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 */
47static int inherit_flags(const struct inode *dir, umode_t mode)
48{
49 int flags;
50 const struct ubifs_inode *ui = ubifs_inode(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 */
77struct 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(sb: c->vfs_sb);
86 ui = ubifs_inode(inode);
87 if (!inode)
88 return ERR_PTR(error: -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(idmap: &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, encrypt_ret: &encrypted);
104 if (err) {
105 ubifs_err(c, fmt: "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(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(lock: &c->cnt_lock);
147 ubifs_err(c, fmt: "out of inode numbers");
148 err = -EINVAL;
149 goto out_iput;
150 }
151 ubifs_warn(c, fmt: "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(lock: &c->cnt_lock);
165
166 if (encrypted) {
167 err = fscrypt_set_context(inode, NULL);
168 if (err) {
169 ubifs_err(c, fmt: "fscrypt_set_context failed: %i", err);
170 goto out_iput;
171 }
172 }
173
174 return inode;
175
176out_iput:
177 make_bad_inode(inode);
178 iput(inode);
179 return ERR_PTR(error: err);
180}
181
182static 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(p: dent->name, fname_name(nm), fname_len(nm)))
191 return -EINVAL;
192 return 0;
193}
194
195static 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, fname: &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(error: err);
213
214 if (fname_len(&nm) > UBIFS_MAX_NLEN) {
215 inode = ERR_PTR(error: -ENAMETOOLONG);
216 goto done;
217 }
218
219 dent = kmalloc(UBIFS_MAX_DENT_NODE_SZ, GFP_NOFS);
220 if (!dent) {
221 inode = ERR_PTR(error: -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: &key, inum: dir->i_ino, hash: nm.hash);
229 err = ubifs_tnc_lookup_dh(c, key: &key, node: dent, secondary_hash: nm.minor_hash);
230 } else {
231 dent_key_init(c, key: &key, inum: dir->i_ino, nm: &nm);
232 err = ubifs_tnc_lookup_nm(c, key: &key, node: dent, nm: &nm);
233 }
234
235 if (err) {
236 if (err == -ENOENT)
237 dbg_gen("not found");
238 else
239 inode = ERR_PTR(error: err);
240 goto done;
241 }
242
243 if (dbg_check_name(c, dent, nm: &nm)) {
244 inode = ERR_PTR(error: -EINVAL);
245 goto done;
246 }
247
248 inode = ubifs_iget(sb: dir->i_sb, le64_to_cpu(dent->inum));
249 if (IS_ERR(ptr: inode)) {
250 /*
251 * This should not happen. Probably the file-system needs
252 * checking.
253 */
254 err = PTR_ERR(ptr: inode);
255 ubifs_err(c, fmt: "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(parent: dir, child: inode)) {
264 ubifs_warn(c, fmt: "Inconsistent encryption contexts: %lu/%lu",
265 dir->i_ino, inode->i_ino);
266 iput(inode);
267 inode = ERR_PTR(error: -EPERM);
268 }
269
270done:
271 kfree(objp: dent);
272 fscrypt_free_filename(fname: &nm);
273 return d_splice_alias(inode, dentry);
274}
275
276static 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(inode: dir, iname: &dentry->d_name, lookup: 0, fname: nm);
283}
284
285static 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(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: &req);
305 if (err)
306 return err;
307
308 err = ubifs_prepare_create(dir, dentry, nm: &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, is_xattr: false);
315 if (IS_ERR(ptr: inode)) {
316 err = PTR_ERR(ptr: inode);
317 goto out_fname;
318 }
319
320 err = ubifs_init_security(dentry: dir, inode, qstr: &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(inode: dir,
328 ts: inode_set_ctime_to_ts(inode: dir, ts: inode_get_ctime(inode)));
329 err = ubifs_jnl_update(c, dir, nm: &nm, inode, deletion: 0, xent: 0);
330 if (err)
331 goto out_cancel;
332 mutex_unlock(lock: &dir_ui->ui_mutex);
333
334 ubifs_release_budget(c, req: &req);
335 fscrypt_free_filename(fname: &nm);
336 insert_inode_hash(inode);
337 d_instantiate(dentry, inode);
338 return 0;
339
340out_cancel:
341 dir->i_size -= sz_change;
342 dir_ui->ui_size = dir->i_size;
343 mutex_unlock(lock: &dir_ui->ui_mutex);
344out_inode:
345 make_bad_inode(inode);
346 iput(inode);
347out_fname:
348 fscrypt_free_filename(fname: &nm);
349out_budg:
350 ubifs_release_budget(c, req: &req);
351 ubifs_err(c, fmt: "cannot create regular file, error %d", err);
352 return err;
353}
354
355static 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, is_xattr: false);
372 if (IS_ERR(ptr: inode)) {
373 err = PTR_ERR(ptr: 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(dentry: dir, inode, qstr: &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
389out_inode:
390 make_bad_inode(inode);
391 iput(inode);
392out_free:
393 ubifs_err(c, fmt: "cannot create whiteout file, error %d", err);
394 return ERR_PTR(error: 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 */
406static void lock_2_inodes(struct inode *inode1, struct inode *inode2)
407{
408 mutex_lock_nested(lock: &ubifs_inode(inode: inode1)->ui_mutex, subclass: WB_MUTEX_1);
409 mutex_lock_nested(lock: &ubifs_inode(inode: inode2)->ui_mutex, subclass: 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 */
417static void unlock_2_inodes(struct inode *inode1, struct inode *inode2)
418{
419 mutex_unlock(lock: &ubifs_inode(inode: inode2)->ui_mutex);
420 mutex_unlock(lock: &ubifs_inode(inode: inode1)->ui_mutex);
421}
422
423static 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(inode: dir, iname: &dentry->d_name, lookup: 0, fname: &nm);
447 if (err)
448 return err;
449
450 err = ubifs_budget_space(c, req: &req);
451 if (err) {
452 fscrypt_free_filename(fname: &nm);
453 return err;
454 }
455
456 err = ubifs_budget_space(c, req: &ino_req);
457 if (err) {
458 ubifs_release_budget(c, req: &req);
459 fscrypt_free_filename(fname: &nm);
460 return err;
461 }
462
463 inode = ubifs_new_inode(c, dir, mode, is_xattr: false);
464 if (IS_ERR(ptr: inode)) {
465 err = PTR_ERR(ptr: inode);
466 goto out_budg;
467 }
468 ui = ubifs_inode(inode);
469
470 err = ubifs_init_security(dentry: dir, inode, qstr: &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(lock: &ui->ui_mutex);
481
482 lock_2_inodes(inode1: dir, inode2: inode);
483 err = ubifs_jnl_update(c, dir, nm: &nm, inode, deletion: 1, xent: 0);
484 if (err)
485 goto out_cancel;
486 unlock_2_inodes(inode1: dir, inode2: inode);
487
488 ubifs_release_budget(c, req: &req);
489 fscrypt_free_filename(fname: &nm);
490
491 return finish_open_simple(file, error: 0);
492
493out_cancel:
494 unlock_2_inodes(inode1: dir, inode2: inode);
495out_inode:
496 make_bad_inode(inode);
497 if (!instantiated)
498 iput(inode);
499out_budg:
500 ubifs_release_budget(c, req: &req);
501 if (!instantiated)
502 ubifs_release_budget(c, req: &ino_req);
503 fscrypt_free_filename(fname: &nm);
504 ubifs_err(c, fmt: "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 */
515static 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 */
555static 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(f: 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, crypto_str: &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(objp: 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(crypto_str: &fstr);
611 return 0;
612 }
613
614 /* Find the first entry in TNC and save it */
615 lowest_dent_key(c, key: &key, inum: dir->i_ino);
616 fname_len(&nm) = 0;
617 dent = ubifs_tnc_next_ent(c, key: &key, nm: &nm);
618 if (IS_ERR(ptr: dent)) {
619 err = PTR_ERR(ptr: dent);
620 goto out;
621 }
622
623 ctx->pos = key_hash_flash(c, k: &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: &key, inum: dir->i_ino, hash: ctx->pos);
634 fname_len(&nm) = 0;
635 dent = ubifs_tnc_next_ent(c, key: &key, nm: &nm);
636 if (IS_ERR(ptr: dent)) {
637 err = PTR_ERR(ptr: dent);
638 goto out;
639 }
640 ctx->pos = key_hash_flash(c, k: &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(inode: dir, hash: key_hash_flash(c,
658 k: &dent->key),
659 le32_to_cpu(dent->cookie),
660 iname: &nm.disk_name, oname: &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, name: fstr.name, namelen: fstr.len,
669 le64_to_cpu(dent->inum),
670 type: vfs_dent_type(type: dent->type))) {
671 if (encrypted)
672 fscrypt_fname_free_buffer(crypto_str: &fstr);
673 return 0;
674 }
675
676 /* Switch to the next entry */
677 key_read(c, from: &dent->key, to: &key);
678 dent = ubifs_tnc_next_ent(c, key: &key, nm: &nm);
679 if (IS_ERR(ptr: dent)) {
680 err = PTR_ERR(ptr: dent);
681 goto out;
682 }
683
684 kfree(objp: file->private_data);
685 ctx->pos = key_hash_flash(c, k: &dent->key);
686 file->private_data = dent;
687 cond_resched();
688 }
689
690out:
691 kfree(objp: file->private_data);
692 file->private_data = NULL;
693
694 if (encrypted)
695 fscrypt_fname_free_buffer(crypto_str: &fstr);
696
697 if (err != -ENOENT)
698 ubifs_err(c, fmt: "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 */
714static int ubifs_dir_release(struct inode *dir, struct file *file)
715{
716 kfree(objp: file->private_data);
717 file->private_data = NULL;
718 return 0;
719}
720
721static 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(dentry: old_dentry);
726 struct ubifs_inode *ui = ubifs_inode(inode);
727 struct ubifs_inode *dir_ui = ubifs_inode(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(inode: dir, iname: &dentry->d_name, lookup: 0, fname: &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: &req);
759 if (err)
760 goto out_fname;
761
762 lock_2_inodes(inode1: dir, inode2: 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, inum: 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(inode: dir,
774 ts: inode_set_ctime_to_ts(inode: dir, ts: inode_get_ctime(inode)));
775 err = ubifs_jnl_update(c, dir, nm: &nm, inode, deletion: 0, xent: 0);
776 if (err)
777 goto out_cancel;
778 unlock_2_inodes(inode1: dir, inode2: inode);
779
780 ubifs_release_budget(c, req: &req);
781 d_instantiate(dentry, inode);
782 fscrypt_free_filename(fname: &nm);
783 return 0;
784
785out_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, inum: inode->i_ino);
791 unlock_2_inodes(inode1: dir, inode2: inode);
792 ubifs_release_budget(c, req: &req);
793 iput(inode);
794out_fname:
795 fscrypt_free_filename(fname: &nm);
796 return err;
797}
798
799static 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(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(inode: dir, iname: &dentry->d_name, lookup: 1, fname: &nm);
821 if (err)
822 return err;
823
824 err = ubifs_purge_xattrs(host: 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: &req);
837 if (err) {
838 if (err != -ENOSPC)
839 goto out_fname;
840 budgeted = 0;
841 }
842
843 lock_2_inodes(inode1: dir, inode2: 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(inode: dir,
849 ts: inode_set_ctime_to_ts(inode: dir, ts: inode_get_ctime(inode)));
850 err = ubifs_jnl_update(c, dir, nm: &nm, inode, deletion: 1, xent: 0);
851 if (err)
852 goto out_cancel;
853 unlock_2_inodes(inode1: dir, inode2: inode);
854
855 if (budgeted)
856 ubifs_release_budget(c, req: &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(fname: &nm);
863 return 0;
864
865out_cancel:
866 dir->i_size += sz_change;
867 dir_ui->ui_size = dir->i_size;
868 set_nlink(inode, nlink: saved_nlink);
869 unlock_2_inodes(inode1: dir, inode2: inode);
870 if (budgeted)
871 ubifs_release_budget(c, req: &req);
872out_fname:
873 fscrypt_free_filename(fname: &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 */
885int 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: &key, inum: dir->i_ino);
894 dent = ubifs_tnc_next_ent(c, key: &key, nm: &nm);
895 if (IS_ERR(ptr: dent)) {
896 err = PTR_ERR(ptr: dent);
897 if (err == -ENOENT)
898 err = 0;
899 } else {
900 kfree(objp: dent);
901 err = -ENOTEMPTY;
902 }
903 return err;
904}
905
906static 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(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(dir: d_inode(dentry));
926 if (err)
927 return err;
928
929 err = fscrypt_setup_filename(inode: dir, iname: &dentry->d_name, lookup: 1, fname: &nm);
930 if (err)
931 return err;
932
933 err = ubifs_purge_xattrs(host: 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: &req);
940 if (err) {
941 if (err != -ENOSPC)
942 goto out_fname;
943 budgeted = 0;
944 }
945
946 lock_2_inodes(inode1: dir, inode2: inode);
947 inode_set_ctime_current(inode);
948 clear_nlink(inode);
949 drop_nlink(inode: dir);
950 dir->i_size -= sz_change;
951 dir_ui->ui_size = dir->i_size;
952 inode_set_mtime_to_ts(inode: dir,
953 ts: inode_set_ctime_to_ts(inode: dir, ts: inode_get_ctime(inode)));
954 err = ubifs_jnl_update(c, dir, nm: &nm, inode, deletion: 1, xent: 0);
955 if (err)
956 goto out_cancel;
957 unlock_2_inodes(inode1: dir, inode2: inode);
958
959 if (budgeted)
960 ubifs_release_budget(c, req: &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(fname: &nm);
967 return 0;
968
969out_cancel:
970 dir->i_size += sz_change;
971 dir_ui->ui_size = dir->i_size;
972 inc_nlink(inode: dir);
973 set_nlink(inode, nlink: 2);
974 unlock_2_inodes(inode1: dir, inode2: inode);
975 if (budgeted)
976 ubifs_release_budget(c, req: &req);
977out_fname:
978 fscrypt_free_filename(fname: &nm);
979 return err;
980}
981
982static 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(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: &req);
1002 if (err)
1003 return err;
1004
1005 err = ubifs_prepare_create(dir, dentry, nm: &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, is_xattr: false);
1012 if (IS_ERR(ptr: inode)) {
1013 err = PTR_ERR(ptr: inode);
1014 goto out_fname;
1015 }
1016
1017 err = ubifs_init_security(dentry: dir, inode, qstr: &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(inode: dir);
1025 dir->i_size += sz_change;
1026 dir_ui->ui_size = dir->i_size;
1027 inode_set_mtime_to_ts(inode: dir,
1028 ts: inode_set_ctime_to_ts(inode: dir, ts: inode_get_ctime(inode)));
1029 err = ubifs_jnl_update(c, dir, nm: &nm, inode, deletion: 0, xent: 0);
1030 if (err) {
1031 ubifs_err(c, fmt: "cannot create directory, error %d", err);
1032 goto out_cancel;
1033 }
1034 mutex_unlock(lock: &dir_ui->ui_mutex);
1035
1036 ubifs_release_budget(c, req: &req);
1037 d_instantiate(dentry, inode);
1038 fscrypt_free_filename(fname: &nm);
1039 return 0;
1040
1041out_cancel:
1042 dir->i_size -= sz_change;
1043 dir_ui->ui_size = dir->i_size;
1044 drop_nlink(inode: dir);
1045 mutex_unlock(lock: &dir_ui->ui_mutex);
1046out_inode:
1047 make_bad_inode(inode);
1048 iput(inode);
1049out_fname:
1050 fscrypt_free_filename(fname: &nm);
1051out_budg:
1052 ubifs_release_budget(c, req: &req);
1053 return err;
1054}
1055
1056static 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(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(size: 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: &req);
1086 if (err) {
1087 kfree(objp: dev);
1088 return err;
1089 }
1090
1091 err = ubifs_prepare_create(dir, dentry, nm: &nm);
1092 if (err) {
1093 kfree(objp: 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, is_xattr: false);
1100 if (IS_ERR(ptr: inode)) {
1101 kfree(objp: dev);
1102 err = PTR_ERR(ptr: 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(dentry: dir, inode, qstr: &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(inode: dir,
1120 ts: inode_set_ctime_to_ts(inode: dir, ts: inode_get_ctime(inode)));
1121 err = ubifs_jnl_update(c, dir, nm: &nm, inode, deletion: 0, xent: 0);
1122 if (err)
1123 goto out_cancel;
1124 mutex_unlock(lock: &dir_ui->ui_mutex);
1125
1126 ubifs_release_budget(c, req: &req);
1127 insert_inode_hash(inode);
1128 d_instantiate(dentry, inode);
1129 fscrypt_free_filename(fname: &nm);
1130 return 0;
1131
1132out_cancel:
1133 dir->i_size -= sz_change;
1134 dir_ui->ui_size = dir->i_size;
1135 mutex_unlock(lock: &dir_ui->ui_mutex);
1136out_inode:
1137 make_bad_inode(inode);
1138 iput(inode);
1139out_fname:
1140 fscrypt_free_filename(fname: &nm);
1141out_budg:
1142 ubifs_release_budget(c, req: &req);
1143 return err;
1144}
1145
1146static 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(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, target: symname, len, UBIFS_MAX_INO_DATA,
1163 disk_link: &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: &req);
1173 if (err)
1174 return err;
1175
1176 err = ubifs_prepare_create(dir, dentry, nm: &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, is_xattr: false);
1183 if (IS_ERR(ptr: inode)) {
1184 err = PTR_ERR(ptr: inode);
1185 goto out_fname;
1186 }
1187
1188 ui = ubifs_inode(inode);
1189 ui->data = kmalloc(size: 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, target: symname, len, disk_link: &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(dentry: dir, inode, qstr: &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(inode: dir,
1221 ts: inode_set_ctime_to_ts(inode: dir, ts: inode_get_ctime(inode)));
1222 err = ubifs_jnl_update(c, dir, nm: &nm, inode, deletion: 0, xent: 0);
1223 if (err)
1224 goto out_cancel;
1225 mutex_unlock(lock: &dir_ui->ui_mutex);
1226
1227 insert_inode_hash(inode);
1228 d_instantiate(dentry, inode);
1229 err = 0;
1230 goto out_fname;
1231
1232out_cancel:
1233 dir->i_size -= sz_change;
1234 dir_ui->ui_size = dir->i_size;
1235 mutex_unlock(lock: &dir_ui->ui_mutex);
1236out_inode:
1237 make_bad_inode(inode);
1238 iput(inode);
1239out_fname:
1240 fscrypt_free_filename(fname: &nm);
1241out_budg:
1242 ubifs_release_budget(c, req: &req);
1243 return err;
1244}
1245
1246/**
1247 * lock_4_inodes - a wrapper for locking three UBIFS inodes.
1248 * @inode1: first inode
1249 * @inode2: second inode
1250 * @inode3: third inode
1251 * @inode4: fourth inode
1252 *
1253 * This function is used for 'ubifs_rename()' and @inode1 may be the same as
1254 * @inode2 whereas @inode3 and @inode4 may be %NULL.
1255 *
1256 * We do not implement any tricks to guarantee strict lock ordering, because
1257 * VFS has already done it for us on the @i_mutex. So this is just a simple
1258 * wrapper function.
1259 */
1260static void lock_4_inodes(struct inode *inode1, struct inode *inode2,
1261 struct inode *inode3, struct inode *inode4)
1262{
1263 mutex_lock_nested(lock: &ubifs_inode(inode: inode1)->ui_mutex, subclass: WB_MUTEX_1);
1264 if (inode2 != inode1)
1265 mutex_lock_nested(lock: &ubifs_inode(inode: inode2)->ui_mutex, subclass: WB_MUTEX_2);
1266 if (inode3)
1267 mutex_lock_nested(lock: &ubifs_inode(inode: inode3)->ui_mutex, subclass: WB_MUTEX_3);
1268 if (inode4)
1269 mutex_lock_nested(lock: &ubifs_inode(inode: inode4)->ui_mutex, subclass: WB_MUTEX_4);
1270}
1271
1272/**
1273 * unlock_4_inodes - a wrapper for unlocking three UBIFS inodes for rename.
1274 * @inode1: first inode
1275 * @inode2: second inode
1276 * @inode3: third inode
1277 * @inode4: fourth inode
1278 */
1279static void unlock_4_inodes(struct inode *inode1, struct inode *inode2,
1280 struct inode *inode3, struct inode *inode4)
1281{
1282 if (inode4)
1283 mutex_unlock(lock: &ubifs_inode(inode: inode4)->ui_mutex);
1284 if (inode3)
1285 mutex_unlock(lock: &ubifs_inode(inode: inode3)->ui_mutex);
1286 if (inode1 != inode2)
1287 mutex_unlock(lock: &ubifs_inode(inode: inode2)->ui_mutex);
1288 mutex_unlock(lock: &ubifs_inode(inode: inode1)->ui_mutex);
1289}
1290
1291static int do_rename(struct inode *old_dir, struct dentry *old_dentry,
1292 struct inode *new_dir, struct dentry *new_dentry,
1293 unsigned int flags)
1294{
1295 struct ubifs_info *c = old_dir->i_sb->s_fs_info;
1296 struct inode *old_inode = d_inode(dentry: old_dentry);
1297 struct inode *new_inode = d_inode(dentry: new_dentry);
1298 struct inode *whiteout = NULL;
1299 struct ubifs_inode *old_inode_ui = ubifs_inode(inode: old_inode);
1300 struct ubifs_inode *whiteout_ui = NULL;
1301 int err, release, sync = 0, move = (new_dir != old_dir);
1302 int is_dir = S_ISDIR(old_inode->i_mode);
1303 int unlink = !!new_inode, new_sz, old_sz;
1304 struct ubifs_budget_req req = { .new_dent = 1, .mod_dent = 1,
1305 .dirtied_ino = 3 };
1306 struct ubifs_budget_req ino_req = { .dirtied_ino = 1,
1307 .dirtied_ino_d = ALIGN(old_inode_ui->data_len, 8) };
1308 struct ubifs_budget_req wht_req;
1309 unsigned int saved_nlink;
1310 struct fscrypt_name old_nm, new_nm;
1311
1312 /*
1313 * Budget request settings:
1314 * req: deletion direntry, new direntry, removing the old inode,
1315 * and changing old and new parent directory inodes.
1316 *
1317 * wht_req: new whiteout inode for RENAME_WHITEOUT.
1318 *
1319 * ino_req: marks the target inode as dirty and does not write it.
1320 */
1321
1322 dbg_gen("dent '%pd' ino %lu in dir ino %lu to dent '%pd' in dir ino %lu flags 0x%x",
1323 old_dentry, old_inode->i_ino, old_dir->i_ino,
1324 new_dentry, new_dir->i_ino, flags);
1325
1326 if (unlink) {
1327 ubifs_assert(c, inode_is_locked(new_inode));
1328
1329 /* Budget for old inode's data when its nlink > 1. */
1330 req.dirtied_ino_d = ALIGN(ubifs_inode(new_inode)->data_len, 8);
1331 err = ubifs_purge_xattrs(host: new_inode);
1332 if (err)
1333 return err;
1334 }
1335
1336 if (unlink && is_dir) {
1337 err = ubifs_check_dir_empty(dir: new_inode);
1338 if (err)
1339 return err;
1340 }
1341
1342 err = fscrypt_setup_filename(inode: old_dir, iname: &old_dentry->d_name, lookup: 0, fname: &old_nm);
1343 if (err)
1344 return err;
1345
1346 err = fscrypt_setup_filename(inode: new_dir, iname: &new_dentry->d_name, lookup: 0, fname: &new_nm);
1347 if (err) {
1348 fscrypt_free_filename(fname: &old_nm);
1349 return err;
1350 }
1351
1352 new_sz = CALC_DENT_SIZE(fname_len(&new_nm));
1353 old_sz = CALC_DENT_SIZE(fname_len(&old_nm));
1354
1355 err = ubifs_budget_space(c, req: &req);
1356 if (err) {
1357 fscrypt_free_filename(fname: &old_nm);
1358 fscrypt_free_filename(fname: &new_nm);
1359 return err;
1360 }
1361 err = ubifs_budget_space(c, req: &ino_req);
1362 if (err) {
1363 fscrypt_free_filename(fname: &old_nm);
1364 fscrypt_free_filename(fname: &new_nm);
1365 ubifs_release_budget(c, req: &req);
1366 return err;
1367 }
1368
1369 if (flags & RENAME_WHITEOUT) {
1370 union ubifs_dev_desc *dev = NULL;
1371
1372 dev = kmalloc(size: sizeof(union ubifs_dev_desc), GFP_NOFS);
1373 if (!dev) {
1374 err = -ENOMEM;
1375 goto out_release;
1376 }
1377
1378 /*
1379 * The whiteout inode without dentry is pinned in memory,
1380 * umount won't happen during rename process because we
1381 * got parent dentry.
1382 */
1383 whiteout = create_whiteout(dir: old_dir, dentry: old_dentry);
1384 if (IS_ERR(ptr: whiteout)) {
1385 err = PTR_ERR(ptr: whiteout);
1386 kfree(objp: dev);
1387 goto out_release;
1388 }
1389
1390 whiteout_ui = ubifs_inode(inode: whiteout);
1391 whiteout_ui->data = dev;
1392 whiteout_ui->data_len = ubifs_encode_dev(dev, MKDEV(0, 0));
1393 ubifs_assert(c, !whiteout_ui->dirty);
1394
1395 memset(&wht_req, 0, sizeof(struct ubifs_budget_req));
1396 wht_req.new_ino = 1;
1397 wht_req.new_ino_d = ALIGN(whiteout_ui->data_len, 8);
1398 /*
1399 * To avoid deadlock between space budget (holds ui_mutex and
1400 * waits wb work) and writeback work(waits ui_mutex), do space
1401 * budget before ubifs inodes locked.
1402 */
1403 err = ubifs_budget_space(c, req: &wht_req);
1404 if (err) {
1405 /*
1406 * Whiteout inode can not be written on flash by
1407 * ubifs_jnl_write_inode(), because it's neither
1408 * dirty nor zero-nlink.
1409 */
1410 iput(whiteout);
1411 goto out_release;
1412 }
1413
1414 /* Add the old_dentry size to the old_dir size. */
1415 old_sz -= CALC_DENT_SIZE(fname_len(&old_nm));
1416 }
1417
1418 lock_4_inodes(inode1: old_dir, inode2: new_dir, inode3: new_inode, inode4: whiteout);
1419
1420 /*
1421 * Like most other Unix systems, set the @i_ctime for inodes on a
1422 * rename.
1423 */
1424 simple_rename_timestamp(old_dir, old_dentry, new_dir, new_dentry);
1425
1426 /* We must adjust parent link count when renaming directories */
1427 if (is_dir) {
1428 if (move) {
1429 /*
1430 * @old_dir loses a link because we are moving
1431 * @old_inode to a different directory.
1432 */
1433 drop_nlink(inode: old_dir);
1434 /*
1435 * @new_dir only gains a link if we are not also
1436 * overwriting an existing directory.
1437 */
1438 if (!unlink)
1439 inc_nlink(inode: new_dir);
1440 } else {
1441 /*
1442 * @old_inode is not moving to a different directory,
1443 * but @old_dir still loses a link if we are
1444 * overwriting an existing directory.
1445 */
1446 if (unlink)
1447 drop_nlink(inode: old_dir);
1448 }
1449 }
1450
1451 old_dir->i_size -= old_sz;
1452 ubifs_inode(inode: old_dir)->ui_size = old_dir->i_size;
1453
1454 /*
1455 * And finally, if we unlinked a direntry which happened to have the
1456 * same name as the moved direntry, we have to decrement @i_nlink of
1457 * the unlinked inode.
1458 */
1459 if (unlink) {
1460 /*
1461 * Directories cannot have hard-links, so if this is a
1462 * directory, just clear @i_nlink.
1463 */
1464 saved_nlink = new_inode->i_nlink;
1465 if (is_dir)
1466 clear_nlink(inode: new_inode);
1467 else
1468 drop_nlink(inode: new_inode);
1469 } else {
1470 new_dir->i_size += new_sz;
1471 ubifs_inode(inode: new_dir)->ui_size = new_dir->i_size;
1472 }
1473
1474 /*
1475 * Do not ask 'ubifs_jnl_rename()' to flush write-buffer if @old_inode
1476 * is dirty, because this will be done later on at the end of
1477 * 'ubifs_rename()'.
1478 */
1479 if (IS_SYNC(old_inode)) {
1480 sync = IS_DIRSYNC(old_dir) || IS_DIRSYNC(new_dir);
1481 if (unlink && IS_SYNC(new_inode))
1482 sync = 1;
1483 /*
1484 * S_SYNC flag of whiteout inherits from the old_dir, and we
1485 * have already checked the old dir inode. So there is no need
1486 * to check whiteout.
1487 */
1488 }
1489
1490 err = ubifs_jnl_rename(c, old_dir, old_inode, old_nm: &old_nm, new_dir,
1491 new_inode, new_nm: &new_nm, whiteout, sync);
1492 if (err)
1493 goto out_cancel;
1494
1495 unlock_4_inodes(inode1: old_dir, inode2: new_dir, inode3: new_inode, inode4: whiteout);
1496 ubifs_release_budget(c, req: &req);
1497
1498 if (whiteout) {
1499 ubifs_release_budget(c, req: &wht_req);
1500 iput(whiteout);
1501 }
1502
1503 mutex_lock(&old_inode_ui->ui_mutex);
1504 release = old_inode_ui->dirty;
1505 mark_inode_dirty_sync(inode: old_inode);
1506 mutex_unlock(lock: &old_inode_ui->ui_mutex);
1507
1508 if (release)
1509 ubifs_release_budget(c, req: &ino_req);
1510 if (IS_SYNC(old_inode))
1511 /*
1512 * Rename finished here. Although old inode cannot be updated
1513 * on flash, old ctime is not a big problem, don't return err
1514 * code to userspace.
1515 */
1516 old_inode->i_sb->s_op->write_inode(old_inode, NULL);
1517
1518 fscrypt_free_filename(fname: &old_nm);
1519 fscrypt_free_filename(fname: &new_nm);
1520 return 0;
1521
1522out_cancel:
1523 if (unlink) {
1524 set_nlink(inode: new_inode, nlink: saved_nlink);
1525 } else {
1526 new_dir->i_size -= new_sz;
1527 ubifs_inode(inode: new_dir)->ui_size = new_dir->i_size;
1528 }
1529 old_dir->i_size += old_sz;
1530 ubifs_inode(inode: old_dir)->ui_size = old_dir->i_size;
1531 if (is_dir) {
1532 if (move) {
1533 inc_nlink(inode: old_dir);
1534 if (!unlink)
1535 drop_nlink(inode: new_dir);
1536 } else {
1537 if (unlink)
1538 inc_nlink(inode: old_dir);
1539 }
1540 }
1541 unlock_4_inodes(inode1: old_dir, inode2: new_dir, inode3: new_inode, inode4: whiteout);
1542 if (whiteout) {
1543 ubifs_release_budget(c, req: &wht_req);
1544 iput(whiteout);
1545 }
1546out_release:
1547 ubifs_release_budget(c, req: &ino_req);
1548 ubifs_release_budget(c, req: &req);
1549 fscrypt_free_filename(fname: &old_nm);
1550 fscrypt_free_filename(fname: &new_nm);
1551 return err;
1552}
1553
1554static int ubifs_xrename(struct inode *old_dir, struct dentry *old_dentry,
1555 struct inode *new_dir, struct dentry *new_dentry)
1556{
1557 struct ubifs_info *c = old_dir->i_sb->s_fs_info;
1558 struct ubifs_budget_req req = { .new_dent = 1, .mod_dent = 1,
1559 .dirtied_ino = 2 };
1560 int sync = IS_DIRSYNC(old_dir) || IS_DIRSYNC(new_dir);
1561 struct inode *fst_inode = d_inode(dentry: old_dentry);
1562 struct inode *snd_inode = d_inode(dentry: new_dentry);
1563 int err;
1564 struct fscrypt_name fst_nm, snd_nm;
1565
1566 ubifs_assert(c, fst_inode && snd_inode);
1567
1568 /*
1569 * Budget request settings: changing two direntries, changing the two
1570 * parent directory inodes.
1571 */
1572
1573 dbg_gen("dent '%pd' ino %lu in dir ino %lu exchange dent '%pd' ino %lu in dir ino %lu",
1574 old_dentry, fst_inode->i_ino, old_dir->i_ino,
1575 new_dentry, snd_inode->i_ino, new_dir->i_ino);
1576
1577 err = fscrypt_setup_filename(inode: old_dir, iname: &old_dentry->d_name, lookup: 0, fname: &fst_nm);
1578 if (err)
1579 return err;
1580
1581 err = fscrypt_setup_filename(inode: new_dir, iname: &new_dentry->d_name, lookup: 0, fname: &snd_nm);
1582 if (err) {
1583 fscrypt_free_filename(fname: &fst_nm);
1584 return err;
1585 }
1586
1587 err = ubifs_budget_space(c, req: &req);
1588 if (err)
1589 goto out;
1590
1591 lock_4_inodes(inode1: old_dir, inode2: new_dir, NULL, NULL);
1592
1593 simple_rename_timestamp(old_dir, old_dentry, new_dir, new_dentry);
1594
1595 if (old_dir != new_dir) {
1596 if (S_ISDIR(fst_inode->i_mode) && !S_ISDIR(snd_inode->i_mode)) {
1597 inc_nlink(inode: new_dir);
1598 drop_nlink(inode: old_dir);
1599 }
1600 else if (!S_ISDIR(fst_inode->i_mode) && S_ISDIR(snd_inode->i_mode)) {
1601 drop_nlink(inode: new_dir);
1602 inc_nlink(inode: old_dir);
1603 }
1604 }
1605
1606 err = ubifs_jnl_xrename(c, fst_dir: old_dir, fst_inode, fst_nm: &fst_nm, snd_dir: new_dir,
1607 snd_inode, snd_nm: &snd_nm, sync);
1608
1609 unlock_4_inodes(inode1: old_dir, inode2: new_dir, NULL, NULL);
1610 ubifs_release_budget(c, req: &req);
1611
1612out:
1613 fscrypt_free_filename(fname: &fst_nm);
1614 fscrypt_free_filename(fname: &snd_nm);
1615 return err;
1616}
1617
1618static int ubifs_rename(struct mnt_idmap *idmap,
1619 struct inode *old_dir, struct dentry *old_dentry,
1620 struct inode *new_dir, struct dentry *new_dentry,
1621 unsigned int flags)
1622{
1623 int err;
1624 struct ubifs_info *c = old_dir->i_sb->s_fs_info;
1625
1626 if (flags & ~(RENAME_NOREPLACE | RENAME_WHITEOUT | RENAME_EXCHANGE))
1627 return -EINVAL;
1628
1629 ubifs_assert(c, inode_is_locked(old_dir));
1630 ubifs_assert(c, inode_is_locked(new_dir));
1631
1632 err = fscrypt_prepare_rename(old_dir, old_dentry, new_dir, new_dentry,
1633 flags);
1634 if (err)
1635 return err;
1636
1637 if (flags & RENAME_EXCHANGE)
1638 return ubifs_xrename(old_dir, old_dentry, new_dir, new_dentry);
1639
1640 return do_rename(old_dir, old_dentry, new_dir, new_dentry, flags);
1641}
1642
1643int ubifs_getattr(struct mnt_idmap *idmap, const struct path *path,
1644 struct kstat *stat, u32 request_mask, unsigned int flags)
1645{
1646 loff_t size;
1647 struct inode *inode = d_inode(dentry: path->dentry);
1648 struct ubifs_inode *ui = ubifs_inode(inode);
1649
1650 mutex_lock(&ui->ui_mutex);
1651
1652 if (ui->flags & UBIFS_APPEND_FL)
1653 stat->attributes |= STATX_ATTR_APPEND;
1654 if (ui->flags & UBIFS_COMPR_FL)
1655 stat->attributes |= STATX_ATTR_COMPRESSED;
1656 if (ui->flags & UBIFS_CRYPT_FL)
1657 stat->attributes |= STATX_ATTR_ENCRYPTED;
1658 if (ui->flags & UBIFS_IMMUTABLE_FL)
1659 stat->attributes |= STATX_ATTR_IMMUTABLE;
1660
1661 stat->attributes_mask |= (STATX_ATTR_APPEND |
1662 STATX_ATTR_COMPRESSED |
1663 STATX_ATTR_ENCRYPTED |
1664 STATX_ATTR_IMMUTABLE);
1665
1666 generic_fillattr(&nop_mnt_idmap, request_mask, inode, stat);
1667 stat->blksize = UBIFS_BLOCK_SIZE;
1668 stat->size = ui->ui_size;
1669
1670 /*
1671 * Unfortunately, the 'stat()' system call was designed for block
1672 * device based file systems, and it is not appropriate for UBIFS,
1673 * because UBIFS does not have notion of "block". For example, it is
1674 * difficult to tell how many block a directory takes - it actually
1675 * takes less than 300 bytes, but we have to round it to block size,
1676 * which introduces large mistake. This makes utilities like 'du' to
1677 * report completely senseless numbers. This is the reason why UBIFS
1678 * goes the same way as JFFS2 - it reports zero blocks for everything
1679 * but regular files, which makes more sense than reporting completely
1680 * wrong sizes.
1681 */
1682 if (S_ISREG(inode->i_mode)) {
1683 size = ui->xattr_size;
1684 size += stat->size;
1685 size = ALIGN(size, UBIFS_BLOCK_SIZE);
1686 /*
1687 * Note, user-space expects 512-byte blocks count irrespectively
1688 * of what was reported in @stat->size.
1689 */
1690 stat->blocks = size >> 9;
1691 } else
1692 stat->blocks = 0;
1693 mutex_unlock(lock: &ui->ui_mutex);
1694 return 0;
1695}
1696
1697const struct inode_operations ubifs_dir_inode_operations = {
1698 .lookup = ubifs_lookup,
1699 .create = ubifs_create,
1700 .link = ubifs_link,
1701 .symlink = ubifs_symlink,
1702 .unlink = ubifs_unlink,
1703 .mkdir = ubifs_mkdir,
1704 .rmdir = ubifs_rmdir,
1705 .mknod = ubifs_mknod,
1706 .rename = ubifs_rename,
1707 .setattr = ubifs_setattr,
1708 .getattr = ubifs_getattr,
1709 .listxattr = ubifs_listxattr,
1710 .update_time = ubifs_update_time,
1711 .tmpfile = ubifs_tmpfile,
1712 .fileattr_get = ubifs_fileattr_get,
1713 .fileattr_set = ubifs_fileattr_set,
1714};
1715
1716const struct file_operations ubifs_dir_operations = {
1717 .llseek = generic_file_llseek,
1718 .release = ubifs_dir_release,
1719 .read = generic_read_dir,
1720 .iterate_shared = ubifs_readdir,
1721 .fsync = ubifs_fsync,
1722 .unlocked_ioctl = ubifs_ioctl,
1723#ifdef CONFIG_COMPAT
1724 .compat_ioctl = ubifs_compat_ioctl,
1725#endif
1726};
1727

source code of linux/fs/ubifs/dir.c