blob: ef5abd38f0bf32a90f30ef6994c81b6d864f93e8 [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
Dmitry Monakhovabf5d082010-03-04 17:32:21 +0300107 inode_init_owner(inode, dir, mode);
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300108 inode->i_mtime = inode->i_atime = inode->i_ctime =
109 ubifs_current_time(inode);
110 inode->i_mapping->nrpages = 0;
111 /* Disable readahead */
112 inode->i_mapping->backing_dev_info = &c->bdi;
113
114 switch (mode & S_IFMT) {
115 case S_IFREG:
116 inode->i_mapping->a_ops = &ubifs_file_address_operations;
117 inode->i_op = &ubifs_file_inode_operations;
118 inode->i_fop = &ubifs_file_operations;
119 break;
120 case S_IFDIR:
121 inode->i_op = &ubifs_dir_inode_operations;
122 inode->i_fop = &ubifs_dir_operations;
123 inode->i_size = ui->ui_size = UBIFS_INO_NODE_SZ;
124 break;
125 case S_IFLNK:
126 inode->i_op = &ubifs_symlink_inode_operations;
127 break;
128 case S_IFSOCK:
129 case S_IFIFO:
130 case S_IFBLK:
131 case S_IFCHR:
132 inode->i_op = &ubifs_file_inode_operations;
133 break;
134 default:
135 BUG();
136 }
137
138 ui->flags = inherit_flags(dir, mode);
139 ubifs_set_inode_flags(inode);
140 if (S_ISREG(mode))
141 ui->compr_type = c->default_compr;
142 else
143 ui->compr_type = UBIFS_COMPR_NONE;
144 ui->synced_i_size = 0;
145
146 spin_lock(&c->cnt_lock);
147 /* Inode number overflow is currently not supported */
148 if (c->highest_inum >= INUM_WARN_WATERMARK) {
149 if (c->highest_inum >= INUM_WATERMARK) {
150 spin_unlock(&c->cnt_lock);
151 ubifs_err("out of inode numbers");
152 make_bad_inode(inode);
153 iput(inode);
154 return ERR_PTR(-EINVAL);
155 }
156 ubifs_warn("running out of inode numbers (current %lu, max %d)",
Artem Bityutskiye84461a2008-10-29 12:08:43 +0200157 (unsigned long)c->highest_inum, INUM_WATERMARK);
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300158 }
159
160 inode->i_ino = ++c->highest_inum;
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300161 /*
162 * The creation sequence number remains with this inode for its
163 * lifetime. All nodes for this inode have a greater sequence number,
164 * and so it is possible to distinguish obsolete nodes belonging to a
165 * previous incarnation of the same inode number - for example, for the
166 * purpose of rebuilding the index.
167 */
168 ui->creat_sqnum = ++c->max_sqnum;
169 spin_unlock(&c->cnt_lock);
170 return inode;
171}
172
173#ifdef CONFIG_UBIFS_FS_DEBUG
174
175static int dbg_check_name(struct ubifs_dent_node *dent, struct qstr *nm)
176{
177 if (!(ubifs_chk_flags & UBIFS_CHK_GEN))
178 return 0;
179 if (le16_to_cpu(dent->nlen) != nm->len)
180 return -EINVAL;
181 if (memcmp(dent->name, nm->name, nm->len))
182 return -EINVAL;
183 return 0;
184}
185
186#else
187
188#define dbg_check_name(dent, nm) 0
189
190#endif
191
192static struct dentry *ubifs_lookup(struct inode *dir, struct dentry *dentry,
193 struct nameidata *nd)
194{
195 int err;
196 union ubifs_key key;
197 struct inode *inode = NULL;
198 struct ubifs_dent_node *dent;
199 struct ubifs_info *c = dir->i_sb->s_fs_info;
200
201 dbg_gen("'%.*s' in dir ino %lu",
202 dentry->d_name.len, dentry->d_name.name, dir->i_ino);
203
204 if (dentry->d_name.len > UBIFS_MAX_NLEN)
205 return ERR_PTR(-ENAMETOOLONG);
206
207 dent = kmalloc(UBIFS_MAX_DENT_NODE_SZ, GFP_NOFS);
208 if (!dent)
209 return ERR_PTR(-ENOMEM);
210
211 dent_key_init(c, &key, dir->i_ino, &dentry->d_name);
212
213 err = ubifs_tnc_lookup_nm(c, &key, dent, &dentry->d_name);
214 if (err) {
Artem Bityutskiy720b4992008-08-13 16:16:31 +0300215 if (err == -ENOENT) {
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300216 dbg_gen("not found");
217 goto done;
218 }
219 goto out;
220 }
221
222 if (dbg_check_name(dent, &dentry->d_name)) {
223 err = -EINVAL;
224 goto out;
225 }
226
227 inode = ubifs_iget(dir->i_sb, le64_to_cpu(dent->inum));
228 if (IS_ERR(inode)) {
229 /*
230 * This should not happen. Probably the file-system needs
231 * checking.
232 */
233 err = PTR_ERR(inode);
234 ubifs_err("dead directory entry '%.*s', error %d",
235 dentry->d_name.len, dentry->d_name.name, err);
236 ubifs_ro_mode(c, err);
237 goto out;
238 }
239
240done:
241 kfree(dent);
242 /*
243 * Note, d_splice_alias() would be required instead if we supported
244 * NFS.
245 */
246 d_add(dentry, inode);
247 return NULL;
248
249out:
250 kfree(dent);
251 return ERR_PTR(err);
252}
253
254static int ubifs_create(struct inode *dir, struct dentry *dentry, int mode,
255 struct nameidata *nd)
256{
257 struct inode *inode;
258 struct ubifs_info *c = dir->i_sb->s_fs_info;
259 int err, sz_change = CALC_DENT_SIZE(dentry->d_name.len);
260 struct ubifs_budget_req req = { .new_ino = 1, .new_dent = 1,
261 .dirtied_ino = 1 };
262 struct ubifs_inode *dir_ui = ubifs_inode(dir);
263
264 /*
265 * Budget request settings: new inode, new direntry, changing the
266 * parent directory inode.
267 */
268
269 dbg_gen("dent '%.*s', mode %#x in dir ino %lu",
270 dentry->d_name.len, dentry->d_name.name, mode, dir->i_ino);
271
272 err = ubifs_budget_space(c, &req);
273 if (err)
274 return err;
275
276 inode = ubifs_new_inode(c, dir, mode);
277 if (IS_ERR(inode)) {
278 err = PTR_ERR(inode);
279 goto out_budg;
280 }
281
282 mutex_lock(&dir_ui->ui_mutex);
283 dir->i_size += sz_change;
284 dir_ui->ui_size = dir->i_size;
285 dir->i_mtime = dir->i_ctime = inode->i_ctime;
286 err = ubifs_jnl_update(c, dir, &dentry->d_name, inode, 0, 0);
287 if (err)
288 goto out_cancel;
289 mutex_unlock(&dir_ui->ui_mutex);
290
291 ubifs_release_budget(c, &req);
292 insert_inode_hash(inode);
293 d_instantiate(dentry, inode);
294 return 0;
295
296out_cancel:
297 dir->i_size -= sz_change;
298 dir_ui->ui_size = dir->i_size;
299 mutex_unlock(&dir_ui->ui_mutex);
300 make_bad_inode(inode);
301 iput(inode);
302out_budg:
303 ubifs_release_budget(c, &req);
304 ubifs_err("cannot create regular file, error %d", err);
305 return err;
306}
307
308/**
309 * vfs_dent_type - get VFS directory entry type.
310 * @type: UBIFS directory entry type
311 *
312 * This function converts UBIFS directory entry type into VFS directory entry
313 * type.
314 */
315static unsigned int vfs_dent_type(uint8_t type)
316{
317 switch (type) {
318 case UBIFS_ITYPE_REG:
319 return DT_REG;
320 case UBIFS_ITYPE_DIR:
321 return DT_DIR;
322 case UBIFS_ITYPE_LNK:
323 return DT_LNK;
324 case UBIFS_ITYPE_BLK:
325 return DT_BLK;
326 case UBIFS_ITYPE_CHR:
327 return DT_CHR;
328 case UBIFS_ITYPE_FIFO:
329 return DT_FIFO;
330 case UBIFS_ITYPE_SOCK:
331 return DT_SOCK;
332 default:
333 BUG();
334 }
335 return 0;
336}
337
338/*
339 * The classical Unix view for directory is that it is a linear array of
340 * (name, inode number) entries. Linux/VFS assumes this model as well.
341 * Particularly, 'readdir()' call wants us to return a directory entry offset
342 * which later may be used to continue 'readdir()'ing the directory or to
343 * 'seek()' to that specific direntry. Obviously UBIFS does not really fit this
344 * model because directory entries are identified by keys, which may collide.
345 *
346 * UBIFS uses directory entry hash value for directory offsets, so
347 * 'seekdir()'/'telldir()' may not always work because of possible key
348 * collisions. But UBIFS guarantees that consecutive 'readdir()' calls work
349 * properly by means of saving full directory entry name in the private field
350 * of the file description object.
351 *
352 * This means that UBIFS cannot support NFS which requires full
353 * 'seekdir()'/'telldir()' support.
354 */
355static int ubifs_readdir(struct file *file, void *dirent, filldir_t filldir)
356{
357 int err, over = 0;
358 struct qstr nm;
359 union ubifs_key key;
360 struct ubifs_dent_node *dent;
361 struct inode *dir = file->f_path.dentry->d_inode;
362 struct ubifs_info *c = dir->i_sb->s_fs_info;
363
364 dbg_gen("dir ino %lu, f_pos %#llx", dir->i_ino, file->f_pos);
365
366 if (file->f_pos > UBIFS_S_KEY_HASH_MASK || file->f_pos == 2)
367 /*
368 * The directory was seek'ed to a senseless position or there
369 * are no more entries.
370 */
371 return 0;
372
373 /* File positions 0 and 1 correspond to "." and ".." */
374 if (file->f_pos == 0) {
375 ubifs_assert(!file->private_data);
376 over = filldir(dirent, ".", 1, 0, dir->i_ino, DT_DIR);
377 if (over)
378 return 0;
379 file->f_pos = 1;
380 }
381
382 if (file->f_pos == 1) {
383 ubifs_assert(!file->private_data);
384 over = filldir(dirent, "..", 2, 1,
385 parent_ino(file->f_path.dentry), DT_DIR);
386 if (over)
387 return 0;
388
389 /* Find the first entry in TNC and save it */
390 lowest_dent_key(c, &key, dir->i_ino);
391 nm.name = NULL;
392 dent = ubifs_tnc_next_ent(c, &key, &nm);
393 if (IS_ERR(dent)) {
394 err = PTR_ERR(dent);
395 goto out;
396 }
397
398 file->f_pos = key_hash_flash(c, &dent->key);
399 file->private_data = dent;
400 }
401
402 dent = file->private_data;
403 if (!dent) {
404 /*
405 * The directory was seek'ed to and is now readdir'ed.
406 * Find the entry corresponding to @file->f_pos or the
407 * closest one.
408 */
409 dent_key_init_hash(c, &key, dir->i_ino, file->f_pos);
410 nm.name = NULL;
411 dent = ubifs_tnc_next_ent(c, &key, &nm);
412 if (IS_ERR(dent)) {
413 err = PTR_ERR(dent);
414 goto out;
415 }
416 file->f_pos = key_hash_flash(c, &dent->key);
417 file->private_data = dent;
418 }
419
420 while (1) {
421 dbg_gen("feed '%s', ino %llu, new f_pos %#x",
Alexander Beregalov7424bac2008-09-17 22:09:41 +0400422 dent->name, (unsigned long long)le64_to_cpu(dent->inum),
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300423 key_hash_flash(c, &dent->key));
Harvey Harrison0ecb9522008-10-24 10:52:57 -0700424 ubifs_assert(le64_to_cpu(dent->ch.sqnum) >
425 ubifs_inode(dir)->creat_sqnum);
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300426
427 nm.len = le16_to_cpu(dent->nlen);
428 over = filldir(dirent, dent->name, nm.len, file->f_pos,
429 le64_to_cpu(dent->inum),
430 vfs_dent_type(dent->type));
431 if (over)
432 return 0;
433
434 /* Switch to the next entry */
435 key_read(c, &dent->key, &key);
436 nm.name = dent->name;
437 dent = ubifs_tnc_next_ent(c, &key, &nm);
438 if (IS_ERR(dent)) {
439 err = PTR_ERR(dent);
440 goto out;
441 }
442
443 kfree(file->private_data);
444 file->f_pos = key_hash_flash(c, &dent->key);
445 file->private_data = dent;
446 cond_resched();
447 }
448
449out:
450 if (err != -ENOENT) {
451 ubifs_err("cannot find next direntry, error %d", err);
452 return err;
453 }
454
455 kfree(file->private_data);
456 file->private_data = NULL;
457 file->f_pos = 2;
458 return 0;
459}
460
461/* If a directory is seeked, we have to free saved readdir() state */
462static loff_t ubifs_dir_llseek(struct file *file, loff_t offset, int origin)
463{
464 kfree(file->private_data);
465 file->private_data = NULL;
466 return generic_file_llseek(file, offset, origin);
467}
468
469/* Free saved readdir() state when the directory is closed */
470static int ubifs_dir_release(struct inode *dir, struct file *file)
471{
472 kfree(file->private_data);
473 file->private_data = NULL;
474 return 0;
475}
476
477/**
Artem Bityutskiy82c15932009-01-20 16:46:02 +0200478 * lock_2_inodes - a wrapper for locking two UBIFS inodes.
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300479 * @inode1: first inode
480 * @inode2: second inode
Artem Bityutskiy82c15932009-01-20 16:46:02 +0200481 *
482 * We do not implement any tricks to guarantee strict lock ordering, because
483 * VFS has already done it for us on the @i_mutex. So this is just a simple
484 * wrapper function.
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300485 */
486static void lock_2_inodes(struct inode *inode1, struct inode *inode2)
487{
Artem Bityutskiy82c15932009-01-20 16:46:02 +0200488 mutex_lock_nested(&ubifs_inode(inode1)->ui_mutex, WB_MUTEX_1);
489 mutex_lock_nested(&ubifs_inode(inode2)->ui_mutex, WB_MUTEX_2);
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300490}
491
492/**
Artem Bityutskiy82c15932009-01-20 16:46:02 +0200493 * unlock_2_inodes - a wrapper for unlocking two UBIFS inodes.
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300494 * @inode1: first inode
495 * @inode2: second inode
496 */
497static void unlock_2_inodes(struct inode *inode1, struct inode *inode2)
498{
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300499 mutex_unlock(&ubifs_inode(inode2)->ui_mutex);
Artem Bityutskiy82c15932009-01-20 16:46:02 +0200500 mutex_unlock(&ubifs_inode(inode1)->ui_mutex);
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300501}
502
503static int ubifs_link(struct dentry *old_dentry, struct inode *dir,
504 struct dentry *dentry)
505{
506 struct ubifs_info *c = dir->i_sb->s_fs_info;
507 struct inode *inode = old_dentry->d_inode;
508 struct ubifs_inode *ui = ubifs_inode(inode);
509 struct ubifs_inode *dir_ui = ubifs_inode(dir);
510 int err, sz_change = CALC_DENT_SIZE(dentry->d_name.len);
511 struct ubifs_budget_req req = { .new_dent = 1, .dirtied_ino = 2,
Artem Bityutskiydab4b4d2008-07-24 14:52:45 +0300512 .dirtied_ino_d = ALIGN(ui->data_len, 8) };
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300513
514 /*
515 * Budget request settings: new direntry, changing the target inode,
516 * changing the parent inode.
517 */
518
519 dbg_gen("dent '%.*s' to ino %lu (nlink %d) in dir ino %lu",
520 dentry->d_name.len, dentry->d_name.name, inode->i_ino,
521 inode->i_nlink, dir->i_ino);
Artem Bityutskiy82c15932009-01-20 16:46:02 +0200522 ubifs_assert(mutex_is_locked(&dir->i_mutex));
523 ubifs_assert(mutex_is_locked(&inode->i_mutex));
Hunter Adrian8b3884a2009-05-14 06:32:30 +0200524
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300525 err = dbg_check_synced_i_size(inode);
526 if (err)
527 return err;
528
529 err = ubifs_budget_space(c, &req);
530 if (err)
531 return err;
532
533 lock_2_inodes(dir, inode);
534 inc_nlink(inode);
Al Viro7de9c6e2010-10-23 11:11:40 -0400535 ihold(inode);
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300536 inode->i_ctime = ubifs_current_time(inode);
537 dir->i_size += sz_change;
538 dir_ui->ui_size = dir->i_size;
539 dir->i_mtime = dir->i_ctime = inode->i_ctime;
540 err = ubifs_jnl_update(c, dir, &dentry->d_name, inode, 0, 0);
541 if (err)
542 goto out_cancel;
543 unlock_2_inodes(dir, inode);
544
545 ubifs_release_budget(c, &req);
546 d_instantiate(dentry, inode);
547 return 0;
548
549out_cancel:
550 dir->i_size -= sz_change;
551 dir_ui->ui_size = dir->i_size;
552 drop_nlink(inode);
553 unlock_2_inodes(dir, inode);
554 ubifs_release_budget(c, &req);
555 iput(inode);
556 return err;
557}
558
559static int ubifs_unlink(struct inode *dir, struct dentry *dentry)
560{
561 struct ubifs_info *c = dir->i_sb->s_fs_info;
562 struct inode *inode = dentry->d_inode;
563 struct ubifs_inode *dir_ui = ubifs_inode(dir);
564 int sz_change = CALC_DENT_SIZE(dentry->d_name.len);
565 int err, budgeted = 1;
566 struct ubifs_budget_req req = { .mod_dent = 1, .dirtied_ino = 2 };
567
568 /*
569 * Budget request settings: deletion direntry, deletion inode (+1 for
570 * @dirtied_ino), changing the parent directory inode. If budgeting
571 * fails, go ahead anyway because we have extra space reserved for
572 * deletions.
573 */
574
575 dbg_gen("dent '%.*s' from ino %lu (nlink %d) in dir ino %lu",
576 dentry->d_name.len, dentry->d_name.name, inode->i_ino,
577 inode->i_nlink, dir->i_ino);
Artem Bityutskiy82c15932009-01-20 16:46:02 +0200578 ubifs_assert(mutex_is_locked(&dir->i_mutex));
579 ubifs_assert(mutex_is_locked(&inode->i_mutex));
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300580 err = dbg_check_synced_i_size(inode);
581 if (err)
582 return err;
583
584 err = ubifs_budget_space(c, &req);
585 if (err) {
586 if (err != -ENOSPC)
587 return err;
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300588 budgeted = 0;
589 }
590
591 lock_2_inodes(dir, inode);
592 inode->i_ctime = ubifs_current_time(dir);
593 drop_nlink(inode);
594 dir->i_size -= sz_change;
595 dir_ui->ui_size = dir->i_size;
596 dir->i_mtime = dir->i_ctime = inode->i_ctime;
597 err = ubifs_jnl_update(c, dir, &dentry->d_name, inode, 1, 0);
598 if (err)
599 goto out_cancel;
600 unlock_2_inodes(dir, inode);
601
602 if (budgeted)
603 ubifs_release_budget(c, &req);
604 else {
605 /* We've deleted something - clean the "no space" flags */
Artem Bityutskiyb1375452011-03-29 18:04:05 +0300606 c->bi.nospace = c->bi.nospace_rp = 0;
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300607 smp_wmb();
608 }
609 return 0;
610
611out_cancel:
612 dir->i_size += sz_change;
613 dir_ui->ui_size = dir->i_size;
614 inc_nlink(inode);
615 unlock_2_inodes(dir, inode);
616 if (budgeted)
617 ubifs_release_budget(c, &req);
618 return err;
619}
620
621/**
622 * check_dir_empty - check if a directory is empty or not.
623 * @c: UBIFS file-system description object
624 * @dir: VFS inode object of the directory to check
625 *
626 * This function checks if directory @dir is empty. Returns zero if the
627 * directory is empty, %-ENOTEMPTY if it is not, and other negative error codes
628 * in case of of errors.
629 */
630static int check_dir_empty(struct ubifs_info *c, struct inode *dir)
631{
632 struct qstr nm = { .name = NULL };
633 struct ubifs_dent_node *dent;
634 union ubifs_key key;
635 int err;
636
637 lowest_dent_key(c, &key, dir->i_ino);
638 dent = ubifs_tnc_next_ent(c, &key, &nm);
639 if (IS_ERR(dent)) {
640 err = PTR_ERR(dent);
641 if (err == -ENOENT)
642 err = 0;
643 } else {
644 kfree(dent);
645 err = -ENOTEMPTY;
646 }
647 return err;
648}
649
650static int ubifs_rmdir(struct inode *dir, struct dentry *dentry)
651{
652 struct ubifs_info *c = dir->i_sb->s_fs_info;
653 struct inode *inode = dentry->d_inode;
654 int sz_change = CALC_DENT_SIZE(dentry->d_name.len);
655 int err, budgeted = 1;
656 struct ubifs_inode *dir_ui = ubifs_inode(dir);
657 struct ubifs_budget_req req = { .mod_dent = 1, .dirtied_ino = 2 };
658
659 /*
660 * Budget request settings: deletion direntry, deletion inode and
661 * changing the parent inode. If budgeting fails, go ahead anyway
662 * because we have extra space reserved for deletions.
663 */
664
665 dbg_gen("directory '%.*s', ino %lu in dir ino %lu", dentry->d_name.len,
666 dentry->d_name.name, inode->i_ino, dir->i_ino);
Artem Bityutskiy82c15932009-01-20 16:46:02 +0200667 ubifs_assert(mutex_is_locked(&dir->i_mutex));
668 ubifs_assert(mutex_is_locked(&inode->i_mutex));
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300669 err = check_dir_empty(c, dentry->d_inode);
670 if (err)
671 return err;
672
673 err = ubifs_budget_space(c, &req);
674 if (err) {
675 if (err != -ENOSPC)
676 return err;
677 budgeted = 0;
678 }
679
680 lock_2_inodes(dir, inode);
681 inode->i_ctime = ubifs_current_time(dir);
682 clear_nlink(inode);
683 drop_nlink(dir);
684 dir->i_size -= sz_change;
685 dir_ui->ui_size = dir->i_size;
686 dir->i_mtime = dir->i_ctime = inode->i_ctime;
687 err = ubifs_jnl_update(c, dir, &dentry->d_name, inode, 1, 0);
688 if (err)
689 goto out_cancel;
690 unlock_2_inodes(dir, inode);
691
692 if (budgeted)
693 ubifs_release_budget(c, &req);
694 else {
695 /* We've deleted something - clean the "no space" flags */
Artem Bityutskiyb1375452011-03-29 18:04:05 +0300696 c->bi.nospace = c->bi.nospace_rp = 0;
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300697 smp_wmb();
698 }
699 return 0;
700
701out_cancel:
702 dir->i_size += sz_change;
703 dir_ui->ui_size = dir->i_size;
704 inc_nlink(dir);
705 inc_nlink(inode);
706 inc_nlink(inode);
707 unlock_2_inodes(dir, inode);
708 if (budgeted)
709 ubifs_release_budget(c, &req);
710 return err;
711}
712
713static int ubifs_mkdir(struct inode *dir, struct dentry *dentry, int mode)
714{
715 struct inode *inode;
716 struct ubifs_inode *dir_ui = ubifs_inode(dir);
717 struct ubifs_info *c = dir->i_sb->s_fs_info;
718 int err, sz_change = CALC_DENT_SIZE(dentry->d_name.len);
Artem Bityutskiy182854b2008-07-18 18:54:29 +0300719 struct ubifs_budget_req req = { .new_ino = 1, .new_dent = 1 };
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300720
721 /*
722 * Budget request settings: new inode, new direntry and changing parent
723 * directory inode.
724 */
725
726 dbg_gen("dent '%.*s', mode %#x in dir ino %lu",
727 dentry->d_name.len, dentry->d_name.name, mode, dir->i_ino);
728
729 err = ubifs_budget_space(c, &req);
730 if (err)
731 return err;
732
733 inode = ubifs_new_inode(c, dir, S_IFDIR | mode);
734 if (IS_ERR(inode)) {
735 err = PTR_ERR(inode);
736 goto out_budg;
737 }
738
739 mutex_lock(&dir_ui->ui_mutex);
740 insert_inode_hash(inode);
741 inc_nlink(inode);
742 inc_nlink(dir);
743 dir->i_size += sz_change;
744 dir_ui->ui_size = dir->i_size;
745 dir->i_mtime = dir->i_ctime = inode->i_ctime;
746 err = ubifs_jnl_update(c, dir, &dentry->d_name, inode, 0, 0);
747 if (err) {
748 ubifs_err("cannot create directory, error %d", err);
749 goto out_cancel;
750 }
751 mutex_unlock(&dir_ui->ui_mutex);
752
753 ubifs_release_budget(c, &req);
754 d_instantiate(dentry, inode);
755 return 0;
756
757out_cancel:
758 dir->i_size -= sz_change;
759 dir_ui->ui_size = dir->i_size;
760 drop_nlink(dir);
761 mutex_unlock(&dir_ui->ui_mutex);
762 make_bad_inode(inode);
763 iput(inode);
764out_budg:
765 ubifs_release_budget(c, &req);
766 return err;
767}
768
769static int ubifs_mknod(struct inode *dir, struct dentry *dentry,
770 int mode, dev_t rdev)
771{
772 struct inode *inode;
773 struct ubifs_inode *ui;
774 struct ubifs_inode *dir_ui = ubifs_inode(dir);
775 struct ubifs_info *c = dir->i_sb->s_fs_info;
776 union ubifs_dev_desc *dev = NULL;
777 int sz_change = CALC_DENT_SIZE(dentry->d_name.len);
778 int err, devlen = 0;
779 struct ubifs_budget_req req = { .new_ino = 1, .new_dent = 1,
Artem Bityutskiydab4b4d2008-07-24 14:52:45 +0300780 .new_ino_d = ALIGN(devlen, 8),
781 .dirtied_ino = 1 };
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300782
783 /*
784 * Budget request settings: new inode, new direntry and changing parent
785 * directory inode.
786 */
787
788 dbg_gen("dent '%.*s' in dir ino %lu",
789 dentry->d_name.len, dentry->d_name.name, dir->i_ino);
790
791 if (!new_valid_dev(rdev))
792 return -EINVAL;
793
794 if (S_ISBLK(mode) || S_ISCHR(mode)) {
795 dev = kmalloc(sizeof(union ubifs_dev_desc), GFP_NOFS);
796 if (!dev)
797 return -ENOMEM;
798 devlen = ubifs_encode_dev(dev, rdev);
799 }
800
801 err = ubifs_budget_space(c, &req);
802 if (err) {
803 kfree(dev);
804 return err;
805 }
806
807 inode = ubifs_new_inode(c, dir, mode);
808 if (IS_ERR(inode)) {
809 kfree(dev);
810 err = PTR_ERR(inode);
811 goto out_budg;
812 }
813
814 init_special_inode(inode, inode->i_mode, rdev);
815 inode->i_size = ubifs_inode(inode)->ui_size = devlen;
816 ui = ubifs_inode(inode);
817 ui->data = dev;
818 ui->data_len = devlen;
819
820 mutex_lock(&dir_ui->ui_mutex);
821 dir->i_size += sz_change;
822 dir_ui->ui_size = dir->i_size;
823 dir->i_mtime = dir->i_ctime = inode->i_ctime;
824 err = ubifs_jnl_update(c, dir, &dentry->d_name, inode, 0, 0);
825 if (err)
826 goto out_cancel;
827 mutex_unlock(&dir_ui->ui_mutex);
828
829 ubifs_release_budget(c, &req);
830 insert_inode_hash(inode);
831 d_instantiate(dentry, inode);
832 return 0;
833
834out_cancel:
835 dir->i_size -= sz_change;
836 dir_ui->ui_size = dir->i_size;
837 mutex_unlock(&dir_ui->ui_mutex);
838 make_bad_inode(inode);
839 iput(inode);
840out_budg:
841 ubifs_release_budget(c, &req);
842 return err;
843}
844
845static int ubifs_symlink(struct inode *dir, struct dentry *dentry,
846 const char *symname)
847{
848 struct inode *inode;
849 struct ubifs_inode *ui;
850 struct ubifs_inode *dir_ui = ubifs_inode(dir);
851 struct ubifs_info *c = dir->i_sb->s_fs_info;
852 int err, len = strlen(symname);
853 int sz_change = CALC_DENT_SIZE(dentry->d_name.len);
854 struct ubifs_budget_req req = { .new_ino = 1, .new_dent = 1,
Artem Bityutskiydab4b4d2008-07-24 14:52:45 +0300855 .new_ino_d = ALIGN(len, 8),
856 .dirtied_ino = 1 };
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300857
858 /*
859 * Budget request settings: new inode, new direntry and changing parent
860 * directory inode.
861 */
862
863 dbg_gen("dent '%.*s', target '%s' in dir ino %lu", dentry->d_name.len,
864 dentry->d_name.name, symname, dir->i_ino);
865
866 if (len > UBIFS_MAX_INO_DATA)
867 return -ENAMETOOLONG;
868
869 err = ubifs_budget_space(c, &req);
870 if (err)
871 return err;
872
873 inode = ubifs_new_inode(c, dir, S_IFLNK | S_IRWXUGO);
874 if (IS_ERR(inode)) {
875 err = PTR_ERR(inode);
876 goto out_budg;
877 }
878
879 ui = ubifs_inode(inode);
880 ui->data = kmalloc(len + 1, GFP_NOFS);
881 if (!ui->data) {
882 err = -ENOMEM;
883 goto out_inode;
884 }
885
886 memcpy(ui->data, symname, len);
887 ((char *)ui->data)[len] = '\0';
888 /*
889 * The terminating zero byte is not written to the flash media and it
890 * is put just to make later in-memory string processing simpler. Thus,
891 * data length is @len, not @len + %1.
892 */
893 ui->data_len = len;
894 inode->i_size = ubifs_inode(inode)->ui_size = len;
895
896 mutex_lock(&dir_ui->ui_mutex);
897 dir->i_size += sz_change;
898 dir_ui->ui_size = dir->i_size;
899 dir->i_mtime = dir->i_ctime = inode->i_ctime;
900 err = ubifs_jnl_update(c, dir, &dentry->d_name, inode, 0, 0);
901 if (err)
902 goto out_cancel;
903 mutex_unlock(&dir_ui->ui_mutex);
904
905 ubifs_release_budget(c, &req);
906 insert_inode_hash(inode);
907 d_instantiate(dentry, inode);
908 return 0;
909
910out_cancel:
911 dir->i_size -= sz_change;
912 dir_ui->ui_size = dir->i_size;
913 mutex_unlock(&dir_ui->ui_mutex);
914out_inode:
915 make_bad_inode(inode);
916 iput(inode);
917out_budg:
918 ubifs_release_budget(c, &req);
919 return err;
920}
921
922/**
Artem Bityutskiy82c15932009-01-20 16:46:02 +0200923 * lock_3_inodes - a wrapper for locking three UBIFS inodes.
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300924 * @inode1: first inode
925 * @inode2: second inode
926 * @inode3: third inode
927 *
Artem Bityutskiy82c15932009-01-20 16:46:02 +0200928 * This function is used for 'ubifs_rename()' and @inode1 may be the same as
929 * @inode2 whereas @inode3 may be %NULL.
930 *
931 * We do not implement any tricks to guarantee strict lock ordering, because
932 * VFS has already done it for us on the @i_mutex. So this is just a simple
933 * wrapper function.
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300934 */
935static void lock_3_inodes(struct inode *inode1, struct inode *inode2,
936 struct inode *inode3)
937{
Artem Bityutskiy82c15932009-01-20 16:46:02 +0200938 mutex_lock_nested(&ubifs_inode(inode1)->ui_mutex, WB_MUTEX_1);
939 if (inode2 != inode1)
940 mutex_lock_nested(&ubifs_inode(inode2)->ui_mutex, WB_MUTEX_2);
941 if (inode3)
942 mutex_lock_nested(&ubifs_inode(inode3)->ui_mutex, WB_MUTEX_3);
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300943}
944
945/**
Artem Bityutskiy82c15932009-01-20 16:46:02 +0200946 * unlock_3_inodes - a wrapper for unlocking three UBIFS inodes for rename.
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300947 * @inode1: first inode
948 * @inode2: second inode
949 * @inode3: third inode
950 */
951static void unlock_3_inodes(struct inode *inode1, struct inode *inode2,
952 struct inode *inode3)
953{
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300954 if (inode3)
955 mutex_unlock(&ubifs_inode(inode3)->ui_mutex);
Artem Bityutskiy82c15932009-01-20 16:46:02 +0200956 if (inode1 != inode2)
957 mutex_unlock(&ubifs_inode(inode2)->ui_mutex);
958 mutex_unlock(&ubifs_inode(inode1)->ui_mutex);
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300959}
960
961static int ubifs_rename(struct inode *old_dir, struct dentry *old_dentry,
962 struct inode *new_dir, struct dentry *new_dentry)
963{
964 struct ubifs_info *c = old_dir->i_sb->s_fs_info;
965 struct inode *old_inode = old_dentry->d_inode;
966 struct inode *new_inode = new_dentry->d_inode;
967 struct ubifs_inode *old_inode_ui = ubifs_inode(old_inode);
968 int err, release, sync = 0, move = (new_dir != old_dir);
969 int is_dir = S_ISDIR(old_inode->i_mode);
970 int unlink = !!new_inode;
971 int new_sz = CALC_DENT_SIZE(new_dentry->d_name.len);
972 int old_sz = CALC_DENT_SIZE(old_dentry->d_name.len);
973 struct ubifs_budget_req req = { .new_dent = 1, .mod_dent = 1,
974 .dirtied_ino = 3 };
975 struct ubifs_budget_req ino_req = { .dirtied_ino = 1,
Artem Bityutskiydab4b4d2008-07-24 14:52:45 +0300976 .dirtied_ino_d = ALIGN(old_inode_ui->data_len, 8) };
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300977 struct timespec time;
978
979 /*
980 * Budget request settings: deletion direntry, new direntry, removing
981 * the old inode, and changing old and new parent directory inodes.
982 *
983 * However, this operation also marks the target inode as dirty and
984 * does not write it, so we allocate budget for the target inode
985 * separately.
986 */
987
988 dbg_gen("dent '%.*s' ino %lu in dir ino %lu to dent '%.*s' in "
989 "dir ino %lu", old_dentry->d_name.len, old_dentry->d_name.name,
990 old_inode->i_ino, old_dir->i_ino, new_dentry->d_name.len,
991 new_dentry->d_name.name, new_dir->i_ino);
Artem Bityutskiy82c15932009-01-20 16:46:02 +0200992 ubifs_assert(mutex_is_locked(&old_dir->i_mutex));
993 ubifs_assert(mutex_is_locked(&new_dir->i_mutex));
994 if (unlink)
995 ubifs_assert(mutex_is_locked(&new_inode->i_mutex));
996
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300997
998 if (unlink && is_dir) {
999 err = check_dir_empty(c, new_inode);
1000 if (err)
1001 return err;
1002 }
1003
1004 err = ubifs_budget_space(c, &req);
1005 if (err)
1006 return err;
1007 err = ubifs_budget_space(c, &ino_req);
1008 if (err) {
1009 ubifs_release_budget(c, &req);
1010 return err;
1011 }
1012
1013 lock_3_inodes(old_dir, new_dir, new_inode);
1014
1015 /*
1016 * Like most other Unix systems, set the @i_ctime for inodes on a
1017 * rename.
1018 */
1019 time = ubifs_current_time(old_dir);
1020 old_inode->i_ctime = time;
1021
1022 /* We must adjust parent link count when renaming directories */
1023 if (is_dir) {
1024 if (move) {
1025 /*
1026 * @old_dir loses a link because we are moving
1027 * @old_inode to a different directory.
1028 */
1029 drop_nlink(old_dir);
1030 /*
1031 * @new_dir only gains a link if we are not also
1032 * overwriting an existing directory.
1033 */
1034 if (!unlink)
1035 inc_nlink(new_dir);
1036 } else {
1037 /*
1038 * @old_inode is not moving to a different directory,
1039 * but @old_dir still loses a link if we are
1040 * overwriting an existing directory.
1041 */
1042 if (unlink)
1043 drop_nlink(old_dir);
1044 }
1045 }
1046
1047 old_dir->i_size -= old_sz;
1048 ubifs_inode(old_dir)->ui_size = old_dir->i_size;
1049 old_dir->i_mtime = old_dir->i_ctime = time;
1050 new_dir->i_mtime = new_dir->i_ctime = time;
1051
1052 /*
1053 * And finally, if we unlinked a direntry which happened to have the
1054 * same name as the moved direntry, we have to decrement @i_nlink of
1055 * the unlinked inode and change its ctime.
1056 */
1057 if (unlink) {
1058 /*
1059 * Directories cannot have hard-links, so if this is a
1060 * directory, decrement its @i_nlink twice because an empty
1061 * directory has @i_nlink 2.
1062 */
1063 if (is_dir)
1064 drop_nlink(new_inode);
1065 new_inode->i_ctime = time;
1066 drop_nlink(new_inode);
1067 } else {
1068 new_dir->i_size += new_sz;
1069 ubifs_inode(new_dir)->ui_size = new_dir->i_size;
1070 }
1071
1072 /*
1073 * Do not ask 'ubifs_jnl_rename()' to flush write-buffer if @old_inode
1074 * is dirty, because this will be done later on at the end of
1075 * 'ubifs_rename()'.
1076 */
1077 if (IS_SYNC(old_inode)) {
1078 sync = IS_DIRSYNC(old_dir) || IS_DIRSYNC(new_dir);
1079 if (unlink && IS_SYNC(new_inode))
1080 sync = 1;
1081 }
1082 err = ubifs_jnl_rename(c, old_dir, old_dentry, new_dir, new_dentry,
1083 sync);
1084 if (err)
1085 goto out_cancel;
1086
1087 unlock_3_inodes(old_dir, new_dir, new_inode);
1088 ubifs_release_budget(c, &req);
1089
1090 mutex_lock(&old_inode_ui->ui_mutex);
1091 release = old_inode_ui->dirty;
1092 mark_inode_dirty_sync(old_inode);
1093 mutex_unlock(&old_inode_ui->ui_mutex);
1094
1095 if (release)
1096 ubifs_release_budget(c, &ino_req);
1097 if (IS_SYNC(old_inode))
Christoph Hellwiga9185b42010-03-05 09:21:37 +01001098 err = old_inode->i_sb->s_op->write_inode(old_inode, NULL);
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001099 return err;
1100
1101out_cancel:
1102 if (unlink) {
1103 if (is_dir)
1104 inc_nlink(new_inode);
1105 inc_nlink(new_inode);
1106 } else {
1107 new_dir->i_size -= new_sz;
1108 ubifs_inode(new_dir)->ui_size = new_dir->i_size;
1109 }
1110 old_dir->i_size += old_sz;
1111 ubifs_inode(old_dir)->ui_size = old_dir->i_size;
1112 if (is_dir) {
1113 if (move) {
1114 inc_nlink(old_dir);
1115 if (!unlink)
1116 drop_nlink(new_dir);
1117 } else {
1118 if (unlink)
1119 inc_nlink(old_dir);
1120 }
1121 }
1122 unlock_3_inodes(old_dir, new_dir, new_inode);
1123 ubifs_release_budget(c, &ino_req);
1124 ubifs_release_budget(c, &req);
1125 return err;
1126}
1127
1128int ubifs_getattr(struct vfsmount *mnt, struct dentry *dentry,
1129 struct kstat *stat)
1130{
1131 loff_t size;
1132 struct inode *inode = dentry->d_inode;
1133 struct ubifs_inode *ui = ubifs_inode(inode);
1134
1135 mutex_lock(&ui->ui_mutex);
1136 stat->dev = inode->i_sb->s_dev;
1137 stat->ino = inode->i_ino;
1138 stat->mode = inode->i_mode;
1139 stat->nlink = inode->i_nlink;
1140 stat->uid = inode->i_uid;
1141 stat->gid = inode->i_gid;
1142 stat->rdev = inode->i_rdev;
1143 stat->atime = inode->i_atime;
1144 stat->mtime = inode->i_mtime;
1145 stat->ctime = inode->i_ctime;
1146 stat->blksize = UBIFS_BLOCK_SIZE;
1147 stat->size = ui->ui_size;
1148
1149 /*
1150 * Unfortunately, the 'stat()' system call was designed for block
1151 * device based file systems, and it is not appropriate for UBIFS,
1152 * because UBIFS does not have notion of "block". For example, it is
1153 * difficult to tell how many block a directory takes - it actually
1154 * takes less than 300 bytes, but we have to round it to block size,
1155 * which introduces large mistake. This makes utilities like 'du' to
1156 * report completely senseless numbers. This is the reason why UBIFS
1157 * goes the same way as JFFS2 - it reports zero blocks for everything
1158 * but regular files, which makes more sense than reporting completely
1159 * wrong sizes.
1160 */
1161 if (S_ISREG(inode->i_mode)) {
1162 size = ui->xattr_size;
1163 size += stat->size;
1164 size = ALIGN(size, UBIFS_BLOCK_SIZE);
1165 /*
1166 * Note, user-space expects 512-byte blocks count irrespectively
1167 * of what was reported in @stat->size.
1168 */
1169 stat->blocks = size >> 9;
1170 } else
1171 stat->blocks = 0;
1172 mutex_unlock(&ui->ui_mutex);
1173 return 0;
1174}
1175
Artem Bityutskiye8b81562009-01-15 17:43:23 +02001176const struct inode_operations ubifs_dir_inode_operations = {
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001177 .lookup = ubifs_lookup,
1178 .create = ubifs_create,
1179 .link = ubifs_link,
1180 .symlink = ubifs_symlink,
1181 .unlink = ubifs_unlink,
1182 .mkdir = ubifs_mkdir,
1183 .rmdir = ubifs_rmdir,
1184 .mknod = ubifs_mknod,
1185 .rename = ubifs_rename,
1186 .setattr = ubifs_setattr,
1187 .getattr = ubifs_getattr,
1188#ifdef CONFIG_UBIFS_FS_XATTR
1189 .setxattr = ubifs_setxattr,
1190 .getxattr = ubifs_getxattr,
1191 .listxattr = ubifs_listxattr,
1192 .removexattr = ubifs_removexattr,
1193#endif
1194};
1195
Artem Bityutskiye8b81562009-01-15 17:43:23 +02001196const struct file_operations ubifs_dir_operations = {
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001197 .llseek = ubifs_dir_llseek,
1198 .release = ubifs_dir_release,
1199 .read = generic_read_dir,
1200 .readdir = ubifs_readdir,
1201 .fsync = ubifs_fsync,
1202 .unlocked_ioctl = ubifs_ioctl,
1203#ifdef CONFIG_COMPAT
1204 .compat_ioctl = ubifs_compat_ioctl,
1205#endif
1206};