blob: 0422c98e17932e41ecca3f25c6dea8aedb10e133 [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)",
Artem Bityutskiye84461a2008-10-29 12:08:43 +0200164 (unsigned long)c->highest_inum, INUM_WATERMARK);
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300165 }
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));
Harvey Harrison0ecb9522008-10-24 10:52:57 -0700431 ubifs_assert(le64_to_cpu(dent->ch.sqnum) >
432 ubifs_inode(dir)->creat_sqnum);
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300433
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;
440
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;
448 }
449
450 kfree(file->private_data);
451 file->f_pos = key_hash_flash(c, &dent->key);
452 file->private_data = dent;
453 cond_resched();
454 }
455
456out:
457 if (err != -ENOENT) {
458 ubifs_err("cannot find next direntry, error %d", err);
459 return err;
460 }
461
462 kfree(file->private_data);
463 file->private_data = NULL;
464 file->f_pos = 2;
465 return 0;
466}
467
468/* If a directory is seeked, we have to free saved readdir() state */
469static loff_t ubifs_dir_llseek(struct file *file, loff_t offset, int origin)
470{
471 kfree(file->private_data);
472 file->private_data = NULL;
473 return generic_file_llseek(file, offset, origin);
474}
475
476/* Free saved readdir() state when the directory is closed */
477static int ubifs_dir_release(struct inode *dir, struct file *file)
478{
479 kfree(file->private_data);
480 file->private_data = NULL;
481 return 0;
482}
483
484/**
485 * lock_2_inodes - lock two UBIFS inodes.
486 * @inode1: first inode
487 * @inode2: second inode
488 */
489static void lock_2_inodes(struct inode *inode1, struct inode *inode2)
490{
491 if (inode1->i_ino < inode2->i_ino) {
492 mutex_lock_nested(&ubifs_inode(inode1)->ui_mutex, WB_MUTEX_2);
493 mutex_lock_nested(&ubifs_inode(inode2)->ui_mutex, WB_MUTEX_3);
494 } else {
495 mutex_lock_nested(&ubifs_inode(inode2)->ui_mutex, WB_MUTEX_2);
496 mutex_lock_nested(&ubifs_inode(inode1)->ui_mutex, WB_MUTEX_3);
497 }
498}
499
500/**
501 * unlock_2_inodes - unlock two UBIFS inodes inodes.
502 * @inode1: first inode
503 * @inode2: second inode
504 */
505static void unlock_2_inodes(struct inode *inode1, struct inode *inode2)
506{
507 mutex_unlock(&ubifs_inode(inode1)->ui_mutex);
508 mutex_unlock(&ubifs_inode(inode2)->ui_mutex);
509}
510
511static int ubifs_link(struct dentry *old_dentry, struct inode *dir,
512 struct dentry *dentry)
513{
514 struct ubifs_info *c = dir->i_sb->s_fs_info;
515 struct inode *inode = old_dentry->d_inode;
516 struct ubifs_inode *ui = ubifs_inode(inode);
517 struct ubifs_inode *dir_ui = ubifs_inode(dir);
518 int err, sz_change = CALC_DENT_SIZE(dentry->d_name.len);
519 struct ubifs_budget_req req = { .new_dent = 1, .dirtied_ino = 2,
Artem Bityutskiydab4b4d2008-07-24 14:52:45 +0300520 .dirtied_ino_d = ALIGN(ui->data_len, 8) };
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300521
522 /*
523 * Budget request settings: new direntry, changing the target inode,
524 * changing the parent inode.
525 */
526
527 dbg_gen("dent '%.*s' to ino %lu (nlink %d) in dir ino %lu",
528 dentry->d_name.len, dentry->d_name.name, inode->i_ino,
529 inode->i_nlink, dir->i_ino);
530 err = dbg_check_synced_i_size(inode);
531 if (err)
532 return err;
533
534 err = ubifs_budget_space(c, &req);
535 if (err)
536 return err;
537
538 lock_2_inodes(dir, inode);
539 inc_nlink(inode);
540 atomic_inc(&inode->i_count);
541 inode->i_ctime = ubifs_current_time(inode);
542 dir->i_size += sz_change;
543 dir_ui->ui_size = dir->i_size;
544 dir->i_mtime = dir->i_ctime = inode->i_ctime;
545 err = ubifs_jnl_update(c, dir, &dentry->d_name, inode, 0, 0);
546 if (err)
547 goto out_cancel;
548 unlock_2_inodes(dir, inode);
549
550 ubifs_release_budget(c, &req);
551 d_instantiate(dentry, inode);
552 return 0;
553
554out_cancel:
555 dir->i_size -= sz_change;
556 dir_ui->ui_size = dir->i_size;
557 drop_nlink(inode);
558 unlock_2_inodes(dir, inode);
559 ubifs_release_budget(c, &req);
560 iput(inode);
561 return err;
562}
563
564static int ubifs_unlink(struct inode *dir, struct dentry *dentry)
565{
566 struct ubifs_info *c = dir->i_sb->s_fs_info;
567 struct inode *inode = dentry->d_inode;
568 struct ubifs_inode *dir_ui = ubifs_inode(dir);
569 int sz_change = CALC_DENT_SIZE(dentry->d_name.len);
570 int err, budgeted = 1;
571 struct ubifs_budget_req req = { .mod_dent = 1, .dirtied_ino = 2 };
572
573 /*
574 * Budget request settings: deletion direntry, deletion inode (+1 for
575 * @dirtied_ino), changing the parent directory inode. If budgeting
576 * fails, go ahead anyway because we have extra space reserved for
577 * deletions.
578 */
579
580 dbg_gen("dent '%.*s' from ino %lu (nlink %d) in dir ino %lu",
581 dentry->d_name.len, dentry->d_name.name, inode->i_ino,
582 inode->i_nlink, dir->i_ino);
583 err = dbg_check_synced_i_size(inode);
584 if (err)
585 return err;
586
587 err = ubifs_budget_space(c, &req);
588 if (err) {
589 if (err != -ENOSPC)
590 return err;
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300591 budgeted = 0;
592 }
593
594 lock_2_inodes(dir, inode);
595 inode->i_ctime = ubifs_current_time(dir);
596 drop_nlink(inode);
597 dir->i_size -= sz_change;
598 dir_ui->ui_size = dir->i_size;
599 dir->i_mtime = dir->i_ctime = inode->i_ctime;
600 err = ubifs_jnl_update(c, dir, &dentry->d_name, inode, 1, 0);
601 if (err)
602 goto out_cancel;
603 unlock_2_inodes(dir, inode);
604
605 if (budgeted)
606 ubifs_release_budget(c, &req);
607 else {
608 /* We've deleted something - clean the "no space" flags */
609 c->nospace = c->nospace_rp = 0;
610 smp_wmb();
611 }
612 return 0;
613
614out_cancel:
615 dir->i_size += sz_change;
616 dir_ui->ui_size = dir->i_size;
617 inc_nlink(inode);
618 unlock_2_inodes(dir, inode);
619 if (budgeted)
620 ubifs_release_budget(c, &req);
621 return err;
622}
623
624/**
625 * check_dir_empty - check if a directory is empty or not.
626 * @c: UBIFS file-system description object
627 * @dir: VFS inode object of the directory to check
628 *
629 * This function checks if directory @dir is empty. Returns zero if the
630 * directory is empty, %-ENOTEMPTY if it is not, and other negative error codes
631 * in case of of errors.
632 */
633static int check_dir_empty(struct ubifs_info *c, struct inode *dir)
634{
635 struct qstr nm = { .name = NULL };
636 struct ubifs_dent_node *dent;
637 union ubifs_key key;
638 int err;
639
640 lowest_dent_key(c, &key, dir->i_ino);
641 dent = ubifs_tnc_next_ent(c, &key, &nm);
642 if (IS_ERR(dent)) {
643 err = PTR_ERR(dent);
644 if (err == -ENOENT)
645 err = 0;
646 } else {
647 kfree(dent);
648 err = -ENOTEMPTY;
649 }
650 return err;
651}
652
653static int ubifs_rmdir(struct inode *dir, struct dentry *dentry)
654{
655 struct ubifs_info *c = dir->i_sb->s_fs_info;
656 struct inode *inode = dentry->d_inode;
657 int sz_change = CALC_DENT_SIZE(dentry->d_name.len);
658 int err, budgeted = 1;
659 struct ubifs_inode *dir_ui = ubifs_inode(dir);
660 struct ubifs_budget_req req = { .mod_dent = 1, .dirtied_ino = 2 };
661
662 /*
663 * Budget request settings: deletion direntry, deletion inode and
664 * changing the parent inode. If budgeting fails, go ahead anyway
665 * because we have extra space reserved for deletions.
666 */
667
668 dbg_gen("directory '%.*s', ino %lu in dir ino %lu", dentry->d_name.len,
669 dentry->d_name.name, inode->i_ino, dir->i_ino);
670
671 err = check_dir_empty(c, dentry->d_inode);
672 if (err)
673 return err;
674
675 err = ubifs_budget_space(c, &req);
676 if (err) {
677 if (err != -ENOSPC)
678 return err;
679 budgeted = 0;
680 }
681
682 lock_2_inodes(dir, inode);
683 inode->i_ctime = ubifs_current_time(dir);
684 clear_nlink(inode);
685 drop_nlink(dir);
686 dir->i_size -= sz_change;
687 dir_ui->ui_size = dir->i_size;
688 dir->i_mtime = dir->i_ctime = inode->i_ctime;
689 err = ubifs_jnl_update(c, dir, &dentry->d_name, inode, 1, 0);
690 if (err)
691 goto out_cancel;
692 unlock_2_inodes(dir, inode);
693
694 if (budgeted)
695 ubifs_release_budget(c, &req);
696 else {
697 /* We've deleted something - clean the "no space" flags */
698 c->nospace = c->nospace_rp = 0;
699 smp_wmb();
700 }
701 return 0;
702
703out_cancel:
704 dir->i_size += sz_change;
705 dir_ui->ui_size = dir->i_size;
706 inc_nlink(dir);
707 inc_nlink(inode);
708 inc_nlink(inode);
709 unlock_2_inodes(dir, inode);
710 if (budgeted)
711 ubifs_release_budget(c, &req);
712 return err;
713}
714
715static int ubifs_mkdir(struct inode *dir, struct dentry *dentry, int mode)
716{
717 struct inode *inode;
718 struct ubifs_inode *dir_ui = ubifs_inode(dir);
719 struct ubifs_info *c = dir->i_sb->s_fs_info;
720 int err, sz_change = CALC_DENT_SIZE(dentry->d_name.len);
Artem Bityutskiy182854b2008-07-18 18:54:29 +0300721 struct ubifs_budget_req req = { .new_ino = 1, .new_dent = 1 };
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300722
723 /*
724 * Budget request settings: new inode, new direntry and changing parent
725 * directory inode.
726 */
727
728 dbg_gen("dent '%.*s', mode %#x in dir ino %lu",
729 dentry->d_name.len, dentry->d_name.name, mode, dir->i_ino);
730
731 err = ubifs_budget_space(c, &req);
732 if (err)
733 return err;
734
735 inode = ubifs_new_inode(c, dir, S_IFDIR | mode);
736 if (IS_ERR(inode)) {
737 err = PTR_ERR(inode);
738 goto out_budg;
739 }
740
741 mutex_lock(&dir_ui->ui_mutex);
742 insert_inode_hash(inode);
743 inc_nlink(inode);
744 inc_nlink(dir);
745 dir->i_size += sz_change;
746 dir_ui->ui_size = dir->i_size;
747 dir->i_mtime = dir->i_ctime = inode->i_ctime;
748 err = ubifs_jnl_update(c, dir, &dentry->d_name, inode, 0, 0);
749 if (err) {
750 ubifs_err("cannot create directory, error %d", err);
751 goto out_cancel;
752 }
753 mutex_unlock(&dir_ui->ui_mutex);
754
755 ubifs_release_budget(c, &req);
756 d_instantiate(dentry, inode);
757 return 0;
758
759out_cancel:
760 dir->i_size -= sz_change;
761 dir_ui->ui_size = dir->i_size;
762 drop_nlink(dir);
763 mutex_unlock(&dir_ui->ui_mutex);
764 make_bad_inode(inode);
765 iput(inode);
766out_budg:
767 ubifs_release_budget(c, &req);
768 return err;
769}
770
771static int ubifs_mknod(struct inode *dir, struct dentry *dentry,
772 int mode, dev_t rdev)
773{
774 struct inode *inode;
775 struct ubifs_inode *ui;
776 struct ubifs_inode *dir_ui = ubifs_inode(dir);
777 struct ubifs_info *c = dir->i_sb->s_fs_info;
778 union ubifs_dev_desc *dev = NULL;
779 int sz_change = CALC_DENT_SIZE(dentry->d_name.len);
780 int err, devlen = 0;
781 struct ubifs_budget_req req = { .new_ino = 1, .new_dent = 1,
Artem Bityutskiydab4b4d2008-07-24 14:52:45 +0300782 .new_ino_d = ALIGN(devlen, 8),
783 .dirtied_ino = 1 };
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300784
785 /*
786 * Budget request settings: new inode, new direntry and changing parent
787 * directory inode.
788 */
789
790 dbg_gen("dent '%.*s' in dir ino %lu",
791 dentry->d_name.len, dentry->d_name.name, dir->i_ino);
792
793 if (!new_valid_dev(rdev))
794 return -EINVAL;
795
796 if (S_ISBLK(mode) || S_ISCHR(mode)) {
797 dev = kmalloc(sizeof(union ubifs_dev_desc), GFP_NOFS);
798 if (!dev)
799 return -ENOMEM;
800 devlen = ubifs_encode_dev(dev, rdev);
801 }
802
803 err = ubifs_budget_space(c, &req);
804 if (err) {
805 kfree(dev);
806 return err;
807 }
808
809 inode = ubifs_new_inode(c, dir, mode);
810 if (IS_ERR(inode)) {
811 kfree(dev);
812 err = PTR_ERR(inode);
813 goto out_budg;
814 }
815
816 init_special_inode(inode, inode->i_mode, rdev);
817 inode->i_size = ubifs_inode(inode)->ui_size = devlen;
818 ui = ubifs_inode(inode);
819 ui->data = dev;
820 ui->data_len = devlen;
821
822 mutex_lock(&dir_ui->ui_mutex);
823 dir->i_size += sz_change;
824 dir_ui->ui_size = dir->i_size;
825 dir->i_mtime = dir->i_ctime = inode->i_ctime;
826 err = ubifs_jnl_update(c, dir, &dentry->d_name, inode, 0, 0);
827 if (err)
828 goto out_cancel;
829 mutex_unlock(&dir_ui->ui_mutex);
830
831 ubifs_release_budget(c, &req);
832 insert_inode_hash(inode);
833 d_instantiate(dentry, inode);
834 return 0;
835
836out_cancel:
837 dir->i_size -= sz_change;
838 dir_ui->ui_size = dir->i_size;
839 mutex_unlock(&dir_ui->ui_mutex);
840 make_bad_inode(inode);
841 iput(inode);
842out_budg:
843 ubifs_release_budget(c, &req);
844 return err;
845}
846
847static int ubifs_symlink(struct inode *dir, struct dentry *dentry,
848 const char *symname)
849{
850 struct inode *inode;
851 struct ubifs_inode *ui;
852 struct ubifs_inode *dir_ui = ubifs_inode(dir);
853 struct ubifs_info *c = dir->i_sb->s_fs_info;
854 int err, len = strlen(symname);
855 int sz_change = CALC_DENT_SIZE(dentry->d_name.len);
856 struct ubifs_budget_req req = { .new_ino = 1, .new_dent = 1,
Artem Bityutskiydab4b4d2008-07-24 14:52:45 +0300857 .new_ino_d = ALIGN(len, 8),
858 .dirtied_ino = 1 };
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300859
860 /*
861 * Budget request settings: new inode, new direntry and changing parent
862 * directory inode.
863 */
864
865 dbg_gen("dent '%.*s', target '%s' in dir ino %lu", dentry->d_name.len,
866 dentry->d_name.name, symname, dir->i_ino);
867
868 if (len > UBIFS_MAX_INO_DATA)
869 return -ENAMETOOLONG;
870
871 err = ubifs_budget_space(c, &req);
872 if (err)
873 return err;
874
875 inode = ubifs_new_inode(c, dir, S_IFLNK | S_IRWXUGO);
876 if (IS_ERR(inode)) {
877 err = PTR_ERR(inode);
878 goto out_budg;
879 }
880
881 ui = ubifs_inode(inode);
882 ui->data = kmalloc(len + 1, GFP_NOFS);
883 if (!ui->data) {
884 err = -ENOMEM;
885 goto out_inode;
886 }
887
888 memcpy(ui->data, symname, len);
889 ((char *)ui->data)[len] = '\0';
890 /*
891 * The terminating zero byte is not written to the flash media and it
892 * is put just to make later in-memory string processing simpler. Thus,
893 * data length is @len, not @len + %1.
894 */
895 ui->data_len = len;
896 inode->i_size = ubifs_inode(inode)->ui_size = len;
897
898 mutex_lock(&dir_ui->ui_mutex);
899 dir->i_size += sz_change;
900 dir_ui->ui_size = dir->i_size;
901 dir->i_mtime = dir->i_ctime = inode->i_ctime;
902 err = ubifs_jnl_update(c, dir, &dentry->d_name, inode, 0, 0);
903 if (err)
904 goto out_cancel;
905 mutex_unlock(&dir_ui->ui_mutex);
906
907 ubifs_release_budget(c, &req);
908 insert_inode_hash(inode);
909 d_instantiate(dentry, inode);
910 return 0;
911
912out_cancel:
913 dir->i_size -= sz_change;
914 dir_ui->ui_size = dir->i_size;
915 mutex_unlock(&dir_ui->ui_mutex);
916out_inode:
917 make_bad_inode(inode);
918 iput(inode);
919out_budg:
920 ubifs_release_budget(c, &req);
921 return err;
922}
923
924/**
925 * lock_3_inodes - lock three UBIFS inodes for rename.
926 * @inode1: first inode
927 * @inode2: second inode
928 * @inode3: third inode
929 *
930 * For 'ubifs_rename()', @inode1 may be the same as @inode2 whereas @inode3 may
931 * be null.
932 */
933static void lock_3_inodes(struct inode *inode1, struct inode *inode2,
934 struct inode *inode3)
935{
936 struct inode *i1, *i2, *i3;
937
938 if (!inode3) {
939 if (inode1 != inode2) {
940 lock_2_inodes(inode1, inode2);
941 return;
942 }
943 mutex_lock_nested(&ubifs_inode(inode1)->ui_mutex, WB_MUTEX_1);
944 return;
945 }
946
947 if (inode1 == inode2) {
948 lock_2_inodes(inode1, inode3);
949 return;
950 }
951
952 /* 3 different inodes */
953 if (inode1 < inode2) {
954 i3 = inode2;
955 if (inode1 < inode3) {
956 i1 = inode1;
957 i2 = inode3;
958 } else {
959 i1 = inode3;
960 i2 = inode1;
961 }
962 } else {
963 i3 = inode1;
964 if (inode2 < inode3) {
965 i1 = inode2;
966 i2 = inode3;
967 } else {
968 i1 = inode3;
969 i2 = inode2;
970 }
971 }
972 mutex_lock_nested(&ubifs_inode(i1)->ui_mutex, WB_MUTEX_1);
973 lock_2_inodes(i2, i3);
974}
975
976/**
977 * unlock_3_inodes - unlock three UBIFS inodes for rename.
978 * @inode1: first inode
979 * @inode2: second inode
980 * @inode3: third inode
981 */
982static void unlock_3_inodes(struct inode *inode1, struct inode *inode2,
983 struct inode *inode3)
984{
985 mutex_unlock(&ubifs_inode(inode1)->ui_mutex);
986 if (inode1 != inode2)
987 mutex_unlock(&ubifs_inode(inode2)->ui_mutex);
988 if (inode3)
989 mutex_unlock(&ubifs_inode(inode3)->ui_mutex);
990}
991
992static int ubifs_rename(struct inode *old_dir, struct dentry *old_dentry,
993 struct inode *new_dir, struct dentry *new_dentry)
994{
995 struct ubifs_info *c = old_dir->i_sb->s_fs_info;
996 struct inode *old_inode = old_dentry->d_inode;
997 struct inode *new_inode = new_dentry->d_inode;
998 struct ubifs_inode *old_inode_ui = ubifs_inode(old_inode);
999 int err, release, sync = 0, move = (new_dir != old_dir);
1000 int is_dir = S_ISDIR(old_inode->i_mode);
1001 int unlink = !!new_inode;
1002 int new_sz = CALC_DENT_SIZE(new_dentry->d_name.len);
1003 int old_sz = CALC_DENT_SIZE(old_dentry->d_name.len);
1004 struct ubifs_budget_req req = { .new_dent = 1, .mod_dent = 1,
1005 .dirtied_ino = 3 };
1006 struct ubifs_budget_req ino_req = { .dirtied_ino = 1,
Artem Bityutskiydab4b4d2008-07-24 14:52:45 +03001007 .dirtied_ino_d = ALIGN(old_inode_ui->data_len, 8) };
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001008 struct timespec time;
1009
1010 /*
1011 * Budget request settings: deletion direntry, new direntry, removing
1012 * the old inode, and changing old and new parent directory inodes.
1013 *
1014 * However, this operation also marks the target inode as dirty and
1015 * does not write it, so we allocate budget for the target inode
1016 * separately.
1017 */
1018
1019 dbg_gen("dent '%.*s' ino %lu in dir ino %lu to dent '%.*s' in "
1020 "dir ino %lu", old_dentry->d_name.len, old_dentry->d_name.name,
1021 old_inode->i_ino, old_dir->i_ino, new_dentry->d_name.len,
1022 new_dentry->d_name.name, new_dir->i_ino);
1023
1024 if (unlink && is_dir) {
1025 err = check_dir_empty(c, new_inode);
1026 if (err)
1027 return err;
1028 }
1029
1030 err = ubifs_budget_space(c, &req);
1031 if (err)
1032 return err;
1033 err = ubifs_budget_space(c, &ino_req);
1034 if (err) {
1035 ubifs_release_budget(c, &req);
1036 return err;
1037 }
1038
1039 lock_3_inodes(old_dir, new_dir, new_inode);
1040
1041 /*
1042 * Like most other Unix systems, set the @i_ctime for inodes on a
1043 * rename.
1044 */
1045 time = ubifs_current_time(old_dir);
1046 old_inode->i_ctime = time;
1047
1048 /* We must adjust parent link count when renaming directories */
1049 if (is_dir) {
1050 if (move) {
1051 /*
1052 * @old_dir loses a link because we are moving
1053 * @old_inode to a different directory.
1054 */
1055 drop_nlink(old_dir);
1056 /*
1057 * @new_dir only gains a link if we are not also
1058 * overwriting an existing directory.
1059 */
1060 if (!unlink)
1061 inc_nlink(new_dir);
1062 } else {
1063 /*
1064 * @old_inode is not moving to a different directory,
1065 * but @old_dir still loses a link if we are
1066 * overwriting an existing directory.
1067 */
1068 if (unlink)
1069 drop_nlink(old_dir);
1070 }
1071 }
1072
1073 old_dir->i_size -= old_sz;
1074 ubifs_inode(old_dir)->ui_size = old_dir->i_size;
1075 old_dir->i_mtime = old_dir->i_ctime = time;
1076 new_dir->i_mtime = new_dir->i_ctime = time;
1077
1078 /*
1079 * And finally, if we unlinked a direntry which happened to have the
1080 * same name as the moved direntry, we have to decrement @i_nlink of
1081 * the unlinked inode and change its ctime.
1082 */
1083 if (unlink) {
1084 /*
1085 * Directories cannot have hard-links, so if this is a
1086 * directory, decrement its @i_nlink twice because an empty
1087 * directory has @i_nlink 2.
1088 */
1089 if (is_dir)
1090 drop_nlink(new_inode);
1091 new_inode->i_ctime = time;
1092 drop_nlink(new_inode);
1093 } else {
1094 new_dir->i_size += new_sz;
1095 ubifs_inode(new_dir)->ui_size = new_dir->i_size;
1096 }
1097
1098 /*
1099 * Do not ask 'ubifs_jnl_rename()' to flush write-buffer if @old_inode
1100 * is dirty, because this will be done later on at the end of
1101 * 'ubifs_rename()'.
1102 */
1103 if (IS_SYNC(old_inode)) {
1104 sync = IS_DIRSYNC(old_dir) || IS_DIRSYNC(new_dir);
1105 if (unlink && IS_SYNC(new_inode))
1106 sync = 1;
1107 }
1108 err = ubifs_jnl_rename(c, old_dir, old_dentry, new_dir, new_dentry,
1109 sync);
1110 if (err)
1111 goto out_cancel;
1112
1113 unlock_3_inodes(old_dir, new_dir, new_inode);
1114 ubifs_release_budget(c, &req);
1115
1116 mutex_lock(&old_inode_ui->ui_mutex);
1117 release = old_inode_ui->dirty;
1118 mark_inode_dirty_sync(old_inode);
1119 mutex_unlock(&old_inode_ui->ui_mutex);
1120
1121 if (release)
1122 ubifs_release_budget(c, &ino_req);
1123 if (IS_SYNC(old_inode))
1124 err = old_inode->i_sb->s_op->write_inode(old_inode, 1);
1125 return err;
1126
1127out_cancel:
1128 if (unlink) {
1129 if (is_dir)
1130 inc_nlink(new_inode);
1131 inc_nlink(new_inode);
1132 } else {
1133 new_dir->i_size -= new_sz;
1134 ubifs_inode(new_dir)->ui_size = new_dir->i_size;
1135 }
1136 old_dir->i_size += old_sz;
1137 ubifs_inode(old_dir)->ui_size = old_dir->i_size;
1138 if (is_dir) {
1139 if (move) {
1140 inc_nlink(old_dir);
1141 if (!unlink)
1142 drop_nlink(new_dir);
1143 } else {
1144 if (unlink)
1145 inc_nlink(old_dir);
1146 }
1147 }
1148 unlock_3_inodes(old_dir, new_dir, new_inode);
1149 ubifs_release_budget(c, &ino_req);
1150 ubifs_release_budget(c, &req);
1151 return err;
1152}
1153
1154int ubifs_getattr(struct vfsmount *mnt, struct dentry *dentry,
1155 struct kstat *stat)
1156{
1157 loff_t size;
1158 struct inode *inode = dentry->d_inode;
1159 struct ubifs_inode *ui = ubifs_inode(inode);
1160
1161 mutex_lock(&ui->ui_mutex);
1162 stat->dev = inode->i_sb->s_dev;
1163 stat->ino = inode->i_ino;
1164 stat->mode = inode->i_mode;
1165 stat->nlink = inode->i_nlink;
1166 stat->uid = inode->i_uid;
1167 stat->gid = inode->i_gid;
1168 stat->rdev = inode->i_rdev;
1169 stat->atime = inode->i_atime;
1170 stat->mtime = inode->i_mtime;
1171 stat->ctime = inode->i_ctime;
1172 stat->blksize = UBIFS_BLOCK_SIZE;
1173 stat->size = ui->ui_size;
1174
1175 /*
1176 * Unfortunately, the 'stat()' system call was designed for block
1177 * device based file systems, and it is not appropriate for UBIFS,
1178 * because UBIFS does not have notion of "block". For example, it is
1179 * difficult to tell how many block a directory takes - it actually
1180 * takes less than 300 bytes, but we have to round it to block size,
1181 * which introduces large mistake. This makes utilities like 'du' to
1182 * report completely senseless numbers. This is the reason why UBIFS
1183 * goes the same way as JFFS2 - it reports zero blocks for everything
1184 * but regular files, which makes more sense than reporting completely
1185 * wrong sizes.
1186 */
1187 if (S_ISREG(inode->i_mode)) {
1188 size = ui->xattr_size;
1189 size += stat->size;
1190 size = ALIGN(size, UBIFS_BLOCK_SIZE);
1191 /*
1192 * Note, user-space expects 512-byte blocks count irrespectively
1193 * of what was reported in @stat->size.
1194 */
1195 stat->blocks = size >> 9;
1196 } else
1197 stat->blocks = 0;
1198 mutex_unlock(&ui->ui_mutex);
1199 return 0;
1200}
1201
1202struct inode_operations ubifs_dir_inode_operations = {
1203 .lookup = ubifs_lookup,
1204 .create = ubifs_create,
1205 .link = ubifs_link,
1206 .symlink = ubifs_symlink,
1207 .unlink = ubifs_unlink,
1208 .mkdir = ubifs_mkdir,
1209 .rmdir = ubifs_rmdir,
1210 .mknod = ubifs_mknod,
1211 .rename = ubifs_rename,
1212 .setattr = ubifs_setattr,
1213 .getattr = ubifs_getattr,
1214#ifdef CONFIG_UBIFS_FS_XATTR
1215 .setxattr = ubifs_setxattr,
1216 .getxattr = ubifs_getxattr,
1217 .listxattr = ubifs_listxattr,
1218 .removexattr = ubifs_removexattr,
1219#endif
1220};
1221
1222struct file_operations ubifs_dir_operations = {
1223 .llseek = ubifs_dir_llseek,
1224 .release = ubifs_dir_release,
1225 .read = generic_read_dir,
1226 .readdir = ubifs_readdir,
1227 .fsync = ubifs_fsync,
1228 .unlocked_ioctl = ubifs_ioctl,
1229#ifdef CONFIG_COMPAT
1230 .compat_ioctl = ubifs_compat_ioctl,
1231#endif
1232};