blob: f55d523c52bbd052b5600dfdc17a99706b48d823 [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
David Howells26bf1942008-11-14 10:39:03 +1100107 inode->i_uid = current_fsuid();
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300108 if (dir->i_mode & S_ISGID) {
109 inode->i_gid = dir->i_gid;
110 if (S_ISDIR(mode))
111 mode |= S_ISGID;
112 } else
David Howells26bf1942008-11-14 10:39:03 +1100113 inode->i_gid = current_fsgid();
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300114 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/**
Artem Bityutskiy82c15932009-01-20 16:46:02 +0200485 * lock_2_inodes - a wrapper for locking two UBIFS inodes.
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300486 * @inode1: first inode
487 * @inode2: second inode
Artem Bityutskiy82c15932009-01-20 16:46:02 +0200488 *
489 * We do not implement any tricks to guarantee strict lock ordering, because
490 * VFS has already done it for us on the @i_mutex. So this is just a simple
491 * wrapper function.
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300492 */
493static void lock_2_inodes(struct inode *inode1, struct inode *inode2)
494{
Artem Bityutskiy82c15932009-01-20 16:46:02 +0200495 mutex_lock_nested(&ubifs_inode(inode1)->ui_mutex, WB_MUTEX_1);
496 mutex_lock_nested(&ubifs_inode(inode2)->ui_mutex, WB_MUTEX_2);
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300497}
498
499/**
Artem Bityutskiy82c15932009-01-20 16:46:02 +0200500 * unlock_2_inodes - a wrapper for unlocking two UBIFS inodes.
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300501 * @inode1: first inode
502 * @inode2: second inode
503 */
504static void unlock_2_inodes(struct inode *inode1, struct inode *inode2)
505{
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300506 mutex_unlock(&ubifs_inode(inode2)->ui_mutex);
Artem Bityutskiy82c15932009-01-20 16:46:02 +0200507 mutex_unlock(&ubifs_inode(inode1)->ui_mutex);
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300508}
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);
Artem Bityutskiy82c15932009-01-20 16:46:02 +0200529 ubifs_assert(mutex_is_locked(&dir->i_mutex));
530 ubifs_assert(mutex_is_locked(&inode->i_mutex));
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300531 err = dbg_check_synced_i_size(inode);
532 if (err)
533 return err;
534
535 err = ubifs_budget_space(c, &req);
536 if (err)
537 return err;
538
539 lock_2_inodes(dir, inode);
540 inc_nlink(inode);
541 atomic_inc(&inode->i_count);
542 inode->i_ctime = ubifs_current_time(inode);
543 dir->i_size += sz_change;
544 dir_ui->ui_size = dir->i_size;
545 dir->i_mtime = dir->i_ctime = inode->i_ctime;
546 err = ubifs_jnl_update(c, dir, &dentry->d_name, inode, 0, 0);
547 if (err)
548 goto out_cancel;
549 unlock_2_inodes(dir, inode);
550
551 ubifs_release_budget(c, &req);
552 d_instantiate(dentry, inode);
553 return 0;
554
555out_cancel:
556 dir->i_size -= sz_change;
557 dir_ui->ui_size = dir->i_size;
558 drop_nlink(inode);
559 unlock_2_inodes(dir, inode);
560 ubifs_release_budget(c, &req);
561 iput(inode);
562 return err;
563}
564
565static int ubifs_unlink(struct inode *dir, struct dentry *dentry)
566{
567 struct ubifs_info *c = dir->i_sb->s_fs_info;
568 struct inode *inode = dentry->d_inode;
569 struct ubifs_inode *dir_ui = ubifs_inode(dir);
570 int sz_change = CALC_DENT_SIZE(dentry->d_name.len);
571 int err, budgeted = 1;
572 struct ubifs_budget_req req = { .mod_dent = 1, .dirtied_ino = 2 };
573
574 /*
575 * Budget request settings: deletion direntry, deletion inode (+1 for
576 * @dirtied_ino), changing the parent directory inode. If budgeting
577 * fails, go ahead anyway because we have extra space reserved for
578 * deletions.
579 */
580
581 dbg_gen("dent '%.*s' from ino %lu (nlink %d) in dir ino %lu",
582 dentry->d_name.len, dentry->d_name.name, inode->i_ino,
583 inode->i_nlink, dir->i_ino);
Artem Bityutskiy82c15932009-01-20 16:46:02 +0200584 ubifs_assert(mutex_is_locked(&dir->i_mutex));
585 ubifs_assert(mutex_is_locked(&inode->i_mutex));
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300586 err = dbg_check_synced_i_size(inode);
587 if (err)
588 return err;
589
590 err = ubifs_budget_space(c, &req);
591 if (err) {
592 if (err != -ENOSPC)
593 return err;
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300594 budgeted = 0;
595 }
596
597 lock_2_inodes(dir, inode);
598 inode->i_ctime = ubifs_current_time(dir);
599 drop_nlink(inode);
600 dir->i_size -= sz_change;
601 dir_ui->ui_size = dir->i_size;
602 dir->i_mtime = dir->i_ctime = inode->i_ctime;
603 err = ubifs_jnl_update(c, dir, &dentry->d_name, inode, 1, 0);
604 if (err)
605 goto out_cancel;
606 unlock_2_inodes(dir, inode);
607
608 if (budgeted)
609 ubifs_release_budget(c, &req);
610 else {
611 /* We've deleted something - clean the "no space" flags */
612 c->nospace = c->nospace_rp = 0;
613 smp_wmb();
614 }
615 return 0;
616
617out_cancel:
618 dir->i_size += sz_change;
619 dir_ui->ui_size = dir->i_size;
620 inc_nlink(inode);
621 unlock_2_inodes(dir, inode);
622 if (budgeted)
623 ubifs_release_budget(c, &req);
624 return err;
625}
626
627/**
628 * check_dir_empty - check if a directory is empty or not.
629 * @c: UBIFS file-system description object
630 * @dir: VFS inode object of the directory to check
631 *
632 * This function checks if directory @dir is empty. Returns zero if the
633 * directory is empty, %-ENOTEMPTY if it is not, and other negative error codes
634 * in case of of errors.
635 */
636static int check_dir_empty(struct ubifs_info *c, struct inode *dir)
637{
638 struct qstr nm = { .name = NULL };
639 struct ubifs_dent_node *dent;
640 union ubifs_key key;
641 int err;
642
643 lowest_dent_key(c, &key, dir->i_ino);
644 dent = ubifs_tnc_next_ent(c, &key, &nm);
645 if (IS_ERR(dent)) {
646 err = PTR_ERR(dent);
647 if (err == -ENOENT)
648 err = 0;
649 } else {
650 kfree(dent);
651 err = -ENOTEMPTY;
652 }
653 return err;
654}
655
656static int ubifs_rmdir(struct inode *dir, struct dentry *dentry)
657{
658 struct ubifs_info *c = dir->i_sb->s_fs_info;
659 struct inode *inode = dentry->d_inode;
660 int sz_change = CALC_DENT_SIZE(dentry->d_name.len);
661 int err, budgeted = 1;
662 struct ubifs_inode *dir_ui = ubifs_inode(dir);
663 struct ubifs_budget_req req = { .mod_dent = 1, .dirtied_ino = 2 };
664
665 /*
666 * Budget request settings: deletion direntry, deletion inode and
667 * changing the parent inode. If budgeting fails, go ahead anyway
668 * because we have extra space reserved for deletions.
669 */
670
671 dbg_gen("directory '%.*s', ino %lu in dir ino %lu", dentry->d_name.len,
672 dentry->d_name.name, inode->i_ino, dir->i_ino);
Artem Bityutskiy82c15932009-01-20 16:46:02 +0200673 ubifs_assert(mutex_is_locked(&dir->i_mutex));
674 ubifs_assert(mutex_is_locked(&inode->i_mutex));
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300675 err = check_dir_empty(c, dentry->d_inode);
676 if (err)
677 return err;
678
679 err = ubifs_budget_space(c, &req);
680 if (err) {
681 if (err != -ENOSPC)
682 return err;
683 budgeted = 0;
684 }
685
686 lock_2_inodes(dir, inode);
687 inode->i_ctime = ubifs_current_time(dir);
688 clear_nlink(inode);
689 drop_nlink(dir);
690 dir->i_size -= sz_change;
691 dir_ui->ui_size = dir->i_size;
692 dir->i_mtime = dir->i_ctime = inode->i_ctime;
693 err = ubifs_jnl_update(c, dir, &dentry->d_name, inode, 1, 0);
694 if (err)
695 goto out_cancel;
696 unlock_2_inodes(dir, inode);
697
698 if (budgeted)
699 ubifs_release_budget(c, &req);
700 else {
701 /* We've deleted something - clean the "no space" flags */
702 c->nospace = c->nospace_rp = 0;
703 smp_wmb();
704 }
705 return 0;
706
707out_cancel:
708 dir->i_size += sz_change;
709 dir_ui->ui_size = dir->i_size;
710 inc_nlink(dir);
711 inc_nlink(inode);
712 inc_nlink(inode);
713 unlock_2_inodes(dir, inode);
714 if (budgeted)
715 ubifs_release_budget(c, &req);
716 return err;
717}
718
719static int ubifs_mkdir(struct inode *dir, struct dentry *dentry, int mode)
720{
721 struct inode *inode;
722 struct ubifs_inode *dir_ui = ubifs_inode(dir);
723 struct ubifs_info *c = dir->i_sb->s_fs_info;
724 int err, sz_change = CALC_DENT_SIZE(dentry->d_name.len);
Artem Bityutskiy182854b2008-07-18 18:54:29 +0300725 struct ubifs_budget_req req = { .new_ino = 1, .new_dent = 1 };
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300726
727 /*
728 * Budget request settings: new inode, new direntry and changing parent
729 * directory inode.
730 */
731
732 dbg_gen("dent '%.*s', mode %#x in dir ino %lu",
733 dentry->d_name.len, dentry->d_name.name, mode, dir->i_ino);
734
735 err = ubifs_budget_space(c, &req);
736 if (err)
737 return err;
738
739 inode = ubifs_new_inode(c, dir, S_IFDIR | mode);
740 if (IS_ERR(inode)) {
741 err = PTR_ERR(inode);
742 goto out_budg;
743 }
744
745 mutex_lock(&dir_ui->ui_mutex);
746 insert_inode_hash(inode);
747 inc_nlink(inode);
748 inc_nlink(dir);
749 dir->i_size += sz_change;
750 dir_ui->ui_size = dir->i_size;
751 dir->i_mtime = dir->i_ctime = inode->i_ctime;
752 err = ubifs_jnl_update(c, dir, &dentry->d_name, inode, 0, 0);
753 if (err) {
754 ubifs_err("cannot create directory, error %d", err);
755 goto out_cancel;
756 }
757 mutex_unlock(&dir_ui->ui_mutex);
758
759 ubifs_release_budget(c, &req);
760 d_instantiate(dentry, inode);
761 return 0;
762
763out_cancel:
764 dir->i_size -= sz_change;
765 dir_ui->ui_size = dir->i_size;
766 drop_nlink(dir);
767 mutex_unlock(&dir_ui->ui_mutex);
768 make_bad_inode(inode);
769 iput(inode);
770out_budg:
771 ubifs_release_budget(c, &req);
772 return err;
773}
774
775static int ubifs_mknod(struct inode *dir, struct dentry *dentry,
776 int mode, dev_t rdev)
777{
778 struct inode *inode;
779 struct ubifs_inode *ui;
780 struct ubifs_inode *dir_ui = ubifs_inode(dir);
781 struct ubifs_info *c = dir->i_sb->s_fs_info;
782 union ubifs_dev_desc *dev = NULL;
783 int sz_change = CALC_DENT_SIZE(dentry->d_name.len);
784 int err, devlen = 0;
785 struct ubifs_budget_req req = { .new_ino = 1, .new_dent = 1,
Artem Bityutskiydab4b4d2008-07-24 14:52:45 +0300786 .new_ino_d = ALIGN(devlen, 8),
787 .dirtied_ino = 1 };
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300788
789 /*
790 * Budget request settings: new inode, new direntry and changing parent
791 * directory inode.
792 */
793
794 dbg_gen("dent '%.*s' in dir ino %lu",
795 dentry->d_name.len, dentry->d_name.name, dir->i_ino);
796
797 if (!new_valid_dev(rdev))
798 return -EINVAL;
799
800 if (S_ISBLK(mode) || S_ISCHR(mode)) {
801 dev = kmalloc(sizeof(union ubifs_dev_desc), GFP_NOFS);
802 if (!dev)
803 return -ENOMEM;
804 devlen = ubifs_encode_dev(dev, rdev);
805 }
806
807 err = ubifs_budget_space(c, &req);
808 if (err) {
809 kfree(dev);
810 return err;
811 }
812
813 inode = ubifs_new_inode(c, dir, mode);
814 if (IS_ERR(inode)) {
815 kfree(dev);
816 err = PTR_ERR(inode);
817 goto out_budg;
818 }
819
820 init_special_inode(inode, inode->i_mode, rdev);
821 inode->i_size = ubifs_inode(inode)->ui_size = devlen;
822 ui = ubifs_inode(inode);
823 ui->data = dev;
824 ui->data_len = devlen;
825
826 mutex_lock(&dir_ui->ui_mutex);
827 dir->i_size += sz_change;
828 dir_ui->ui_size = dir->i_size;
829 dir->i_mtime = dir->i_ctime = inode->i_ctime;
830 err = ubifs_jnl_update(c, dir, &dentry->d_name, inode, 0, 0);
831 if (err)
832 goto out_cancel;
833 mutex_unlock(&dir_ui->ui_mutex);
834
835 ubifs_release_budget(c, &req);
836 insert_inode_hash(inode);
837 d_instantiate(dentry, inode);
838 return 0;
839
840out_cancel:
841 dir->i_size -= sz_change;
842 dir_ui->ui_size = dir->i_size;
843 mutex_unlock(&dir_ui->ui_mutex);
844 make_bad_inode(inode);
845 iput(inode);
846out_budg:
847 ubifs_release_budget(c, &req);
848 return err;
849}
850
851static int ubifs_symlink(struct inode *dir, struct dentry *dentry,
852 const char *symname)
853{
854 struct inode *inode;
855 struct ubifs_inode *ui;
856 struct ubifs_inode *dir_ui = ubifs_inode(dir);
857 struct ubifs_info *c = dir->i_sb->s_fs_info;
858 int err, len = strlen(symname);
859 int sz_change = CALC_DENT_SIZE(dentry->d_name.len);
860 struct ubifs_budget_req req = { .new_ino = 1, .new_dent = 1,
Artem Bityutskiydab4b4d2008-07-24 14:52:45 +0300861 .new_ino_d = ALIGN(len, 8),
862 .dirtied_ino = 1 };
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300863
864 /*
865 * Budget request settings: new inode, new direntry and changing parent
866 * directory inode.
867 */
868
869 dbg_gen("dent '%.*s', target '%s' in dir ino %lu", dentry->d_name.len,
870 dentry->d_name.name, symname, dir->i_ino);
871
872 if (len > UBIFS_MAX_INO_DATA)
873 return -ENAMETOOLONG;
874
875 err = ubifs_budget_space(c, &req);
876 if (err)
877 return err;
878
879 inode = ubifs_new_inode(c, dir, S_IFLNK | S_IRWXUGO);
880 if (IS_ERR(inode)) {
881 err = PTR_ERR(inode);
882 goto out_budg;
883 }
884
885 ui = ubifs_inode(inode);
886 ui->data = kmalloc(len + 1, GFP_NOFS);
887 if (!ui->data) {
888 err = -ENOMEM;
889 goto out_inode;
890 }
891
892 memcpy(ui->data, symname, len);
893 ((char *)ui->data)[len] = '\0';
894 /*
895 * The terminating zero byte is not written to the flash media and it
896 * is put just to make later in-memory string processing simpler. Thus,
897 * data length is @len, not @len + %1.
898 */
899 ui->data_len = len;
900 inode->i_size = ubifs_inode(inode)->ui_size = len;
901
902 mutex_lock(&dir_ui->ui_mutex);
903 dir->i_size += sz_change;
904 dir_ui->ui_size = dir->i_size;
905 dir->i_mtime = dir->i_ctime = inode->i_ctime;
906 err = ubifs_jnl_update(c, dir, &dentry->d_name, inode, 0, 0);
907 if (err)
908 goto out_cancel;
909 mutex_unlock(&dir_ui->ui_mutex);
910
911 ubifs_release_budget(c, &req);
912 insert_inode_hash(inode);
913 d_instantiate(dentry, inode);
914 return 0;
915
916out_cancel:
917 dir->i_size -= sz_change;
918 dir_ui->ui_size = dir->i_size;
919 mutex_unlock(&dir_ui->ui_mutex);
920out_inode:
921 make_bad_inode(inode);
922 iput(inode);
923out_budg:
924 ubifs_release_budget(c, &req);
925 return err;
926}
927
928/**
Artem Bityutskiy82c15932009-01-20 16:46:02 +0200929 * lock_3_inodes - a wrapper for locking three UBIFS inodes.
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300930 * @inode1: first inode
931 * @inode2: second inode
932 * @inode3: third inode
933 *
Artem Bityutskiy82c15932009-01-20 16:46:02 +0200934 * This function is used for 'ubifs_rename()' and @inode1 may be the same as
935 * @inode2 whereas @inode3 may be %NULL.
936 *
937 * We do not implement any tricks to guarantee strict lock ordering, because
938 * VFS has already done it for us on the @i_mutex. So this is just a simple
939 * wrapper function.
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300940 */
941static void lock_3_inodes(struct inode *inode1, struct inode *inode2,
942 struct inode *inode3)
943{
Artem Bityutskiy82c15932009-01-20 16:46:02 +0200944 mutex_lock_nested(&ubifs_inode(inode1)->ui_mutex, WB_MUTEX_1);
945 if (inode2 != inode1)
946 mutex_lock_nested(&ubifs_inode(inode2)->ui_mutex, WB_MUTEX_2);
947 if (inode3)
948 mutex_lock_nested(&ubifs_inode(inode3)->ui_mutex, WB_MUTEX_3);
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300949}
950
951/**
Artem Bityutskiy82c15932009-01-20 16:46:02 +0200952 * unlock_3_inodes - a wrapper for unlocking three UBIFS inodes for rename.
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300953 * @inode1: first inode
954 * @inode2: second inode
955 * @inode3: third inode
956 */
957static void unlock_3_inodes(struct inode *inode1, struct inode *inode2,
958 struct inode *inode3)
959{
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300960 if (inode3)
961 mutex_unlock(&ubifs_inode(inode3)->ui_mutex);
Artem Bityutskiy82c15932009-01-20 16:46:02 +0200962 if (inode1 != inode2)
963 mutex_unlock(&ubifs_inode(inode2)->ui_mutex);
964 mutex_unlock(&ubifs_inode(inode1)->ui_mutex);
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300965}
966
967static int ubifs_rename(struct inode *old_dir, struct dentry *old_dentry,
968 struct inode *new_dir, struct dentry *new_dentry)
969{
970 struct ubifs_info *c = old_dir->i_sb->s_fs_info;
971 struct inode *old_inode = old_dentry->d_inode;
972 struct inode *new_inode = new_dentry->d_inode;
973 struct ubifs_inode *old_inode_ui = ubifs_inode(old_inode);
974 int err, release, sync = 0, move = (new_dir != old_dir);
975 int is_dir = S_ISDIR(old_inode->i_mode);
976 int unlink = !!new_inode;
977 int new_sz = CALC_DENT_SIZE(new_dentry->d_name.len);
978 int old_sz = CALC_DENT_SIZE(old_dentry->d_name.len);
979 struct ubifs_budget_req req = { .new_dent = 1, .mod_dent = 1,
980 .dirtied_ino = 3 };
981 struct ubifs_budget_req ino_req = { .dirtied_ino = 1,
Artem Bityutskiydab4b4d2008-07-24 14:52:45 +0300982 .dirtied_ino_d = ALIGN(old_inode_ui->data_len, 8) };
Artem Bityutskiy1e517642008-07-14 19:08:37 +0300983 struct timespec time;
984
985 /*
986 * Budget request settings: deletion direntry, new direntry, removing
987 * the old inode, and changing old and new parent directory inodes.
988 *
989 * However, this operation also marks the target inode as dirty and
990 * does not write it, so we allocate budget for the target inode
991 * separately.
992 */
993
994 dbg_gen("dent '%.*s' ino %lu in dir ino %lu to dent '%.*s' in "
995 "dir ino %lu", old_dentry->d_name.len, old_dentry->d_name.name,
996 old_inode->i_ino, old_dir->i_ino, new_dentry->d_name.len,
997 new_dentry->d_name.name, new_dir->i_ino);
Artem Bityutskiy82c15932009-01-20 16:46:02 +0200998 ubifs_assert(mutex_is_locked(&old_dir->i_mutex));
999 ubifs_assert(mutex_is_locked(&new_dir->i_mutex));
1000 if (unlink)
1001 ubifs_assert(mutex_is_locked(&new_inode->i_mutex));
1002
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001003
1004 if (unlink && is_dir) {
1005 err = check_dir_empty(c, new_inode);
1006 if (err)
1007 return err;
1008 }
1009
1010 err = ubifs_budget_space(c, &req);
1011 if (err)
1012 return err;
1013 err = ubifs_budget_space(c, &ino_req);
1014 if (err) {
1015 ubifs_release_budget(c, &req);
1016 return err;
1017 }
1018
1019 lock_3_inodes(old_dir, new_dir, new_inode);
1020
1021 /*
1022 * Like most other Unix systems, set the @i_ctime for inodes on a
1023 * rename.
1024 */
1025 time = ubifs_current_time(old_dir);
1026 old_inode->i_ctime = time;
1027
1028 /* We must adjust parent link count when renaming directories */
1029 if (is_dir) {
1030 if (move) {
1031 /*
1032 * @old_dir loses a link because we are moving
1033 * @old_inode to a different directory.
1034 */
1035 drop_nlink(old_dir);
1036 /*
1037 * @new_dir only gains a link if we are not also
1038 * overwriting an existing directory.
1039 */
1040 if (!unlink)
1041 inc_nlink(new_dir);
1042 } else {
1043 /*
1044 * @old_inode is not moving to a different directory,
1045 * but @old_dir still loses a link if we are
1046 * overwriting an existing directory.
1047 */
1048 if (unlink)
1049 drop_nlink(old_dir);
1050 }
1051 }
1052
1053 old_dir->i_size -= old_sz;
1054 ubifs_inode(old_dir)->ui_size = old_dir->i_size;
1055 old_dir->i_mtime = old_dir->i_ctime = time;
1056 new_dir->i_mtime = new_dir->i_ctime = time;
1057
1058 /*
1059 * And finally, if we unlinked a direntry which happened to have the
1060 * same name as the moved direntry, we have to decrement @i_nlink of
1061 * the unlinked inode and change its ctime.
1062 */
1063 if (unlink) {
1064 /*
1065 * Directories cannot have hard-links, so if this is a
1066 * directory, decrement its @i_nlink twice because an empty
1067 * directory has @i_nlink 2.
1068 */
1069 if (is_dir)
1070 drop_nlink(new_inode);
1071 new_inode->i_ctime = time;
1072 drop_nlink(new_inode);
1073 } else {
1074 new_dir->i_size += new_sz;
1075 ubifs_inode(new_dir)->ui_size = new_dir->i_size;
1076 }
1077
1078 /*
1079 * Do not ask 'ubifs_jnl_rename()' to flush write-buffer if @old_inode
1080 * is dirty, because this will be done later on at the end of
1081 * 'ubifs_rename()'.
1082 */
1083 if (IS_SYNC(old_inode)) {
1084 sync = IS_DIRSYNC(old_dir) || IS_DIRSYNC(new_dir);
1085 if (unlink && IS_SYNC(new_inode))
1086 sync = 1;
1087 }
1088 err = ubifs_jnl_rename(c, old_dir, old_dentry, new_dir, new_dentry,
1089 sync);
1090 if (err)
1091 goto out_cancel;
1092
1093 unlock_3_inodes(old_dir, new_dir, new_inode);
1094 ubifs_release_budget(c, &req);
1095
1096 mutex_lock(&old_inode_ui->ui_mutex);
1097 release = old_inode_ui->dirty;
1098 mark_inode_dirty_sync(old_inode);
1099 mutex_unlock(&old_inode_ui->ui_mutex);
1100
1101 if (release)
1102 ubifs_release_budget(c, &ino_req);
1103 if (IS_SYNC(old_inode))
1104 err = old_inode->i_sb->s_op->write_inode(old_inode, 1);
1105 return err;
1106
1107out_cancel:
1108 if (unlink) {
1109 if (is_dir)
1110 inc_nlink(new_inode);
1111 inc_nlink(new_inode);
1112 } else {
1113 new_dir->i_size -= new_sz;
1114 ubifs_inode(new_dir)->ui_size = new_dir->i_size;
1115 }
1116 old_dir->i_size += old_sz;
1117 ubifs_inode(old_dir)->ui_size = old_dir->i_size;
1118 if (is_dir) {
1119 if (move) {
1120 inc_nlink(old_dir);
1121 if (!unlink)
1122 drop_nlink(new_dir);
1123 } else {
1124 if (unlink)
1125 inc_nlink(old_dir);
1126 }
1127 }
1128 unlock_3_inodes(old_dir, new_dir, new_inode);
1129 ubifs_release_budget(c, &ino_req);
1130 ubifs_release_budget(c, &req);
1131 return err;
1132}
1133
1134int ubifs_getattr(struct vfsmount *mnt, struct dentry *dentry,
1135 struct kstat *stat)
1136{
1137 loff_t size;
1138 struct inode *inode = dentry->d_inode;
1139 struct ubifs_inode *ui = ubifs_inode(inode);
1140
1141 mutex_lock(&ui->ui_mutex);
1142 stat->dev = inode->i_sb->s_dev;
1143 stat->ino = inode->i_ino;
1144 stat->mode = inode->i_mode;
1145 stat->nlink = inode->i_nlink;
1146 stat->uid = inode->i_uid;
1147 stat->gid = inode->i_gid;
1148 stat->rdev = inode->i_rdev;
1149 stat->atime = inode->i_atime;
1150 stat->mtime = inode->i_mtime;
1151 stat->ctime = inode->i_ctime;
1152 stat->blksize = UBIFS_BLOCK_SIZE;
1153 stat->size = ui->ui_size;
1154
1155 /*
1156 * Unfortunately, the 'stat()' system call was designed for block
1157 * device based file systems, and it is not appropriate for UBIFS,
1158 * because UBIFS does not have notion of "block". For example, it is
1159 * difficult to tell how many block a directory takes - it actually
1160 * takes less than 300 bytes, but we have to round it to block size,
1161 * which introduces large mistake. This makes utilities like 'du' to
1162 * report completely senseless numbers. This is the reason why UBIFS
1163 * goes the same way as JFFS2 - it reports zero blocks for everything
1164 * but regular files, which makes more sense than reporting completely
1165 * wrong sizes.
1166 */
1167 if (S_ISREG(inode->i_mode)) {
1168 size = ui->xattr_size;
1169 size += stat->size;
1170 size = ALIGN(size, UBIFS_BLOCK_SIZE);
1171 /*
1172 * Note, user-space expects 512-byte blocks count irrespectively
1173 * of what was reported in @stat->size.
1174 */
1175 stat->blocks = size >> 9;
1176 } else
1177 stat->blocks = 0;
1178 mutex_unlock(&ui->ui_mutex);
1179 return 0;
1180}
1181
Artem Bityutskiye8b81562009-01-15 17:43:23 +02001182const struct inode_operations ubifs_dir_inode_operations = {
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001183 .lookup = ubifs_lookup,
1184 .create = ubifs_create,
1185 .link = ubifs_link,
1186 .symlink = ubifs_symlink,
1187 .unlink = ubifs_unlink,
1188 .mkdir = ubifs_mkdir,
1189 .rmdir = ubifs_rmdir,
1190 .mknod = ubifs_mknod,
1191 .rename = ubifs_rename,
1192 .setattr = ubifs_setattr,
1193 .getattr = ubifs_getattr,
1194#ifdef CONFIG_UBIFS_FS_XATTR
1195 .setxattr = ubifs_setxattr,
1196 .getxattr = ubifs_getxattr,
1197 .listxattr = ubifs_listxattr,
1198 .removexattr = ubifs_removexattr,
1199#endif
1200};
1201
Artem Bityutskiye8b81562009-01-15 17:43:23 +02001202const struct file_operations ubifs_dir_operations = {
Artem Bityutskiy1e517642008-07-14 19:08:37 +03001203 .llseek = ubifs_dir_llseek,
1204 .release = ubifs_dir_release,
1205 .read = generic_read_dir,
1206 .readdir = ubifs_readdir,
1207 .fsync = ubifs_fsync,
1208 .unlocked_ioctl = ubifs_ioctl,
1209#ifdef CONFIG_COMPAT
1210 .compat_ioctl = ubifs_compat_ioctl,
1211#endif
1212};