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-rw-r--r--fs/ubifs/dir.c1240
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diff --git a/fs/ubifs/dir.c b/fs/ubifs/dir.c
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1/* * This file is part of UBIFS.
2 *
3 * Copyright (C) 2006-2008 Nokia Corporation.
4 * Copyright (C) 2006, 2007 University of Szeged, Hungary
5 *
6 * This program is free software; you can redistribute it and/or modify it
7 * under the terms of the GNU General Public License version 2 as published by
8 * the Free Software Foundation.
9 *
10 * This program is distributed in the hope that it will be useful, but WITHOUT
11 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
12 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
13 * more details.
14 *
15 * You should have received a copy of the GNU General Public License along with
16 * this program; if not, write to the Free Software Foundation, Inc., 51
17 * Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
18 *
19 * Authors: Artem Bityutskiy (Битюцкий Артём)
20 * Adrian Hunter
21 * Zoltan Sogor
22 */
23
24/*
25 * This file implements directory operations.
26 *
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.
33 *
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.
41 */
42
43#include "ubifs.h"
44
45/**
46 * inherit_flags - inherit flags of the parent inode.
47 * @dir: parent inode
48 * @mode: new inode mode flags
49 *
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.
56 *
57 * This function returns the inherited flags.
58 */
59static int inherit_flags(const struct inode *dir, int mode)
60{
61 int flags;
62 const struct ubifs_inode *ui = ubifs_inode(dir);
63
64 if (!S_ISDIR(dir->i_mode))
65 /*
66 * The parent is not a directory, which means that an extended
67 * attribute inode is being created. No flags.
68 */
69 return 0;
70
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;
76}
77
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
83 *
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.
87 */
88struct inode *ubifs_new_inode(struct ubifs_info *c, const struct inode *dir,
89 int mode)
90{
91 struct inode *inode;
92 struct ubifs_inode *ui;
93
94 inode = new_inode(c->vfs_sb);
95 ui = ubifs_inode(inode);
96 if (!inode)
97 return ERR_PTR(-ENOMEM);
98
99 /*
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.
104 */
105 inode->i_flags |= (S_NOCMTIME);
106
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;
120
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();
143 }
144
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;
152
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);
162 }
163 ubifs_warn("running out of inode numbers (current %lu, max %d)",
164 c->highest_inum, INUM_WATERMARK);
165 }
166
167 inode->i_ino = ++c->highest_inum;
168 inode->i_generation = ++c->vfs_gen;
169 /*
170 * The creation sequence number remains with this inode for its
171 * lifetime. All nodes for this inode have a greater sequence number,
172 * and so it is possible to distinguish obsolete nodes belonging to a
173 * previous incarnation of the same inode number - for example, for the
174 * purpose of rebuilding the index.
175 */
176 ui->creat_sqnum = ++c->max_sqnum;
177 spin_unlock(&c->cnt_lock);
178 return inode;
179}
180
181#ifdef CONFIG_UBIFS_FS_DEBUG
182
183static int dbg_check_name(struct ubifs_dent_node *dent, struct qstr *nm)
184{
185 if (!(ubifs_chk_flags & UBIFS_CHK_GEN))
186 return 0;
187 if (le16_to_cpu(dent->nlen) != nm->len)
188 return -EINVAL;
189 if (memcmp(dent->name, nm->name, nm->len))
190 return -EINVAL;
191 return 0;
192}
193
194#else
195
196#define dbg_check_name(dent, nm) 0
197
198#endif
199
200static struct dentry *ubifs_lookup(struct inode *dir, struct dentry *dentry,
201 struct nameidata *nd)
202{
203 int err;
204 union ubifs_key key;
205 struct inode *inode = NULL;
206 struct ubifs_dent_node *dent;
207 struct ubifs_info *c = dir->i_sb->s_fs_info;
208
209 dbg_gen("'%.*s' in dir ino %lu",
210 dentry->d_name.len, dentry->d_name.name, dir->i_ino);
211
212 if (dentry->d_name.len > UBIFS_MAX_NLEN)
213 return ERR_PTR(-ENAMETOOLONG);
214
215 dent = kmalloc(UBIFS_MAX_DENT_NODE_SZ, GFP_NOFS);
216 if (!dent)
217 return ERR_PTR(-ENOMEM);
218
219 dent_key_init(c, &key, dir->i_ino, &dentry->d_name);
220
221 err = ubifs_tnc_lookup_nm(c, &key, dent, &dentry->d_name);
222 if (err) {
223 /*
224 * Do not hash the direntry if parent 'i_nlink' is zero, because
225 * this has side-effects - '->delete_inode()' call will not be
226 * called for the parent orphan inode, because 'd_count' of its
227 * direntry will stay 1 (it'll be negative direntry I guess)
228 * and prevent 'iput_final()' until the dentry is destroyed due
229 * to unmount or memory pressure.
230 */
231 if (err == -ENOENT && dir->i_nlink != 0) {
232 dbg_gen("not found");
233 goto done;
234 }
235 goto out;
236 }
237
238 if (dbg_check_name(dent, &dentry->d_name)) {
239 err = -EINVAL;
240 goto out;
241 }
242
243 inode = ubifs_iget(dir->i_sb, le64_to_cpu(dent->inum));
244 if (IS_ERR(inode)) {
245 /*
246 * This should not happen. Probably the file-system needs
247 * checking.
248 */
249 err = PTR_ERR(inode);
250 ubifs_err("dead directory entry '%.*s', error %d",
251 dentry->d_name.len, dentry->d_name.name, err);
252 ubifs_ro_mode(c, err);
253 goto out;
254 }
255
256done:
257 kfree(dent);
258 /*
259 * Note, d_splice_alias() would be required instead if we supported
260 * NFS.
261 */
262 d_add(dentry, inode);
263 return NULL;
264
265out:
266 kfree(dent);
267 return ERR_PTR(err);
268}
269
270static int ubifs_create(struct inode *dir, struct dentry *dentry, int mode,
271 struct nameidata *nd)
272{
273 struct inode *inode;
274 struct ubifs_info *c = dir->i_sb->s_fs_info;
275 int err, sz_change = CALC_DENT_SIZE(dentry->d_name.len);
276 struct ubifs_budget_req req = { .new_ino = 1, .new_dent = 1,
277 .dirtied_ino = 1 };
278 struct ubifs_inode *dir_ui = ubifs_inode(dir);
279
280 /*
281 * Budget request settings: new inode, new direntry, changing the
282 * parent directory inode.
283 */
284
285 dbg_gen("dent '%.*s', mode %#x in dir ino %lu",
286 dentry->d_name.len, dentry->d_name.name, mode, dir->i_ino);
287
288 err = ubifs_budget_space(c, &req);
289 if (err)
290 return err;
291
292 inode = ubifs_new_inode(c, dir, mode);
293 if (IS_ERR(inode)) {
294 err = PTR_ERR(inode);
295 goto out_budg;
296 }
297
298 mutex_lock(&dir_ui->ui_mutex);
299 dir->i_size += sz_change;
300 dir_ui->ui_size = dir->i_size;
301 dir->i_mtime = dir->i_ctime = inode->i_ctime;
302 err = ubifs_jnl_update(c, dir, &dentry->d_name, inode, 0, 0);
303 if (err)
304 goto out_cancel;
305 mutex_unlock(&dir_ui->ui_mutex);
306
307 ubifs_release_budget(c, &req);
308 insert_inode_hash(inode);
309 d_instantiate(dentry, inode);
310 return 0;
311
312out_cancel:
313 dir->i_size -= sz_change;
314 dir_ui->ui_size = dir->i_size;
315 mutex_unlock(&dir_ui->ui_mutex);
316 make_bad_inode(inode);
317 iput(inode);
318out_budg:
319 ubifs_release_budget(c, &req);
320 ubifs_err("cannot create regular file, error %d", err);
321 return err;
322}
323
324/**
325 * vfs_dent_type - get VFS directory entry type.
326 * @type: UBIFS directory entry type
327 *
328 * This function converts UBIFS directory entry type into VFS directory entry
329 * type.
330 */
331static unsigned int vfs_dent_type(uint8_t type)
332{
333 switch (type) {
334 case UBIFS_ITYPE_REG:
335 return DT_REG;
336 case UBIFS_ITYPE_DIR:
337 return DT_DIR;
338 case UBIFS_ITYPE_LNK:
339 return DT_LNK;
340 case UBIFS_ITYPE_BLK:
341 return DT_BLK;
342 case UBIFS_ITYPE_CHR:
343 return DT_CHR;
344 case UBIFS_ITYPE_FIFO:
345 return DT_FIFO;
346 case UBIFS_ITYPE_SOCK:
347 return DT_SOCK;
348 default:
349 BUG();
350 }
351 return 0;
352}
353
354/*
355 * The classical Unix view for directory is that it is a linear array of
356 * (name, inode number) entries. Linux/VFS assumes this model as well.
357 * Particularly, 'readdir()' call wants us to return a directory entry offset
358 * which later may be used to continue 'readdir()'ing the directory or to
359 * 'seek()' to that specific direntry. Obviously UBIFS does not really fit this
360 * model because directory entries are identified by keys, which may collide.
361 *
362 * UBIFS uses directory entry hash value for directory offsets, so
363 * 'seekdir()'/'telldir()' may not always work because of possible key
364 * collisions. But UBIFS guarantees that consecutive 'readdir()' calls work
365 * properly by means of saving full directory entry name in the private field
366 * of the file description object.
367 *
368 * This means that UBIFS cannot support NFS which requires full
369 * 'seekdir()'/'telldir()' support.
370 */
371static int ubifs_readdir(struct file *file, void *dirent, filldir_t filldir)
372{
373 int err, over = 0;
374 struct qstr nm;
375 union ubifs_key key;
376 struct ubifs_dent_node *dent;
377 struct inode *dir = file->f_path.dentry->d_inode;
378 struct ubifs_info *c = dir->i_sb->s_fs_info;
379
380 dbg_gen("dir ino %lu, f_pos %#llx", dir->i_ino, file->f_pos);
381
382 if (file->f_pos > UBIFS_S_KEY_HASH_MASK || file->f_pos == 2)
383 /*
384 * The directory was seek'ed to a senseless position or there
385 * are no more entries.
386 */
387 return 0;
388
389 /* File positions 0 and 1 correspond to "." and ".." */
390 if (file->f_pos == 0) {
391 ubifs_assert(!file->private_data);
392 over = filldir(dirent, ".", 1, 0, dir->i_ino, DT_DIR);
393 if (over)
394 return 0;
395 file->f_pos = 1;
396 }
397
398 if (file->f_pos == 1) {
399 ubifs_assert(!file->private_data);
400 over = filldir(dirent, "..", 2, 1,
401 parent_ino(file->f_path.dentry), DT_DIR);
402 if (over)
403 return 0;
404
405 /* Find the first entry in TNC and save it */
406 lowest_dent_key(c, &key, dir->i_ino);
407 nm.name = NULL;
408 dent = ubifs_tnc_next_ent(c, &key, &nm);
409 if (IS_ERR(dent)) {
410 err = PTR_ERR(dent);
411 goto out;
412 }
413
414 file->f_pos = key_hash_flash(c, &dent->key);
415 file->private_data = dent;
416 }
417
418 dent = file->private_data;
419 if (!dent) {
420 /*
421 * The directory was seek'ed to and is now readdir'ed.
422 * Find the entry corresponding to @file->f_pos or the
423 * closest one.
424 */
425 dent_key_init_hash(c, &key, dir->i_ino, file->f_pos);
426 nm.name = NULL;
427 dent = ubifs_tnc_next_ent(c, &key, &nm);
428 if (IS_ERR(dent)) {
429 err = PTR_ERR(dent);
430 goto out;
431 }
432 file->f_pos = key_hash_flash(c, &dent->key);
433 file->private_data = dent;
434 }
435
436 while (1) {
437 dbg_gen("feed '%s', ino %llu, new f_pos %#x",
438 dent->name, le64_to_cpu(dent->inum),
439 key_hash_flash(c, &dent->key));
440 ubifs_assert(dent->ch.sqnum > ubifs_inode(dir)->creat_sqnum);
441
442 nm.len = le16_to_cpu(dent->nlen);
443 over = filldir(dirent, dent->name, nm.len, file->f_pos,
444 le64_to_cpu(dent->inum),
445 vfs_dent_type(dent->type));
446 if (over)
447 return 0;
448
449 /* Switch to the next entry */
450 key_read(c, &dent->key, &key);
451 nm.name = dent->name;
452 dent = ubifs_tnc_next_ent(c, &key, &nm);
453 if (IS_ERR(dent)) {
454 err = PTR_ERR(dent);
455 goto out;
456 }
457
458 kfree(file->private_data);
459 file->f_pos = key_hash_flash(c, &dent->key);
460 file->private_data = dent;
461 cond_resched();
462 }
463
464out:
465 if (err != -ENOENT) {
466 ubifs_err("cannot find next direntry, error %d", err);
467 return err;
468 }
469
470 kfree(file->private_data);
471 file->private_data = NULL;
472 file->f_pos = 2;
473 return 0;
474}
475
476/* If a directory is seeked, we have to free saved readdir() state */
477static loff_t ubifs_dir_llseek(struct file *file, loff_t offset, int origin)
478{
479 kfree(file->private_data);
480 file->private_data = NULL;
481 return generic_file_llseek(file, offset, origin);
482}
483
484/* Free saved readdir() state when the directory is closed */
485static int ubifs_dir_release(struct inode *dir, struct file *file)
486{
487 kfree(file->private_data);
488 file->private_data = NULL;
489 return 0;
490}
491
492/**
493 * lock_2_inodes - lock two UBIFS inodes.
494 * @inode1: first inode
495 * @inode2: second inode
496 */
497static void lock_2_inodes(struct inode *inode1, struct inode *inode2)
498{
499 if (inode1->i_ino < inode2->i_ino) {
500 mutex_lock_nested(&ubifs_inode(inode1)->ui_mutex, WB_MUTEX_2);
501 mutex_lock_nested(&ubifs_inode(inode2)->ui_mutex, WB_MUTEX_3);
502 } else {
503 mutex_lock_nested(&ubifs_inode(inode2)->ui_mutex, WB_MUTEX_2);
504 mutex_lock_nested(&ubifs_inode(inode1)->ui_mutex, WB_MUTEX_3);
505 }
506}
507
508/**
509 * unlock_2_inodes - unlock two UBIFS inodes inodes.
510 * @inode1: first inode
511 * @inode2: second inode
512 */
513static void unlock_2_inodes(struct inode *inode1, struct inode *inode2)
514{
515 mutex_unlock(&ubifs_inode(inode1)->ui_mutex);
516 mutex_unlock(&ubifs_inode(inode2)->ui_mutex);
517}
518
519static int ubifs_link(struct dentry *old_dentry, struct inode *dir,
520 struct dentry *dentry)
521{
522 struct ubifs_info *c = dir->i_sb->s_fs_info;
523 struct inode *inode = old_dentry->d_inode;
524 struct ubifs_inode *ui = ubifs_inode(inode);
525 struct ubifs_inode *dir_ui = ubifs_inode(dir);
526 int err, sz_change = CALC_DENT_SIZE(dentry->d_name.len);
527 struct ubifs_budget_req req = { .new_dent = 1, .dirtied_ino = 2,
528 .dirtied_ino_d = ui->data_len };
529
530 /*
531 * Budget request settings: new direntry, changing the target inode,
532 * changing the parent inode.
533 */
534
535 dbg_gen("dent '%.*s' to ino %lu (nlink %d) in dir ino %lu",
536 dentry->d_name.len, dentry->d_name.name, inode->i_ino,
537 inode->i_nlink, dir->i_ino);
538 err = dbg_check_synced_i_size(inode);
539 if (err)
540 return err;
541
542 err = ubifs_budget_space(c, &req);
543 if (err)
544 return err;
545
546 lock_2_inodes(dir, inode);
547 inc_nlink(inode);
548 atomic_inc(&inode->i_count);
549 inode->i_ctime = ubifs_current_time(inode);
550 dir->i_size += sz_change;
551 dir_ui->ui_size = dir->i_size;
552 dir->i_mtime = dir->i_ctime = inode->i_ctime;
553 err = ubifs_jnl_update(c, dir, &dentry->d_name, inode, 0, 0);
554 if (err)
555 goto out_cancel;
556 unlock_2_inodes(dir, inode);
557
558 ubifs_release_budget(c, &req);
559 d_instantiate(dentry, inode);
560 return 0;
561
562out_cancel:
563 dir->i_size -= sz_change;
564 dir_ui->ui_size = dir->i_size;
565 drop_nlink(inode);
566 unlock_2_inodes(dir, inode);
567 ubifs_release_budget(c, &req);
568 iput(inode);
569 return err;
570}
571
572static int ubifs_unlink(struct inode *dir, struct dentry *dentry)
573{
574 struct ubifs_info *c = dir->i_sb->s_fs_info;
575 struct inode *inode = dentry->d_inode;
576 struct ubifs_inode *dir_ui = ubifs_inode(dir);
577 int sz_change = CALC_DENT_SIZE(dentry->d_name.len);
578 int err, budgeted = 1;
579 struct ubifs_budget_req req = { .mod_dent = 1, .dirtied_ino = 2 };
580
581 /*
582 * Budget request settings: deletion direntry, deletion inode (+1 for
583 * @dirtied_ino), changing the parent directory inode. If budgeting
584 * fails, go ahead anyway because we have extra space reserved for
585 * deletions.
586 */
587
588 dbg_gen("dent '%.*s' from ino %lu (nlink %d) in dir ino %lu",
589 dentry->d_name.len, dentry->d_name.name, inode->i_ino,
590 inode->i_nlink, dir->i_ino);
591 err = dbg_check_synced_i_size(inode);
592 if (err)
593 return err;
594
595 err = ubifs_budget_space(c, &req);
596 if (err) {
597 if (err != -ENOSPC)
598 return err;
599 err = 0;
600 budgeted = 0;
601 }
602
603 lock_2_inodes(dir, inode);
604 inode->i_ctime = ubifs_current_time(dir);
605 drop_nlink(inode);
606 dir->i_size -= sz_change;
607 dir_ui->ui_size = dir->i_size;
608 dir->i_mtime = dir->i_ctime = inode->i_ctime;
609 err = ubifs_jnl_update(c, dir, &dentry->d_name, inode, 1, 0);
610 if (err)
611 goto out_cancel;
612 unlock_2_inodes(dir, inode);
613
614 if (budgeted)
615 ubifs_release_budget(c, &req);
616 else {
617 /* We've deleted something - clean the "no space" flags */
618 c->nospace = c->nospace_rp = 0;
619 smp_wmb();
620 }
621 return 0;
622
623out_cancel:
624 dir->i_size += sz_change;
625 dir_ui->ui_size = dir->i_size;
626 inc_nlink(inode);
627 unlock_2_inodes(dir, inode);
628 if (budgeted)
629 ubifs_release_budget(c, &req);
630 return err;
631}
632
633/**
634 * check_dir_empty - check if a directory is empty or not.
635 * @c: UBIFS file-system description object
636 * @dir: VFS inode object of the directory to check
637 *
638 * This function checks if directory @dir is empty. Returns zero if the
639 * directory is empty, %-ENOTEMPTY if it is not, and other negative error codes
640 * in case of of errors.
641 */
642static int check_dir_empty(struct ubifs_info *c, struct inode *dir)
643{
644 struct qstr nm = { .name = NULL };
645 struct ubifs_dent_node *dent;
646 union ubifs_key key;
647 int err;
648
649 lowest_dent_key(c, &key, dir->i_ino);
650 dent = ubifs_tnc_next_ent(c, &key, &nm);
651 if (IS_ERR(dent)) {
652 err = PTR_ERR(dent);
653 if (err == -ENOENT)
654 err = 0;
655 } else {
656 kfree(dent);
657 err = -ENOTEMPTY;
658 }
659 return err;
660}
661
662static int ubifs_rmdir(struct inode *dir, struct dentry *dentry)
663{
664 struct ubifs_info *c = dir->i_sb->s_fs_info;
665 struct inode *inode = dentry->d_inode;
666 int sz_change = CALC_DENT_SIZE(dentry->d_name.len);
667 int err, budgeted = 1;
668 struct ubifs_inode *dir_ui = ubifs_inode(dir);
669 struct ubifs_budget_req req = { .mod_dent = 1, .dirtied_ino = 2 };
670
671 /*
672 * Budget request settings: deletion direntry, deletion inode and
673 * changing the parent inode. If budgeting fails, go ahead anyway
674 * because we have extra space reserved for deletions.
675 */
676
677 dbg_gen("directory '%.*s', ino %lu in dir ino %lu", dentry->d_name.len,
678 dentry->d_name.name, inode->i_ino, dir->i_ino);
679
680 err = check_dir_empty(c, dentry->d_inode);
681 if (err)
682 return err;
683
684 err = ubifs_budget_space(c, &req);
685 if (err) {
686 if (err != -ENOSPC)
687 return err;
688 budgeted = 0;
689 }
690
691 lock_2_inodes(dir, inode);
692 inode->i_ctime = ubifs_current_time(dir);
693 clear_nlink(inode);
694 drop_nlink(dir);
695 dir->i_size -= sz_change;
696 dir_ui->ui_size = dir->i_size;
697 dir->i_mtime = dir->i_ctime = inode->i_ctime;
698 err = ubifs_jnl_update(c, dir, &dentry->d_name, inode, 1, 0);
699 if (err)
700 goto out_cancel;
701 unlock_2_inodes(dir, inode);
702
703 if (budgeted)
704 ubifs_release_budget(c, &req);
705 else {
706 /* We've deleted something - clean the "no space" flags */
707 c->nospace = c->nospace_rp = 0;
708 smp_wmb();
709 }
710 return 0;
711
712out_cancel:
713 dir->i_size += sz_change;
714 dir_ui->ui_size = dir->i_size;
715 inc_nlink(dir);
716 inc_nlink(inode);
717 inc_nlink(inode);
718 unlock_2_inodes(dir, inode);
719 if (budgeted)
720 ubifs_release_budget(c, &req);
721 return err;
722}
723
724static int ubifs_mkdir(struct inode *dir, struct dentry *dentry, int mode)
725{
726 struct inode *inode;
727 struct ubifs_inode *dir_ui = ubifs_inode(dir);
728 struct ubifs_info *c = dir->i_sb->s_fs_info;
729 int err, sz_change = CALC_DENT_SIZE(dentry->d_name.len);
730 struct ubifs_budget_req req = { .new_ino = 1, .new_dent = 1,
731 .dirtied_ino_d = 1 };
732
733 /*
734 * Budget request settings: new inode, new direntry and changing parent
735 * directory inode.
736 */
737
738 dbg_gen("dent '%.*s', mode %#x in dir ino %lu",
739 dentry->d_name.len, dentry->d_name.name, mode, dir->i_ino);
740
741 err = ubifs_budget_space(c, &req);
742 if (err)
743 return err;
744
745 inode = ubifs_new_inode(c, dir, S_IFDIR | mode);
746 if (IS_ERR(inode)) {
747 err = PTR_ERR(inode);
748 goto out_budg;
749 }
750
751 mutex_lock(&dir_ui->ui_mutex);
752 insert_inode_hash(inode);
753 inc_nlink(inode);
754 inc_nlink(dir);
755 dir->i_size += sz_change;
756 dir_ui->ui_size = dir->i_size;
757 dir->i_mtime = dir->i_ctime = inode->i_ctime;
758 err = ubifs_jnl_update(c, dir, &dentry->d_name, inode, 0, 0);
759 if (err) {
760 ubifs_err("cannot create directory, error %d", err);
761 goto out_cancel;
762 }
763 mutex_unlock(&dir_ui->ui_mutex);
764
765 ubifs_release_budget(c, &req);
766 d_instantiate(dentry, inode);
767 return 0;
768
769out_cancel:
770 dir->i_size -= sz_change;
771 dir_ui->ui_size = dir->i_size;
772 drop_nlink(dir);
773 mutex_unlock(&dir_ui->ui_mutex);
774 make_bad_inode(inode);
775 iput(inode);
776out_budg:
777 ubifs_release_budget(c, &req);
778 return err;
779}
780
781static int ubifs_mknod(struct inode *dir, struct dentry *dentry,
782 int mode, dev_t rdev)
783{
784 struct inode *inode;
785 struct ubifs_inode *ui;
786 struct ubifs_inode *dir_ui = ubifs_inode(dir);
787 struct ubifs_info *c = dir->i_sb->s_fs_info;
788 union ubifs_dev_desc *dev = NULL;
789 int sz_change = CALC_DENT_SIZE(dentry->d_name.len);
790 int err, devlen = 0;
791 struct ubifs_budget_req req = { .new_ino = 1, .new_dent = 1,
792 .new_ino_d = devlen, .dirtied_ino = 1 };
793
794 /*
795 * Budget request settings: new inode, new direntry and changing parent
796 * directory inode.
797 */
798
799 dbg_gen("dent '%.*s' in dir ino %lu",
800 dentry->d_name.len, dentry->d_name.name, dir->i_ino);
801
802 if (!new_valid_dev(rdev))
803 return -EINVAL;
804
805 if (S_ISBLK(mode) || S_ISCHR(mode)) {
806 dev = kmalloc(sizeof(union ubifs_dev_desc), GFP_NOFS);
807 if (!dev)
808 return -ENOMEM;
809 devlen = ubifs_encode_dev(dev, rdev);
810 }
811
812 err = ubifs_budget_space(c, &req);
813 if (err) {
814 kfree(dev);
815 return err;
816 }
817
818 inode = ubifs_new_inode(c, dir, mode);
819 if (IS_ERR(inode)) {
820 kfree(dev);
821 err = PTR_ERR(inode);
822 goto out_budg;
823 }
824
825 init_special_inode(inode, inode->i_mode, rdev);
826 inode->i_size = ubifs_inode(inode)->ui_size = devlen;
827 ui = ubifs_inode(inode);
828 ui->data = dev;
829 ui->data_len = devlen;
830
831 mutex_lock(&dir_ui->ui_mutex);
832 dir->i_size += sz_change;
833 dir_ui->ui_size = dir->i_size;
834 dir->i_mtime = dir->i_ctime = inode->i_ctime;
835 err = ubifs_jnl_update(c, dir, &dentry->d_name, inode, 0, 0);
836 if (err)
837 goto out_cancel;
838 mutex_unlock(&dir_ui->ui_mutex);
839
840 ubifs_release_budget(c, &req);
841 insert_inode_hash(inode);
842 d_instantiate(dentry, inode);
843 return 0;
844
845out_cancel:
846 dir->i_size -= sz_change;
847 dir_ui->ui_size = dir->i_size;
848 mutex_unlock(&dir_ui->ui_mutex);
849 make_bad_inode(inode);
850 iput(inode);
851out_budg:
852 ubifs_release_budget(c, &req);
853 return err;
854}
855
856static int ubifs_symlink(struct inode *dir, struct dentry *dentry,
857 const char *symname)
858{
859 struct inode *inode;
860 struct ubifs_inode *ui;
861 struct ubifs_inode *dir_ui = ubifs_inode(dir);
862 struct ubifs_info *c = dir->i_sb->s_fs_info;
863 int err, len = strlen(symname);
864 int sz_change = CALC_DENT_SIZE(dentry->d_name.len);
865 struct ubifs_budget_req req = { .new_ino = 1, .new_dent = 1,
866 .new_ino_d = len, .dirtied_ino = 1 };
867
868 /*
869 * Budget request settings: new inode, new direntry and changing parent
870 * directory inode.
871 */
872
873 dbg_gen("dent '%.*s', target '%s' in dir ino %lu", dentry->d_name.len,
874 dentry->d_name.name, symname, dir->i_ino);
875
876 if (len > UBIFS_MAX_INO_DATA)
877 return -ENAMETOOLONG;
878
879 err = ubifs_budget_space(c, &req);
880 if (err)
881 return err;
882
883 inode = ubifs_new_inode(c, dir, S_IFLNK | S_IRWXUGO);
884 if (IS_ERR(inode)) {
885 err = PTR_ERR(inode);
886 goto out_budg;
887 }
888
889 ui = ubifs_inode(inode);
890 ui->data = kmalloc(len + 1, GFP_NOFS);
891 if (!ui->data) {
892 err = -ENOMEM;
893 goto out_inode;
894 }
895
896 memcpy(ui->data, symname, len);
897 ((char *)ui->data)[len] = '\0';
898 /*
899 * The terminating zero byte is not written to the flash media and it
900 * is put just to make later in-memory string processing simpler. Thus,
901 * data length is @len, not @len + %1.
902 */
903 ui->data_len = len;
904 inode->i_size = ubifs_inode(inode)->ui_size = len;
905
906 mutex_lock(&dir_ui->ui_mutex);
907 dir->i_size += sz_change;
908 dir_ui->ui_size = dir->i_size;
909 dir->i_mtime = dir->i_ctime = inode->i_ctime;
910 err = ubifs_jnl_update(c, dir, &dentry->d_name, inode, 0, 0);
911 if (err)
912 goto out_cancel;
913 mutex_unlock(&dir_ui->ui_mutex);
914
915 ubifs_release_budget(c, &req);
916 insert_inode_hash(inode);
917 d_instantiate(dentry, inode);
918 return 0;
919
920out_cancel:
921 dir->i_size -= sz_change;
922 dir_ui->ui_size = dir->i_size;
923 mutex_unlock(&dir_ui->ui_mutex);
924out_inode:
925 make_bad_inode(inode);
926 iput(inode);
927out_budg:
928 ubifs_release_budget(c, &req);
929 return err;
930}
931
932/**
933 * lock_3_inodes - lock three UBIFS inodes for rename.
934 * @inode1: first inode
935 * @inode2: second inode
936 * @inode3: third inode
937 *
938 * For 'ubifs_rename()', @inode1 may be the same as @inode2 whereas @inode3 may
939 * be null.
940 */
941static void lock_3_inodes(struct inode *inode1, struct inode *inode2,
942 struct inode *inode3)
943{
944 struct inode *i1, *i2, *i3;
945
946 if (!inode3) {
947 if (inode1 != inode2) {
948 lock_2_inodes(inode1, inode2);
949 return;
950 }
951 mutex_lock_nested(&ubifs_inode(inode1)->ui_mutex, WB_MUTEX_1);
952 return;
953 }
954
955 if (inode1 == inode2) {
956 lock_2_inodes(inode1, inode3);
957 return;
958 }
959
960 /* 3 different inodes */
961 if (inode1 < inode2) {
962 i3 = inode2;
963 if (inode1 < inode3) {
964 i1 = inode1;
965 i2 = inode3;
966 } else {
967 i1 = inode3;
968 i2 = inode1;
969 }
970 } else {
971 i3 = inode1;
972 if (inode2 < inode3) {
973 i1 = inode2;
974 i2 = inode3;
975 } else {
976 i1 = inode3;
977 i2 = inode2;
978 }
979 }
980 mutex_lock_nested(&ubifs_inode(i1)->ui_mutex, WB_MUTEX_1);
981 lock_2_inodes(i2, i3);
982}
983
984/**
985 * unlock_3_inodes - unlock three UBIFS inodes for rename.
986 * @inode1: first inode
987 * @inode2: second inode
988 * @inode3: third inode
989 */
990static void unlock_3_inodes(struct inode *inode1, struct inode *inode2,
991 struct inode *inode3)
992{
993 mutex_unlock(&ubifs_inode(inode1)->ui_mutex);
994 if (inode1 != inode2)
995 mutex_unlock(&ubifs_inode(inode2)->ui_mutex);
996 if (inode3)
997 mutex_unlock(&ubifs_inode(inode3)->ui_mutex);
998}
999
1000static int ubifs_rename(struct inode *old_dir, struct dentry *old_dentry,
1001 struct inode *new_dir, struct dentry *new_dentry)
1002{
1003 struct ubifs_info *c = old_dir->i_sb->s_fs_info;
1004 struct inode *old_inode = old_dentry->d_inode;
1005 struct inode *new_inode = new_dentry->d_inode;
1006 struct ubifs_inode *old_inode_ui = ubifs_inode(old_inode);
1007 int err, release, sync = 0, move = (new_dir != old_dir);
1008 int is_dir = S_ISDIR(old_inode->i_mode);
1009 int unlink = !!new_inode;
1010 int new_sz = CALC_DENT_SIZE(new_dentry->d_name.len);
1011 int old_sz = CALC_DENT_SIZE(old_dentry->d_name.len);
1012 struct ubifs_budget_req req = { .new_dent = 1, .mod_dent = 1,
1013 .dirtied_ino = 3 };
1014 struct ubifs_budget_req ino_req = { .dirtied_ino = 1,
1015 .dirtied_ino_d = old_inode_ui->data_len };
1016 struct timespec time;
1017
1018 /*
1019 * Budget request settings: deletion direntry, new direntry, removing
1020 * the old inode, and changing old and new parent directory inodes.
1021 *
1022 * However, this operation also marks the target inode as dirty and
1023 * does not write it, so we allocate budget for the target inode
1024 * separately.
1025 */
1026
1027 dbg_gen("dent '%.*s' ino %lu in dir ino %lu to dent '%.*s' in "
1028 "dir ino %lu", old_dentry->d_name.len, old_dentry->d_name.name,
1029 old_inode->i_ino, old_dir->i_ino, new_dentry->d_name.len,
1030 new_dentry->d_name.name, new_dir->i_ino);
1031
1032 if (unlink && is_dir) {
1033 err = check_dir_empty(c, new_inode);
1034 if (err)
1035 return err;
1036 }
1037
1038 err = ubifs_budget_space(c, &req);
1039 if (err)
1040 return err;
1041 err = ubifs_budget_space(c, &ino_req);
1042 if (err) {
1043 ubifs_release_budget(c, &req);
1044 return err;
1045 }
1046
1047 lock_3_inodes(old_dir, new_dir, new_inode);
1048
1049 /*
1050 * Like most other Unix systems, set the @i_ctime for inodes on a
1051 * rename.
1052 */
1053 time = ubifs_current_time(old_dir);
1054 old_inode->i_ctime = time;
1055
1056 /* We must adjust parent link count when renaming directories */
1057 if (is_dir) {
1058 if (move) {
1059 /*
1060 * @old_dir loses a link because we are moving
1061 * @old_inode to a different directory.
1062 */
1063 drop_nlink(old_dir);
1064 /*
1065 * @new_dir only gains a link if we are not also
1066 * overwriting an existing directory.
1067 */
1068 if (!unlink)
1069 inc_nlink(new_dir);
1070 } else {
1071 /*
1072 * @old_inode is not moving to a different directory,
1073 * but @old_dir still loses a link if we are
1074 * overwriting an existing directory.
1075 */
1076 if (unlink)
1077 drop_nlink(old_dir);
1078 }
1079 }
1080
1081 old_dir->i_size -= old_sz;
1082 ubifs_inode(old_dir)->ui_size = old_dir->i_size;
1083 old_dir->i_mtime = old_dir->i_ctime = time;
1084 new_dir->i_mtime = new_dir->i_ctime = time;
1085
1086 /*
1087 * And finally, if we unlinked a direntry which happened to have the
1088 * same name as the moved direntry, we have to decrement @i_nlink of
1089 * the unlinked inode and change its ctime.
1090 */
1091 if (unlink) {
1092 /*
1093 * Directories cannot have hard-links, so if this is a
1094 * directory, decrement its @i_nlink twice because an empty
1095 * directory has @i_nlink 2.
1096 */
1097 if (is_dir)
1098 drop_nlink(new_inode);
1099 new_inode->i_ctime = time;
1100 drop_nlink(new_inode);
1101 } else {
1102 new_dir->i_size += new_sz;
1103 ubifs_inode(new_dir)->ui_size = new_dir->i_size;
1104 }
1105
1106 /*
1107 * Do not ask 'ubifs_jnl_rename()' to flush write-buffer if @old_inode
1108 * is dirty, because this will be done later on at the end of
1109 * 'ubifs_rename()'.
1110 */
1111 if (IS_SYNC(old_inode)) {
1112 sync = IS_DIRSYNC(old_dir) || IS_DIRSYNC(new_dir);
1113 if (unlink && IS_SYNC(new_inode))
1114 sync = 1;
1115 }
1116 err = ubifs_jnl_rename(c, old_dir, old_dentry, new_dir, new_dentry,
1117 sync);
1118 if (err)
1119 goto out_cancel;
1120
1121 unlock_3_inodes(old_dir, new_dir, new_inode);
1122 ubifs_release_budget(c, &req);
1123
1124 mutex_lock(&old_inode_ui->ui_mutex);
1125 release = old_inode_ui->dirty;
1126 mark_inode_dirty_sync(old_inode);
1127 mutex_unlock(&old_inode_ui->ui_mutex);
1128
1129 if (release)
1130 ubifs_release_budget(c, &ino_req);
1131 if (IS_SYNC(old_inode))
1132 err = old_inode->i_sb->s_op->write_inode(old_inode, 1);
1133 return err;
1134
1135out_cancel:
1136 if (unlink) {
1137 if (is_dir)
1138 inc_nlink(new_inode);
1139 inc_nlink(new_inode);
1140 } else {
1141 new_dir->i_size -= new_sz;
1142 ubifs_inode(new_dir)->ui_size = new_dir->i_size;
1143 }
1144 old_dir->i_size += old_sz;
1145 ubifs_inode(old_dir)->ui_size = old_dir->i_size;
1146 if (is_dir) {
1147 if (move) {
1148 inc_nlink(old_dir);
1149 if (!unlink)
1150 drop_nlink(new_dir);
1151 } else {
1152 if (unlink)
1153 inc_nlink(old_dir);
1154 }
1155 }
1156 unlock_3_inodes(old_dir, new_dir, new_inode);
1157 ubifs_release_budget(c, &ino_req);
1158 ubifs_release_budget(c, &req);
1159 return err;
1160}
1161
1162int ubifs_getattr(struct vfsmount *mnt, struct dentry *dentry,
1163 struct kstat *stat)
1164{
1165 loff_t size;
1166 struct inode *inode = dentry->d_inode;
1167 struct ubifs_inode *ui = ubifs_inode(inode);
1168
1169 mutex_lock(&ui->ui_mutex);
1170 stat->dev = inode->i_sb->s_dev;
1171 stat->ino = inode->i_ino;
1172 stat->mode = inode->i_mode;
1173 stat->nlink = inode->i_nlink;
1174 stat->uid = inode->i_uid;
1175 stat->gid = inode->i_gid;
1176 stat->rdev = inode->i_rdev;
1177 stat->atime = inode->i_atime;
1178 stat->mtime = inode->i_mtime;
1179 stat->ctime = inode->i_ctime;
1180 stat->blksize = UBIFS_BLOCK_SIZE;
1181 stat->size = ui->ui_size;
1182
1183 /*
1184 * Unfortunately, the 'stat()' system call was designed for block
1185 * device based file systems, and it is not appropriate for UBIFS,
1186 * because UBIFS does not have notion of "block". For example, it is
1187 * difficult to tell how many block a directory takes - it actually
1188 * takes less than 300 bytes, but we have to round it to block size,
1189 * which introduces large mistake. This makes utilities like 'du' to
1190 * report completely senseless numbers. This is the reason why UBIFS
1191 * goes the same way as JFFS2 - it reports zero blocks for everything
1192 * but regular files, which makes more sense than reporting completely
1193 * wrong sizes.
1194 */
1195 if (S_ISREG(inode->i_mode)) {
1196 size = ui->xattr_size;
1197 size += stat->size;
1198 size = ALIGN(size, UBIFS_BLOCK_SIZE);
1199 /*
1200 * Note, user-space expects 512-byte blocks count irrespectively
1201 * of what was reported in @stat->size.
1202 */
1203 stat->blocks = size >> 9;
1204 } else
1205 stat->blocks = 0;
1206 mutex_unlock(&ui->ui_mutex);
1207 return 0;
1208}
1209
1210struct inode_operations ubifs_dir_inode_operations = {
1211 .lookup = ubifs_lookup,
1212 .create = ubifs_create,
1213 .link = ubifs_link,
1214 .symlink = ubifs_symlink,
1215 .unlink = ubifs_unlink,
1216 .mkdir = ubifs_mkdir,
1217 .rmdir = ubifs_rmdir,
1218 .mknod = ubifs_mknod,
1219 .rename = ubifs_rename,
1220 .setattr = ubifs_setattr,
1221 .getattr = ubifs_getattr,
1222#ifdef CONFIG_UBIFS_FS_XATTR
1223 .setxattr = ubifs_setxattr,
1224 .getxattr = ubifs_getxattr,
1225 .listxattr = ubifs_listxattr,
1226 .removexattr = ubifs_removexattr,
1227#endif
1228};
1229
1230struct file_operations ubifs_dir_operations = {
1231 .llseek = ubifs_dir_llseek,
1232 .release = ubifs_dir_release,
1233 .read = generic_read_dir,
1234 .readdir = ubifs_readdir,
1235 .fsync = ubifs_fsync,
1236 .unlocked_ioctl = ubifs_ioctl,
1237#ifdef CONFIG_COMPAT
1238 .compat_ioctl = ubifs_compat_ioctl,
1239#endif
1240};
generated by cgit v1.2.2 (git 2.25.0) at 2024-11-06 23:33:01 -0500