1 // SPDX-License-Identifier: GPL-2.0-only
2 /* * This file is part of UBIFS.
3 *
4 * Copyright (C) 2006-2008 Nokia Corporation.
5 * Copyright (C) 2006, 2007 University of Szeged, Hungary
6 *
7 * Authors: Artem Bityutskiy (Битюцкий Артём)
8 * Adrian Hunter
9 * Zoltan Sogor
10 */
11
12 /*
13 * This file implements directory operations.
14 *
15 * All FS operations in this file allocate budget before writing anything to the
16 * media. If they fail to allocate it, the error is returned. The only
17 * exceptions are 'ubifs_unlink()' and 'ubifs_rmdir()' which keep working even
18 * if they unable to allocate the budget, because deletion %-ENOSPC failure is
19 * not what users are usually ready to get. UBIFS budgeting subsystem has some
20 * space reserved for these purposes.
21 *
22 * All operations in this file write all inodes which they change straight
23 * away, instead of marking them dirty. For example, 'ubifs_link()' changes
24 * @i_size of the parent inode and writes the parent inode together with the
25 * target inode. This was done to simplify file-system recovery which would
26 * otherwise be very difficult to do. The only exception is rename which marks
27 * the re-named inode dirty (because its @i_ctime is updated) but does not
28 * write it, but just marks it as dirty.
29 */
30
31 #include "ubifs.h"
32
33 /**
34 * inherit_flags - inherit flags of the parent inode.
35 * @dir: parent inode
36 * @mode: new inode mode flags
37 *
38 * This is a helper function for 'ubifs_new_inode()' which inherits flag of the
39 * parent directory inode @dir. UBIFS inodes inherit the following flags:
40 * o %UBIFS_COMPR_FL, which is useful to switch compression on/of on
41 * sub-directory basis;
42 * o %UBIFS_SYNC_FL - useful for the same reasons;
43 * o %UBIFS_DIRSYNC_FL - similar, but relevant only to directories.
44 *
45 * This function returns the inherited flags.
46 */
inherit_flags(const struct inode * dir,umode_t mode)47 static int inherit_flags(const struct inode *dir, umode_t mode)
48 {
49 int flags;
50 const struct ubifs_inode *ui = ubifs_inode(dir);
51
52 if (!S_ISDIR(dir->i_mode))
53 /*
54 * The parent is not a directory, which means that an extended
55 * attribute inode is being created. No flags.
56 */
57 return 0;
58
59 flags = ui->flags & (UBIFS_COMPR_FL | UBIFS_SYNC_FL | UBIFS_DIRSYNC_FL);
60 if (!S_ISDIR(mode))
61 /* The "DIRSYNC" flag only applies to directories */
62 flags &= ~UBIFS_DIRSYNC_FL;
63 return flags;
64 }
65
66 /**
67 * ubifs_new_inode - allocate new UBIFS inode object.
68 * @c: UBIFS file-system description object
69 * @dir: parent directory inode
70 * @mode: inode mode flags
71 * @is_xattr: whether the inode is xattr inode
72 *
73 * This function finds an unused inode number, allocates new inode and
74 * initializes it. Returns new inode in case of success and an error code in
75 * case of failure.
76 */
ubifs_new_inode(struct ubifs_info * c,struct inode * dir,umode_t mode,bool is_xattr)77 struct inode *ubifs_new_inode(struct ubifs_info *c, struct inode *dir,
78 umode_t mode, bool is_xattr)
79 {
80 int err;
81 struct inode *inode;
82 struct ubifs_inode *ui;
83 bool encrypted = false;
84
85 inode = new_inode(c->vfs_sb);
86 ui = ubifs_inode(inode);
87 if (!inode)
88 return ERR_PTR(-ENOMEM);
89
90 /*
91 * Set 'S_NOCMTIME' to prevent VFS form updating [mc]time of inodes and
92 * marking them dirty in file write path (see 'file_update_time()').
93 * UBIFS has to fully control "clean <-> dirty" transitions of inodes
94 * to make budgeting work.
95 */
96 inode->i_flags |= S_NOCMTIME;
97
98 inode_init_owner(&nop_mnt_idmap, inode, dir, mode);
99 simple_inode_init_ts(inode);
100 inode->i_mapping->nrpages = 0;
101
102 if (!is_xattr) {
103 err = fscrypt_prepare_new_inode(dir, inode, &encrypted);
104 if (err) {
105 ubifs_err(c, "fscrypt_prepare_new_inode failed: %i", err);
106 goto out_iput;
107 }
108 }
109
110 switch (mode & S_IFMT) {
111 case S_IFREG:
112 inode->i_mapping->a_ops = &ubifs_file_address_operations;
113 inode->i_op = &ubifs_file_inode_operations;
114 inode->i_fop = &ubifs_file_operations;
115 break;
116 case S_IFDIR:
117 inode->i_op = &ubifs_dir_inode_operations;
118 inode->i_fop = &ubifs_dir_operations;
119 inode->i_size = ui->ui_size = UBIFS_INO_NODE_SZ;
120 break;
121 case S_IFLNK:
122 inode->i_op = &ubifs_symlink_inode_operations;
123 break;
124 case S_IFSOCK:
125 case S_IFIFO:
126 case S_IFBLK:
127 case S_IFCHR:
128 inode->i_op = &ubifs_file_inode_operations;
129 break;
130 default:
131 BUG();
132 }
133
134 ui->flags = inherit_flags(dir, mode);
135 ubifs_set_inode_flags(inode);
136 if (S_ISREG(mode))
137 ui->compr_type = c->default_compr;
138 else
139 ui->compr_type = UBIFS_COMPR_NONE;
140 ui->synced_i_size = 0;
141
142 spin_lock(&c->cnt_lock);
143 /* Inode number overflow is currently not supported */
144 if (c->highest_inum >= INUM_WARN_WATERMARK) {
145 if (c->highest_inum >= INUM_WATERMARK) {
146 spin_unlock(&c->cnt_lock);
147 ubifs_err(c, "out of inode numbers");
148 err = -EINVAL;
149 goto out_iput;
150 }
151 ubifs_warn(c, "running out of inode numbers (current %lu, max %u)",
152 (unsigned long)c->highest_inum, INUM_WATERMARK);
153 }
154
155 inode->i_ino = ++c->highest_inum;
156 /*
157 * The creation sequence number remains with this inode for its
158 * lifetime. All nodes for this inode have a greater sequence number,
159 * and so it is possible to distinguish obsolete nodes belonging to a
160 * previous incarnation of the same inode number - for example, for the
161 * purpose of rebuilding the index.
162 */
163 ui->creat_sqnum = ++c->max_sqnum;
164 spin_unlock(&c->cnt_lock);
165
166 if (encrypted) {
167 err = fscrypt_set_context(inode, NULL);
168 if (err) {
169 ubifs_err(c, "fscrypt_set_context failed: %i", err);
170 goto out_iput;
171 }
172 }
173
174 return inode;
175
176 out_iput:
177 make_bad_inode(inode);
178 iput(inode);
179 return ERR_PTR(err);
180 }
181
dbg_check_name(const struct ubifs_info * c,const struct ubifs_dent_node * dent,const struct fscrypt_name * nm)182 static int dbg_check_name(const struct ubifs_info *c,
183 const struct ubifs_dent_node *dent,
184 const struct fscrypt_name *nm)
185 {
186 if (!dbg_is_chk_gen(c))
187 return 0;
188 if (le16_to_cpu(dent->nlen) != fname_len(nm))
189 return -EINVAL;
190 if (memcmp(dent->name, fname_name(nm), fname_len(nm)))
191 return -EINVAL;
192 return 0;
193 }
194
ubifs_lookup(struct inode * dir,struct dentry * dentry,unsigned int flags)195 static struct dentry *ubifs_lookup(struct inode *dir, struct dentry *dentry,
196 unsigned int flags)
197 {
198 int err;
199 union ubifs_key key;
200 struct inode *inode = NULL;
201 struct ubifs_dent_node *dent = NULL;
202 struct ubifs_info *c = dir->i_sb->s_fs_info;
203 struct fscrypt_name nm;
204
205 dbg_gen("'%pd' in dir ino %lu", dentry, dir->i_ino);
206
207 err = fscrypt_prepare_lookup(dir, dentry, &nm);
208 generic_set_encrypted_ci_d_ops(dentry);
209 if (err == -ENOENT)
210 return d_splice_alias(NULL, dentry);
211 if (err)
212 return ERR_PTR(err);
213
214 if (fname_len(&nm) > UBIFS_MAX_NLEN) {
215 inode = ERR_PTR(-ENAMETOOLONG);
216 goto done;
217 }
218
219 dent = kmalloc(UBIFS_MAX_DENT_NODE_SZ, GFP_NOFS);
220 if (!dent) {
221 inode = ERR_PTR(-ENOMEM);
222 goto done;
223 }
224
225 if (fname_name(&nm) == NULL) {
226 if (nm.hash & ~UBIFS_S_KEY_HASH_MASK)
227 goto done; /* ENOENT */
228 dent_key_init_hash(c, &key, dir->i_ino, nm.hash);
229 err = ubifs_tnc_lookup_dh(c, &key, dent, nm.minor_hash);
230 } else {
231 dent_key_init(c, &key, dir->i_ino, &nm);
232 err = ubifs_tnc_lookup_nm(c, &key, dent, &nm);
233 }
234
235 if (err) {
236 if (err == -ENOENT)
237 dbg_gen("not found");
238 else
239 inode = ERR_PTR(err);
240 goto done;
241 }
242
243 if (dbg_check_name(c, dent, &nm)) {
244 inode = ERR_PTR(-EINVAL);
245 goto done;
246 }
247
248 inode = ubifs_iget(dir->i_sb, le64_to_cpu(dent->inum));
249 if (IS_ERR(inode)) {
250 /*
251 * This should not happen. Probably the file-system needs
252 * checking.
253 */
254 err = PTR_ERR(inode);
255 ubifs_err(c, "dead directory entry '%pd', error %d",
256 dentry, err);
257 ubifs_ro_mode(c, err);
258 goto done;
259 }
260
261 if (IS_ENCRYPTED(dir) &&
262 (S_ISDIR(inode->i_mode) || S_ISLNK(inode->i_mode)) &&
263 !fscrypt_has_permitted_context(dir, inode)) {
264 ubifs_warn(c, "Inconsistent encryption contexts: %lu/%lu",
265 dir->i_ino, inode->i_ino);
266 iput(inode);
267 inode = ERR_PTR(-EPERM);
268 }
269
270 done:
271 kfree(dent);
272 fscrypt_free_filename(&nm);
273 return d_splice_alias(inode, dentry);
274 }
275
ubifs_prepare_create(struct inode * dir,struct dentry * dentry,struct fscrypt_name * nm)276 static int ubifs_prepare_create(struct inode *dir, struct dentry *dentry,
277 struct fscrypt_name *nm)
278 {
279 if (fscrypt_is_nokey_name(dentry))
280 return -ENOKEY;
281
282 return fscrypt_setup_filename(dir, &dentry->d_name, 0, nm);
283 }
284
ubifs_create(struct mnt_idmap * idmap,struct inode * dir,struct dentry * dentry,umode_t mode,bool excl)285 static int ubifs_create(struct mnt_idmap *idmap, struct inode *dir,
286 struct dentry *dentry, umode_t mode, bool excl)
287 {
288 struct inode *inode;
289 struct ubifs_info *c = dir->i_sb->s_fs_info;
290 struct ubifs_budget_req req = { .new_ino = 1, .new_dent = 1,
291 .dirtied_ino = 1 };
292 struct ubifs_inode *dir_ui = ubifs_inode(dir);
293 struct fscrypt_name nm;
294 int err, sz_change;
295
296 /*
297 * Budget request settings: new inode, new direntry, changing the
298 * parent directory inode.
299 */
300
301 dbg_gen("dent '%pd', mode %#hx in dir ino %lu",
302 dentry, mode, dir->i_ino);
303
304 err = ubifs_budget_space(c, &req);
305 if (err)
306 return err;
307
308 err = ubifs_prepare_create(dir, dentry, &nm);
309 if (err)
310 goto out_budg;
311
312 sz_change = CALC_DENT_SIZE(fname_len(&nm));
313
314 inode = ubifs_new_inode(c, dir, mode, false);
315 if (IS_ERR(inode)) {
316 err = PTR_ERR(inode);
317 goto out_fname;
318 }
319
320 err = ubifs_init_security(dir, inode, &dentry->d_name);
321 if (err)
322 goto out_inode;
323
324 mutex_lock(&dir_ui->ui_mutex);
325 dir->i_size += sz_change;
326 dir_ui->ui_size = dir->i_size;
327 inode_set_mtime_to_ts(dir,
328 inode_set_ctime_to_ts(dir, inode_get_ctime(inode)));
329 err = ubifs_jnl_update(c, dir, &nm, inode, 0, 0);
330 if (err)
331 goto out_cancel;
332 mutex_unlock(&dir_ui->ui_mutex);
333
334 ubifs_release_budget(c, &req);
335 fscrypt_free_filename(&nm);
336 insert_inode_hash(inode);
337 d_instantiate(dentry, inode);
338 return 0;
339
340 out_cancel:
341 dir->i_size -= sz_change;
342 dir_ui->ui_size = dir->i_size;
343 mutex_unlock(&dir_ui->ui_mutex);
344 out_inode:
345 make_bad_inode(inode);
346 iput(inode);
347 out_fname:
348 fscrypt_free_filename(&nm);
349 out_budg:
350 ubifs_release_budget(c, &req);
351 ubifs_err(c, "cannot create regular file, error %d", err);
352 return err;
353 }
354
create_whiteout(struct inode * dir,struct dentry * dentry)355 static struct inode *create_whiteout(struct inode *dir, struct dentry *dentry)
356 {
357 int err;
358 umode_t mode = S_IFCHR | WHITEOUT_MODE;
359 struct inode *inode;
360 struct ubifs_info *c = dir->i_sb->s_fs_info;
361
362 /*
363 * Create an inode('nlink = 1') for whiteout without updating journal,
364 * let ubifs_jnl_rename() store it on flash to complete rename whiteout
365 * atomically.
366 */
367
368 dbg_gen("dent '%pd', mode %#hx in dir ino %lu",
369 dentry, mode, dir->i_ino);
370
371 inode = ubifs_new_inode(c, dir, mode, false);
372 if (IS_ERR(inode)) {
373 err = PTR_ERR(inode);
374 goto out_free;
375 }
376
377 init_special_inode(inode, inode->i_mode, WHITEOUT_DEV);
378 ubifs_assert(c, inode->i_op == &ubifs_file_inode_operations);
379
380 err = ubifs_init_security(dir, inode, &dentry->d_name);
381 if (err)
382 goto out_inode;
383
384 /* The dir size is updated by do_rename. */
385 insert_inode_hash(inode);
386
387 return inode;
388
389 out_inode:
390 make_bad_inode(inode);
391 iput(inode);
392 out_free:
393 ubifs_err(c, "cannot create whiteout file, error %d", err);
394 return ERR_PTR(err);
395 }
396
397 /**
398 * lock_2_inodes - a wrapper for locking two UBIFS inodes.
399 * @inode1: first inode
400 * @inode2: second inode
401 *
402 * We do not implement any tricks to guarantee strict lock ordering, because
403 * VFS has already done it for us on the @i_mutex. So this is just a simple
404 * wrapper function.
405 */
lock_2_inodes(struct inode * inode1,struct inode * inode2)406 static void lock_2_inodes(struct inode *inode1, struct inode *inode2)
407 {
408 mutex_lock_nested(&ubifs_inode(inode1)->ui_mutex, WB_MUTEX_1);
409 mutex_lock_nested(&ubifs_inode(inode2)->ui_mutex, WB_MUTEX_2);
410 }
411
412 /**
413 * unlock_2_inodes - a wrapper for unlocking two UBIFS inodes.
414 * @inode1: first inode
415 * @inode2: second inode
416 */
unlock_2_inodes(struct inode * inode1,struct inode * inode2)417 static void unlock_2_inodes(struct inode *inode1, struct inode *inode2)
418 {
419 mutex_unlock(&ubifs_inode(inode2)->ui_mutex);
420 mutex_unlock(&ubifs_inode(inode1)->ui_mutex);
421 }
422
ubifs_tmpfile(struct mnt_idmap * idmap,struct inode * dir,struct file * file,umode_t mode)423 static int ubifs_tmpfile(struct mnt_idmap *idmap, struct inode *dir,
424 struct file *file, umode_t mode)
425 {
426 struct dentry *dentry = file->f_path.dentry;
427 struct inode *inode;
428 struct ubifs_info *c = dir->i_sb->s_fs_info;
429 struct ubifs_budget_req req = { .new_ino = 1, .new_dent = 1,
430 .dirtied_ino = 1};
431 struct ubifs_budget_req ino_req = { .dirtied_ino = 1 };
432 struct ubifs_inode *ui;
433 int err, instantiated = 0;
434 struct fscrypt_name nm;
435
436 /*
437 * Budget request settings: new inode, new direntry, changing the
438 * parent directory inode.
439 * Allocate budget separately for new dirtied inode, the budget will
440 * be released via writeback.
441 */
442
443 dbg_gen("dent '%pd', mode %#hx in dir ino %lu",
444 dentry, mode, dir->i_ino);
445
446 err = fscrypt_setup_filename(dir, &dentry->d_name, 0, &nm);
447 if (err)
448 return err;
449
450 err = ubifs_budget_space(c, &req);
451 if (err) {
452 fscrypt_free_filename(&nm);
453 return err;
454 }
455
456 err = ubifs_budget_space(c, &ino_req);
457 if (err) {
458 ubifs_release_budget(c, &req);
459 fscrypt_free_filename(&nm);
460 return err;
461 }
462
463 inode = ubifs_new_inode(c, dir, mode, false);
464 if (IS_ERR(inode)) {
465 err = PTR_ERR(inode);
466 goto out_budg;
467 }
468 ui = ubifs_inode(inode);
469
470 err = ubifs_init_security(dir, inode, &dentry->d_name);
471 if (err)
472 goto out_inode;
473
474 mutex_lock(&ui->ui_mutex);
475 insert_inode_hash(inode);
476 d_tmpfile(file, inode);
477 ubifs_assert(c, ui->dirty);
478
479 instantiated = 1;
480 mutex_unlock(&ui->ui_mutex);
481
482 lock_2_inodes(dir, inode);
483 err = ubifs_jnl_update(c, dir, &nm, inode, 1, 0);
484 if (err)
485 goto out_cancel;
486 unlock_2_inodes(dir, inode);
487
488 ubifs_release_budget(c, &req);
489 fscrypt_free_filename(&nm);
490
491 return finish_open_simple(file, 0);
492
493 out_cancel:
494 unlock_2_inodes(dir, inode);
495 out_inode:
496 make_bad_inode(inode);
497 if (!instantiated)
498 iput(inode);
499 out_budg:
500 ubifs_release_budget(c, &req);
501 if (!instantiated)
502 ubifs_release_budget(c, &ino_req);
503 fscrypt_free_filename(&nm);
504 ubifs_err(c, "cannot create temporary file, error %d", err);
505 return err;
506 }
507
508 /**
509 * vfs_dent_type - get VFS directory entry type.
510 * @type: UBIFS directory entry type
511 *
512 * This function converts UBIFS directory entry type into VFS directory entry
513 * type.
514 */
vfs_dent_type(uint8_t type)515 static unsigned int vfs_dent_type(uint8_t type)
516 {
517 switch (type) {
518 case UBIFS_ITYPE_REG:
519 return DT_REG;
520 case UBIFS_ITYPE_DIR:
521 return DT_DIR;
522 case UBIFS_ITYPE_LNK:
523 return DT_LNK;
524 case UBIFS_ITYPE_BLK:
525 return DT_BLK;
526 case UBIFS_ITYPE_CHR:
527 return DT_CHR;
528 case UBIFS_ITYPE_FIFO:
529 return DT_FIFO;
530 case UBIFS_ITYPE_SOCK:
531 return DT_SOCK;
532 default:
533 BUG();
534 }
535 return 0;
536 }
537
538 /*
539 * The classical Unix view for directory is that it is a linear array of
540 * (name, inode number) entries. Linux/VFS assumes this model as well.
541 * Particularly, 'readdir()' call wants us to return a directory entry offset
542 * which later may be used to continue 'readdir()'ing the directory or to
543 * 'seek()' to that specific direntry. Obviously UBIFS does not really fit this
544 * model because directory entries are identified by keys, which may collide.
545 *
546 * UBIFS uses directory entry hash value for directory offsets, so
547 * 'seekdir()'/'telldir()' may not always work because of possible key
548 * collisions. But UBIFS guarantees that consecutive 'readdir()' calls work
549 * properly by means of saving full directory entry name in the private field
550 * of the file description object.
551 *
552 * This means that UBIFS cannot support NFS which requires full
553 * 'seekdir()'/'telldir()' support.
554 */
ubifs_readdir(struct file * file,struct dir_context * ctx)555 static int ubifs_readdir(struct file *file, struct dir_context *ctx)
556 {
557 int fstr_real_len = 0, err = 0;
558 struct fscrypt_name nm;
559 struct fscrypt_str fstr = {0};
560 union ubifs_key key;
561 struct ubifs_dent_node *dent;
562 struct inode *dir = file_inode(file);
563 struct ubifs_info *c = dir->i_sb->s_fs_info;
564 bool encrypted = IS_ENCRYPTED(dir);
565
566 dbg_gen("dir ino %lu, f_pos %#llx", dir->i_ino, ctx->pos);
567
568 if (ctx->pos > UBIFS_S_KEY_HASH_MASK || ctx->pos == 2)
569 /*
570 * The directory was seek'ed to a senseless position or there
571 * are no more entries.
572 */
573 return 0;
574
575 if (encrypted) {
576 err = fscrypt_prepare_readdir(dir);
577 if (err)
578 return err;
579
580 err = fscrypt_fname_alloc_buffer(UBIFS_MAX_NLEN, &fstr);
581 if (err)
582 return err;
583
584 fstr_real_len = fstr.len;
585 }
586
587 if (file->f_version == 0) {
588 /*
589 * The file was seek'ed, which means that @file->private_data
590 * is now invalid. This may also be just the first
591 * 'ubifs_readdir()' invocation, in which case
592 * @file->private_data is NULL, and the below code is
593 * basically a no-op.
594 */
595 kfree(file->private_data);
596 file->private_data = NULL;
597 }
598
599 /*
600 * 'generic_file_llseek()' unconditionally sets @file->f_version to
601 * zero, and we use this for detecting whether the file was seek'ed.
602 */
603 file->f_version = 1;
604
605 /* File positions 0 and 1 correspond to "." and ".." */
606 if (ctx->pos < 2) {
607 ubifs_assert(c, !file->private_data);
608 if (!dir_emit_dots(file, ctx)) {
609 if (encrypted)
610 fscrypt_fname_free_buffer(&fstr);
611 return 0;
612 }
613
614 /* Find the first entry in TNC and save it */
615 lowest_dent_key(c, &key, dir->i_ino);
616 fname_len(&nm) = 0;
617 dent = ubifs_tnc_next_ent(c, &key, &nm);
618 if (IS_ERR(dent)) {
619 err = PTR_ERR(dent);
620 goto out;
621 }
622
623 ctx->pos = key_hash_flash(c, &dent->key);
624 file->private_data = dent;
625 }
626
627 dent = file->private_data;
628 if (!dent) {
629 /*
630 * The directory was seek'ed to and is now readdir'ed.
631 * Find the entry corresponding to @ctx->pos or the closest one.
632 */
633 dent_key_init_hash(c, &key, dir->i_ino, ctx->pos);
634 fname_len(&nm) = 0;
635 dent = ubifs_tnc_next_ent(c, &key, &nm);
636 if (IS_ERR(dent)) {
637 err = PTR_ERR(dent);
638 goto out;
639 }
640 ctx->pos = key_hash_flash(c, &dent->key);
641 file->private_data = dent;
642 }
643
644 while (1) {
645 dbg_gen("ino %llu, new f_pos %#x",
646 (unsigned long long)le64_to_cpu(dent->inum),
647 key_hash_flash(c, &dent->key));
648 ubifs_assert(c, le64_to_cpu(dent->ch.sqnum) >
649 ubifs_inode(dir)->creat_sqnum);
650
651 fname_len(&nm) = le16_to_cpu(dent->nlen);
652 fname_name(&nm) = dent->name;
653
654 if (encrypted) {
655 fstr.len = fstr_real_len;
656
657 err = fscrypt_fname_disk_to_usr(dir, key_hash_flash(c,
658 &dent->key),
659 le32_to_cpu(dent->cookie),
660 &nm.disk_name, &fstr);
661 if (err)
662 goto out;
663 } else {
664 fstr.len = fname_len(&nm);
665 fstr.name = fname_name(&nm);
666 }
667
668 if (!dir_emit(ctx, fstr.name, fstr.len,
669 le64_to_cpu(dent->inum),
670 vfs_dent_type(dent->type))) {
671 if (encrypted)
672 fscrypt_fname_free_buffer(&fstr);
673 return 0;
674 }
675
676 /* Switch to the next entry */
677 key_read(c, &dent->key, &key);
678 dent = ubifs_tnc_next_ent(c, &key, &nm);
679 if (IS_ERR(dent)) {
680 err = PTR_ERR(dent);
681 goto out;
682 }
683
684 kfree(file->private_data);
685 ctx->pos = key_hash_flash(c, &dent->key);
686 file->private_data = dent;
687 cond_resched();
688 }
689
690 out:
691 kfree(file->private_data);
692 file->private_data = NULL;
693
694 if (encrypted)
695 fscrypt_fname_free_buffer(&fstr);
696
697 if (err != -ENOENT)
698 ubifs_err(c, "cannot find next direntry, error %d", err);
699 else
700 /*
701 * -ENOENT is a non-fatal error in this context, the TNC uses
702 * it to indicate that the cursor moved past the current directory
703 * and readdir() has to stop.
704 */
705 err = 0;
706
707
708 /* 2 is a special value indicating that there are no more direntries */
709 ctx->pos = 2;
710 return err;
711 }
712
713 /* Free saved readdir() state when the directory is closed */
ubifs_dir_release(struct inode * dir,struct file * file)714 static int ubifs_dir_release(struct inode *dir, struct file *file)
715 {
716 kfree(file->private_data);
717 file->private_data = NULL;
718 return 0;
719 }
720
ubifs_link(struct dentry * old_dentry,struct inode * dir,struct dentry * dentry)721 static int ubifs_link(struct dentry *old_dentry, struct inode *dir,
722 struct dentry *dentry)
723 {
724 struct ubifs_info *c = dir->i_sb->s_fs_info;
725 struct inode *inode = d_inode(old_dentry);
726 struct ubifs_inode *ui = ubifs_inode(inode);
727 struct ubifs_inode *dir_ui = ubifs_inode(dir);
728 int err, sz_change;
729 struct ubifs_budget_req req = { .new_dent = 1, .dirtied_ino = 2,
730 .dirtied_ino_d = ALIGN(ui->data_len, 8) };
731 struct fscrypt_name nm;
732
733 /*
734 * Budget request settings: new direntry, changing the target inode,
735 * changing the parent inode.
736 */
737
738 dbg_gen("dent '%pd' to ino %lu (nlink %d) in dir ino %lu",
739 dentry, inode->i_ino,
740 inode->i_nlink, dir->i_ino);
741 ubifs_assert(c, inode_is_locked(dir));
742 ubifs_assert(c, inode_is_locked(inode));
743
744 err = fscrypt_prepare_link(old_dentry, dir, dentry);
745 if (err)
746 return err;
747
748 err = fscrypt_setup_filename(dir, &dentry->d_name, 0, &nm);
749 if (err)
750 return err;
751
752 sz_change = CALC_DENT_SIZE(fname_len(&nm));
753
754 err = dbg_check_synced_i_size(c, inode);
755 if (err)
756 goto out_fname;
757
758 err = ubifs_budget_space(c, &req);
759 if (err)
760 goto out_fname;
761
762 lock_2_inodes(dir, inode);
763
764 /* Handle O_TMPFILE corner case, it is allowed to link a O_TMPFILE. */
765 if (inode->i_nlink == 0)
766 ubifs_delete_orphan(c, inode->i_ino);
767
768 inc_nlink(inode);
769 ihold(inode);
770 inode_set_ctime_current(inode);
771 dir->i_size += sz_change;
772 dir_ui->ui_size = dir->i_size;
773 inode_set_mtime_to_ts(dir,
774 inode_set_ctime_to_ts(dir, inode_get_ctime(inode)));
775 err = ubifs_jnl_update(c, dir, &nm, inode, 0, 0);
776 if (err)
777 goto out_cancel;
778 unlock_2_inodes(dir, inode);
779
780 ubifs_release_budget(c, &req);
781 d_instantiate(dentry, inode);
782 fscrypt_free_filename(&nm);
783 return 0;
784
785 out_cancel:
786 dir->i_size -= sz_change;
787 dir_ui->ui_size = dir->i_size;
788 drop_nlink(inode);
789 if (inode->i_nlink == 0)
790 ubifs_add_orphan(c, inode->i_ino);
791 unlock_2_inodes(dir, inode);
792 ubifs_release_budget(c, &req);
793 iput(inode);
794 out_fname:
795 fscrypt_free_filename(&nm);
796 return err;
797 }
798
ubifs_unlink(struct inode * dir,struct dentry * dentry)799 static int ubifs_unlink(struct inode *dir, struct dentry *dentry)
800 {
801 struct ubifs_info *c = dir->i_sb->s_fs_info;
802 struct inode *inode = d_inode(dentry);
803 struct ubifs_inode *dir_ui = ubifs_inode(dir);
804 int err, sz_change, budgeted = 1;
805 struct ubifs_budget_req req = { .mod_dent = 1, .dirtied_ino = 2 };
806 unsigned int saved_nlink = inode->i_nlink;
807 struct fscrypt_name nm;
808
809 /*
810 * Budget request settings: deletion direntry, deletion inode (+1 for
811 * @dirtied_ino), changing the parent directory inode. If budgeting
812 * fails, go ahead anyway because we have extra space reserved for
813 * deletions.
814 */
815
816 dbg_gen("dent '%pd' from ino %lu (nlink %d) in dir ino %lu",
817 dentry, inode->i_ino,
818 inode->i_nlink, dir->i_ino);
819
820 err = fscrypt_setup_filename(dir, &dentry->d_name, 1, &nm);
821 if (err)
822 return err;
823
824 err = ubifs_purge_xattrs(inode);
825 if (err)
826 return err;
827
828 sz_change = CALC_DENT_SIZE(fname_len(&nm));
829
830 ubifs_assert(c, inode_is_locked(dir));
831 ubifs_assert(c, inode_is_locked(inode));
832 err = dbg_check_synced_i_size(c, inode);
833 if (err)
834 goto out_fname;
835
836 err = ubifs_budget_space(c, &req);
837 if (err) {
838 if (err != -ENOSPC)
839 goto out_fname;
840 budgeted = 0;
841 }
842
843 lock_2_inodes(dir, inode);
844 inode_set_ctime_current(inode);
845 drop_nlink(inode);
846 dir->i_size -= sz_change;
847 dir_ui->ui_size = dir->i_size;
848 inode_set_mtime_to_ts(dir,
849 inode_set_ctime_to_ts(dir, inode_get_ctime(inode)));
850 err = ubifs_jnl_update(c, dir, &nm, inode, 1, 0);
851 if (err)
852 goto out_cancel;
853 unlock_2_inodes(dir, inode);
854
855 if (budgeted)
856 ubifs_release_budget(c, &req);
857 else {
858 /* We've deleted something - clean the "no space" flags */
859 c->bi.nospace = c->bi.nospace_rp = 0;
860 smp_wmb();
861 }
862 fscrypt_free_filename(&nm);
863 return 0;
864
865 out_cancel:
866 dir->i_size += sz_change;
867 dir_ui->ui_size = dir->i_size;
868 set_nlink(inode, saved_nlink);
869 unlock_2_inodes(dir, inode);
870 if (budgeted)
871 ubifs_release_budget(c, &req);
872 out_fname:
873 fscrypt_free_filename(&nm);
874 return err;
875 }
876
877 /**
878 * ubifs_check_dir_empty - check if a directory is empty or not.
879 * @dir: VFS inode object of the directory to check
880 *
881 * This function checks if directory @dir is empty. Returns zero if the
882 * directory is empty, %-ENOTEMPTY if it is not, and other negative error codes
883 * in case of errors.
884 */
ubifs_check_dir_empty(struct inode * dir)885 int ubifs_check_dir_empty(struct inode *dir)
886 {
887 struct ubifs_info *c = dir->i_sb->s_fs_info;
888 struct fscrypt_name nm = { 0 };
889 struct ubifs_dent_node *dent;
890 union ubifs_key key;
891 int err;
892
893 lowest_dent_key(c, &key, dir->i_ino);
894 dent = ubifs_tnc_next_ent(c, &key, &nm);
895 if (IS_ERR(dent)) {
896 err = PTR_ERR(dent);
897 if (err == -ENOENT)
898 err = 0;
899 } else {
900 kfree(dent);
901 err = -ENOTEMPTY;
902 }
903 return err;
904 }
905
ubifs_rmdir(struct inode * dir,struct dentry * dentry)906 static int ubifs_rmdir(struct inode *dir, struct dentry *dentry)
907 {
908 struct ubifs_info *c = dir->i_sb->s_fs_info;
909 struct inode *inode = d_inode(dentry);
910 int err, sz_change, budgeted = 1;
911 struct ubifs_inode *dir_ui = ubifs_inode(dir);
912 struct ubifs_budget_req req = { .mod_dent = 1, .dirtied_ino = 2 };
913 struct fscrypt_name nm;
914
915 /*
916 * Budget request settings: deletion direntry, deletion inode and
917 * changing the parent inode. If budgeting fails, go ahead anyway
918 * because we have extra space reserved for deletions.
919 */
920
921 dbg_gen("directory '%pd', ino %lu in dir ino %lu", dentry,
922 inode->i_ino, dir->i_ino);
923 ubifs_assert(c, inode_is_locked(dir));
924 ubifs_assert(c, inode_is_locked(inode));
925 err = ubifs_check_dir_empty(d_inode(dentry));
926 if (err)
927 return err;
928
929 err = fscrypt_setup_filename(dir, &dentry->d_name, 1, &nm);
930 if (err)
931 return err;
932
933 err = ubifs_purge_xattrs(inode);
934 if (err)
935 return err;
936
937 sz_change = CALC_DENT_SIZE(fname_len(&nm));
938
939 err = ubifs_budget_space(c, &req);
940 if (err) {
941 if (err != -ENOSPC)
942 goto out_fname;
943 budgeted = 0;
944 }
945
946 lock_2_inodes(dir, inode);
947 inode_set_ctime_current(inode);
948 clear_nlink(inode);
949 drop_nlink(dir);
950 dir->i_size -= sz_change;
951 dir_ui->ui_size = dir->i_size;
952 inode_set_mtime_to_ts(dir,
953 inode_set_ctime_to_ts(dir, inode_get_ctime(inode)));
954 err = ubifs_jnl_update(c, dir, &nm, inode, 1, 0);
955 if (err)
956 goto out_cancel;
957 unlock_2_inodes(dir, inode);
958
959 if (budgeted)
960 ubifs_release_budget(c, &req);
961 else {
962 /* We've deleted something - clean the "no space" flags */
963 c->bi.nospace = c->bi.nospace_rp = 0;
964 smp_wmb();
965 }
966 fscrypt_free_filename(&nm);
967 return 0;
968
969 out_cancel:
970 dir->i_size += sz_change;
971 dir_ui->ui_size = dir->i_size;
972 inc_nlink(dir);
973 set_nlink(inode, 2);
974 unlock_2_inodes(dir, inode);
975 if (budgeted)
976 ubifs_release_budget(c, &req);
977 out_fname:
978 fscrypt_free_filename(&nm);
979 return err;
980 }
981
ubifs_mkdir(struct mnt_idmap * idmap,struct inode * dir,struct dentry * dentry,umode_t mode)982 static int ubifs_mkdir(struct mnt_idmap *idmap, struct inode *dir,
983 struct dentry *dentry, umode_t mode)
984 {
985 struct inode *inode;
986 struct ubifs_inode *dir_ui = ubifs_inode(dir);
987 struct ubifs_info *c = dir->i_sb->s_fs_info;
988 int err, sz_change;
989 struct ubifs_budget_req req = { .new_ino = 1, .new_dent = 1,
990 .dirtied_ino = 1};
991 struct fscrypt_name nm;
992
993 /*
994 * Budget request settings: new inode, new direntry and changing parent
995 * directory inode.
996 */
997
998 dbg_gen("dent '%pd', mode %#hx in dir ino %lu",
999 dentry, mode, dir->i_ino);
1000
1001 err = ubifs_budget_space(c, &req);
1002 if (err)
1003 return err;
1004
1005 err = ubifs_prepare_create(dir, dentry, &nm);
1006 if (err)
1007 goto out_budg;
1008
1009 sz_change = CALC_DENT_SIZE(fname_len(&nm));
1010
1011 inode = ubifs_new_inode(c, dir, S_IFDIR | mode, false);
1012 if (IS_ERR(inode)) {
1013 err = PTR_ERR(inode);
1014 goto out_fname;
1015 }
1016
1017 err = ubifs_init_security(dir, inode, &dentry->d_name);
1018 if (err)
1019 goto out_inode;
1020
1021 mutex_lock(&dir_ui->ui_mutex);
1022 insert_inode_hash(inode);
1023 inc_nlink(inode);
1024 inc_nlink(dir);
1025 dir->i_size += sz_change;
1026 dir_ui->ui_size = dir->i_size;
1027 inode_set_mtime_to_ts(dir,
1028 inode_set_ctime_to_ts(dir, inode_get_ctime(inode)));
1029 err = ubifs_jnl_update(c, dir, &nm, inode, 0, 0);
1030 if (err) {
1031 ubifs_err(c, "cannot create directory, error %d", err);
1032 goto out_cancel;
1033 }
1034 mutex_unlock(&dir_ui->ui_mutex);
1035
1036 ubifs_release_budget(c, &req);
1037 d_instantiate(dentry, inode);
1038 fscrypt_free_filename(&nm);
1039 return 0;
1040
1041 out_cancel:
1042 dir->i_size -= sz_change;
1043 dir_ui->ui_size = dir->i_size;
1044 drop_nlink(dir);
1045 mutex_unlock(&dir_ui->ui_mutex);
1046 out_inode:
1047 make_bad_inode(inode);
1048 iput(inode);
1049 out_fname:
1050 fscrypt_free_filename(&nm);
1051 out_budg:
1052 ubifs_release_budget(c, &req);
1053 return err;
1054 }
1055
ubifs_mknod(struct mnt_idmap * idmap,struct inode * dir,struct dentry * dentry,umode_t mode,dev_t rdev)1056 static int ubifs_mknod(struct mnt_idmap *idmap, struct inode *dir,
1057 struct dentry *dentry, umode_t mode, dev_t rdev)
1058 {
1059 struct inode *inode;
1060 struct ubifs_inode *ui;
1061 struct ubifs_inode *dir_ui = ubifs_inode(dir);
1062 struct ubifs_info *c = dir->i_sb->s_fs_info;
1063 union ubifs_dev_desc *dev = NULL;
1064 int sz_change;
1065 int err, devlen = 0;
1066 struct ubifs_budget_req req = { .new_ino = 1, .new_dent = 1,
1067 .dirtied_ino = 1 };
1068 struct fscrypt_name nm;
1069
1070 /*
1071 * Budget request settings: new inode, new direntry and changing parent
1072 * directory inode.
1073 */
1074
1075 dbg_gen("dent '%pd' in dir ino %lu", dentry, dir->i_ino);
1076
1077 if (S_ISBLK(mode) || S_ISCHR(mode)) {
1078 dev = kmalloc(sizeof(union ubifs_dev_desc), GFP_NOFS);
1079 if (!dev)
1080 return -ENOMEM;
1081 devlen = ubifs_encode_dev(dev, rdev);
1082 }
1083
1084 req.new_ino_d = ALIGN(devlen, 8);
1085 err = ubifs_budget_space(c, &req);
1086 if (err) {
1087 kfree(dev);
1088 return err;
1089 }
1090
1091 err = ubifs_prepare_create(dir, dentry, &nm);
1092 if (err) {
1093 kfree(dev);
1094 goto out_budg;
1095 }
1096
1097 sz_change = CALC_DENT_SIZE(fname_len(&nm));
1098
1099 inode = ubifs_new_inode(c, dir, mode, false);
1100 if (IS_ERR(inode)) {
1101 kfree(dev);
1102 err = PTR_ERR(inode);
1103 goto out_fname;
1104 }
1105
1106 init_special_inode(inode, inode->i_mode, rdev);
1107 inode->i_size = ubifs_inode(inode)->ui_size = devlen;
1108 ui = ubifs_inode(inode);
1109 ui->data = dev;
1110 ui->data_len = devlen;
1111
1112 err = ubifs_init_security(dir, inode, &dentry->d_name);
1113 if (err)
1114 goto out_inode;
1115
1116 mutex_lock(&dir_ui->ui_mutex);
1117 dir->i_size += sz_change;
1118 dir_ui->ui_size = dir->i_size;
1119 inode_set_mtime_to_ts(dir,
1120 inode_set_ctime_to_ts(dir, inode_get_ctime(inode)));
1121 err = ubifs_jnl_update(c, dir, &nm, inode, 0, 0);
1122 if (err)
1123 goto out_cancel;
1124 mutex_unlock(&dir_ui->ui_mutex);
1125
1126 ubifs_release_budget(c, &req);
1127 insert_inode_hash(inode);
1128 d_instantiate(dentry, inode);
1129 fscrypt_free_filename(&nm);
1130 return 0;
1131
1132 out_cancel:
1133 dir->i_size -= sz_change;
1134 dir_ui->ui_size = dir->i_size;
1135 mutex_unlock(&dir_ui->ui_mutex);
1136 out_inode:
1137 make_bad_inode(inode);
1138 iput(inode);
1139 out_fname:
1140 fscrypt_free_filename(&nm);
1141 out_budg:
1142 ubifs_release_budget(c, &req);
1143 return err;
1144 }
1145
ubifs_symlink(struct mnt_idmap * idmap,struct inode * dir,struct dentry * dentry,const char * symname)1146 static int ubifs_symlink(struct mnt_idmap *idmap, struct inode *dir,
1147 struct dentry *dentry, const char *symname)
1148 {
1149 struct inode *inode;
1150 struct ubifs_inode *ui;
1151 struct ubifs_inode *dir_ui = ubifs_inode(dir);
1152 struct ubifs_info *c = dir->i_sb->s_fs_info;
1153 int err, sz_change, len = strlen(symname);
1154 struct fscrypt_str disk_link;
1155 struct ubifs_budget_req req = { .new_ino = 1, .new_dent = 1,
1156 .dirtied_ino = 1 };
1157 struct fscrypt_name nm;
1158
1159 dbg_gen("dent '%pd', target '%s' in dir ino %lu", dentry,
1160 symname, dir->i_ino);
1161
1162 err = fscrypt_prepare_symlink(dir, symname, len, UBIFS_MAX_INO_DATA,
1163 &disk_link);
1164 if (err)
1165 return err;
1166
1167 /*
1168 * Budget request settings: new inode, new direntry and changing parent
1169 * directory inode.
1170 */
1171 req.new_ino_d = ALIGN(disk_link.len - 1, 8);
1172 err = ubifs_budget_space(c, &req);
1173 if (err)
1174 return err;
1175
1176 err = ubifs_prepare_create(dir, dentry, &nm);
1177 if (err)
1178 goto out_budg;
1179
1180 sz_change = CALC_DENT_SIZE(fname_len(&nm));
1181
1182 inode = ubifs_new_inode(c, dir, S_IFLNK | S_IRWXUGO, false);
1183 if (IS_ERR(inode)) {
1184 err = PTR_ERR(inode);
1185 goto out_fname;
1186 }
1187
1188 ui = ubifs_inode(inode);
1189 ui->data = kmalloc(disk_link.len, GFP_NOFS);
1190 if (!ui->data) {
1191 err = -ENOMEM;
1192 goto out_inode;
1193 }
1194
1195 if (IS_ENCRYPTED(inode)) {
1196 disk_link.name = ui->data; /* encrypt directly into ui->data */
1197 err = fscrypt_encrypt_symlink(inode, symname, len, &disk_link);
1198 if (err)
1199 goto out_inode;
1200 } else {
1201 memcpy(ui->data, disk_link.name, disk_link.len);
1202 inode->i_link = ui->data;
1203 }
1204
1205 /*
1206 * The terminating zero byte is not written to the flash media and it
1207 * is put just to make later in-memory string processing simpler. Thus,
1208 * data length is @disk_link.len - 1, not @disk_link.len.
1209 */
1210 ui->data_len = disk_link.len - 1;
1211 inode->i_size = ubifs_inode(inode)->ui_size = disk_link.len - 1;
1212
1213 err = ubifs_init_security(dir, inode, &dentry->d_name);
1214 if (err)
1215 goto out_inode;
1216
1217 mutex_lock(&dir_ui->ui_mutex);
1218 dir->i_size += sz_change;
1219 dir_ui->ui_size = dir->i_size;
1220 inode_set_mtime_to_ts(dir,
1221 inode_set_ctime_to_ts(dir, inode_get_ctime(inode)));
1222 err = ubifs_jnl_update(c, dir, &nm, inode, 0, 0);
1223 if (err)
1224 goto out_cancel;
1225 mutex_unlock(&dir_ui->ui_mutex);
1226
1227 insert_inode_hash(inode);
1228 d_instantiate(dentry, inode);
1229 err = 0;
1230 goto out_fname;
1231
1232 out_cancel:
1233 dir->i_size -= sz_change;
1234 dir_ui->ui_size = dir->i_size;
1235 mutex_unlock(&dir_ui->ui_mutex);
1236 out_inode:
1237 /* Free inode->i_link before inode is marked as bad. */
1238 fscrypt_free_inode(inode);
1239 make_bad_inode(inode);
1240 iput(inode);
1241 out_fname:
1242 fscrypt_free_filename(&nm);
1243 out_budg:
1244 ubifs_release_budget(c, &req);
1245 return err;
1246 }
1247
1248 /**
1249 * lock_4_inodes - a wrapper for locking three UBIFS inodes.
1250 * @inode1: first inode
1251 * @inode2: second inode
1252 * @inode3: third inode
1253 * @inode4: fourth inode
1254 *
1255 * This function is used for 'ubifs_rename()' and @inode1 may be the same as
1256 * @inode2 whereas @inode3 and @inode4 may be %NULL.
1257 *
1258 * We do not implement any tricks to guarantee strict lock ordering, because
1259 * VFS has already done it for us on the @i_mutex. So this is just a simple
1260 * wrapper function.
1261 */
lock_4_inodes(struct inode * inode1,struct inode * inode2,struct inode * inode3,struct inode * inode4)1262 static void lock_4_inodes(struct inode *inode1, struct inode *inode2,
1263 struct inode *inode3, struct inode *inode4)
1264 {
1265 mutex_lock_nested(&ubifs_inode(inode1)->ui_mutex, WB_MUTEX_1);
1266 if (inode2 != inode1)
1267 mutex_lock_nested(&ubifs_inode(inode2)->ui_mutex, WB_MUTEX_2);
1268 if (inode3)
1269 mutex_lock_nested(&ubifs_inode(inode3)->ui_mutex, WB_MUTEX_3);
1270 if (inode4)
1271 mutex_lock_nested(&ubifs_inode(inode4)->ui_mutex, WB_MUTEX_4);
1272 }
1273
1274 /**
1275 * unlock_4_inodes - a wrapper for unlocking three UBIFS inodes for rename.
1276 * @inode1: first inode
1277 * @inode2: second inode
1278 * @inode3: third inode
1279 * @inode4: fourth inode
1280 */
unlock_4_inodes(struct inode * inode1,struct inode * inode2,struct inode * inode3,struct inode * inode4)1281 static void unlock_4_inodes(struct inode *inode1, struct inode *inode2,
1282 struct inode *inode3, struct inode *inode4)
1283 {
1284 if (inode4)
1285 mutex_unlock(&ubifs_inode(inode4)->ui_mutex);
1286 if (inode3)
1287 mutex_unlock(&ubifs_inode(inode3)->ui_mutex);
1288 if (inode1 != inode2)
1289 mutex_unlock(&ubifs_inode(inode2)->ui_mutex);
1290 mutex_unlock(&ubifs_inode(inode1)->ui_mutex);
1291 }
1292
do_rename(struct inode * old_dir,struct dentry * old_dentry,struct inode * new_dir,struct dentry * new_dentry,unsigned int flags)1293 static int do_rename(struct inode *old_dir, struct dentry *old_dentry,
1294 struct inode *new_dir, struct dentry *new_dentry,
1295 unsigned int flags)
1296 {
1297 struct ubifs_info *c = old_dir->i_sb->s_fs_info;
1298 struct inode *old_inode = d_inode(old_dentry);
1299 struct inode *new_inode = d_inode(new_dentry);
1300 struct inode *whiteout = NULL;
1301 struct ubifs_inode *old_inode_ui = ubifs_inode(old_inode);
1302 struct ubifs_inode *whiteout_ui = NULL;
1303 int err, release, sync = 0, move = (new_dir != old_dir);
1304 int is_dir = S_ISDIR(old_inode->i_mode);
1305 int unlink = !!new_inode, new_sz, old_sz;
1306 struct ubifs_budget_req req = { .new_dent = 1, .mod_dent = 1,
1307 .dirtied_ino = 3 };
1308 struct ubifs_budget_req ino_req = { .dirtied_ino = 1,
1309 .dirtied_ino_d = ALIGN(old_inode_ui->data_len, 8) };
1310 struct ubifs_budget_req wht_req;
1311 unsigned int saved_nlink;
1312 struct fscrypt_name old_nm, new_nm;
1313
1314 /*
1315 * Budget request settings:
1316 * req: deletion direntry, new direntry, removing the old inode,
1317 * and changing old and new parent directory inodes.
1318 *
1319 * wht_req: new whiteout inode for RENAME_WHITEOUT.
1320 *
1321 * ino_req: marks the target inode as dirty and does not write it.
1322 */
1323
1324 dbg_gen("dent '%pd' ino %lu in dir ino %lu to dent '%pd' in dir ino %lu flags 0x%x",
1325 old_dentry, old_inode->i_ino, old_dir->i_ino,
1326 new_dentry, new_dir->i_ino, flags);
1327
1328 if (unlink) {
1329 ubifs_assert(c, inode_is_locked(new_inode));
1330
1331 /* Budget for old inode's data when its nlink > 1. */
1332 req.dirtied_ino_d = ALIGN(ubifs_inode(new_inode)->data_len, 8);
1333 err = ubifs_purge_xattrs(new_inode);
1334 if (err)
1335 return err;
1336 }
1337
1338 if (unlink && is_dir) {
1339 err = ubifs_check_dir_empty(new_inode);
1340 if (err)
1341 return err;
1342 }
1343
1344 err = fscrypt_setup_filename(old_dir, &old_dentry->d_name, 0, &old_nm);
1345 if (err)
1346 return err;
1347
1348 err = fscrypt_setup_filename(new_dir, &new_dentry->d_name, 0, &new_nm);
1349 if (err) {
1350 fscrypt_free_filename(&old_nm);
1351 return err;
1352 }
1353
1354 new_sz = CALC_DENT_SIZE(fname_len(&new_nm));
1355 old_sz = CALC_DENT_SIZE(fname_len(&old_nm));
1356
1357 err = ubifs_budget_space(c, &req);
1358 if (err) {
1359 fscrypt_free_filename(&old_nm);
1360 fscrypt_free_filename(&new_nm);
1361 return err;
1362 }
1363 err = ubifs_budget_space(c, &ino_req);
1364 if (err) {
1365 fscrypt_free_filename(&old_nm);
1366 fscrypt_free_filename(&new_nm);
1367 ubifs_release_budget(c, &req);
1368 return err;
1369 }
1370
1371 if (flags & RENAME_WHITEOUT) {
1372 union ubifs_dev_desc *dev = NULL;
1373
1374 dev = kmalloc(sizeof(union ubifs_dev_desc), GFP_NOFS);
1375 if (!dev) {
1376 err = -ENOMEM;
1377 goto out_release;
1378 }
1379
1380 /*
1381 * The whiteout inode without dentry is pinned in memory,
1382 * umount won't happen during rename process because we
1383 * got parent dentry.
1384 */
1385 whiteout = create_whiteout(old_dir, old_dentry);
1386 if (IS_ERR(whiteout)) {
1387 err = PTR_ERR(whiteout);
1388 kfree(dev);
1389 goto out_release;
1390 }
1391
1392 whiteout_ui = ubifs_inode(whiteout);
1393 whiteout_ui->data = dev;
1394 whiteout_ui->data_len = ubifs_encode_dev(dev, MKDEV(0, 0));
1395 ubifs_assert(c, !whiteout_ui->dirty);
1396
1397 memset(&wht_req, 0, sizeof(struct ubifs_budget_req));
1398 wht_req.new_ino = 1;
1399 wht_req.new_ino_d = ALIGN(whiteout_ui->data_len, 8);
1400 /*
1401 * To avoid deadlock between space budget (holds ui_mutex and
1402 * waits wb work) and writeback work(waits ui_mutex), do space
1403 * budget before ubifs inodes locked.
1404 */
1405 err = ubifs_budget_space(c, &wht_req);
1406 if (err) {
1407 /*
1408 * Whiteout inode can not be written on flash by
1409 * ubifs_jnl_write_inode(), because it's neither
1410 * dirty nor zero-nlink.
1411 */
1412 iput(whiteout);
1413 goto out_release;
1414 }
1415
1416 /* Add the old_dentry size to the old_dir size. */
1417 old_sz -= CALC_DENT_SIZE(fname_len(&old_nm));
1418 }
1419
1420 lock_4_inodes(old_dir, new_dir, new_inode, whiteout);
1421
1422 /*
1423 * Like most other Unix systems, set the @i_ctime for inodes on a
1424 * rename.
1425 */
1426 simple_rename_timestamp(old_dir, old_dentry, new_dir, new_dentry);
1427
1428 /* We must adjust parent link count when renaming directories */
1429 if (is_dir) {
1430 if (move) {
1431 /*
1432 * @old_dir loses a link because we are moving
1433 * @old_inode to a different directory.
1434 */
1435 drop_nlink(old_dir);
1436 /*
1437 * @new_dir only gains a link if we are not also
1438 * overwriting an existing directory.
1439 */
1440 if (!unlink)
1441 inc_nlink(new_dir);
1442 } else {
1443 /*
1444 * @old_inode is not moving to a different directory,
1445 * but @old_dir still loses a link if we are
1446 * overwriting an existing directory.
1447 */
1448 if (unlink)
1449 drop_nlink(old_dir);
1450 }
1451 }
1452
1453 old_dir->i_size -= old_sz;
1454 ubifs_inode(old_dir)->ui_size = old_dir->i_size;
1455
1456 /*
1457 * And finally, if we unlinked a direntry which happened to have the
1458 * same name as the moved direntry, we have to decrement @i_nlink of
1459 * the unlinked inode.
1460 */
1461 if (unlink) {
1462 /*
1463 * Directories cannot have hard-links, so if this is a
1464 * directory, just clear @i_nlink.
1465 */
1466 saved_nlink = new_inode->i_nlink;
1467 if (is_dir)
1468 clear_nlink(new_inode);
1469 else
1470 drop_nlink(new_inode);
1471 } else {
1472 new_dir->i_size += new_sz;
1473 ubifs_inode(new_dir)->ui_size = new_dir->i_size;
1474 }
1475
1476 /*
1477 * Do not ask 'ubifs_jnl_rename()' to flush write-buffer if @old_inode
1478 * is dirty, because this will be done later on at the end of
1479 * 'ubifs_rename()'.
1480 */
1481 if (IS_SYNC(old_inode)) {
1482 sync = IS_DIRSYNC(old_dir) || IS_DIRSYNC(new_dir);
1483 if (unlink && IS_SYNC(new_inode))
1484 sync = 1;
1485 /*
1486 * S_SYNC flag of whiteout inherits from the old_dir, and we
1487 * have already checked the old dir inode. So there is no need
1488 * to check whiteout.
1489 */
1490 }
1491
1492 err = ubifs_jnl_rename(c, old_dir, old_inode, &old_nm, new_dir,
1493 new_inode, &new_nm, whiteout, sync);
1494 if (err)
1495 goto out_cancel;
1496
1497 unlock_4_inodes(old_dir, new_dir, new_inode, whiteout);
1498 ubifs_release_budget(c, &req);
1499
1500 if (whiteout) {
1501 ubifs_release_budget(c, &wht_req);
1502 iput(whiteout);
1503 }
1504
1505 mutex_lock(&old_inode_ui->ui_mutex);
1506 release = old_inode_ui->dirty;
1507 mark_inode_dirty_sync(old_inode);
1508 mutex_unlock(&old_inode_ui->ui_mutex);
1509
1510 if (release)
1511 ubifs_release_budget(c, &ino_req);
1512 if (IS_SYNC(old_inode))
1513 /*
1514 * Rename finished here. Although old inode cannot be updated
1515 * on flash, old ctime is not a big problem, don't return err
1516 * code to userspace.
1517 */
1518 old_inode->i_sb->s_op->write_inode(old_inode, NULL);
1519
1520 fscrypt_free_filename(&old_nm);
1521 fscrypt_free_filename(&new_nm);
1522 return 0;
1523
1524 out_cancel:
1525 if (unlink) {
1526 set_nlink(new_inode, saved_nlink);
1527 } else {
1528 new_dir->i_size -= new_sz;
1529 ubifs_inode(new_dir)->ui_size = new_dir->i_size;
1530 }
1531 old_dir->i_size += old_sz;
1532 ubifs_inode(old_dir)->ui_size = old_dir->i_size;
1533 if (is_dir) {
1534 if (move) {
1535 inc_nlink(old_dir);
1536 if (!unlink)
1537 drop_nlink(new_dir);
1538 } else {
1539 if (unlink)
1540 inc_nlink(old_dir);
1541 }
1542 }
1543 unlock_4_inodes(old_dir, new_dir, new_inode, whiteout);
1544 if (whiteout) {
1545 ubifs_release_budget(c, &wht_req);
1546 iput(whiteout);
1547 }
1548 out_release:
1549 ubifs_release_budget(c, &ino_req);
1550 ubifs_release_budget(c, &req);
1551 fscrypt_free_filename(&old_nm);
1552 fscrypt_free_filename(&new_nm);
1553 return err;
1554 }
1555
ubifs_xrename(struct inode * old_dir,struct dentry * old_dentry,struct inode * new_dir,struct dentry * new_dentry)1556 static int ubifs_xrename(struct inode *old_dir, struct dentry *old_dentry,
1557 struct inode *new_dir, struct dentry *new_dentry)
1558 {
1559 struct ubifs_info *c = old_dir->i_sb->s_fs_info;
1560 struct ubifs_budget_req req = { .new_dent = 1, .mod_dent = 1,
1561 .dirtied_ino = 2 };
1562 int sync = IS_DIRSYNC(old_dir) || IS_DIRSYNC(new_dir);
1563 struct inode *fst_inode = d_inode(old_dentry);
1564 struct inode *snd_inode = d_inode(new_dentry);
1565 int err;
1566 struct fscrypt_name fst_nm, snd_nm;
1567
1568 ubifs_assert(c, fst_inode && snd_inode);
1569
1570 /*
1571 * Budget request settings: changing two direntries, changing the two
1572 * parent directory inodes.
1573 */
1574
1575 dbg_gen("dent '%pd' ino %lu in dir ino %lu exchange dent '%pd' ino %lu in dir ino %lu",
1576 old_dentry, fst_inode->i_ino, old_dir->i_ino,
1577 new_dentry, snd_inode->i_ino, new_dir->i_ino);
1578
1579 err = fscrypt_setup_filename(old_dir, &old_dentry->d_name, 0, &fst_nm);
1580 if (err)
1581 return err;
1582
1583 err = fscrypt_setup_filename(new_dir, &new_dentry->d_name, 0, &snd_nm);
1584 if (err) {
1585 fscrypt_free_filename(&fst_nm);
1586 return err;
1587 }
1588
1589 err = ubifs_budget_space(c, &req);
1590 if (err)
1591 goto out;
1592
1593 lock_4_inodes(old_dir, new_dir, NULL, NULL);
1594
1595 simple_rename_timestamp(old_dir, old_dentry, new_dir, new_dentry);
1596
1597 if (old_dir != new_dir) {
1598 if (S_ISDIR(fst_inode->i_mode) && !S_ISDIR(snd_inode->i_mode)) {
1599 inc_nlink(new_dir);
1600 drop_nlink(old_dir);
1601 }
1602 else if (!S_ISDIR(fst_inode->i_mode) && S_ISDIR(snd_inode->i_mode)) {
1603 drop_nlink(new_dir);
1604 inc_nlink(old_dir);
1605 }
1606 }
1607
1608 err = ubifs_jnl_xrename(c, old_dir, fst_inode, &fst_nm, new_dir,
1609 snd_inode, &snd_nm, sync);
1610
1611 unlock_4_inodes(old_dir, new_dir, NULL, NULL);
1612 ubifs_release_budget(c, &req);
1613
1614 out:
1615 fscrypt_free_filename(&fst_nm);
1616 fscrypt_free_filename(&snd_nm);
1617 return err;
1618 }
1619
ubifs_rename(struct mnt_idmap * idmap,struct inode * old_dir,struct dentry * old_dentry,struct inode * new_dir,struct dentry * new_dentry,unsigned int flags)1620 static int ubifs_rename(struct mnt_idmap *idmap,
1621 struct inode *old_dir, struct dentry *old_dentry,
1622 struct inode *new_dir, struct dentry *new_dentry,
1623 unsigned int flags)
1624 {
1625 int err;
1626 struct ubifs_info *c = old_dir->i_sb->s_fs_info;
1627
1628 if (flags & ~(RENAME_NOREPLACE | RENAME_WHITEOUT | RENAME_EXCHANGE))
1629 return -EINVAL;
1630
1631 ubifs_assert(c, inode_is_locked(old_dir));
1632 ubifs_assert(c, inode_is_locked(new_dir));
1633
1634 err = fscrypt_prepare_rename(old_dir, old_dentry, new_dir, new_dentry,
1635 flags);
1636 if (err)
1637 return err;
1638
1639 if (flags & RENAME_EXCHANGE)
1640 return ubifs_xrename(old_dir, old_dentry, new_dir, new_dentry);
1641
1642 return do_rename(old_dir, old_dentry, new_dir, new_dentry, flags);
1643 }
1644
ubifs_getattr(struct mnt_idmap * idmap,const struct path * path,struct kstat * stat,u32 request_mask,unsigned int flags)1645 int ubifs_getattr(struct mnt_idmap *idmap, const struct path *path,
1646 struct kstat *stat, u32 request_mask, unsigned int flags)
1647 {
1648 loff_t size;
1649 struct inode *inode = d_inode(path->dentry);
1650 struct ubifs_inode *ui = ubifs_inode(inode);
1651
1652 mutex_lock(&ui->ui_mutex);
1653
1654 if (ui->flags & UBIFS_APPEND_FL)
1655 stat->attributes |= STATX_ATTR_APPEND;
1656 if (ui->flags & UBIFS_COMPR_FL)
1657 stat->attributes |= STATX_ATTR_COMPRESSED;
1658 if (ui->flags & UBIFS_CRYPT_FL)
1659 stat->attributes |= STATX_ATTR_ENCRYPTED;
1660 if (ui->flags & UBIFS_IMMUTABLE_FL)
1661 stat->attributes |= STATX_ATTR_IMMUTABLE;
1662
1663 stat->attributes_mask |= (STATX_ATTR_APPEND |
1664 STATX_ATTR_COMPRESSED |
1665 STATX_ATTR_ENCRYPTED |
1666 STATX_ATTR_IMMUTABLE);
1667
1668 generic_fillattr(&nop_mnt_idmap, request_mask, inode, stat);
1669 stat->blksize = UBIFS_BLOCK_SIZE;
1670 stat->size = ui->ui_size;
1671
1672 /*
1673 * Unfortunately, the 'stat()' system call was designed for block
1674 * device based file systems, and it is not appropriate for UBIFS,
1675 * because UBIFS does not have notion of "block". For example, it is
1676 * difficult to tell how many block a directory takes - it actually
1677 * takes less than 300 bytes, but we have to round it to block size,
1678 * which introduces large mistake. This makes utilities like 'du' to
1679 * report completely senseless numbers. This is the reason why UBIFS
1680 * goes the same way as JFFS2 - it reports zero blocks for everything
1681 * but regular files, which makes more sense than reporting completely
1682 * wrong sizes.
1683 */
1684 if (S_ISREG(inode->i_mode)) {
1685 size = ui->xattr_size;
1686 size += stat->size;
1687 size = ALIGN(size, UBIFS_BLOCK_SIZE);
1688 /*
1689 * Note, user-space expects 512-byte blocks count irrespectively
1690 * of what was reported in @stat->size.
1691 */
1692 stat->blocks = size >> 9;
1693 } else
1694 stat->blocks = 0;
1695 mutex_unlock(&ui->ui_mutex);
1696 return 0;
1697 }
1698
1699 const struct inode_operations ubifs_dir_inode_operations = {
1700 .lookup = ubifs_lookup,
1701 .create = ubifs_create,
1702 .link = ubifs_link,
1703 .symlink = ubifs_symlink,
1704 .unlink = ubifs_unlink,
1705 .mkdir = ubifs_mkdir,
1706 .rmdir = ubifs_rmdir,
1707 .mknod = ubifs_mknod,
1708 .rename = ubifs_rename,
1709 .setattr = ubifs_setattr,
1710 .getattr = ubifs_getattr,
1711 .listxattr = ubifs_listxattr,
1712 .update_time = ubifs_update_time,
1713 .tmpfile = ubifs_tmpfile,
1714 .fileattr_get = ubifs_fileattr_get,
1715 .fileattr_set = ubifs_fileattr_set,
1716 };
1717
1718 const struct file_operations ubifs_dir_operations = {
1719 .llseek = generic_file_llseek,
1720 .release = ubifs_dir_release,
1721 .read = generic_read_dir,
1722 .iterate_shared = ubifs_readdir,
1723 .fsync = ubifs_fsync,
1724 .unlocked_ioctl = ubifs_ioctl,
1725 #ifdef CONFIG_COMPAT
1726 .compat_ioctl = ubifs_compat_ioctl,
1727 #endif
1728 };
1729