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1 /* * This file is part of UBIFS.
2 *
3 * Copyright (C) 2006-2008 Nokia Corporation.
4 * Copyright (C) 2006, 2007 University of Szeged, Hungary
5 *
6 * This program is free software; you can redistribute it and/or modify it
7 * under the terms of the GNU General Public License version 2 as published by
8 * the Free Software Foundation.
9 *
10 * This program is distributed in the hope that it will be useful, but WITHOUT
11 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
12 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
13 * more details.
14 *
15 * You should have received a copy of the GNU General Public License along with
16 * this program; if not, write to the Free Software Foundation, Inc., 51
17 * Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
18 *
19 * Authors: Artem Bityutskiy (Битюцкий Артём)
20 * Adrian Hunter
21 * Zoltan Sogor
22 */
23
24 /*
25 * This file implements directory operations.
26 *
27 * All FS operations in this file allocate budget before writing anything to the
28 * media. If they fail to allocate it, the error is returned. The only
29 * exceptions are 'ubifs_unlink()' and 'ubifs_rmdir()' which keep working even
30 * if they unable to allocate the budget, because deletion %-ENOSPC failure is
31 * not what users are usually ready to get. UBIFS budgeting subsystem has some
32 * space reserved for these purposes.
33 *
34 * All operations in this file write all inodes which they change straight
35 * away, instead of marking them dirty. For example, 'ubifs_link()' changes
36 * @i_size of the parent inode and writes the parent inode together with the
37 * target inode. This was done to simplify file-system recovery which would
38 * otherwise be very difficult to do. The only exception is rename which marks
39 * the re-named inode dirty (because its @i_ctime is updated) but does not
40 * write it, but just marks it as dirty.
41 */
42
43 #include "ubifs.h"
44
45 /**
46 * inherit_flags - inherit flags of the parent inode.
47 * @dir: parent inode
48 * @mode: new inode mode flags
49 *
50 * This is a helper function for 'ubifs_new_inode()' which inherits flag of the
51 * parent directory inode @dir. UBIFS inodes inherit the following flags:
52 * o %UBIFS_COMPR_FL, which is useful to switch compression on/of on
53 * sub-directory basis;
54 * o %UBIFS_SYNC_FL - useful for the same reasons;
55 * o %UBIFS_DIRSYNC_FL - similar, but relevant only to directories.
56 *
57 * This function returns the inherited flags.
58 */
59 static int inherit_flags(const struct inode *dir, umode_t 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 */
88 struct inode *ubifs_new_inode(struct ubifs_info *c, struct inode *dir,
89 umode_t mode)
90 {
91 int err;
92 struct inode *inode;
93 struct ubifs_inode *ui;
94 bool encrypted = false;
95
96 if (ubifs_crypt_is_encrypted(dir)) {
97 err = fscrypt_get_encryption_info(dir);
98 if (err) {
99 ubifs_err(c, "fscrypt_get_encryption_info failed: %i", err);
100 return ERR_PTR(err);
101 }
102
103 if (!fscrypt_has_encryption_key(dir))
104 return ERR_PTR(-EPERM);
105
106 encrypted = true;
107 }
108
109 inode = new_inode(c->vfs_sb);
110 ui = ubifs_inode(inode);
111 if (!inode)
112 return ERR_PTR(-ENOMEM);
113
114 /*
115 * Set 'S_NOCMTIME' to prevent VFS form updating [mc]time of inodes and
116 * marking them dirty in file write path (see 'file_update_time()').
117 * UBIFS has to fully control "clean <-> dirty" transitions of inodes
118 * to make budgeting work.
119 */
120 inode->i_flags |= S_NOCMTIME;
121
122 inode_init_owner(inode, dir, mode);
123 inode->i_mtime = inode->i_atime = inode->i_ctime =
124 current_time(inode);
125 inode->i_mapping->nrpages = 0;
126
127 switch (mode & S_IFMT) {
128 case S_IFREG:
129 inode->i_mapping->a_ops = &ubifs_file_address_operations;
130 inode->i_op = &ubifs_file_inode_operations;
131 inode->i_fop = &ubifs_file_operations;
132 break;
133 case S_IFDIR:
134 inode->i_op = &ubifs_dir_inode_operations;
135 inode->i_fop = &ubifs_dir_operations;
136 inode->i_size = ui->ui_size = UBIFS_INO_NODE_SZ;
137 break;
138 case S_IFLNK:
139 inode->i_op = &ubifs_symlink_inode_operations;
140 break;
141 case S_IFSOCK:
142 case S_IFIFO:
143 case S_IFBLK:
144 case S_IFCHR:
145 inode->i_op = &ubifs_file_inode_operations;
146 break;
147 default:
148 BUG();
149 }
150
151 ui->flags = inherit_flags(dir, mode);
152 ubifs_set_inode_flags(inode);
153 if (S_ISREG(mode))
154 ui->compr_type = c->default_compr;
155 else
156 ui->compr_type = UBIFS_COMPR_NONE;
157 ui->synced_i_size = 0;
158
159 spin_lock(&c->cnt_lock);
160 /* Inode number overflow is currently not supported */
161 if (c->highest_inum >= INUM_WARN_WATERMARK) {
162 if (c->highest_inum >= INUM_WATERMARK) {
163 spin_unlock(&c->cnt_lock);
164 ubifs_err(c, "out of inode numbers");
165 make_bad_inode(inode);
166 iput(inode);
167 return ERR_PTR(-EINVAL);
168 }
169 ubifs_warn(c, "running out of inode numbers (current %lu, max %u)",
170 (unsigned long)c->highest_inum, INUM_WATERMARK);
171 }
172
173 inode->i_ino = ++c->highest_inum;
174 /*
175 * The creation sequence number remains with this inode for its
176 * lifetime. All nodes for this inode have a greater sequence number,
177 * and so it is possible to distinguish obsolete nodes belonging to a
178 * previous incarnation of the same inode number - for example, for the
179 * purpose of rebuilding the index.
180 */
181 ui->creat_sqnum = ++c->max_sqnum;
182 spin_unlock(&c->cnt_lock);
183
184 if (encrypted) {
185 err = fscrypt_inherit_context(dir, inode, &encrypted, true);
186 if (err) {
187 ubifs_err(c, "fscrypt_inherit_context failed: %i", err);
188 make_bad_inode(inode);
189 iput(inode);
190 return ERR_PTR(err);
191 }
192 }
193
194 return inode;
195 }
196
197 static int dbg_check_name(const struct ubifs_info *c,
198 const struct ubifs_dent_node *dent,
199 const struct fscrypt_name *nm)
200 {
201 if (!dbg_is_chk_gen(c))
202 return 0;
203 if (le16_to_cpu(dent->nlen) != fname_len(nm))
204 return -EINVAL;
205 if (memcmp(dent->name, fname_name(nm), fname_len(nm)))
206 return -EINVAL;
207 return 0;
208 }
209
210 static struct dentry *ubifs_lookup(struct inode *dir, struct dentry *dentry,
211 unsigned int flags)
212 {
213 int err;
214 union ubifs_key key;
215 struct inode *inode = NULL;
216 struct ubifs_dent_node *dent;
217 struct ubifs_info *c = dir->i_sb->s_fs_info;
218 struct fscrypt_name nm;
219
220 dbg_gen("'%pd' in dir ino %lu", dentry, dir->i_ino);
221
222 if (ubifs_crypt_is_encrypted(dir)) {
223 err = fscrypt_get_encryption_info(dir);
224
225 /*
226 * DCACHE_ENCRYPTED_WITH_KEY is set if the dentry is
227 * created while the directory was encrypted and we
228 * have access to the key.
229 */
230 if (fscrypt_has_encryption_key(dir))
231 fscrypt_set_encrypted_dentry(dentry);
232 fscrypt_set_d_op(dentry);
233 if (err && err != -ENOKEY)
234 return ERR_PTR(err);
235 }
236
237 err = fscrypt_setup_filename(dir, &dentry->d_name, 1, &nm);
238 if (err)
239 return ERR_PTR(err);
240
241 if (fname_len(&nm) > UBIFS_MAX_NLEN) {
242 err = -ENAMETOOLONG;
243 goto out_fname;
244 }
245
246 dent = kmalloc(UBIFS_MAX_DENT_NODE_SZ, GFP_NOFS);
247 if (!dent) {
248 err = -ENOMEM;
249 goto out_fname;
250 }
251
252 if (nm.hash) {
253 ubifs_assert(fname_len(&nm) == 0);
254 ubifs_assert(fname_name(&nm) == NULL);
255 dent_key_init_hash(c, &key, dir->i_ino, nm.hash);
256 err = ubifs_tnc_lookup_dh(c, &key, dent, nm.minor_hash);
257 } else {
258 dent_key_init(c, &key, dir->i_ino, &nm);
259 err = ubifs_tnc_lookup_nm(c, &key, dent, &nm);
260 }
261
262 if (err) {
263 if (err == -ENOENT) {
264 dbg_gen("not found");
265 goto done;
266 }
267 goto out_dent;
268 }
269
270 if (dbg_check_name(c, dent, &nm)) {
271 err = -EINVAL;
272 goto out_dent;
273 }
274
275 inode = ubifs_iget(dir->i_sb, le64_to_cpu(dent->inum));
276 if (IS_ERR(inode)) {
277 /*
278 * This should not happen. Probably the file-system needs
279 * checking.
280 */
281 err = PTR_ERR(inode);
282 ubifs_err(c, "dead directory entry '%pd', error %d",
283 dentry, err);
284 ubifs_ro_mode(c, err);
285 goto out_dent;
286 }
287
288 done:
289 kfree(dent);
290 fscrypt_free_filename(&nm);
291 /*
292 * Note, d_splice_alias() would be required instead if we supported
293 * NFS.
294 */
295 d_add(dentry, inode);
296 return NULL;
297
298 out_dent:
299 kfree(dent);
300 out_fname:
301 fscrypt_free_filename(&nm);
302 return ERR_PTR(err);
303 }
304
305 static int ubifs_create(struct inode *dir, struct dentry *dentry, umode_t mode,
306 bool excl)
307 {
308 struct inode *inode;
309 struct ubifs_info *c = dir->i_sb->s_fs_info;
310 struct ubifs_budget_req req = { .new_ino = 1, .new_dent = 1,
311 .dirtied_ino = 1 };
312 struct ubifs_inode *dir_ui = ubifs_inode(dir);
313 struct fscrypt_name nm;
314 int err, sz_change;
315
316 /*
317 * Budget request settings: new inode, new direntry, changing the
318 * parent directory inode.
319 */
320
321 dbg_gen("dent '%pd', mode %#hx in dir ino %lu",
322 dentry, mode, dir->i_ino);
323
324 err = ubifs_budget_space(c, &req);
325 if (err)
326 return err;
327
328 err = fscrypt_setup_filename(dir, &dentry->d_name, 0, &nm);
329 if (err)
330 goto out_budg;
331
332 sz_change = CALC_DENT_SIZE(fname_len(&nm));
333
334 inode = ubifs_new_inode(c, dir, mode);
335 if (IS_ERR(inode)) {
336 err = PTR_ERR(inode);
337 goto out_fname;
338 }
339
340 err = ubifs_init_security(dir, inode, &dentry->d_name);
341 if (err)
342 goto out_inode;
343
344 mutex_lock(&dir_ui->ui_mutex);
345 dir->i_size += sz_change;
346 dir_ui->ui_size = dir->i_size;
347 dir->i_mtime = dir->i_ctime = inode->i_ctime;
348 err = ubifs_jnl_update(c, dir, &nm, inode, 0, 0);
349 if (err)
350 goto out_cancel;
351 mutex_unlock(&dir_ui->ui_mutex);
352
353 ubifs_release_budget(c, &req);
354 fscrypt_free_filename(&nm);
355 insert_inode_hash(inode);
356 d_instantiate(dentry, inode);
357 return 0;
358
359 out_cancel:
360 dir->i_size -= sz_change;
361 dir_ui->ui_size = dir->i_size;
362 mutex_unlock(&dir_ui->ui_mutex);
363 out_inode:
364 make_bad_inode(inode);
365 iput(inode);
366 out_fname:
367 fscrypt_free_filename(&nm);
368 out_budg:
369 ubifs_release_budget(c, &req);
370 ubifs_err(c, "cannot create regular file, error %d", err);
371 return err;
372 }
373
374 static int do_tmpfile(struct inode *dir, struct dentry *dentry,
375 umode_t mode, struct inode **whiteout)
376 {
377 struct inode *inode;
378 struct ubifs_info *c = dir->i_sb->s_fs_info;
379 struct ubifs_budget_req req = { .new_ino = 1, .new_dent = 1};
380 struct ubifs_budget_req ino_req = { .dirtied_ino = 1 };
381 struct ubifs_inode *ui, *dir_ui = ubifs_inode(dir);
382 int err, instantiated = 0;
383 struct fscrypt_name nm;
384
385 /*
386 * Budget request settings: new dirty inode, new direntry,
387 * budget for dirtied inode will be released via writeback.
388 */
389
390 dbg_gen("dent '%pd', mode %#hx in dir ino %lu",
391 dentry, mode, dir->i_ino);
392
393 err = fscrypt_setup_filename(dir, &dentry->d_name, 0, &nm);
394 if (err)
395 return err;
396
397 err = ubifs_budget_space(c, &req);
398 if (err) {
399 fscrypt_free_filename(&nm);
400 return err;
401 }
402
403 err = ubifs_budget_space(c, &ino_req);
404 if (err) {
405 ubifs_release_budget(c, &req);
406 fscrypt_free_filename(&nm);
407 return err;
408 }
409
410 inode = ubifs_new_inode(c, dir, mode);
411 if (IS_ERR(inode)) {
412 err = PTR_ERR(inode);
413 goto out_budg;
414 }
415 ui = ubifs_inode(inode);
416
417 if (whiteout) {
418 init_special_inode(inode, inode->i_mode, WHITEOUT_DEV);
419 ubifs_assert(inode->i_op == &ubifs_file_inode_operations);
420 }
421
422 err = ubifs_init_security(dir, inode, &dentry->d_name);
423 if (err)
424 goto out_inode;
425
426 mutex_lock(&ui->ui_mutex);
427 insert_inode_hash(inode);
428
429 if (whiteout) {
430 mark_inode_dirty(inode);
431 drop_nlink(inode);
432 *whiteout = inode;
433 } else {
434 d_tmpfile(dentry, inode);
435 }
436 ubifs_assert(ui->dirty);
437
438 instantiated = 1;
439 mutex_unlock(&ui->ui_mutex);
440
441 mutex_lock(&dir_ui->ui_mutex);
442 err = ubifs_jnl_update(c, dir, &nm, inode, 1, 0);
443 if (err)
444 goto out_cancel;
445 mutex_unlock(&dir_ui->ui_mutex);
446
447 ubifs_release_budget(c, &req);
448
449 return 0;
450
451 out_cancel:
452 mutex_unlock(&dir_ui->ui_mutex);
453 out_inode:
454 make_bad_inode(inode);
455 if (!instantiated)
456 iput(inode);
457 out_budg:
458 ubifs_release_budget(c, &req);
459 if (!instantiated)
460 ubifs_release_budget(c, &ino_req);
461 fscrypt_free_filename(&nm);
462 ubifs_err(c, "cannot create temporary file, error %d", err);
463 return err;
464 }
465
466 static int ubifs_tmpfile(struct inode *dir, struct dentry *dentry,
467 umode_t mode)
468 {
469 return do_tmpfile(dir, dentry, mode, NULL);
470 }
471
472 /**
473 * vfs_dent_type - get VFS directory entry type.
474 * @type: UBIFS directory entry type
475 *
476 * This function converts UBIFS directory entry type into VFS directory entry
477 * type.
478 */
479 static unsigned int vfs_dent_type(uint8_t type)
480 {
481 switch (type) {
482 case UBIFS_ITYPE_REG:
483 return DT_REG;
484 case UBIFS_ITYPE_DIR:
485 return DT_DIR;
486 case UBIFS_ITYPE_LNK:
487 return DT_LNK;
488 case UBIFS_ITYPE_BLK:
489 return DT_BLK;
490 case UBIFS_ITYPE_CHR:
491 return DT_CHR;
492 case UBIFS_ITYPE_FIFO:
493 return DT_FIFO;
494 case UBIFS_ITYPE_SOCK:
495 return DT_SOCK;
496 default:
497 BUG();
498 }
499 return 0;
500 }
501
502 /*
503 * The classical Unix view for directory is that it is a linear array of
504 * (name, inode number) entries. Linux/VFS assumes this model as well.
505 * Particularly, 'readdir()' call wants us to return a directory entry offset
506 * which later may be used to continue 'readdir()'ing the directory or to
507 * 'seek()' to that specific direntry. Obviously UBIFS does not really fit this
508 * model because directory entries are identified by keys, which may collide.
509 *
510 * UBIFS uses directory entry hash value for directory offsets, so
511 * 'seekdir()'/'telldir()' may not always work because of possible key
512 * collisions. But UBIFS guarantees that consecutive 'readdir()' calls work
513 * properly by means of saving full directory entry name in the private field
514 * of the file description object.
515 *
516 * This means that UBIFS cannot support NFS which requires full
517 * 'seekdir()'/'telldir()' support.
518 */
519 static int ubifs_readdir(struct file *file, struct dir_context *ctx)
520 {
521 int fstr_real_len = 0, err = 0;
522 struct fscrypt_name nm;
523 struct fscrypt_str fstr = {0};
524 union ubifs_key key;
525 struct ubifs_dent_node *dent;
526 struct inode *dir = file_inode(file);
527 struct ubifs_info *c = dir->i_sb->s_fs_info;
528 bool encrypted = ubifs_crypt_is_encrypted(dir);
529
530 dbg_gen("dir ino %lu, f_pos %#llx", dir->i_ino, ctx->pos);
531
532 if (ctx->pos > UBIFS_S_KEY_HASH_MASK || ctx->pos == 2)
533 /*
534 * The directory was seek'ed to a senseless position or there
535 * are no more entries.
536 */
537 return 0;
538
539 if (encrypted) {
540 err = fscrypt_get_encryption_info(dir);
541 if (err && err != -ENOKEY)
542 return err;
543
544 err = fscrypt_fname_alloc_buffer(dir, UBIFS_MAX_NLEN, &fstr);
545 if (err)
546 return err;
547
548 fstr_real_len = fstr.len;
549 }
550
551 if (file->f_version == 0) {
552 /*
553 * The file was seek'ed, which means that @file->private_data
554 * is now invalid. This may also be just the first
555 * 'ubifs_readdir()' invocation, in which case
556 * @file->private_data is NULL, and the below code is
557 * basically a no-op.
558 */
559 kfree(file->private_data);
560 file->private_data = NULL;
561 }
562
563 /*
564 * 'generic_file_llseek()' unconditionally sets @file->f_version to
565 * zero, and we use this for detecting whether the file was seek'ed.
566 */
567 file->f_version = 1;
568
569 /* File positions 0 and 1 correspond to "." and ".." */
570 if (ctx->pos < 2) {
571 ubifs_assert(!file->private_data);
572 if (!dir_emit_dots(file, ctx)) {
573 if (encrypted)
574 fscrypt_fname_free_buffer(&fstr);
575 return 0;
576 }
577
578 /* Find the first entry in TNC and save it */
579 lowest_dent_key(c, &key, dir->i_ino);
580 fname_len(&nm) = 0;
581 dent = ubifs_tnc_next_ent(c, &key, &nm);
582 if (IS_ERR(dent)) {
583 err = PTR_ERR(dent);
584 goto out;
585 }
586
587 ctx->pos = key_hash_flash(c, &dent->key);
588 file->private_data = dent;
589 }
590
591 dent = file->private_data;
592 if (!dent) {
593 /*
594 * The directory was seek'ed to and is now readdir'ed.
595 * Find the entry corresponding to @ctx->pos or the closest one.
596 */
597 dent_key_init_hash(c, &key, dir->i_ino, ctx->pos);
598 fname_len(&nm) = 0;
599 dent = ubifs_tnc_next_ent(c, &key, &nm);
600 if (IS_ERR(dent)) {
601 err = PTR_ERR(dent);
602 goto out;
603 }
604 ctx->pos = key_hash_flash(c, &dent->key);
605 file->private_data = dent;
606 }
607
608 while (1) {
609 dbg_gen("ino %llu, new f_pos %#x",
610 (unsigned long long)le64_to_cpu(dent->inum),
611 key_hash_flash(c, &dent->key));
612 ubifs_assert(le64_to_cpu(dent->ch.sqnum) >
613 ubifs_inode(dir)->creat_sqnum);
614
615 fname_len(&nm) = le16_to_cpu(dent->nlen);
616 fname_name(&nm) = dent->name;
617
618 if (encrypted) {
619 fstr.len = fstr_real_len;
620
621 err = fscrypt_fname_disk_to_usr(dir, key_hash_flash(c,
622 &dent->key),
623 le32_to_cpu(dent->cookie),
624 &nm.disk_name, &fstr);
625 if (err)
626 goto out;
627 } else {
628 fstr.len = fname_len(&nm);
629 fstr.name = fname_name(&nm);
630 }
631
632 if (!dir_emit(ctx, fstr.name, fstr.len,
633 le64_to_cpu(dent->inum),
634 vfs_dent_type(dent->type))) {
635 if (encrypted)
636 fscrypt_fname_free_buffer(&fstr);
637 return 0;
638 }
639
640 /* Switch to the next entry */
641 key_read(c, &dent->key, &key);
642 dent = ubifs_tnc_next_ent(c, &key, &nm);
643 if (IS_ERR(dent)) {
644 err = PTR_ERR(dent);
645 goto out;
646 }
647
648 kfree(file->private_data);
649 ctx->pos = key_hash_flash(c, &dent->key);
650 file->private_data = dent;
651 cond_resched();
652 }
653
654 out:
655 kfree(file->private_data);
656 file->private_data = NULL;
657
658 if (encrypted)
659 fscrypt_fname_free_buffer(&fstr);
660
661 if (err != -ENOENT)
662 ubifs_err(c, "cannot find next direntry, error %d", err);
663 else
664 /*
665 * -ENOENT is a non-fatal error in this context, the TNC uses
666 * it to indicate that the cursor moved past the current directory
667 * and readdir() has to stop.
668 */
669 err = 0;
670
671
672 /* 2 is a special value indicating that there are no more direntries */
673 ctx->pos = 2;
674 return err;
675 }
676
677 /* Free saved readdir() state when the directory is closed */
678 static int ubifs_dir_release(struct inode *dir, struct file *file)
679 {
680 kfree(file->private_data);
681 file->private_data = NULL;
682 return 0;
683 }
684
685 /**
686 * lock_2_inodes - a wrapper for locking two UBIFS inodes.
687 * @inode1: first inode
688 * @inode2: second inode
689 *
690 * We do not implement any tricks to guarantee strict lock ordering, because
691 * VFS has already done it for us on the @i_mutex. So this is just a simple
692 * wrapper function.
693 */
694 static void lock_2_inodes(struct inode *inode1, struct inode *inode2)
695 {
696 mutex_lock_nested(&ubifs_inode(inode1)->ui_mutex, WB_MUTEX_1);
697 mutex_lock_nested(&ubifs_inode(inode2)->ui_mutex, WB_MUTEX_2);
698 }
699
700 /**
701 * unlock_2_inodes - a wrapper for unlocking two UBIFS inodes.
702 * @inode1: first inode
703 * @inode2: second inode
704 */
705 static void unlock_2_inodes(struct inode *inode1, struct inode *inode2)
706 {
707 mutex_unlock(&ubifs_inode(inode2)->ui_mutex);
708 mutex_unlock(&ubifs_inode(inode1)->ui_mutex);
709 }
710
711 static int ubifs_link(struct dentry *old_dentry, struct inode *dir,
712 struct dentry *dentry)
713 {
714 struct ubifs_info *c = dir->i_sb->s_fs_info;
715 struct inode *inode = d_inode(old_dentry);
716 struct ubifs_inode *ui = ubifs_inode(inode);
717 struct ubifs_inode *dir_ui = ubifs_inode(dir);
718 int err, sz_change = CALC_DENT_SIZE(dentry->d_name.len);
719 struct ubifs_budget_req req = { .new_dent = 1, .dirtied_ino = 2,
720 .dirtied_ino_d = ALIGN(ui->data_len, 8) };
721 struct fscrypt_name nm;
722
723 /*
724 * Budget request settings: new direntry, changing the target inode,
725 * changing the parent inode.
726 */
727
728 dbg_gen("dent '%pd' to ino %lu (nlink %d) in dir ino %lu",
729 dentry, inode->i_ino,
730 inode->i_nlink, dir->i_ino);
731 ubifs_assert(inode_is_locked(dir));
732 ubifs_assert(inode_is_locked(inode));
733
734 if (ubifs_crypt_is_encrypted(dir) &&
735 !fscrypt_has_permitted_context(dir, inode))
736 return -EPERM;
737
738 err = fscrypt_setup_filename(dir, &dentry->d_name, 0, &nm);
739 if (err)
740 return err;
741
742 err = dbg_check_synced_i_size(c, inode);
743 if (err)
744 goto out_fname;
745
746 err = ubifs_budget_space(c, &req);
747 if (err)
748 goto out_fname;
749
750 lock_2_inodes(dir, inode);
751
752 /* Handle O_TMPFILE corner case, it is allowed to link a O_TMPFILE. */
753 if (inode->i_nlink == 0)
754 ubifs_delete_orphan(c, inode->i_ino);
755
756 inc_nlink(inode);
757 ihold(inode);
758 inode->i_ctime = current_time(inode);
759 dir->i_size += sz_change;
760 dir_ui->ui_size = dir->i_size;
761 dir->i_mtime = dir->i_ctime = inode->i_ctime;
762 err = ubifs_jnl_update(c, dir, &nm, inode, 0, 0);
763 if (err)
764 goto out_cancel;
765 unlock_2_inodes(dir, inode);
766
767 ubifs_release_budget(c, &req);
768 d_instantiate(dentry, inode);
769 fscrypt_free_filename(&nm);
770 return 0;
771
772 out_cancel:
773 dir->i_size -= sz_change;
774 dir_ui->ui_size = dir->i_size;
775 drop_nlink(inode);
776 if (inode->i_nlink == 0)
777 ubifs_add_orphan(c, inode->i_ino);
778 unlock_2_inodes(dir, inode);
779 ubifs_release_budget(c, &req);
780 iput(inode);
781 out_fname:
782 fscrypt_free_filename(&nm);
783 return err;
784 }
785
786 static int ubifs_unlink(struct inode *dir, struct dentry *dentry)
787 {
788 struct ubifs_info *c = dir->i_sb->s_fs_info;
789 struct inode *inode = d_inode(dentry);
790 struct ubifs_inode *dir_ui = ubifs_inode(dir);
791 int err, sz_change, budgeted = 1;
792 struct ubifs_budget_req req = { .mod_dent = 1, .dirtied_ino = 2 };
793 unsigned int saved_nlink = inode->i_nlink;
794 struct fscrypt_name nm;
795
796 /*
797 * Budget request settings: deletion direntry, deletion inode (+1 for
798 * @dirtied_ino), changing the parent directory inode. If budgeting
799 * fails, go ahead anyway because we have extra space reserved for
800 * deletions.
801 */
802
803 dbg_gen("dent '%pd' from ino %lu (nlink %d) in dir ino %lu",
804 dentry, inode->i_ino,
805 inode->i_nlink, dir->i_ino);
806
807 if (ubifs_crypt_is_encrypted(dir)) {
808 err = fscrypt_get_encryption_info(dir);
809 if (err && err != -ENOKEY)
810 return err;
811 }
812
813 err = fscrypt_setup_filename(dir, &dentry->d_name, 1, &nm);
814 if (err)
815 return err;
816
817 sz_change = CALC_DENT_SIZE(fname_len(&nm));
818
819 ubifs_assert(inode_is_locked(dir));
820 ubifs_assert(inode_is_locked(inode));
821 err = dbg_check_synced_i_size(c, inode);
822 if (err)
823 goto out_fname;
824
825 err = ubifs_budget_space(c, &req);
826 if (err) {
827 if (err != -ENOSPC)
828 goto out_fname;
829 budgeted = 0;
830 }
831
832 lock_2_inodes(dir, inode);
833 inode->i_ctime = current_time(dir);
834 drop_nlink(inode);
835 dir->i_size -= sz_change;
836 dir_ui->ui_size = dir->i_size;
837 dir->i_mtime = dir->i_ctime = inode->i_ctime;
838 err = ubifs_jnl_update(c, dir, &nm, inode, 1, 0);
839 if (err)
840 goto out_cancel;
841 unlock_2_inodes(dir, inode);
842
843 if (budgeted)
844 ubifs_release_budget(c, &req);
845 else {
846 /* We've deleted something - clean the "no space" flags */
847 c->bi.nospace = c->bi.nospace_rp = 0;
848 smp_wmb();
849 }
850 fscrypt_free_filename(&nm);
851 return 0;
852
853 out_cancel:
854 dir->i_size += sz_change;
855 dir_ui->ui_size = dir->i_size;
856 set_nlink(inode, saved_nlink);
857 unlock_2_inodes(dir, inode);
858 if (budgeted)
859 ubifs_release_budget(c, &req);
860 out_fname:
861 fscrypt_free_filename(&nm);
862 return err;
863 }
864
865 /**
866 * check_dir_empty - check if a directory is empty or not.
867 * @dir: VFS inode object of the directory to check
868 *
869 * This function checks if directory @dir is empty. Returns zero if the
870 * directory is empty, %-ENOTEMPTY if it is not, and other negative error codes
871 * in case of of errors.
872 */
873 int ubifs_check_dir_empty(struct inode *dir)
874 {
875 struct ubifs_info *c = dir->i_sb->s_fs_info;
876 struct fscrypt_name nm = { 0 };
877 struct ubifs_dent_node *dent;
878 union ubifs_key key;
879 int err;
880
881 lowest_dent_key(c, &key, dir->i_ino);
882 dent = ubifs_tnc_next_ent(c, &key, &nm);
883 if (IS_ERR(dent)) {
884 err = PTR_ERR(dent);
885 if (err == -ENOENT)
886 err = 0;
887 } else {
888 kfree(dent);
889 err = -ENOTEMPTY;
890 }
891 return err;
892 }
893
894 static int ubifs_rmdir(struct inode *dir, struct dentry *dentry)
895 {
896 struct ubifs_info *c = dir->i_sb->s_fs_info;
897 struct inode *inode = d_inode(dentry);
898 int err, sz_change, budgeted = 1;
899 struct ubifs_inode *dir_ui = ubifs_inode(dir);
900 struct ubifs_budget_req req = { .mod_dent = 1, .dirtied_ino = 2 };
901 struct fscrypt_name nm;
902
903 /*
904 * Budget request settings: deletion direntry, deletion inode and
905 * changing the parent inode. If budgeting fails, go ahead anyway
906 * because we have extra space reserved for deletions.
907 */
908
909 dbg_gen("directory '%pd', ino %lu in dir ino %lu", dentry,
910 inode->i_ino, dir->i_ino);
911 ubifs_assert(inode_is_locked(dir));
912 ubifs_assert(inode_is_locked(inode));
913 err = ubifs_check_dir_empty(d_inode(dentry));
914 if (err)
915 return err;
916
917 if (ubifs_crypt_is_encrypted(dir)) {
918 err = fscrypt_get_encryption_info(dir);
919 if (err && err != -ENOKEY)
920 return err;
921 }
922
923 err = fscrypt_setup_filename(dir, &dentry->d_name, 1, &nm);
924 if (err)
925 return err;
926
927 sz_change = CALC_DENT_SIZE(fname_len(&nm));
928
929 err = ubifs_budget_space(c, &req);
930 if (err) {
931 if (err != -ENOSPC)
932 goto out_fname;
933 budgeted = 0;
934 }
935
936 lock_2_inodes(dir, inode);
937 inode->i_ctime = current_time(dir);
938 clear_nlink(inode);
939 drop_nlink(dir);
940 dir->i_size -= sz_change;
941 dir_ui->ui_size = dir->i_size;
942 dir->i_mtime = dir->i_ctime = inode->i_ctime;
943 err = ubifs_jnl_update(c, dir, &nm, inode, 1, 0);
944 if (err)
945 goto out_cancel;
946 unlock_2_inodes(dir, inode);
947
948 if (budgeted)
949 ubifs_release_budget(c, &req);
950 else {
951 /* We've deleted something - clean the "no space" flags */
952 c->bi.nospace = c->bi.nospace_rp = 0;
953 smp_wmb();
954 }
955 fscrypt_free_filename(&nm);
956 return 0;
957
958 out_cancel:
959 dir->i_size += sz_change;
960 dir_ui->ui_size = dir->i_size;
961 inc_nlink(dir);
962 set_nlink(inode, 2);
963 unlock_2_inodes(dir, inode);
964 if (budgeted)
965 ubifs_release_budget(c, &req);
966 out_fname:
967 fscrypt_free_filename(&nm);
968 return err;
969 }
970
971 static int ubifs_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode)
972 {
973 struct inode *inode;
974 struct ubifs_inode *dir_ui = ubifs_inode(dir);
975 struct ubifs_info *c = dir->i_sb->s_fs_info;
976 int err, sz_change;
977 struct ubifs_budget_req req = { .new_ino = 1, .new_dent = 1 };
978 struct fscrypt_name nm;
979
980 /*
981 * Budget request settings: new inode, new direntry and changing parent
982 * directory inode.
983 */
984
985 dbg_gen("dent '%pd', mode %#hx in dir ino %lu",
986 dentry, mode, dir->i_ino);
987
988 err = ubifs_budget_space(c, &req);
989 if (err)
990 return err;
991
992 err = fscrypt_setup_filename(dir, &dentry->d_name, 0, &nm);
993 if (err)
994 goto out_budg;
995
996 sz_change = CALC_DENT_SIZE(fname_len(&nm));
997
998 inode = ubifs_new_inode(c, dir, S_IFDIR | mode);
999 if (IS_ERR(inode)) {
1000 err = PTR_ERR(inode);
1001 goto out_fname;
1002 }
1003
1004 err = ubifs_init_security(dir, inode, &dentry->d_name);
1005 if (err)
1006 goto out_inode;
1007
1008 mutex_lock(&dir_ui->ui_mutex);
1009 insert_inode_hash(inode);
1010 inc_nlink(inode);
1011 inc_nlink(dir);
1012 dir->i_size += sz_change;
1013 dir_ui->ui_size = dir->i_size;
1014 dir->i_mtime = dir->i_ctime = inode->i_ctime;
1015 err = ubifs_jnl_update(c, dir, &nm, inode, 0, 0);
1016 if (err) {
1017 ubifs_err(c, "cannot create directory, error %d", err);
1018 goto out_cancel;
1019 }
1020 mutex_unlock(&dir_ui->ui_mutex);
1021
1022 ubifs_release_budget(c, &req);
1023 d_instantiate(dentry, inode);
1024 fscrypt_free_filename(&nm);
1025 return 0;
1026
1027 out_cancel:
1028 dir->i_size -= sz_change;
1029 dir_ui->ui_size = dir->i_size;
1030 drop_nlink(dir);
1031 mutex_unlock(&dir_ui->ui_mutex);
1032 out_inode:
1033 make_bad_inode(inode);
1034 iput(inode);
1035 out_fname:
1036 fscrypt_free_filename(&nm);
1037 out_budg:
1038 ubifs_release_budget(c, &req);
1039 return err;
1040 }
1041
1042 static int ubifs_mknod(struct inode *dir, struct dentry *dentry,
1043 umode_t mode, dev_t rdev)
1044 {
1045 struct inode *inode;
1046 struct ubifs_inode *ui;
1047 struct ubifs_inode *dir_ui = ubifs_inode(dir);
1048 struct ubifs_info *c = dir->i_sb->s_fs_info;
1049 union ubifs_dev_desc *dev = NULL;
1050 int sz_change;
1051 int err, devlen = 0;
1052 struct ubifs_budget_req req = { .new_ino = 1, .new_dent = 1,
1053 .new_ino_d = ALIGN(devlen, 8),
1054 .dirtied_ino = 1 };
1055 struct fscrypt_name nm;
1056
1057 /*
1058 * Budget request settings: new inode, new direntry and changing parent
1059 * directory inode.
1060 */
1061
1062 dbg_gen("dent '%pd' in dir ino %lu", dentry, dir->i_ino);
1063
1064 if (S_ISBLK(mode) || S_ISCHR(mode)) {
1065 dev = kmalloc(sizeof(union ubifs_dev_desc), GFP_NOFS);
1066 if (!dev)
1067 return -ENOMEM;
1068 devlen = ubifs_encode_dev(dev, rdev);
1069 }
1070
1071 err = ubifs_budget_space(c, &req);
1072 if (err) {
1073 kfree(dev);
1074 return err;
1075 }
1076
1077 err = fscrypt_setup_filename(dir, &dentry->d_name, 0, &nm);
1078 if (err) {
1079 kfree(dev);
1080 goto out_budg;
1081 }
1082
1083 sz_change = CALC_DENT_SIZE(fname_len(&nm));
1084
1085 inode = ubifs_new_inode(c, dir, mode);
1086 if (IS_ERR(inode)) {
1087 kfree(dev);
1088 err = PTR_ERR(inode);
1089 goto out_fname;
1090 }
1091
1092 init_special_inode(inode, inode->i_mode, rdev);
1093 inode->i_size = ubifs_inode(inode)->ui_size = devlen;
1094 ui = ubifs_inode(inode);
1095 ui->data = dev;
1096 ui->data_len = devlen;
1097
1098 err = ubifs_init_security(dir, inode, &dentry->d_name);
1099 if (err)
1100 goto out_inode;
1101
1102 mutex_lock(&dir_ui->ui_mutex);
1103 dir->i_size += sz_change;
1104 dir_ui->ui_size = dir->i_size;
1105 dir->i_mtime = dir->i_ctime = inode->i_ctime;
1106 err = ubifs_jnl_update(c, dir, &nm, inode, 0, 0);
1107 if (err)
1108 goto out_cancel;
1109 mutex_unlock(&dir_ui->ui_mutex);
1110
1111 ubifs_release_budget(c, &req);
1112 insert_inode_hash(inode);
1113 d_instantiate(dentry, inode);
1114 fscrypt_free_filename(&nm);
1115 return 0;
1116
1117 out_cancel:
1118 dir->i_size -= sz_change;
1119 dir_ui->ui_size = dir->i_size;
1120 mutex_unlock(&dir_ui->ui_mutex);
1121 out_inode:
1122 make_bad_inode(inode);
1123 iput(inode);
1124 out_fname:
1125 fscrypt_free_filename(&nm);
1126 out_budg:
1127 ubifs_release_budget(c, &req);
1128 return err;
1129 }
1130
1131 static int ubifs_symlink(struct inode *dir, struct dentry *dentry,
1132 const char *symname)
1133 {
1134 struct inode *inode;
1135 struct ubifs_inode *ui;
1136 struct ubifs_inode *dir_ui = ubifs_inode(dir);
1137 struct ubifs_info *c = dir->i_sb->s_fs_info;
1138 int err, len = strlen(symname);
1139 int sz_change = CALC_DENT_SIZE(len);
1140 struct fscrypt_str disk_link = FSTR_INIT((char *)symname, len + 1);
1141 struct fscrypt_symlink_data *sd = NULL;
1142 struct ubifs_budget_req req = { .new_ino = 1, .new_dent = 1,
1143 .new_ino_d = ALIGN(len, 8),
1144 .dirtied_ino = 1 };
1145 struct fscrypt_name nm;
1146
1147 if (ubifs_crypt_is_encrypted(dir)) {
1148 err = fscrypt_get_encryption_info(dir);
1149 if (err)
1150 goto out_budg;
1151
1152 if (!fscrypt_has_encryption_key(dir)) {
1153 err = -EPERM;
1154 goto out_budg;
1155 }
1156
1157 disk_link.len = (fscrypt_fname_encrypted_size(dir, len) +
1158 sizeof(struct fscrypt_symlink_data));
1159 }
1160
1161 /*
1162 * Budget request settings: new inode, new direntry and changing parent
1163 * directory inode.
1164 */
1165
1166 dbg_gen("dent '%pd', target '%s' in dir ino %lu", dentry,
1167 symname, dir->i_ino);
1168
1169 if (disk_link.len > UBIFS_MAX_INO_DATA)
1170 return -ENAMETOOLONG;
1171
1172 err = ubifs_budget_space(c, &req);
1173 if (err)
1174 return err;
1175
1176 err = fscrypt_setup_filename(dir, &dentry->d_name, 0, &nm);
1177 if (err)
1178 goto out_budg;
1179
1180 inode = ubifs_new_inode(c, dir, S_IFLNK | S_IRWXUGO);
1181 if (IS_ERR(inode)) {
1182 err = PTR_ERR(inode);
1183 goto out_fname;
1184 }
1185
1186 ui = ubifs_inode(inode);
1187 ui->data = kmalloc(disk_link.len, GFP_NOFS);
1188 if (!ui->data) {
1189 err = -ENOMEM;
1190 goto out_inode;
1191 }
1192
1193 if (ubifs_crypt_is_encrypted(dir)) {
1194 struct qstr istr = QSTR_INIT(symname, len);
1195 struct fscrypt_str ostr;
1196
1197 sd = kzalloc(disk_link.len, GFP_NOFS);
1198 if (!sd) {
1199 err = -ENOMEM;
1200 goto out_inode;
1201 }
1202
1203 ostr.name = sd->encrypted_path;
1204 ostr.len = disk_link.len;
1205
1206 err = fscrypt_fname_usr_to_disk(inode, &istr, &ostr);
1207 if (err) {
1208 kfree(sd);
1209 goto out_inode;
1210 }
1211
1212 sd->len = cpu_to_le16(ostr.len);
1213 disk_link.name = (char *)sd;
1214 } else {
1215 inode->i_link = ui->data;
1216 }
1217
1218 memcpy(ui->data, disk_link.name, disk_link.len);
1219 ((char *)ui->data)[disk_link.len - 1] = '\0';
1220
1221 /*
1222 * The terminating zero byte is not written to the flash media and it
1223 * is put just to make later in-memory string processing simpler. Thus,
1224 * data length is @len, not @len + %1.
1225 */
1226 ui->data_len = disk_link.len - 1;
1227 inode->i_size = ubifs_inode(inode)->ui_size = disk_link.len - 1;
1228
1229 err = ubifs_init_security(dir, inode, &dentry->d_name);
1230 if (err)
1231 goto out_inode;
1232
1233 mutex_lock(&dir_ui->ui_mutex);
1234 dir->i_size += sz_change;
1235 dir_ui->ui_size = dir->i_size;
1236 dir->i_mtime = dir->i_ctime = inode->i_ctime;
1237 err = ubifs_jnl_update(c, dir, &nm, inode, 0, 0);
1238 if (err)
1239 goto out_cancel;
1240 mutex_unlock(&dir_ui->ui_mutex);
1241
1242 ubifs_release_budget(c, &req);
1243 insert_inode_hash(inode);
1244 d_instantiate(dentry, inode);
1245 fscrypt_free_filename(&nm);
1246 return 0;
1247
1248 out_cancel:
1249 dir->i_size -= sz_change;
1250 dir_ui->ui_size = dir->i_size;
1251 mutex_unlock(&dir_ui->ui_mutex);
1252 out_inode:
1253 make_bad_inode(inode);
1254 iput(inode);
1255 out_fname:
1256 fscrypt_free_filename(&nm);
1257 out_budg:
1258 ubifs_release_budget(c, &req);
1259 return err;
1260 }
1261
1262 /**
1263 * lock_4_inodes - a wrapper for locking three UBIFS inodes.
1264 * @inode1: first inode
1265 * @inode2: second inode
1266 * @inode3: third inode
1267 * @inode4: fouth inode
1268 *
1269 * This function is used for 'ubifs_rename()' and @inode1 may be the same as
1270 * @inode2 whereas @inode3 and @inode4 may be %NULL.
1271 *
1272 * We do not implement any tricks to guarantee strict lock ordering, because
1273 * VFS has already done it for us on the @i_mutex. So this is just a simple
1274 * wrapper function.
1275 */
1276 static void lock_4_inodes(struct inode *inode1, struct inode *inode2,
1277 struct inode *inode3, struct inode *inode4)
1278 {
1279 mutex_lock_nested(&ubifs_inode(inode1)->ui_mutex, WB_MUTEX_1);
1280 if (inode2 != inode1)
1281 mutex_lock_nested(&ubifs_inode(inode2)->ui_mutex, WB_MUTEX_2);
1282 if (inode3)
1283 mutex_lock_nested(&ubifs_inode(inode3)->ui_mutex, WB_MUTEX_3);
1284 if (inode4)
1285 mutex_lock_nested(&ubifs_inode(inode4)->ui_mutex, WB_MUTEX_4);
1286 }
1287
1288 /**
1289 * unlock_4_inodes - a wrapper for unlocking three UBIFS inodes for rename.
1290 * @inode1: first inode
1291 * @inode2: second inode
1292 * @inode3: third inode
1293 * @inode4: fouth inode
1294 */
1295 static void unlock_4_inodes(struct inode *inode1, struct inode *inode2,
1296 struct inode *inode3, struct inode *inode4)
1297 {
1298 if (inode4)
1299 mutex_unlock(&ubifs_inode(inode4)->ui_mutex);
1300 if (inode3)
1301 mutex_unlock(&ubifs_inode(inode3)->ui_mutex);
1302 if (inode1 != inode2)
1303 mutex_unlock(&ubifs_inode(inode2)->ui_mutex);
1304 mutex_unlock(&ubifs_inode(inode1)->ui_mutex);
1305 }
1306
1307 static int do_rename(struct inode *old_dir, struct dentry *old_dentry,
1308 struct inode *new_dir, struct dentry *new_dentry,
1309 unsigned int flags)
1310 {
1311 struct ubifs_info *c = old_dir->i_sb->s_fs_info;
1312 struct inode *old_inode = d_inode(old_dentry);
1313 struct inode *new_inode = d_inode(new_dentry);
1314 struct inode *whiteout = NULL;
1315 struct ubifs_inode *old_inode_ui = ubifs_inode(old_inode);
1316 struct ubifs_inode *whiteout_ui = NULL;
1317 int err, release, sync = 0, move = (new_dir != old_dir);
1318 int is_dir = S_ISDIR(old_inode->i_mode);
1319 int unlink = !!new_inode, new_sz, old_sz;
1320 struct ubifs_budget_req req = { .new_dent = 1, .mod_dent = 1,
1321 .dirtied_ino = 3 };
1322 struct ubifs_budget_req ino_req = { .dirtied_ino = 1,
1323 .dirtied_ino_d = ALIGN(old_inode_ui->data_len, 8) };
1324 struct timespec time;
1325 unsigned int uninitialized_var(saved_nlink);
1326 struct fscrypt_name old_nm, new_nm;
1327
1328 /*
1329 * Budget request settings: deletion direntry, new direntry, removing
1330 * the old inode, and changing old and new parent directory inodes.
1331 *
1332 * However, this operation also marks the target inode as dirty and
1333 * does not write it, so we allocate budget for the target inode
1334 * separately.
1335 */
1336
1337 dbg_gen("dent '%pd' ino %lu in dir ino %lu to dent '%pd' in dir ino %lu flags 0x%x",
1338 old_dentry, old_inode->i_ino, old_dir->i_ino,
1339 new_dentry, new_dir->i_ino, flags);
1340
1341 if (unlink)
1342 ubifs_assert(inode_is_locked(new_inode));
1343
1344 if (old_dir != new_dir) {
1345 if (ubifs_crypt_is_encrypted(new_dir) &&
1346 !fscrypt_has_permitted_context(new_dir, old_inode))
1347 return -EPERM;
1348 }
1349
1350 if (unlink && is_dir) {
1351 err = ubifs_check_dir_empty(new_inode);
1352 if (err)
1353 return err;
1354 }
1355
1356 err = fscrypt_setup_filename(old_dir, &old_dentry->d_name, 0, &old_nm);
1357 if (err)
1358 return err;
1359
1360 err = fscrypt_setup_filename(new_dir, &new_dentry->d_name, 0, &new_nm);
1361 if (err) {
1362 fscrypt_free_filename(&old_nm);
1363 return err;
1364 }
1365
1366 new_sz = CALC_DENT_SIZE(fname_len(&new_nm));
1367 old_sz = CALC_DENT_SIZE(fname_len(&old_nm));
1368
1369 err = ubifs_budget_space(c, &req);
1370 if (err) {
1371 fscrypt_free_filename(&old_nm);
1372 fscrypt_free_filename(&new_nm);
1373 return err;
1374 }
1375 err = ubifs_budget_space(c, &ino_req);
1376 if (err) {
1377 fscrypt_free_filename(&old_nm);
1378 fscrypt_free_filename(&new_nm);
1379 ubifs_release_budget(c, &req);
1380 return err;
1381 }
1382
1383 if (flags & RENAME_WHITEOUT) {
1384 union ubifs_dev_desc *dev = NULL;
1385
1386 dev = kmalloc(sizeof(union ubifs_dev_desc), GFP_NOFS);
1387 if (!dev) {
1388 ubifs_release_budget(c, &req);
1389 ubifs_release_budget(c, &ino_req);
1390 return -ENOMEM;
1391 }
1392
1393 err = do_tmpfile(old_dir, old_dentry, S_IFCHR | WHITEOUT_MODE, &whiteout);
1394 if (err) {
1395 ubifs_release_budget(c, &req);
1396 ubifs_release_budget(c, &ino_req);
1397 kfree(dev);
1398 return err;
1399 }
1400
1401 whiteout->i_state |= I_LINKABLE;
1402 whiteout_ui = ubifs_inode(whiteout);
1403 whiteout_ui->data = dev;
1404 whiteout_ui->data_len = ubifs_encode_dev(dev, MKDEV(0, 0));
1405 ubifs_assert(!whiteout_ui->dirty);
1406 }
1407
1408 lock_4_inodes(old_dir, new_dir, new_inode, whiteout);
1409
1410 /*
1411 * Like most other Unix systems, set the @i_ctime for inodes on a
1412 * rename.
1413 */
1414 time = current_time(old_dir);
1415 old_inode->i_ctime = time;
1416
1417 /* We must adjust parent link count when renaming directories */
1418 if (is_dir) {
1419 if (move) {
1420 /*
1421 * @old_dir loses a link because we are moving
1422 * @old_inode to a different directory.
1423 */
1424 drop_nlink(old_dir);
1425 /*
1426 * @new_dir only gains a link if we are not also
1427 * overwriting an existing directory.
1428 */
1429 if (!unlink)
1430 inc_nlink(new_dir);
1431 } else {
1432 /*
1433 * @old_inode is not moving to a different directory,
1434 * but @old_dir still loses a link if we are
1435 * overwriting an existing directory.
1436 */
1437 if (unlink)
1438 drop_nlink(old_dir);
1439 }
1440 }
1441
1442 old_dir->i_size -= old_sz;
1443 ubifs_inode(old_dir)->ui_size = old_dir->i_size;
1444 old_dir->i_mtime = old_dir->i_ctime = time;
1445 new_dir->i_mtime = new_dir->i_ctime = time;
1446
1447 /*
1448 * And finally, if we unlinked a direntry which happened to have the
1449 * same name as the moved direntry, we have to decrement @i_nlink of
1450 * the unlinked inode and change its ctime.
1451 */
1452 if (unlink) {
1453 /*
1454 * Directories cannot have hard-links, so if this is a
1455 * directory, just clear @i_nlink.
1456 */
1457 saved_nlink = new_inode->i_nlink;
1458 if (is_dir)
1459 clear_nlink(new_inode);
1460 else
1461 drop_nlink(new_inode);
1462 new_inode->i_ctime = time;
1463 } else {
1464 new_dir->i_size += new_sz;
1465 ubifs_inode(new_dir)->ui_size = new_dir->i_size;
1466 }
1467
1468 /*
1469 * Do not ask 'ubifs_jnl_rename()' to flush write-buffer if @old_inode
1470 * is dirty, because this will be done later on at the end of
1471 * 'ubifs_rename()'.
1472 */
1473 if (IS_SYNC(old_inode)) {
1474 sync = IS_DIRSYNC(old_dir) || IS_DIRSYNC(new_dir);
1475 if (unlink && IS_SYNC(new_inode))
1476 sync = 1;
1477 }
1478
1479 if (whiteout) {
1480 struct ubifs_budget_req wht_req = { .dirtied_ino = 1,
1481 .dirtied_ino_d = \
1482 ALIGN(ubifs_inode(whiteout)->data_len, 8) };
1483
1484 err = ubifs_budget_space(c, &wht_req);
1485 if (err) {
1486 ubifs_release_budget(c, &req);
1487 ubifs_release_budget(c, &ino_req);
1488 kfree(whiteout_ui->data);
1489 whiteout_ui->data_len = 0;
1490 iput(whiteout);
1491 return err;
1492 }
1493
1494 inc_nlink(whiteout);
1495 mark_inode_dirty(whiteout);
1496 whiteout->i_state &= ~I_LINKABLE;
1497 iput(whiteout);
1498 }
1499
1500 err = ubifs_jnl_rename(c, old_dir, old_inode, &old_nm, new_dir,
1501 new_inode, &new_nm, whiteout, sync);
1502 if (err)
1503 goto out_cancel;
1504
1505 unlock_4_inodes(old_dir, new_dir, new_inode, whiteout);
1506 ubifs_release_budget(c, &req);
1507
1508 mutex_lock(&old_inode_ui->ui_mutex);
1509 release = old_inode_ui->dirty;
1510 mark_inode_dirty_sync(old_inode);
1511 mutex_unlock(&old_inode_ui->ui_mutex);
1512
1513 if (release)
1514 ubifs_release_budget(c, &ino_req);
1515 if (IS_SYNC(old_inode))
1516 err = old_inode->i_sb->s_op->write_inode(old_inode, NULL);
1517
1518 fscrypt_free_filename(&old_nm);
1519 fscrypt_free_filename(&new_nm);
1520 return err;
1521
1522 out_cancel:
1523 if (unlink) {
1524 set_nlink(new_inode, saved_nlink);
1525 } else {
1526 new_dir->i_size -= new_sz;
1527 ubifs_inode(new_dir)->ui_size = new_dir->i_size;
1528 }
1529 old_dir->i_size += old_sz;
1530 ubifs_inode(old_dir)->ui_size = old_dir->i_size;
1531 if (is_dir) {
1532 if (move) {
1533 inc_nlink(old_dir);
1534 if (!unlink)
1535 drop_nlink(new_dir);
1536 } else {
1537 if (unlink)
1538 inc_nlink(old_dir);
1539 }
1540 }
1541 if (whiteout) {
1542 drop_nlink(whiteout);
1543 iput(whiteout);
1544 }
1545 unlock_4_inodes(old_dir, new_dir, new_inode, whiteout);
1546 ubifs_release_budget(c, &ino_req);
1547 ubifs_release_budget(c, &req);
1548 fscrypt_free_filename(&old_nm);
1549 fscrypt_free_filename(&new_nm);
1550 return err;
1551 }
1552
1553 static int ubifs_xrename(struct inode *old_dir, struct dentry *old_dentry,
1554 struct inode *new_dir, struct dentry *new_dentry)
1555 {
1556 struct ubifs_info *c = old_dir->i_sb->s_fs_info;
1557 struct ubifs_budget_req req = { .new_dent = 1, .mod_dent = 1,
1558 .dirtied_ino = 2 };
1559 int sync = IS_DIRSYNC(old_dir) || IS_DIRSYNC(new_dir);
1560 struct inode *fst_inode = d_inode(old_dentry);
1561 struct inode *snd_inode = d_inode(new_dentry);
1562 struct timespec time;
1563 int err;
1564 struct fscrypt_name fst_nm, snd_nm;
1565
1566 ubifs_assert(fst_inode && snd_inode);
1567
1568 if ((ubifs_crypt_is_encrypted(old_dir) ||
1569 ubifs_crypt_is_encrypted(new_dir)) &&
1570 (old_dir != new_dir) &&
1571 (!fscrypt_has_permitted_context(new_dir, fst_inode) ||
1572 !fscrypt_has_permitted_context(old_dir, snd_inode)))
1573 return -EPERM;
1574
1575 err = fscrypt_setup_filename(old_dir, &old_dentry->d_name, 0, &fst_nm);
1576 if (err)
1577 return err;
1578
1579 err = fscrypt_setup_filename(new_dir, &new_dentry->d_name, 0, &snd_nm);
1580 if (err) {
1581 fscrypt_free_filename(&fst_nm);
1582 return err;
1583 }
1584
1585 lock_4_inodes(old_dir, new_dir, NULL, NULL);
1586
1587 time = current_time(old_dir);
1588 fst_inode->i_ctime = time;
1589 snd_inode->i_ctime = time;
1590 old_dir->i_mtime = old_dir->i_ctime = time;
1591 new_dir->i_mtime = new_dir->i_ctime = time;
1592
1593 if (old_dir != new_dir) {
1594 if (S_ISDIR(fst_inode->i_mode) && !S_ISDIR(snd_inode->i_mode)) {
1595 inc_nlink(new_dir);
1596 drop_nlink(old_dir);
1597 }
1598 else if (!S_ISDIR(fst_inode->i_mode) && S_ISDIR(snd_inode->i_mode)) {
1599 drop_nlink(new_dir);
1600 inc_nlink(old_dir);
1601 }
1602 }
1603
1604 err = ubifs_jnl_xrename(c, old_dir, fst_inode, &fst_nm, new_dir,
1605 snd_inode, &snd_nm, sync);
1606
1607 unlock_4_inodes(old_dir, new_dir, NULL, NULL);
1608 ubifs_release_budget(c, &req);
1609
1610 fscrypt_free_filename(&fst_nm);
1611 fscrypt_free_filename(&snd_nm);
1612 return err;
1613 }
1614
1615 static int ubifs_rename(struct inode *old_dir, struct dentry *old_dentry,
1616 struct inode *new_dir, struct dentry *new_dentry,
1617 unsigned int flags)
1618 {
1619 if (flags & ~(RENAME_NOREPLACE | RENAME_WHITEOUT | RENAME_EXCHANGE))
1620 return -EINVAL;
1621
1622 ubifs_assert(inode_is_locked(old_dir));
1623 ubifs_assert(inode_is_locked(new_dir));
1624
1625 if (flags & RENAME_EXCHANGE)
1626 return ubifs_xrename(old_dir, old_dentry, new_dir, new_dentry);
1627
1628 return do_rename(old_dir, old_dentry, new_dir, new_dentry, flags);
1629 }
1630
1631 int ubifs_getattr(const struct path *path, struct kstat *stat,
1632 u32 request_mask, unsigned int flags)
1633 {
1634 loff_t size;
1635 struct inode *inode = d_inode(path->dentry);
1636 struct ubifs_inode *ui = ubifs_inode(inode);
1637
1638 mutex_lock(&ui->ui_mutex);
1639 generic_fillattr(inode, stat);
1640 stat->blksize = UBIFS_BLOCK_SIZE;
1641 stat->size = ui->ui_size;
1642
1643 /*
1644 * Unfortunately, the 'stat()' system call was designed for block
1645 * device based file systems, and it is not appropriate for UBIFS,
1646 * because UBIFS does not have notion of "block". For example, it is
1647 * difficult to tell how many block a directory takes - it actually
1648 * takes less than 300 bytes, but we have to round it to block size,
1649 * which introduces large mistake. This makes utilities like 'du' to
1650 * report completely senseless numbers. This is the reason why UBIFS
1651 * goes the same way as JFFS2 - it reports zero blocks for everything
1652 * but regular files, which makes more sense than reporting completely
1653 * wrong sizes.
1654 */
1655 if (S_ISREG(inode->i_mode)) {
1656 size = ui->xattr_size;
1657 size += stat->size;
1658 size = ALIGN(size, UBIFS_BLOCK_SIZE);
1659 /*
1660 * Note, user-space expects 512-byte blocks count irrespectively
1661 * of what was reported in @stat->size.
1662 */
1663 stat->blocks = size >> 9;
1664 } else
1665 stat->blocks = 0;
1666 mutex_unlock(&ui->ui_mutex);
1667 return 0;
1668 }
1669
1670 static int ubifs_dir_open(struct inode *dir, struct file *file)
1671 {
1672 if (ubifs_crypt_is_encrypted(dir))
1673 return fscrypt_get_encryption_info(dir) ? -EACCES : 0;
1674
1675 return 0;
1676 }
1677
1678 const struct inode_operations ubifs_dir_inode_operations = {
1679 .lookup = ubifs_lookup,
1680 .create = ubifs_create,
1681 .link = ubifs_link,
1682 .symlink = ubifs_symlink,
1683 .unlink = ubifs_unlink,
1684 .mkdir = ubifs_mkdir,
1685 .rmdir = ubifs_rmdir,
1686 .mknod = ubifs_mknod,
1687 .rename = ubifs_rename,
1688 .setattr = ubifs_setattr,
1689 .getattr = ubifs_getattr,
1690 .listxattr = ubifs_listxattr,
1691 #ifdef CONFIG_UBIFS_ATIME_SUPPORT
1692 .update_time = ubifs_update_time,
1693 #endif
1694 .tmpfile = ubifs_tmpfile,
1695 };
1696
1697 const struct file_operations ubifs_dir_operations = {
1698 .llseek = generic_file_llseek,
1699 .release = ubifs_dir_release,
1700 .read = generic_read_dir,
1701 .iterate_shared = ubifs_readdir,
1702 .fsync = ubifs_fsync,
1703 .unlocked_ioctl = ubifs_ioctl,
1704 .open = ubifs_dir_open,
1705 #ifdef CONFIG_COMPAT
1706 .compat_ioctl = ubifs_compat_ioctl,
1707 #endif
1708 };