blob: 526c01ec80032be9205e6057c48f9188b136b6e8 [file] [log] [blame]
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001/* * 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;
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300168 /*
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.
174 */
175 ui->creat_sqnum = ++c->max_sqnum;
176 spin_unlock(&c->cnt_lock);
177 return inode;
178}
179
180#ifdef CONFIG_UBIFS_FS_DEBUG
181
182static int dbg_check_name(struct ubifs_dent_node *dent, struct qstr *nm)
183{
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;
191}
192
193#else
194
195#define dbg_check_name(dent, nm) 0
196
197#endif
198
199static struct dentry *ubifs_lookup(struct inode *dir, struct dentry *dentry,
200 struct nameidata *nd)
201{
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;
207
208 dbg_gen("'%.*s' in dir ino %lu",
209 dentry->d_name.len, dentry->d_name.name, dir->i_ino);
210
211 if (dentry->d_name.len > UBIFS_MAX_NLEN)
212 return ERR_PTR(-ENAMETOOLONG);
213
214 dent = kmalloc(UBIFS_MAX_DENT_NODE_SZ, GFP_NOFS);
215 if (!dent)
216 return ERR_PTR(-ENOMEM);
217
218 dent_key_init(c, &key, dir->i_ino, &dentry->d_name);
219
220 err = ubifs_tnc_lookup_nm(c, &key, dent, &dentry->d_name);
221 if (err) {
Artem Bityutskiy720b4992008-08-13 16:16:31 +0300222 if (err == -ENOENT) {
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300223 dbg_gen("not found");
224 goto done;
225 }
226 goto out;
227 }
228
229 if (dbg_check_name(dent, &dentry->d_name)) {
230 err = -EINVAL;
231 goto out;
232 }
233
234 inode = ubifs_iget(dir->i_sb, le64_to_cpu(dent->inum));
235 if (IS_ERR(inode)) {
236 /*
237 * This should not happen. Probably the file-system needs
238 * checking.
239 */
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;
245 }
246
247done:
248 kfree(dent);
249 /*
250 * Note, d_splice_alias() would be required instead if we supported
251 * NFS.
252 */
253 d_add(dentry, inode);
254 return NULL;
255
256out:
257 kfree(dent);
258 return ERR_PTR(err);
259}
260
261static int ubifs_create(struct inode *dir, struct dentry *dentry, int mode,
262 struct nameidata *nd)
263{
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);
270
271 /*
272 * Budget request settings: new inode, new direntry, changing the
273 * parent directory inode.
274 */
275
276 dbg_gen("dent '%.*s', mode %#x in dir ino %lu",
277 dentry->d_name.len, dentry->d_name.name, mode, dir->i_ino);
278
279 err = ubifs_budget_space(c, &req);
280 if (err)
281 return err;
282
283 inode = ubifs_new_inode(c, dir, mode);
284 if (IS_ERR(inode)) {
285 err = PTR_ERR(inode);
286 goto out_budg;
287 }
288
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);
297
298 ubifs_release_budget(c, &req);
299 insert_inode_hash(inode);
300 d_instantiate(dentry, inode);
301 return 0;
302
303out_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);
309out_budg:
310 ubifs_release_budget(c, &req);
311 ubifs_err("cannot create regular file, error %d", err);
312 return err;
313}
314
315/**
316 * vfs_dent_type - get VFS directory entry type.
317 * @type: UBIFS directory entry type
318 *
319 * This function converts UBIFS directory entry type into VFS directory entry
320 * type.
321 */
322static unsigned int vfs_dent_type(uint8_t type)
323{
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();
341 }
342 return 0;
343}
344
345/*
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.
352 *
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.
358 *
359 * This means that UBIFS cannot support NFS which requires full
360 * 'seekdir()'/'telldir()' support.
361 */
362static int ubifs_readdir(struct file *file, void *dirent, filldir_t filldir)
363{
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;
370
371 dbg_gen("dir ino %lu, f_pos %#llx", dir->i_ino, file->f_pos);
372
373 if (file->f_pos > UBIFS_S_KEY_HASH_MASK || file->f_pos == 2)
374 /*
375 * The directory was seek'ed to a senseless position or there
376 * are no more entries.
377 */
378 return 0;
379
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;
387 }
388
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;
395
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;
403 }
404
405 file->f_pos = key_hash_flash(c, &dent->key);
406 file->private_data = dent;
407 }
408
409 dent = file->private_data;
410 if (!dent) {
411 /*
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.
415 */
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;
422 }
423 file->f_pos = key_hash_flash(c, &dent->key);
424 file->private_data = dent;
425 }
426
427 while (1) {
428 dbg_gen("feed '%s', ino %llu, new f_pos %#x",
Alexander Beregalov7424bac2008-09-17 22:09:41 +0400429 dent->name, (unsigned long long)le64_to_cpu(dent->inum),
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300430 key_hash_flash(c, &dent->key));
431 ubifs_assert(dent->ch.sqnum > ubifs_inode(dir)->creat_sqnum);
432
433 nm.len = le16_to_cpu(dent->nlen);
434 over = filldir(dirent, dent->name, nm.len, file->f_pos,
435 le64_to_cpu(dent->inum),
436 vfs_dent_type(dent->type));
437 if (over)
438 return 0;
439
440 /* Switch to the next entry */
441 key_read(c, &dent->key, &key);
442 nm.name = dent->name;
443 dent = ubifs_tnc_next_ent(c, &key, &nm);
444 if (IS_ERR(dent)) {
445 err = PTR_ERR(dent);
446 goto out;
447 }
448
449 kfree(file->private_data);
450 file->f_pos = key_hash_flash(c, &dent->key);
451 file->private_data = dent;
452 cond_resched();
453 }
454
455out:
456 if (err != -ENOENT) {
457 ubifs_err("cannot find next direntry, error %d", err);
458 return err;
459 }
460
461 kfree(file->private_data);
462 file->private_data = NULL;
463 file->f_pos = 2;
464 return 0;
465}
466
467/* If a directory is seeked, we have to free saved readdir() state */
468static loff_t ubifs_dir_llseek(struct file *file, loff_t offset, int origin)
469{
470 kfree(file->private_data);
471 file->private_data = NULL;
472 return generic_file_llseek(file, offset, origin);
473}
474
475/* Free saved readdir() state when the directory is closed */
476static int ubifs_dir_release(struct inode *dir, struct file *file)
477{
478 kfree(file->private_data);
479 file->private_data = NULL;
480 return 0;
481}
482
483/**
484 * lock_2_inodes - lock two UBIFS inodes.
485 * @inode1: first inode
486 * @inode2: second inode
487 */
488static void lock_2_inodes(struct inode *inode1, struct inode *inode2)
489{
490 if (inode1->i_ino < inode2->i_ino) {
491 mutex_lock_nested(&ubifs_inode(inode1)->ui_mutex, WB_MUTEX_2);
492 mutex_lock_nested(&ubifs_inode(inode2)->ui_mutex, WB_MUTEX_3);
493 } else {
494 mutex_lock_nested(&ubifs_inode(inode2)->ui_mutex, WB_MUTEX_2);
495 mutex_lock_nested(&ubifs_inode(inode1)->ui_mutex, WB_MUTEX_3);
496 }
497}
498
499/**
500 * unlock_2_inodes - unlock two UBIFS inodes inodes.
501 * @inode1: first inode
502 * @inode2: second inode
503 */
504static void unlock_2_inodes(struct inode *inode1, struct inode *inode2)
505{
506 mutex_unlock(&ubifs_inode(inode1)->ui_mutex);
507 mutex_unlock(&ubifs_inode(inode2)->ui_mutex);
508}
509
510static int ubifs_link(struct dentry *old_dentry, struct inode *dir,
511 struct dentry *dentry)
512{
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,
Artem Bityutskiydab4b4d2008-07-24 14:52:45 +0300519 .dirtied_ino_d = ALIGN(ui->data_len, 8) };
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300520
521 /*
522 * Budget request settings: new direntry, changing the target inode,
523 * changing the parent inode.
524 */
525
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 err = dbg_check_synced_i_size(inode);
530 if (err)
531 return err;
532
533 err = ubifs_budget_space(c, &req);
534 if (err)
535 return err;
536
537 lock_2_inodes(dir, inode);
538 inc_nlink(inode);
539 atomic_inc(&inode->i_count);
540 inode->i_ctime = ubifs_current_time(inode);
541 dir->i_size += sz_change;
542 dir_ui->ui_size = dir->i_size;
543 dir->i_mtime = dir->i_ctime = inode->i_ctime;
544 err = ubifs_jnl_update(c, dir, &dentry->d_name, inode, 0, 0);
545 if (err)
546 goto out_cancel;
547 unlock_2_inodes(dir, inode);
548
549 ubifs_release_budget(c, &req);
550 d_instantiate(dentry, inode);
551 return 0;
552
553out_cancel:
554 dir->i_size -= sz_change;
555 dir_ui->ui_size = dir->i_size;
556 drop_nlink(inode);
557 unlock_2_inodes(dir, inode);
558 ubifs_release_budget(c, &req);
559 iput(inode);
560 return err;
561}
562
563static int ubifs_unlink(struct inode *dir, struct dentry *dentry)
564{
565 struct ubifs_info *c = dir->i_sb->s_fs_info;
566 struct inode *inode = dentry->d_inode;
567 struct ubifs_inode *dir_ui = ubifs_inode(dir);
568 int sz_change = CALC_DENT_SIZE(dentry->d_name.len);
569 int err, budgeted = 1;
570 struct ubifs_budget_req req = { .mod_dent = 1, .dirtied_ino = 2 };
571
572 /*
573 * Budget request settings: deletion direntry, deletion inode (+1 for
574 * @dirtied_ino), changing the parent directory inode. If budgeting
575 * fails, go ahead anyway because we have extra space reserved for
576 * deletions.
577 */
578
579 dbg_gen("dent '%.*s' from ino %lu (nlink %d) in dir ino %lu",
580 dentry->d_name.len, dentry->d_name.name, inode->i_ino,
581 inode->i_nlink, dir->i_ino);
582 err = dbg_check_synced_i_size(inode);
583 if (err)
584 return err;
585
586 err = ubifs_budget_space(c, &req);
587 if (err) {
588 if (err != -ENOSPC)
589 return err;
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300590 budgeted = 0;
591 }
592
593 lock_2_inodes(dir, inode);
594 inode->i_ctime = ubifs_current_time(dir);
595 drop_nlink(inode);
596 dir->i_size -= sz_change;
597 dir_ui->ui_size = dir->i_size;
598 dir->i_mtime = dir->i_ctime = inode->i_ctime;
599 err = ubifs_jnl_update(c, dir, &dentry->d_name, inode, 1, 0);
600 if (err)
601 goto out_cancel;
602 unlock_2_inodes(dir, inode);
603
604 if (budgeted)
605 ubifs_release_budget(c, &req);
606 else {
607 /* We've deleted something - clean the "no space" flags */
608 c->nospace = c->nospace_rp = 0;
609 smp_wmb();
610 }
611 return 0;
612
613out_cancel:
614 dir->i_size += sz_change;
615 dir_ui->ui_size = dir->i_size;
616 inc_nlink(inode);
617 unlock_2_inodes(dir, inode);
618 if (budgeted)
619 ubifs_release_budget(c, &req);
620 return err;
621}
622
623/**
624 * check_dir_empty - check if a directory is empty or not.
625 * @c: UBIFS file-system description object
626 * @dir: VFS inode object of the directory to check
627 *
628 * This function checks if directory @dir is empty. Returns zero if the
629 * directory is empty, %-ENOTEMPTY if it is not, and other negative error codes
630 * in case of of errors.
631 */
632static int check_dir_empty(struct ubifs_info *c, struct inode *dir)
633{
634 struct qstr nm = { .name = NULL };
635 struct ubifs_dent_node *dent;
636 union ubifs_key key;
637 int err;
638
639 lowest_dent_key(c, &key, dir->i_ino);
640 dent = ubifs_tnc_next_ent(c, &key, &nm);
641 if (IS_ERR(dent)) {
642 err = PTR_ERR(dent);
643 if (err == -ENOENT)
644 err = 0;
645 } else {
646 kfree(dent);
647 err = -ENOTEMPTY;
648 }
649 return err;
650}
651
652static int ubifs_rmdir(struct inode *dir, struct dentry *dentry)
653{
654 struct ubifs_info *c = dir->i_sb->s_fs_info;
655 struct inode *inode = dentry->d_inode;
656 int sz_change = CALC_DENT_SIZE(dentry->d_name.len);
657 int err, budgeted = 1;
658 struct ubifs_inode *dir_ui = ubifs_inode(dir);
659 struct ubifs_budget_req req = { .mod_dent = 1, .dirtied_ino = 2 };
660
661 /*
662 * Budget request settings: deletion direntry, deletion inode and
663 * changing the parent inode. If budgeting fails, go ahead anyway
664 * because we have extra space reserved for deletions.
665 */
666
667 dbg_gen("directory '%.*s', ino %lu in dir ino %lu", dentry->d_name.len,
668 dentry->d_name.name, inode->i_ino, dir->i_ino);
669
670 err = check_dir_empty(c, dentry->d_inode);
671 if (err)
672 return err;
673
674 err = ubifs_budget_space(c, &req);
675 if (err) {
676 if (err != -ENOSPC)
677 return err;
678 budgeted = 0;
679 }
680
681 lock_2_inodes(dir, inode);
682 inode->i_ctime = ubifs_current_time(dir);
683 clear_nlink(inode);
684 drop_nlink(dir);
685 dir->i_size -= sz_change;
686 dir_ui->ui_size = dir->i_size;
687 dir->i_mtime = dir->i_ctime = inode->i_ctime;
688 err = ubifs_jnl_update(c, dir, &dentry->d_name, inode, 1, 0);
689 if (err)
690 goto out_cancel;
691 unlock_2_inodes(dir, inode);
692
693 if (budgeted)
694 ubifs_release_budget(c, &req);
695 else {
696 /* We've deleted something - clean the "no space" flags */
697 c->nospace = c->nospace_rp = 0;
698 smp_wmb();
699 }
700 return 0;
701
702out_cancel:
703 dir->i_size += sz_change;
704 dir_ui->ui_size = dir->i_size;
705 inc_nlink(dir);
706 inc_nlink(inode);
707 inc_nlink(inode);
708 unlock_2_inodes(dir, inode);
709 if (budgeted)
710 ubifs_release_budget(c, &req);
711 return err;
712}
713
714static int ubifs_mkdir(struct inode *dir, struct dentry *dentry, int mode)
715{
716 struct inode *inode;
717 struct ubifs_inode *dir_ui = ubifs_inode(dir);
718 struct ubifs_info *c = dir->i_sb->s_fs_info;
719 int err, sz_change = CALC_DENT_SIZE(dentry->d_name.len);
Artem Bityutskiy182854b2008-07-18 18:54:29 +0300720 struct ubifs_budget_req req = { .new_ino = 1, .new_dent = 1 };
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300721
722 /*
723 * Budget request settings: new inode, new direntry and changing parent
724 * directory inode.
725 */
726
727 dbg_gen("dent '%.*s', mode %#x in dir ino %lu",
728 dentry->d_name.len, dentry->d_name.name, mode, dir->i_ino);
729
730 err = ubifs_budget_space(c, &req);
731 if (err)
732 return err;
733
734 inode = ubifs_new_inode(c, dir, S_IFDIR | mode);
735 if (IS_ERR(inode)) {
736 err = PTR_ERR(inode);
737 goto out_budg;
738 }
739
740 mutex_lock(&dir_ui->ui_mutex);
741 insert_inode_hash(inode);
742 inc_nlink(inode);
743 inc_nlink(dir);
744 dir->i_size += sz_change;
745 dir_ui->ui_size = dir->i_size;
746 dir->i_mtime = dir->i_ctime = inode->i_ctime;
747 err = ubifs_jnl_update(c, dir, &dentry->d_name, inode, 0, 0);
748 if (err) {
749 ubifs_err("cannot create directory, error %d", err);
750 goto out_cancel;
751 }
752 mutex_unlock(&dir_ui->ui_mutex);
753
754 ubifs_release_budget(c, &req);
755 d_instantiate(dentry, inode);
756 return 0;
757
758out_cancel:
759 dir->i_size -= sz_change;
760 dir_ui->ui_size = dir->i_size;
761 drop_nlink(dir);
762 mutex_unlock(&dir_ui->ui_mutex);
763 make_bad_inode(inode);
764 iput(inode);
765out_budg:
766 ubifs_release_budget(c, &req);
767 return err;
768}
769
770static int ubifs_mknod(struct inode *dir, struct dentry *dentry,
771 int mode, dev_t rdev)
772{
773 struct inode *inode;
774 struct ubifs_inode *ui;
775 struct ubifs_inode *dir_ui = ubifs_inode(dir);
776 struct ubifs_info *c = dir->i_sb->s_fs_info;
777 union ubifs_dev_desc *dev = NULL;
778 int sz_change = CALC_DENT_SIZE(dentry->d_name.len);
779 int err, devlen = 0;
780 struct ubifs_budget_req req = { .new_ino = 1, .new_dent = 1,
Artem Bityutskiydab4b4d2008-07-24 14:52:45 +0300781 .new_ino_d = ALIGN(devlen, 8),
782 .dirtied_ino = 1 };
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300783
784 /*
785 * Budget request settings: new inode, new direntry and changing parent
786 * directory inode.
787 */
788
789 dbg_gen("dent '%.*s' in dir ino %lu",
790 dentry->d_name.len, dentry->d_name.name, dir->i_ino);
791
792 if (!new_valid_dev(rdev))
793 return -EINVAL;
794
795 if (S_ISBLK(mode) || S_ISCHR(mode)) {
796 dev = kmalloc(sizeof(union ubifs_dev_desc), GFP_NOFS);
797 if (!dev)
798 return -ENOMEM;
799 devlen = ubifs_encode_dev(dev, rdev);
800 }
801
802 err = ubifs_budget_space(c, &req);
803 if (err) {
804 kfree(dev);
805 return err;
806 }
807
808 inode = ubifs_new_inode(c, dir, mode);
809 if (IS_ERR(inode)) {
810 kfree(dev);
811 err = PTR_ERR(inode);
812 goto out_budg;
813 }
814
815 init_special_inode(inode, inode->i_mode, rdev);
816 inode->i_size = ubifs_inode(inode)->ui_size = devlen;
817 ui = ubifs_inode(inode);
818 ui->data = dev;
819 ui->data_len = devlen;
820
821 mutex_lock(&dir_ui->ui_mutex);
822 dir->i_size += sz_change;
823 dir_ui->ui_size = dir->i_size;
824 dir->i_mtime = dir->i_ctime = inode->i_ctime;
825 err = ubifs_jnl_update(c, dir, &dentry->d_name, inode, 0, 0);
826 if (err)
827 goto out_cancel;
828 mutex_unlock(&dir_ui->ui_mutex);
829
830 ubifs_release_budget(c, &req);
831 insert_inode_hash(inode);
832 d_instantiate(dentry, inode);
833 return 0;
834
835out_cancel:
836 dir->i_size -= sz_change;
837 dir_ui->ui_size = dir->i_size;
838 mutex_unlock(&dir_ui->ui_mutex);
839 make_bad_inode(inode);
840 iput(inode);
841out_budg:
842 ubifs_release_budget(c, &req);
843 return err;
844}
845
846static int ubifs_symlink(struct inode *dir, struct dentry *dentry,
847 const char *symname)
848{
849 struct inode *inode;
850 struct ubifs_inode *ui;
851 struct ubifs_inode *dir_ui = ubifs_inode(dir);
852 struct ubifs_info *c = dir->i_sb->s_fs_info;
853 int err, len = strlen(symname);
854 int sz_change = CALC_DENT_SIZE(dentry->d_name.len);
855 struct ubifs_budget_req req = { .new_ino = 1, .new_dent = 1,
Artem Bityutskiydab4b4d2008-07-24 14:52:45 +0300856 .new_ino_d = ALIGN(len, 8),
857 .dirtied_ino = 1 };
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300858
859 /*
860 * Budget request settings: new inode, new direntry and changing parent
861 * directory inode.
862 */
863
864 dbg_gen("dent '%.*s', target '%s' in dir ino %lu", dentry->d_name.len,
865 dentry->d_name.name, symname, dir->i_ino);
866
867 if (len > UBIFS_MAX_INO_DATA)
868 return -ENAMETOOLONG;
869
870 err = ubifs_budget_space(c, &req);
871 if (err)
872 return err;
873
874 inode = ubifs_new_inode(c, dir, S_IFLNK | S_IRWXUGO);
875 if (IS_ERR(inode)) {
876 err = PTR_ERR(inode);
877 goto out_budg;
878 }
879
880 ui = ubifs_inode(inode);
881 ui->data = kmalloc(len + 1, GFP_NOFS);
882 if (!ui->data) {
883 err = -ENOMEM;
884 goto out_inode;
885 }
886
887 memcpy(ui->data, symname, len);
888 ((char *)ui->data)[len] = '\0';
889 /*
890 * The terminating zero byte is not written to the flash media and it
891 * is put just to make later in-memory string processing simpler. Thus,
892 * data length is @len, not @len + %1.
893 */
894 ui->data_len = len;
895 inode->i_size = ubifs_inode(inode)->ui_size = len;
896
897 mutex_lock(&dir_ui->ui_mutex);
898 dir->i_size += sz_change;
899 dir_ui->ui_size = dir->i_size;
900 dir->i_mtime = dir->i_ctime = inode->i_ctime;
901 err = ubifs_jnl_update(c, dir, &dentry->d_name, inode, 0, 0);
902 if (err)
903 goto out_cancel;
904 mutex_unlock(&dir_ui->ui_mutex);
905
906 ubifs_release_budget(c, &req);
907 insert_inode_hash(inode);
908 d_instantiate(dentry, inode);
909 return 0;
910
911out_cancel:
912 dir->i_size -= sz_change;
913 dir_ui->ui_size = dir->i_size;
914 mutex_unlock(&dir_ui->ui_mutex);
915out_inode:
916 make_bad_inode(inode);
917 iput(inode);
918out_budg:
919 ubifs_release_budget(c, &req);
920 return err;
921}
922
923/**
924 * lock_3_inodes - lock three UBIFS inodes for rename.
925 * @inode1: first inode
926 * @inode2: second inode
927 * @inode3: third inode
928 *
929 * For 'ubifs_rename()', @inode1 may be the same as @inode2 whereas @inode3 may
930 * be null.
931 */
932static void lock_3_inodes(struct inode *inode1, struct inode *inode2,
933 struct inode *inode3)
934{
935 struct inode *i1, *i2, *i3;
936
937 if (!inode3) {
938 if (inode1 != inode2) {
939 lock_2_inodes(inode1, inode2);
940 return;
941 }
942 mutex_lock_nested(&ubifs_inode(inode1)->ui_mutex, WB_MUTEX_1);
943 return;
944 }
945
946 if (inode1 == inode2) {
947 lock_2_inodes(inode1, inode3);
948 return;
949 }
950
951 /* 3 different inodes */
952 if (inode1 < inode2) {
953 i3 = inode2;
954 if (inode1 < inode3) {
955 i1 = inode1;
956 i2 = inode3;
957 } else {
958 i1 = inode3;
959 i2 = inode1;
960 }
961 } else {
962 i3 = inode1;
963 if (inode2 < inode3) {
964 i1 = inode2;
965 i2 = inode3;
966 } else {
967 i1 = inode3;
968 i2 = inode2;
969 }
970 }
971 mutex_lock_nested(&ubifs_inode(i1)->ui_mutex, WB_MUTEX_1);
972 lock_2_inodes(i2, i3);
973}
974
975/**
976 * unlock_3_inodes - unlock three UBIFS inodes for rename.
977 * @inode1: first inode
978 * @inode2: second inode
979 * @inode3: third inode
980 */
981static void unlock_3_inodes(struct inode *inode1, struct inode *inode2,
982 struct inode *inode3)
983{
984 mutex_unlock(&ubifs_inode(inode1)->ui_mutex);
985 if (inode1 != inode2)
986 mutex_unlock(&ubifs_inode(inode2)->ui_mutex);
987 if (inode3)
988 mutex_unlock(&ubifs_inode(inode3)->ui_mutex);
989}
990
991static int ubifs_rename(struct inode *old_dir, struct dentry *old_dentry,
992 struct inode *new_dir, struct dentry *new_dentry)
993{
994 struct ubifs_info *c = old_dir->i_sb->s_fs_info;
995 struct inode *old_inode = old_dentry->d_inode;
996 struct inode *new_inode = new_dentry->d_inode;
997 struct ubifs_inode *old_inode_ui = ubifs_inode(old_inode);
998 int err, release, sync = 0, move = (new_dir != old_dir);
999 int is_dir = S_ISDIR(old_inode->i_mode);
1000 int unlink = !!new_inode;
1001 int new_sz = CALC_DENT_SIZE(new_dentry->d_name.len);
1002 int old_sz = CALC_DENT_SIZE(old_dentry->d_name.len);
1003 struct ubifs_budget_req req = { .new_dent = 1, .mod_dent = 1,
1004 .dirtied_ino = 3 };
1005 struct ubifs_budget_req ino_req = { .dirtied_ino = 1,
Artem Bityutskiydab4b4d2008-07-24 14:52:45 +03001006 .dirtied_ino_d = ALIGN(old_inode_ui->data_len, 8) };
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001007 struct timespec time;
1008
1009 /*
1010 * Budget request settings: deletion direntry, new direntry, removing
1011 * the old inode, and changing old and new parent directory inodes.
1012 *
1013 * However, this operation also marks the target inode as dirty and
1014 * does not write it, so we allocate budget for the target inode
1015 * separately.
1016 */
1017
1018 dbg_gen("dent '%.*s' ino %lu in dir ino %lu to dent '%.*s' in "
1019 "dir ino %lu", old_dentry->d_name.len, old_dentry->d_name.name,
1020 old_inode->i_ino, old_dir->i_ino, new_dentry->d_name.len,
1021 new_dentry->d_name.name, new_dir->i_ino);
1022
1023 if (unlink && is_dir) {
1024 err = check_dir_empty(c, new_inode);
1025 if (err)
1026 return err;
1027 }
1028
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;
1036 }
1037
1038 lock_3_inodes(old_dir, new_dir, new_inode);
1039
1040 /*
1041 * Like most other Unix systems, set the @i_ctime for inodes on a
1042 * rename.
1043 */
1044 time = ubifs_current_time(old_dir);
1045 old_inode->i_ctime = time;
1046
1047 /* We must adjust parent link count when renaming directories */
1048 if (is_dir) {
1049 if (move) {
1050 /*
1051 * @old_dir loses a link because we are moving
1052 * @old_inode to a different directory.
1053 */
1054 drop_nlink(old_dir);
1055 /*
1056 * @new_dir only gains a link if we are not also
1057 * overwriting an existing directory.
1058 */
1059 if (!unlink)
1060 inc_nlink(new_dir);
1061 } else {
1062 /*
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.
1066 */
1067 if (unlink)
1068 drop_nlink(old_dir);
1069 }
1070 }
1071
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;
1076
1077 /*
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.
1081 */
1082 if (unlink) {
1083 /*
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.
1087 */
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;
1095 }
1096
1097 /*
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()'.
1101 */
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;
1106 }
1107 err = ubifs_jnl_rename(c, old_dir, old_dentry, new_dir, new_dentry,
1108 sync);
1109 if (err)
1110 goto out_cancel;
1111
1112 unlock_3_inodes(old_dir, new_dir, new_inode);
1113 ubifs_release_budget(c, &req);
1114
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);
1119
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;
1125
1126out_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;
1134 }
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);
1145 }
1146 }
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;
1151}
1152
1153int ubifs_getattr(struct vfsmount *mnt, struct dentry *dentry,
1154 struct kstat *stat)
1155{
1156 loff_t size;
1157 struct inode *inode = dentry->d_inode;
1158 struct ubifs_inode *ui = ubifs_inode(inode);
1159
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;
1173
1174 /*
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.
1185 */
1186 if (S_ISREG(inode->i_mode)) {
1187 size = ui->xattr_size;
1188 size += stat->size;
1189 size = ALIGN(size, UBIFS_BLOCK_SIZE);
1190 /*
1191 * Note, user-space expects 512-byte blocks count irrespectively
1192 * of what was reported in @stat->size.
1193 */
1194 stat->blocks = size >> 9;
1195 } else
1196 stat->blocks = 0;
1197 mutex_unlock(&ui->ui_mutex);
1198 return 0;
1199}
1200
1201struct 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
1219};
1220
1221struct 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
1231};