookup,
1203 .create = ubifs_create,
1204 .link = ubifs_link,
1205 .symlink = ubifs_symlink,
1206 .unlink = ubifs_unlink,
1207 .mkdir = ubifs_mkdir,
1208 .rmdir = ubifs_rmdir,
1209 .mknod = ubifs_mknod,
1210 .rename = ubifs_rename,
1211 .setattr = ubifs_setattr,
1212 .getattr = ubifs_getattr,
1213 #ifdef CONFIG_UBIFS_FS_XATTR
1214 .setxattr = ubifs_setxattr,
1215 .getxattr = ubifs_getxattr,
1216 .listxattr = ubifs_listxattr,
1217 .removexattr = ubifs_removexattr,
1218 #endif
1221 const struct file_operations ubifs_dir_operations = {
1222 .llseek = ubifs_dir_llseek,
1223 .release = ubifs_dir_release,
1224 .read = generic_read_dir,
1225 .readdir = ubifs_readdir,
1226 .fsync = ubifs_fsync,
1227 .unlocked_ioctl = ubifs_ioctl,
1228 #ifdef CONFIG_COMPAT
1229 .compat_ioctl = ubifs_compat_ioctl,
1230 #endif