xref: /linux/fs/ubifs/super.c (revision 79790b6818e96c58fe2bffee1b418c16e64e7b80)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * This file is part of UBIFS.
4  *
5  * Copyright (C) 2006-2008 Nokia Corporation.
6  *
7  * Authors: Artem Bityutskiy (Битюцкий Артём)
8  *          Adrian Hunter
9  */
10 
11 /*
12  * This file implements UBIFS initialization and VFS superblock operations. Some
13  * initialization stuff which is rather large and complex is placed at
14  * corresponding subsystems, but most of it is here.
15  */
16 
17 #include <linux/init.h>
18 #include <linux/slab.h>
19 #include <linux/module.h>
20 #include <linux/ctype.h>
21 #include <linux/kthread.h>
22 #include <linux/parser.h>
23 #include <linux/seq_file.h>
24 #include <linux/mount.h>
25 #include <linux/math64.h>
26 #include <linux/writeback.h>
27 #include "ubifs.h"
28 
ubifs_default_version_set(const char * val,const struct kernel_param * kp)29 static int ubifs_default_version_set(const char *val, const struct kernel_param *kp)
30 {
31 	int n = 0, ret;
32 
33 	ret = kstrtoint(val, 10, &n);
34 	if (ret != 0 || n < 4 || n > UBIFS_FORMAT_VERSION)
35 		return -EINVAL;
36 	return param_set_int(val, kp);
37 }
38 
39 static const struct kernel_param_ops ubifs_default_version_ops = {
40 	.set = ubifs_default_version_set,
41 	.get = param_get_int,
42 };
43 
44 int ubifs_default_version = UBIFS_FORMAT_VERSION;
45 module_param_cb(default_version, &ubifs_default_version_ops, &ubifs_default_version, 0600);
46 
47 /*
48  * Maximum amount of memory we may 'kmalloc()' without worrying that we are
49  * allocating too much.
50  */
51 #define UBIFS_KMALLOC_OK (128*1024)
52 
53 /* Slab cache for UBIFS inodes */
54 static struct kmem_cache *ubifs_inode_slab;
55 
56 /* UBIFS TNC shrinker description */
57 static struct shrinker *ubifs_shrinker_info;
58 
59 /**
60  * validate_inode - validate inode.
61  * @c: UBIFS file-system description object
62  * @inode: the inode to validate
63  *
64  * This is a helper function for 'ubifs_iget()' which validates various fields
65  * of a newly built inode to make sure they contain sane values and prevent
66  * possible vulnerabilities. Returns zero if the inode is all right and
67  * a non-zero error code if not.
68  */
validate_inode(struct ubifs_info * c,const struct inode * inode)69 static int validate_inode(struct ubifs_info *c, const struct inode *inode)
70 {
71 	int err;
72 	const struct ubifs_inode *ui = ubifs_inode(inode);
73 
74 	if (inode->i_size > c->max_inode_sz) {
75 		ubifs_err(c, "inode is too large (%lld)",
76 			  (long long)inode->i_size);
77 		return 1;
78 	}
79 
80 	if (ui->compr_type >= UBIFS_COMPR_TYPES_CNT) {
81 		ubifs_err(c, "unknown compression type %d", ui->compr_type);
82 		return 2;
83 	}
84 
85 	if (ui->xattr_names + ui->xattr_cnt > XATTR_LIST_MAX)
86 		return 3;
87 
88 	if (ui->data_len < 0 || ui->data_len > UBIFS_MAX_INO_DATA)
89 		return 4;
90 
91 	if (ui->xattr && !S_ISREG(inode->i_mode))
92 		return 5;
93 
94 	if (!ubifs_compr_present(c, ui->compr_type)) {
95 		ubifs_warn(c, "inode %lu uses '%s' compression, but it was not compiled in",
96 			   inode->i_ino, ubifs_compr_name(c, ui->compr_type));
97 	}
98 
99 	err = dbg_check_dir(c, inode);
100 	return err;
101 }
102 
ubifs_iget(struct super_block * sb,unsigned long inum)103 struct inode *ubifs_iget(struct super_block *sb, unsigned long inum)
104 {
105 	int err;
106 	union ubifs_key key;
107 	struct ubifs_ino_node *ino;
108 	struct ubifs_info *c = sb->s_fs_info;
109 	struct inode *inode;
110 	struct ubifs_inode *ui;
111 
112 	dbg_gen("inode %lu", inum);
113 
114 	inode = iget_locked(sb, inum);
115 	if (!inode)
116 		return ERR_PTR(-ENOMEM);
117 	if (!(inode->i_state & I_NEW))
118 		return inode;
119 	ui = ubifs_inode(inode);
120 
121 	ino = kmalloc(UBIFS_MAX_INO_NODE_SZ, GFP_NOFS);
122 	if (!ino) {
123 		err = -ENOMEM;
124 		goto out;
125 	}
126 
127 	ino_key_init(c, &key, inode->i_ino);
128 
129 	err = ubifs_tnc_lookup(c, &key, ino);
130 	if (err)
131 		goto out_ino;
132 
133 	inode->i_flags |= S_NOCMTIME;
134 
135 	if (!IS_ENABLED(CONFIG_UBIFS_ATIME_SUPPORT))
136 		inode->i_flags |= S_NOATIME;
137 
138 	set_nlink(inode, le32_to_cpu(ino->nlink));
139 	i_uid_write(inode, le32_to_cpu(ino->uid));
140 	i_gid_write(inode, le32_to_cpu(ino->gid));
141 	inode_set_atime(inode, (int64_t)le64_to_cpu(ino->atime_sec),
142 			le32_to_cpu(ino->atime_nsec));
143 	inode_set_mtime(inode, (int64_t)le64_to_cpu(ino->mtime_sec),
144 			le32_to_cpu(ino->mtime_nsec));
145 	inode_set_ctime(inode, (int64_t)le64_to_cpu(ino->ctime_sec),
146 			le32_to_cpu(ino->ctime_nsec));
147 	inode->i_mode = le32_to_cpu(ino->mode);
148 	inode->i_size = le64_to_cpu(ino->size);
149 
150 	ui->data_len    = le32_to_cpu(ino->data_len);
151 	ui->flags       = le32_to_cpu(ino->flags);
152 	ui->compr_type  = le16_to_cpu(ino->compr_type);
153 	ui->creat_sqnum = le64_to_cpu(ino->creat_sqnum);
154 	ui->xattr_cnt   = le32_to_cpu(ino->xattr_cnt);
155 	ui->xattr_size  = le32_to_cpu(ino->xattr_size);
156 	ui->xattr_names = le32_to_cpu(ino->xattr_names);
157 	ui->synced_i_size = ui->ui_size = inode->i_size;
158 
159 	ui->xattr = (ui->flags & UBIFS_XATTR_FL) ? 1 : 0;
160 
161 	err = validate_inode(c, inode);
162 	if (err)
163 		goto out_invalid;
164 
165 	switch (inode->i_mode & S_IFMT) {
166 	case S_IFREG:
167 		inode->i_mapping->a_ops = &ubifs_file_address_operations;
168 		inode->i_op = &ubifs_file_inode_operations;
169 		inode->i_fop = &ubifs_file_operations;
170 		if (ui->xattr) {
171 			ui->data = kmalloc(ui->data_len + 1, GFP_NOFS);
172 			if (!ui->data) {
173 				err = -ENOMEM;
174 				goto out_ino;
175 			}
176 			memcpy(ui->data, ino->data, ui->data_len);
177 			((char *)ui->data)[ui->data_len] = '\0';
178 		} else if (ui->data_len != 0) {
179 			err = 10;
180 			goto out_invalid;
181 		}
182 		break;
183 	case S_IFDIR:
184 		inode->i_op  = &ubifs_dir_inode_operations;
185 		inode->i_fop = &ubifs_dir_operations;
186 		if (ui->data_len != 0) {
187 			err = 11;
188 			goto out_invalid;
189 		}
190 		break;
191 	case S_IFLNK:
192 		inode->i_op = &ubifs_symlink_inode_operations;
193 		if (ui->data_len <= 0 || ui->data_len > UBIFS_MAX_INO_DATA) {
194 			err = 12;
195 			goto out_invalid;
196 		}
197 		ui->data = kmalloc(ui->data_len + 1, GFP_NOFS);
198 		if (!ui->data) {
199 			err = -ENOMEM;
200 			goto out_ino;
201 		}
202 		memcpy(ui->data, ino->data, ui->data_len);
203 		((char *)ui->data)[ui->data_len] = '\0';
204 		break;
205 	case S_IFBLK:
206 	case S_IFCHR:
207 	{
208 		dev_t rdev;
209 		union ubifs_dev_desc *dev;
210 
211 		ui->data = kmalloc(sizeof(union ubifs_dev_desc), GFP_NOFS);
212 		if (!ui->data) {
213 			err = -ENOMEM;
214 			goto out_ino;
215 		}
216 
217 		dev = (union ubifs_dev_desc *)ino->data;
218 		if (ui->data_len == sizeof(dev->new))
219 			rdev = new_decode_dev(le32_to_cpu(dev->new));
220 		else if (ui->data_len == sizeof(dev->huge))
221 			rdev = huge_decode_dev(le64_to_cpu(dev->huge));
222 		else {
223 			err = 13;
224 			goto out_invalid;
225 		}
226 		memcpy(ui->data, ino->data, ui->data_len);
227 		inode->i_op = &ubifs_file_inode_operations;
228 		init_special_inode(inode, inode->i_mode, rdev);
229 		break;
230 	}
231 	case S_IFSOCK:
232 	case S_IFIFO:
233 		inode->i_op = &ubifs_file_inode_operations;
234 		init_special_inode(inode, inode->i_mode, 0);
235 		if (ui->data_len != 0) {
236 			err = 14;
237 			goto out_invalid;
238 		}
239 		break;
240 	default:
241 		err = 15;
242 		goto out_invalid;
243 	}
244 
245 	kfree(ino);
246 	ubifs_set_inode_flags(inode);
247 	unlock_new_inode(inode);
248 	return inode;
249 
250 out_invalid:
251 	ubifs_err(c, "inode %lu validation failed, error %d", inode->i_ino, err);
252 	ubifs_dump_node(c, ino, UBIFS_MAX_INO_NODE_SZ);
253 	ubifs_dump_inode(c, inode);
254 	err = -EINVAL;
255 out_ino:
256 	kfree(ino);
257 out:
258 	ubifs_err(c, "failed to read inode %lu, error %d", inode->i_ino, err);
259 	iget_failed(inode);
260 	return ERR_PTR(err);
261 }
262 
ubifs_alloc_inode(struct super_block * sb)263 static struct inode *ubifs_alloc_inode(struct super_block *sb)
264 {
265 	struct ubifs_inode *ui;
266 
267 	ui = alloc_inode_sb(sb, ubifs_inode_slab, GFP_NOFS);
268 	if (!ui)
269 		return NULL;
270 
271 	memset((void *)ui + sizeof(struct inode), 0,
272 	       sizeof(struct ubifs_inode) - sizeof(struct inode));
273 	mutex_init(&ui->ui_mutex);
274 	init_rwsem(&ui->xattr_sem);
275 	spin_lock_init(&ui->ui_lock);
276 	return &ui->vfs_inode;
277 };
278 
ubifs_free_inode(struct inode * inode)279 static void ubifs_free_inode(struct inode *inode)
280 {
281 	struct ubifs_inode *ui = ubifs_inode(inode);
282 
283 	kfree(ui->data);
284 	fscrypt_free_inode(inode);
285 
286 	kmem_cache_free(ubifs_inode_slab, ui);
287 }
288 
289 /*
290  * Note, Linux write-back code calls this without 'i_mutex'.
291  */
ubifs_write_inode(struct inode * inode,struct writeback_control * wbc)292 static int ubifs_write_inode(struct inode *inode, struct writeback_control *wbc)
293 {
294 	int err = 0;
295 	struct ubifs_info *c = inode->i_sb->s_fs_info;
296 	struct ubifs_inode *ui = ubifs_inode(inode);
297 
298 	ubifs_assert(c, !ui->xattr);
299 	if (is_bad_inode(inode))
300 		return 0;
301 
302 	mutex_lock(&ui->ui_mutex);
303 	/*
304 	 * Due to races between write-back forced by budgeting
305 	 * (see 'sync_some_inodes()') and background write-back, the inode may
306 	 * have already been synchronized, do not do this again. This might
307 	 * also happen if it was synchronized in an VFS operation, e.g.
308 	 * 'ubifs_link()'.
309 	 */
310 	if (!ui->dirty) {
311 		mutex_unlock(&ui->ui_mutex);
312 		return 0;
313 	}
314 
315 	/*
316 	 * As an optimization, do not write orphan inodes to the media just
317 	 * because this is not needed.
318 	 */
319 	dbg_gen("inode %lu, mode %#x, nlink %u",
320 		inode->i_ino, (int)inode->i_mode, inode->i_nlink);
321 	if (inode->i_nlink) {
322 		err = ubifs_jnl_write_inode(c, inode);
323 		if (err)
324 			ubifs_err(c, "can't write inode %lu, error %d",
325 				  inode->i_ino, err);
326 		else
327 			err = dbg_check_inode_size(c, inode, ui->ui_size);
328 	}
329 
330 	ui->dirty = 0;
331 	mutex_unlock(&ui->ui_mutex);
332 	ubifs_release_dirty_inode_budget(c, ui);
333 	return err;
334 }
335 
ubifs_drop_inode(struct inode * inode)336 static int ubifs_drop_inode(struct inode *inode)
337 {
338 	int drop = generic_drop_inode(inode);
339 
340 	if (!drop)
341 		drop = fscrypt_drop_inode(inode);
342 
343 	return drop;
344 }
345 
ubifs_evict_inode(struct inode * inode)346 static void ubifs_evict_inode(struct inode *inode)
347 {
348 	int err;
349 	struct ubifs_info *c = inode->i_sb->s_fs_info;
350 	struct ubifs_inode *ui = ubifs_inode(inode);
351 
352 	if (ui->xattr)
353 		/*
354 		 * Extended attribute inode deletions are fully handled in
355 		 * 'ubifs_removexattr()'. These inodes are special and have
356 		 * limited usage, so there is nothing to do here.
357 		 */
358 		goto out;
359 
360 	dbg_gen("inode %lu, mode %#x", inode->i_ino, (int)inode->i_mode);
361 	ubifs_assert(c, !atomic_read(&inode->i_count));
362 
363 	truncate_inode_pages_final(&inode->i_data);
364 
365 	if (inode->i_nlink)
366 		goto done;
367 
368 	if (is_bad_inode(inode))
369 		goto out;
370 
371 	ui->ui_size = inode->i_size = 0;
372 	err = ubifs_jnl_delete_inode(c, inode);
373 	if (err)
374 		/*
375 		 * Worst case we have a lost orphan inode wasting space, so a
376 		 * simple error message is OK here.
377 		 */
378 		ubifs_err(c, "can't delete inode %lu, error %d",
379 			  inode->i_ino, err);
380 
381 out:
382 	if (ui->dirty)
383 		ubifs_release_dirty_inode_budget(c, ui);
384 	else {
385 		/* We've deleted something - clean the "no space" flags */
386 		c->bi.nospace = c->bi.nospace_rp = 0;
387 		smp_wmb();
388 	}
389 done:
390 	clear_inode(inode);
391 	fscrypt_put_encryption_info(inode);
392 }
393 
ubifs_dirty_inode(struct inode * inode,int flags)394 static void ubifs_dirty_inode(struct inode *inode, int flags)
395 {
396 	struct ubifs_info *c = inode->i_sb->s_fs_info;
397 	struct ubifs_inode *ui = ubifs_inode(inode);
398 
399 	ubifs_assert(c, mutex_is_locked(&ui->ui_mutex));
400 	if (!ui->dirty) {
401 		ui->dirty = 1;
402 		dbg_gen("inode %lu",  inode->i_ino);
403 	}
404 }
405 
ubifs_statfs(struct dentry * dentry,struct kstatfs * buf)406 static int ubifs_statfs(struct dentry *dentry, struct kstatfs *buf)
407 {
408 	struct ubifs_info *c = dentry->d_sb->s_fs_info;
409 	unsigned long long free;
410 	__le32 *uuid = (__le32 *)c->uuid;
411 
412 	free = ubifs_get_free_space(c);
413 	dbg_gen("free space %lld bytes (%lld blocks)",
414 		free, free >> UBIFS_BLOCK_SHIFT);
415 
416 	buf->f_type = UBIFS_SUPER_MAGIC;
417 	buf->f_bsize = UBIFS_BLOCK_SIZE;
418 	buf->f_blocks = c->block_cnt;
419 	buf->f_bfree = free >> UBIFS_BLOCK_SHIFT;
420 	if (free > c->report_rp_size)
421 		buf->f_bavail = (free - c->report_rp_size) >> UBIFS_BLOCK_SHIFT;
422 	else
423 		buf->f_bavail = 0;
424 	buf->f_files = 0;
425 	buf->f_ffree = 0;
426 	buf->f_namelen = UBIFS_MAX_NLEN;
427 	buf->f_fsid.val[0] = le32_to_cpu(uuid[0]) ^ le32_to_cpu(uuid[2]);
428 	buf->f_fsid.val[1] = le32_to_cpu(uuid[1]) ^ le32_to_cpu(uuid[3]);
429 	ubifs_assert(c, buf->f_bfree <= c->block_cnt);
430 	return 0;
431 }
432 
ubifs_show_options(struct seq_file * s,struct dentry * root)433 static int ubifs_show_options(struct seq_file *s, struct dentry *root)
434 {
435 	struct ubifs_info *c = root->d_sb->s_fs_info;
436 
437 	if (c->mount_opts.unmount_mode == 2)
438 		seq_puts(s, ",fast_unmount");
439 	else if (c->mount_opts.unmount_mode == 1)
440 		seq_puts(s, ",norm_unmount");
441 
442 	if (c->mount_opts.bulk_read == 2)
443 		seq_puts(s, ",bulk_read");
444 	else if (c->mount_opts.bulk_read == 1)
445 		seq_puts(s, ",no_bulk_read");
446 
447 	if (c->mount_opts.chk_data_crc == 2)
448 		seq_puts(s, ",chk_data_crc");
449 	else if (c->mount_opts.chk_data_crc == 1)
450 		seq_puts(s, ",no_chk_data_crc");
451 
452 	if (c->mount_opts.override_compr) {
453 		seq_printf(s, ",compr=%s",
454 			   ubifs_compr_name(c, c->mount_opts.compr_type));
455 	}
456 
457 	seq_printf(s, ",assert=%s", ubifs_assert_action_name(c));
458 	seq_printf(s, ",ubi=%d,vol=%d", c->vi.ubi_num, c->vi.vol_id);
459 
460 	return 0;
461 }
462 
ubifs_sync_fs(struct super_block * sb,int wait)463 static int ubifs_sync_fs(struct super_block *sb, int wait)
464 {
465 	int i, err;
466 	struct ubifs_info *c = sb->s_fs_info;
467 
468 	/*
469 	 * Zero @wait is just an advisory thing to help the file system shove
470 	 * lots of data into the queues, and there will be the second
471 	 * '->sync_fs()' call, with non-zero @wait.
472 	 */
473 	if (!wait)
474 		return 0;
475 
476 	/*
477 	 * Synchronize write buffers, because 'ubifs_run_commit()' does not
478 	 * do this if it waits for an already running commit.
479 	 */
480 	for (i = 0; i < c->jhead_cnt; i++) {
481 		err = ubifs_wbuf_sync(&c->jheads[i].wbuf);
482 		if (err)
483 			return err;
484 	}
485 
486 	/*
487 	 * Strictly speaking, it is not necessary to commit the journal here,
488 	 * synchronizing write-buffers would be enough. But committing makes
489 	 * UBIFS free space predictions much more accurate, so we want to let
490 	 * the user be able to get more accurate results of 'statfs()' after
491 	 * they synchronize the file system.
492 	 */
493 	err = ubifs_run_commit(c);
494 	if (err)
495 		return err;
496 
497 	return ubi_sync(c->vi.ubi_num);
498 }
499 
500 /**
501  * init_constants_early - initialize UBIFS constants.
502  * @c: UBIFS file-system description object
503  *
504  * This function initialize UBIFS constants which do not need the superblock to
505  * be read. It also checks that the UBI volume satisfies basic UBIFS
506  * requirements. Returns zero in case of success and a negative error code in
507  * case of failure.
508  */
init_constants_early(struct ubifs_info * c)509 static int init_constants_early(struct ubifs_info *c)
510 {
511 	if (c->vi.corrupted) {
512 		ubifs_warn(c, "UBI volume is corrupted - read-only mode");
513 		c->ro_media = 1;
514 	}
515 
516 	if (c->di.ro_mode) {
517 		ubifs_msg(c, "read-only UBI device");
518 		c->ro_media = 1;
519 	}
520 
521 	if (c->vi.vol_type == UBI_STATIC_VOLUME) {
522 		ubifs_msg(c, "static UBI volume - read-only mode");
523 		c->ro_media = 1;
524 	}
525 
526 	c->leb_cnt = c->vi.size;
527 	c->leb_size = c->vi.usable_leb_size;
528 	c->leb_start = c->di.leb_start;
529 	c->half_leb_size = c->leb_size / 2;
530 	c->min_io_size = c->di.min_io_size;
531 	c->min_io_shift = fls(c->min_io_size) - 1;
532 	c->max_write_size = c->di.max_write_size;
533 	c->max_write_shift = fls(c->max_write_size) - 1;
534 
535 	if (c->leb_size < UBIFS_MIN_LEB_SZ) {
536 		ubifs_errc(c, "too small LEBs (%d bytes), min. is %d bytes",
537 			   c->leb_size, UBIFS_MIN_LEB_SZ);
538 		return -EINVAL;
539 	}
540 
541 	if (c->leb_cnt < UBIFS_MIN_LEB_CNT) {
542 		ubifs_errc(c, "too few LEBs (%d), min. is %d",
543 			   c->leb_cnt, UBIFS_MIN_LEB_CNT);
544 		return -EINVAL;
545 	}
546 
547 	if (!is_power_of_2(c->min_io_size)) {
548 		ubifs_errc(c, "bad min. I/O size %d", c->min_io_size);
549 		return -EINVAL;
550 	}
551 
552 	/*
553 	 * Maximum write size has to be greater or equivalent to min. I/O
554 	 * size, and be multiple of min. I/O size.
555 	 */
556 	if (c->max_write_size < c->min_io_size ||
557 	    c->max_write_size % c->min_io_size ||
558 	    !is_power_of_2(c->max_write_size)) {
559 		ubifs_errc(c, "bad write buffer size %d for %d min. I/O unit",
560 			   c->max_write_size, c->min_io_size);
561 		return -EINVAL;
562 	}
563 
564 	/*
565 	 * UBIFS aligns all node to 8-byte boundary, so to make function in
566 	 * io.c simpler, assume minimum I/O unit size to be 8 bytes if it is
567 	 * less than 8.
568 	 */
569 	if (c->min_io_size < 8) {
570 		c->min_io_size = 8;
571 		c->min_io_shift = 3;
572 		if (c->max_write_size < c->min_io_size) {
573 			c->max_write_size = c->min_io_size;
574 			c->max_write_shift = c->min_io_shift;
575 		}
576 	}
577 
578 	c->ref_node_alsz = ALIGN(UBIFS_REF_NODE_SZ, c->min_io_size);
579 	c->mst_node_alsz = ALIGN(UBIFS_MST_NODE_SZ, c->min_io_size);
580 
581 	/*
582 	 * Initialize node length ranges which are mostly needed for node
583 	 * length validation.
584 	 */
585 	c->ranges[UBIFS_PAD_NODE].len  = UBIFS_PAD_NODE_SZ;
586 	c->ranges[UBIFS_SB_NODE].len   = UBIFS_SB_NODE_SZ;
587 	c->ranges[UBIFS_MST_NODE].len  = UBIFS_MST_NODE_SZ;
588 	c->ranges[UBIFS_REF_NODE].len  = UBIFS_REF_NODE_SZ;
589 	c->ranges[UBIFS_TRUN_NODE].len = UBIFS_TRUN_NODE_SZ;
590 	c->ranges[UBIFS_CS_NODE].len   = UBIFS_CS_NODE_SZ;
591 	c->ranges[UBIFS_AUTH_NODE].min_len = UBIFS_AUTH_NODE_SZ;
592 	c->ranges[UBIFS_AUTH_NODE].max_len = UBIFS_AUTH_NODE_SZ +
593 				UBIFS_MAX_HMAC_LEN;
594 	c->ranges[UBIFS_SIG_NODE].min_len = UBIFS_SIG_NODE_SZ;
595 	c->ranges[UBIFS_SIG_NODE].max_len = c->leb_size - UBIFS_SB_NODE_SZ;
596 
597 	c->ranges[UBIFS_INO_NODE].min_len  = UBIFS_INO_NODE_SZ;
598 	c->ranges[UBIFS_INO_NODE].max_len  = UBIFS_MAX_INO_NODE_SZ;
599 	c->ranges[UBIFS_ORPH_NODE].min_len =
600 				UBIFS_ORPH_NODE_SZ + sizeof(__le64);
601 	c->ranges[UBIFS_ORPH_NODE].max_len = c->leb_size;
602 	c->ranges[UBIFS_DENT_NODE].min_len = UBIFS_DENT_NODE_SZ;
603 	c->ranges[UBIFS_DENT_NODE].max_len = UBIFS_MAX_DENT_NODE_SZ;
604 	c->ranges[UBIFS_XENT_NODE].min_len = UBIFS_XENT_NODE_SZ;
605 	c->ranges[UBIFS_XENT_NODE].max_len = UBIFS_MAX_XENT_NODE_SZ;
606 	c->ranges[UBIFS_DATA_NODE].min_len = UBIFS_DATA_NODE_SZ;
607 	c->ranges[UBIFS_DATA_NODE].max_len = UBIFS_MAX_DATA_NODE_SZ;
608 	/*
609 	 * Minimum indexing node size is amended later when superblock is
610 	 * read and the key length is known.
611 	 */
612 	c->ranges[UBIFS_IDX_NODE].min_len = UBIFS_IDX_NODE_SZ + UBIFS_BRANCH_SZ;
613 	/*
614 	 * Maximum indexing node size is amended later when superblock is
615 	 * read and the fanout is known.
616 	 */
617 	c->ranges[UBIFS_IDX_NODE].max_len = INT_MAX;
618 
619 	/*
620 	 * Initialize dead and dark LEB space watermarks. See gc.c for comments
621 	 * about these values.
622 	 */
623 	c->dead_wm = ALIGN(MIN_WRITE_SZ, c->min_io_size);
624 	c->dark_wm = ALIGN(UBIFS_MAX_NODE_SZ, c->min_io_size);
625 
626 	/*
627 	 * Calculate how many bytes would be wasted at the end of LEB if it was
628 	 * fully filled with data nodes of maximum size. This is used in
629 	 * calculations when reporting free space.
630 	 */
631 	c->leb_overhead = c->leb_size % UBIFS_MAX_DATA_NODE_SZ;
632 
633 	/* Buffer size for bulk-reads */
634 	c->max_bu_buf_len = UBIFS_MAX_BULK_READ * UBIFS_MAX_DATA_NODE_SZ;
635 	if (c->max_bu_buf_len > c->leb_size)
636 		c->max_bu_buf_len = c->leb_size;
637 
638 	/* Log is ready, preserve one LEB for commits. */
639 	c->min_log_bytes = c->leb_size;
640 
641 	return 0;
642 }
643 
644 /**
645  * bud_wbuf_callback - bud LEB write-buffer synchronization call-back.
646  * @c: UBIFS file-system description object
647  * @lnum: LEB the write-buffer was synchronized to
648  * @free: how many free bytes left in this LEB
649  * @pad: how many bytes were padded
650  *
651  * This is a callback function which is called by the I/O unit when the
652  * write-buffer is synchronized. We need this to correctly maintain space
653  * accounting in bud logical eraseblocks. This function returns zero in case of
654  * success and a negative error code in case of failure.
655  *
656  * This function actually belongs to the journal, but we keep it here because
657  * we want to keep it static.
658  */
bud_wbuf_callback(struct ubifs_info * c,int lnum,int free,int pad)659 static int bud_wbuf_callback(struct ubifs_info *c, int lnum, int free, int pad)
660 {
661 	return ubifs_update_one_lp(c, lnum, free, pad, 0, 0);
662 }
663 
664 /*
665  * init_constants_sb - initialize UBIFS constants.
666  * @c: UBIFS file-system description object
667  *
668  * This is a helper function which initializes various UBIFS constants after
669  * the superblock has been read. It also checks various UBIFS parameters and
670  * makes sure they are all right. Returns zero in case of success and a
671  * negative error code in case of failure.
672  */
init_constants_sb(struct ubifs_info * c)673 static int init_constants_sb(struct ubifs_info *c)
674 {
675 	int tmp, err;
676 	long long tmp64;
677 
678 	c->main_bytes = (long long)c->main_lebs * c->leb_size;
679 	c->max_znode_sz = sizeof(struct ubifs_znode) +
680 				c->fanout * sizeof(struct ubifs_zbranch);
681 
682 	tmp = ubifs_idx_node_sz(c, 1);
683 	c->ranges[UBIFS_IDX_NODE].min_len = tmp;
684 	c->min_idx_node_sz = ALIGN(tmp, 8);
685 
686 	tmp = ubifs_idx_node_sz(c, c->fanout);
687 	c->ranges[UBIFS_IDX_NODE].max_len = tmp;
688 	c->max_idx_node_sz = ALIGN(tmp, 8);
689 
690 	/* Make sure LEB size is large enough to fit full commit */
691 	tmp = UBIFS_CS_NODE_SZ + UBIFS_REF_NODE_SZ * c->jhead_cnt;
692 	tmp = ALIGN(tmp, c->min_io_size);
693 	if (tmp > c->leb_size) {
694 		ubifs_err(c, "too small LEB size %d, at least %d needed",
695 			  c->leb_size, tmp);
696 		return -EINVAL;
697 	}
698 
699 	/*
700 	 * Make sure that the log is large enough to fit reference nodes for
701 	 * all buds plus one reserved LEB.
702 	 */
703 	tmp64 = c->max_bud_bytes + c->leb_size - 1;
704 	c->max_bud_cnt = div_u64(tmp64, c->leb_size);
705 	tmp = (c->ref_node_alsz * c->max_bud_cnt + c->leb_size - 1);
706 	tmp /= c->leb_size;
707 	tmp += 1;
708 	if (c->log_lebs < tmp) {
709 		ubifs_err(c, "too small log %d LEBs, required min. %d LEBs",
710 			  c->log_lebs, tmp);
711 		return -EINVAL;
712 	}
713 
714 	/*
715 	 * When budgeting we assume worst-case scenarios when the pages are not
716 	 * be compressed and direntries are of the maximum size.
717 	 *
718 	 * Note, data, which may be stored in inodes is budgeted separately, so
719 	 * it is not included into 'c->bi.inode_budget'.
720 	 */
721 	c->bi.page_budget = UBIFS_MAX_DATA_NODE_SZ * UBIFS_BLOCKS_PER_PAGE;
722 	c->bi.inode_budget = UBIFS_INO_NODE_SZ;
723 	c->bi.dent_budget = UBIFS_MAX_DENT_NODE_SZ;
724 
725 	/*
726 	 * When the amount of flash space used by buds becomes
727 	 * 'c->max_bud_bytes', UBIFS just blocks all writers and starts commit.
728 	 * The writers are unblocked when the commit is finished. To avoid
729 	 * writers to be blocked UBIFS initiates background commit in advance,
730 	 * when number of bud bytes becomes above the limit defined below.
731 	 */
732 	c->bg_bud_bytes = (c->max_bud_bytes * 13) >> 4;
733 
734 	/*
735 	 * Ensure minimum journal size. All the bytes in the journal heads are
736 	 * considered to be used, when calculating the current journal usage.
737 	 * Consequently, if the journal is too small, UBIFS will treat it as
738 	 * always full.
739 	 */
740 	tmp64 = (long long)(c->jhead_cnt + 1) * c->leb_size + 1;
741 	if (c->bg_bud_bytes < tmp64)
742 		c->bg_bud_bytes = tmp64;
743 	if (c->max_bud_bytes < tmp64 + c->leb_size)
744 		c->max_bud_bytes = tmp64 + c->leb_size;
745 
746 	err = ubifs_calc_lpt_geom(c);
747 	if (err)
748 		return err;
749 
750 	/* Initialize effective LEB size used in budgeting calculations */
751 	c->idx_leb_size = c->leb_size - c->max_idx_node_sz;
752 	return 0;
753 }
754 
755 /*
756  * init_constants_master - initialize UBIFS constants.
757  * @c: UBIFS file-system description object
758  *
759  * This is a helper function which initializes various UBIFS constants after
760  * the master node has been read. It also checks various UBIFS parameters and
761  * makes sure they are all right.
762  */
init_constants_master(struct ubifs_info * c)763 static void init_constants_master(struct ubifs_info *c)
764 {
765 	long long tmp64;
766 
767 	c->bi.min_idx_lebs = ubifs_calc_min_idx_lebs(c);
768 	c->report_rp_size = ubifs_reported_space(c, c->rp_size);
769 
770 	/*
771 	 * Calculate total amount of FS blocks. This number is not used
772 	 * internally because it does not make much sense for UBIFS, but it is
773 	 * necessary to report something for the 'statfs()' call.
774 	 *
775 	 * Subtract the LEB reserved for GC, the LEB which is reserved for
776 	 * deletions, minimum LEBs for the index, and assume only one journal
777 	 * head is available.
778 	 */
779 	tmp64 = c->main_lebs - 1 - 1 - MIN_INDEX_LEBS - c->jhead_cnt + 1;
780 	tmp64 *= (long long)c->leb_size - c->leb_overhead;
781 	tmp64 = ubifs_reported_space(c, tmp64);
782 	c->block_cnt = tmp64 >> UBIFS_BLOCK_SHIFT;
783 }
784 
785 /**
786  * take_gc_lnum - reserve GC LEB.
787  * @c: UBIFS file-system description object
788  *
789  * This function ensures that the LEB reserved for garbage collection is marked
790  * as "taken" in lprops. We also have to set free space to LEB size and dirty
791  * space to zero, because lprops may contain out-of-date information if the
792  * file-system was un-mounted before it has been committed. This function
793  * returns zero in case of success and a negative error code in case of
794  * failure.
795  */
take_gc_lnum(struct ubifs_info * c)796 static int take_gc_lnum(struct ubifs_info *c)
797 {
798 	int err;
799 
800 	if (c->gc_lnum == -1) {
801 		ubifs_err(c, "no LEB for GC");
802 		return -EINVAL;
803 	}
804 
805 	/* And we have to tell lprops that this LEB is taken */
806 	err = ubifs_change_one_lp(c, c->gc_lnum, c->leb_size, 0,
807 				  LPROPS_TAKEN, 0, 0);
808 	return err;
809 }
810 
811 /**
812  * alloc_wbufs - allocate write-buffers.
813  * @c: UBIFS file-system description object
814  *
815  * This helper function allocates and initializes UBIFS write-buffers. Returns
816  * zero in case of success and %-ENOMEM in case of failure.
817  */
alloc_wbufs(struct ubifs_info * c)818 static int alloc_wbufs(struct ubifs_info *c)
819 {
820 	int i, err;
821 
822 	c->jheads = kcalloc(c->jhead_cnt, sizeof(struct ubifs_jhead),
823 			    GFP_KERNEL);
824 	if (!c->jheads)
825 		return -ENOMEM;
826 
827 	/* Initialize journal heads */
828 	for (i = 0; i < c->jhead_cnt; i++) {
829 		INIT_LIST_HEAD(&c->jheads[i].buds_list);
830 		err = ubifs_wbuf_init(c, &c->jheads[i].wbuf);
831 		if (err)
832 			goto out_wbuf;
833 
834 		c->jheads[i].wbuf.sync_callback = &bud_wbuf_callback;
835 		c->jheads[i].wbuf.jhead = i;
836 		c->jheads[i].grouped = 1;
837 		c->jheads[i].log_hash = ubifs_hash_get_desc(c);
838 		if (IS_ERR(c->jheads[i].log_hash)) {
839 			err = PTR_ERR(c->jheads[i].log_hash);
840 			goto out_log_hash;
841 		}
842 	}
843 
844 	/*
845 	 * Garbage Collector head does not need to be synchronized by timer.
846 	 * Also GC head nodes are not grouped.
847 	 */
848 	c->jheads[GCHD].wbuf.no_timer = 1;
849 	c->jheads[GCHD].grouped = 0;
850 
851 	return 0;
852 
853 out_log_hash:
854 	kfree(c->jheads[i].wbuf.buf);
855 	kfree(c->jheads[i].wbuf.inodes);
856 
857 out_wbuf:
858 	while (i--) {
859 		kfree(c->jheads[i].wbuf.buf);
860 		kfree(c->jheads[i].wbuf.inodes);
861 		kfree(c->jheads[i].log_hash);
862 	}
863 	kfree(c->jheads);
864 	c->jheads = NULL;
865 
866 	return err;
867 }
868 
869 /**
870  * free_wbufs - free write-buffers.
871  * @c: UBIFS file-system description object
872  */
free_wbufs(struct ubifs_info * c)873 static void free_wbufs(struct ubifs_info *c)
874 {
875 	int i;
876 
877 	if (c->jheads) {
878 		for (i = 0; i < c->jhead_cnt; i++) {
879 			kfree(c->jheads[i].wbuf.buf);
880 			kfree(c->jheads[i].wbuf.inodes);
881 			kfree(c->jheads[i].log_hash);
882 		}
883 		kfree(c->jheads);
884 		c->jheads = NULL;
885 	}
886 }
887 
888 /**
889  * free_orphans - free orphans.
890  * @c: UBIFS file-system description object
891  */
free_orphans(struct ubifs_info * c)892 static void free_orphans(struct ubifs_info *c)
893 {
894 	struct ubifs_orphan *orph;
895 
896 	while (c->orph_dnext) {
897 		orph = c->orph_dnext;
898 		c->orph_dnext = orph->dnext;
899 		list_del(&orph->list);
900 		kfree(orph);
901 	}
902 
903 	while (!list_empty(&c->orph_list)) {
904 		orph = list_entry(c->orph_list.next, struct ubifs_orphan, list);
905 		list_del(&orph->list);
906 		kfree(orph);
907 		ubifs_err(c, "orphan list not empty at unmount");
908 	}
909 
910 	vfree(c->orph_buf);
911 	c->orph_buf = NULL;
912 }
913 
914 /**
915  * free_buds - free per-bud objects.
916  * @c: UBIFS file-system description object
917  */
free_buds(struct ubifs_info * c)918 static void free_buds(struct ubifs_info *c)
919 {
920 	struct ubifs_bud *bud, *n;
921 
922 	rbtree_postorder_for_each_entry_safe(bud, n, &c->buds, rb) {
923 		kfree(bud->log_hash);
924 		kfree(bud);
925 	}
926 }
927 
928 /**
929  * check_volume_empty - check if the UBI volume is empty.
930  * @c: UBIFS file-system description object
931  *
932  * This function checks if the UBIFS volume is empty by looking if its LEBs are
933  * mapped or not. The result of checking is stored in the @c->empty variable.
934  * Returns zero in case of success and a negative error code in case of
935  * failure.
936  */
check_volume_empty(struct ubifs_info * c)937 static int check_volume_empty(struct ubifs_info *c)
938 {
939 	int lnum, err;
940 
941 	c->empty = 1;
942 	for (lnum = 0; lnum < c->leb_cnt; lnum++) {
943 		err = ubifs_is_mapped(c, lnum);
944 		if (unlikely(err < 0))
945 			return err;
946 		if (err == 1) {
947 			c->empty = 0;
948 			break;
949 		}
950 
951 		cond_resched();
952 	}
953 
954 	return 0;
955 }
956 
957 /*
958  * UBIFS mount options.
959  *
960  * Opt_fast_unmount: do not run a journal commit before un-mounting
961  * Opt_norm_unmount: run a journal commit before un-mounting
962  * Opt_bulk_read: enable bulk-reads
963  * Opt_no_bulk_read: disable bulk-reads
964  * Opt_chk_data_crc: check CRCs when reading data nodes
965  * Opt_no_chk_data_crc: do not check CRCs when reading data nodes
966  * Opt_override_compr: override default compressor
967  * Opt_assert: set ubifs_assert() action
968  * Opt_auth_key: The key name used for authentication
969  * Opt_auth_hash_name: The hash type used for authentication
970  * Opt_err: just end of array marker
971  */
972 enum {
973 	Opt_fast_unmount,
974 	Opt_norm_unmount,
975 	Opt_bulk_read,
976 	Opt_no_bulk_read,
977 	Opt_chk_data_crc,
978 	Opt_no_chk_data_crc,
979 	Opt_override_compr,
980 	Opt_assert,
981 	Opt_auth_key,
982 	Opt_auth_hash_name,
983 	Opt_ignore,
984 	Opt_err,
985 };
986 
987 static const match_table_t tokens = {
988 	{Opt_fast_unmount, "fast_unmount"},
989 	{Opt_norm_unmount, "norm_unmount"},
990 	{Opt_bulk_read, "bulk_read"},
991 	{Opt_no_bulk_read, "no_bulk_read"},
992 	{Opt_chk_data_crc, "chk_data_crc"},
993 	{Opt_no_chk_data_crc, "no_chk_data_crc"},
994 	{Opt_override_compr, "compr=%s"},
995 	{Opt_auth_key, "auth_key=%s"},
996 	{Opt_auth_hash_name, "auth_hash_name=%s"},
997 	{Opt_ignore, "ubi=%s"},
998 	{Opt_ignore, "vol=%s"},
999 	{Opt_assert, "assert=%s"},
1000 	{Opt_err, NULL},
1001 };
1002 
1003 /**
1004  * parse_standard_option - parse a standard mount option.
1005  * @option: the option to parse
1006  *
1007  * Normally, standard mount options like "sync" are passed to file-systems as
1008  * flags. However, when a "rootflags=" kernel boot parameter is used, they may
1009  * be present in the options string. This function tries to deal with this
1010  * situation and parse standard options. Returns 0 if the option was not
1011  * recognized, and the corresponding integer flag if it was.
1012  *
1013  * UBIFS is only interested in the "sync" option, so do not check for anything
1014  * else.
1015  */
parse_standard_option(const char * option)1016 static int parse_standard_option(const char *option)
1017 {
1018 
1019 	pr_notice("UBIFS: parse %s\n", option);
1020 	if (!strcmp(option, "sync"))
1021 		return SB_SYNCHRONOUS;
1022 	return 0;
1023 }
1024 
1025 /**
1026  * ubifs_parse_options - parse mount parameters.
1027  * @c: UBIFS file-system description object
1028  * @options: parameters to parse
1029  * @is_remount: non-zero if this is FS re-mount
1030  *
1031  * This function parses UBIFS mount options and returns zero in case success
1032  * and a negative error code in case of failure.
1033  */
ubifs_parse_options(struct ubifs_info * c,char * options,int is_remount)1034 static int ubifs_parse_options(struct ubifs_info *c, char *options,
1035 			       int is_remount)
1036 {
1037 	char *p;
1038 	substring_t args[MAX_OPT_ARGS];
1039 
1040 	if (!options)
1041 		return 0;
1042 
1043 	while ((p = strsep(&options, ","))) {
1044 		int token;
1045 
1046 		if (!*p)
1047 			continue;
1048 
1049 		token = match_token(p, tokens, args);
1050 		switch (token) {
1051 		/*
1052 		 * %Opt_fast_unmount and %Opt_norm_unmount options are ignored.
1053 		 * We accept them in order to be backward-compatible. But this
1054 		 * should be removed at some point.
1055 		 */
1056 		case Opt_fast_unmount:
1057 			c->mount_opts.unmount_mode = 2;
1058 			break;
1059 		case Opt_norm_unmount:
1060 			c->mount_opts.unmount_mode = 1;
1061 			break;
1062 		case Opt_bulk_read:
1063 			c->mount_opts.bulk_read = 2;
1064 			c->bulk_read = 1;
1065 			break;
1066 		case Opt_no_bulk_read:
1067 			c->mount_opts.bulk_read = 1;
1068 			c->bulk_read = 0;
1069 			break;
1070 		case Opt_chk_data_crc:
1071 			c->mount_opts.chk_data_crc = 2;
1072 			c->no_chk_data_crc = 0;
1073 			break;
1074 		case Opt_no_chk_data_crc:
1075 			c->mount_opts.chk_data_crc = 1;
1076 			c->no_chk_data_crc = 1;
1077 			break;
1078 		case Opt_override_compr:
1079 		{
1080 			char *name = match_strdup(&args[0]);
1081 
1082 			if (!name)
1083 				return -ENOMEM;
1084 			if (!strcmp(name, "none"))
1085 				c->mount_opts.compr_type = UBIFS_COMPR_NONE;
1086 			else if (!strcmp(name, "lzo"))
1087 				c->mount_opts.compr_type = UBIFS_COMPR_LZO;
1088 			else if (!strcmp(name, "zlib"))
1089 				c->mount_opts.compr_type = UBIFS_COMPR_ZLIB;
1090 			else if (!strcmp(name, "zstd"))
1091 				c->mount_opts.compr_type = UBIFS_COMPR_ZSTD;
1092 			else {
1093 				ubifs_err(c, "unknown compressor \"%s\"", name); //FIXME: is c ready?
1094 				kfree(name);
1095 				return -EINVAL;
1096 			}
1097 			kfree(name);
1098 			c->mount_opts.override_compr = 1;
1099 			c->default_compr = c->mount_opts.compr_type;
1100 			break;
1101 		}
1102 		case Opt_assert:
1103 		{
1104 			char *act = match_strdup(&args[0]);
1105 
1106 			if (!act)
1107 				return -ENOMEM;
1108 			if (!strcmp(act, "report"))
1109 				c->assert_action = ASSACT_REPORT;
1110 			else if (!strcmp(act, "read-only"))
1111 				c->assert_action = ASSACT_RO;
1112 			else if (!strcmp(act, "panic"))
1113 				c->assert_action = ASSACT_PANIC;
1114 			else {
1115 				ubifs_err(c, "unknown assert action \"%s\"", act);
1116 				kfree(act);
1117 				return -EINVAL;
1118 			}
1119 			kfree(act);
1120 			break;
1121 		}
1122 		case Opt_auth_key:
1123 			if (!is_remount) {
1124 				c->auth_key_name = kstrdup(args[0].from,
1125 								GFP_KERNEL);
1126 				if (!c->auth_key_name)
1127 					return -ENOMEM;
1128 			}
1129 			break;
1130 		case Opt_auth_hash_name:
1131 			if (!is_remount) {
1132 				c->auth_hash_name = kstrdup(args[0].from,
1133 								GFP_KERNEL);
1134 				if (!c->auth_hash_name)
1135 					return -ENOMEM;
1136 			}
1137 			break;
1138 		case Opt_ignore:
1139 			break;
1140 		default:
1141 		{
1142 			unsigned long flag;
1143 			struct super_block *sb = c->vfs_sb;
1144 
1145 			flag = parse_standard_option(p);
1146 			if (!flag) {
1147 				ubifs_err(c, "unrecognized mount option \"%s\" or missing value",
1148 					  p);
1149 				return -EINVAL;
1150 			}
1151 			sb->s_flags |= flag;
1152 			break;
1153 		}
1154 		}
1155 	}
1156 
1157 	return 0;
1158 }
1159 
1160 /*
1161  * ubifs_release_options - release mount parameters which have been dumped.
1162  * @c: UBIFS file-system description object
1163  */
ubifs_release_options(struct ubifs_info * c)1164 static void ubifs_release_options(struct ubifs_info *c)
1165 {
1166 	kfree(c->auth_key_name);
1167 	c->auth_key_name = NULL;
1168 	kfree(c->auth_hash_name);
1169 	c->auth_hash_name = NULL;
1170 }
1171 
1172 /**
1173  * destroy_journal - destroy journal data structures.
1174  * @c: UBIFS file-system description object
1175  *
1176  * This function destroys journal data structures including those that may have
1177  * been created by recovery functions.
1178  */
destroy_journal(struct ubifs_info * c)1179 static void destroy_journal(struct ubifs_info *c)
1180 {
1181 	while (!list_empty(&c->unclean_leb_list)) {
1182 		struct ubifs_unclean_leb *ucleb;
1183 
1184 		ucleb = list_entry(c->unclean_leb_list.next,
1185 				   struct ubifs_unclean_leb, list);
1186 		list_del(&ucleb->list);
1187 		kfree(ucleb);
1188 	}
1189 	while (!list_empty(&c->old_buds)) {
1190 		struct ubifs_bud *bud;
1191 
1192 		bud = list_entry(c->old_buds.next, struct ubifs_bud, list);
1193 		list_del(&bud->list);
1194 		kfree(bud->log_hash);
1195 		kfree(bud);
1196 	}
1197 	ubifs_destroy_idx_gc(c);
1198 	ubifs_destroy_size_tree(c);
1199 	ubifs_tnc_close(c);
1200 	free_buds(c);
1201 }
1202 
1203 /**
1204  * bu_init - initialize bulk-read information.
1205  * @c: UBIFS file-system description object
1206  */
bu_init(struct ubifs_info * c)1207 static void bu_init(struct ubifs_info *c)
1208 {
1209 	ubifs_assert(c, c->bulk_read == 1);
1210 
1211 	if (c->bu.buf)
1212 		return; /* Already initialized */
1213 
1214 again:
1215 	c->bu.buf = kmalloc(c->max_bu_buf_len, GFP_KERNEL | __GFP_NOWARN);
1216 	if (!c->bu.buf) {
1217 		if (c->max_bu_buf_len > UBIFS_KMALLOC_OK) {
1218 			c->max_bu_buf_len = UBIFS_KMALLOC_OK;
1219 			goto again;
1220 		}
1221 
1222 		/* Just disable bulk-read */
1223 		ubifs_warn(c, "cannot allocate %d bytes of memory for bulk-read, disabling it",
1224 			   c->max_bu_buf_len);
1225 		c->mount_opts.bulk_read = 1;
1226 		c->bulk_read = 0;
1227 		return;
1228 	}
1229 }
1230 
1231 /**
1232  * check_free_space - check if there is enough free space to mount.
1233  * @c: UBIFS file-system description object
1234  *
1235  * This function makes sure UBIFS has enough free space to be mounted in
1236  * read/write mode. UBIFS must always have some free space to allow deletions.
1237  */
check_free_space(struct ubifs_info * c)1238 static int check_free_space(struct ubifs_info *c)
1239 {
1240 	ubifs_assert(c, c->dark_wm > 0);
1241 	if (c->lst.total_free + c->lst.total_dirty < c->dark_wm) {
1242 		ubifs_err(c, "insufficient free space to mount in R/W mode");
1243 		ubifs_dump_budg(c, &c->bi);
1244 		ubifs_dump_lprops(c);
1245 		return -ENOSPC;
1246 	}
1247 	return 0;
1248 }
1249 
1250 /**
1251  * mount_ubifs - mount UBIFS file-system.
1252  * @c: UBIFS file-system description object
1253  *
1254  * This function mounts UBIFS file system. Returns zero in case of success and
1255  * a negative error code in case of failure.
1256  */
mount_ubifs(struct ubifs_info * c)1257 static int mount_ubifs(struct ubifs_info *c)
1258 {
1259 	int err;
1260 	long long x, y;
1261 	size_t sz;
1262 
1263 	c->ro_mount = !!sb_rdonly(c->vfs_sb);
1264 	/* Suppress error messages while probing if SB_SILENT is set */
1265 	c->probing = !!(c->vfs_sb->s_flags & SB_SILENT);
1266 
1267 	err = init_constants_early(c);
1268 	if (err)
1269 		return err;
1270 
1271 	err = ubifs_debugging_init(c);
1272 	if (err)
1273 		return err;
1274 
1275 	err = ubifs_sysfs_register(c);
1276 	if (err)
1277 		goto out_debugging;
1278 
1279 	err = check_volume_empty(c);
1280 	if (err)
1281 		goto out_free;
1282 
1283 	if (c->empty && (c->ro_mount || c->ro_media)) {
1284 		/*
1285 		 * This UBI volume is empty, and read-only, or the file system
1286 		 * is mounted read-only - we cannot format it.
1287 		 */
1288 		ubifs_err(c, "can't format empty UBI volume: read-only %s",
1289 			  c->ro_media ? "UBI volume" : "mount");
1290 		err = -EROFS;
1291 		goto out_free;
1292 	}
1293 
1294 	if (c->ro_media && !c->ro_mount) {
1295 		ubifs_err(c, "cannot mount read-write - read-only media");
1296 		err = -EROFS;
1297 		goto out_free;
1298 	}
1299 
1300 	/*
1301 	 * The requirement for the buffer is that it should fit indexing B-tree
1302 	 * height amount of integers. We assume the height if the TNC tree will
1303 	 * never exceed 64.
1304 	 */
1305 	err = -ENOMEM;
1306 	c->bottom_up_buf = kmalloc_array(BOTTOM_UP_HEIGHT, sizeof(int),
1307 					 GFP_KERNEL);
1308 	if (!c->bottom_up_buf)
1309 		goto out_free;
1310 
1311 	c->sbuf = vmalloc(c->leb_size);
1312 	if (!c->sbuf)
1313 		goto out_free;
1314 
1315 	if (!c->ro_mount) {
1316 		c->ileb_buf = vmalloc(c->leb_size);
1317 		if (!c->ileb_buf)
1318 			goto out_free;
1319 	}
1320 
1321 	if (c->bulk_read == 1)
1322 		bu_init(c);
1323 
1324 	if (!c->ro_mount) {
1325 		c->write_reserve_buf = kmalloc(COMPRESSED_DATA_NODE_BUF_SZ + \
1326 					       UBIFS_CIPHER_BLOCK_SIZE,
1327 					       GFP_KERNEL);
1328 		if (!c->write_reserve_buf)
1329 			goto out_free;
1330 	}
1331 
1332 	c->mounting = 1;
1333 
1334 	if (c->auth_key_name) {
1335 		if (IS_ENABLED(CONFIG_UBIFS_FS_AUTHENTICATION)) {
1336 			err = ubifs_init_authentication(c);
1337 			if (err)
1338 				goto out_free;
1339 		} else {
1340 			ubifs_err(c, "auth_key_name, but UBIFS is built without"
1341 				  " authentication support");
1342 			err = -EINVAL;
1343 			goto out_free;
1344 		}
1345 	}
1346 
1347 	err = ubifs_read_superblock(c);
1348 	if (err)
1349 		goto out_auth;
1350 
1351 	c->probing = 0;
1352 
1353 	/*
1354 	 * Make sure the compressor which is set as default in the superblock
1355 	 * or overridden by mount options is actually compiled in.
1356 	 */
1357 	if (!ubifs_compr_present(c, c->default_compr)) {
1358 		ubifs_err(c, "'compressor \"%s\" is not compiled in",
1359 			  ubifs_compr_name(c, c->default_compr));
1360 		err = -ENOTSUPP;
1361 		goto out_auth;
1362 	}
1363 
1364 	err = init_constants_sb(c);
1365 	if (err)
1366 		goto out_auth;
1367 
1368 	sz = ALIGN(c->max_idx_node_sz, c->min_io_size) * 2;
1369 	c->cbuf = kmalloc(sz, GFP_NOFS);
1370 	if (!c->cbuf) {
1371 		err = -ENOMEM;
1372 		goto out_auth;
1373 	}
1374 
1375 	err = alloc_wbufs(c);
1376 	if (err)
1377 		goto out_cbuf;
1378 
1379 	sprintf(c->bgt_name, BGT_NAME_PATTERN, c->vi.ubi_num, c->vi.vol_id);
1380 	if (!c->ro_mount) {
1381 		/* Create background thread */
1382 		c->bgt = kthread_run(ubifs_bg_thread, c, "%s", c->bgt_name);
1383 		if (IS_ERR(c->bgt)) {
1384 			err = PTR_ERR(c->bgt);
1385 			c->bgt = NULL;
1386 			ubifs_err(c, "cannot spawn \"%s\", error %d",
1387 				  c->bgt_name, err);
1388 			goto out_wbufs;
1389 		}
1390 	}
1391 
1392 	err = ubifs_read_master(c);
1393 	if (err)
1394 		goto out_master;
1395 
1396 	init_constants_master(c);
1397 
1398 	if ((c->mst_node->flags & cpu_to_le32(UBIFS_MST_DIRTY)) != 0) {
1399 		ubifs_msg(c, "recovery needed");
1400 		c->need_recovery = 1;
1401 	}
1402 
1403 	if (c->need_recovery && !c->ro_mount) {
1404 		err = ubifs_recover_inl_heads(c, c->sbuf);
1405 		if (err)
1406 			goto out_master;
1407 	}
1408 
1409 	err = ubifs_lpt_init(c, 1, !c->ro_mount);
1410 	if (err)
1411 		goto out_master;
1412 
1413 	if (!c->ro_mount && c->space_fixup) {
1414 		err = ubifs_fixup_free_space(c);
1415 		if (err)
1416 			goto out_lpt;
1417 	}
1418 
1419 	if (!c->ro_mount && !c->need_recovery) {
1420 		/*
1421 		 * Set the "dirty" flag so that if we reboot uncleanly we
1422 		 * will notice this immediately on the next mount.
1423 		 */
1424 		c->mst_node->flags |= cpu_to_le32(UBIFS_MST_DIRTY);
1425 		err = ubifs_write_master(c);
1426 		if (err)
1427 			goto out_lpt;
1428 	}
1429 
1430 	/*
1431 	 * Handle offline signed images: Now that the master node is
1432 	 * written and its validation no longer depends on the hash
1433 	 * in the superblock, we can update the offline signed
1434 	 * superblock with a HMAC version,
1435 	 */
1436 	if (ubifs_authenticated(c) && ubifs_hmac_zero(c, c->sup_node->hmac)) {
1437 		err = ubifs_hmac_wkm(c, c->sup_node->hmac_wkm);
1438 		if (err)
1439 			goto out_lpt;
1440 		c->superblock_need_write = 1;
1441 	}
1442 
1443 	if (!c->ro_mount && c->superblock_need_write) {
1444 		err = ubifs_write_sb_node(c, c->sup_node);
1445 		if (err)
1446 			goto out_lpt;
1447 		c->superblock_need_write = 0;
1448 	}
1449 
1450 	err = dbg_check_idx_size(c, c->bi.old_idx_sz);
1451 	if (err)
1452 		goto out_lpt;
1453 
1454 	err = ubifs_replay_journal(c);
1455 	if (err)
1456 		goto out_journal;
1457 
1458 	/* Calculate 'min_idx_lebs' after journal replay */
1459 	c->bi.min_idx_lebs = ubifs_calc_min_idx_lebs(c);
1460 
1461 	err = ubifs_mount_orphans(c, c->need_recovery, c->ro_mount);
1462 	if (err)
1463 		goto out_orphans;
1464 
1465 	if (!c->ro_mount) {
1466 		int lnum;
1467 
1468 		err = check_free_space(c);
1469 		if (err)
1470 			goto out_orphans;
1471 
1472 		/* Check for enough log space */
1473 		lnum = c->lhead_lnum + 1;
1474 		if (lnum >= UBIFS_LOG_LNUM + c->log_lebs)
1475 			lnum = UBIFS_LOG_LNUM;
1476 		if (lnum == c->ltail_lnum) {
1477 			err = ubifs_consolidate_log(c);
1478 			if (err)
1479 				goto out_orphans;
1480 		}
1481 
1482 		if (c->need_recovery) {
1483 			if (!ubifs_authenticated(c)) {
1484 				err = ubifs_recover_size(c, true);
1485 				if (err)
1486 					goto out_orphans;
1487 			}
1488 
1489 			err = ubifs_rcvry_gc_commit(c);
1490 			if (err)
1491 				goto out_orphans;
1492 
1493 			if (ubifs_authenticated(c)) {
1494 				err = ubifs_recover_size(c, false);
1495 				if (err)
1496 					goto out_orphans;
1497 			}
1498 		} else {
1499 			err = take_gc_lnum(c);
1500 			if (err)
1501 				goto out_orphans;
1502 
1503 			/*
1504 			 * GC LEB may contain garbage if there was an unclean
1505 			 * reboot, and it should be un-mapped.
1506 			 */
1507 			err = ubifs_leb_unmap(c, c->gc_lnum);
1508 			if (err)
1509 				goto out_orphans;
1510 		}
1511 
1512 		err = dbg_check_lprops(c);
1513 		if (err)
1514 			goto out_orphans;
1515 	} else if (c->need_recovery) {
1516 		err = ubifs_recover_size(c, false);
1517 		if (err)
1518 			goto out_orphans;
1519 	} else {
1520 		/*
1521 		 * Even if we mount read-only, we have to set space in GC LEB
1522 		 * to proper value because this affects UBIFS free space
1523 		 * reporting. We do not want to have a situation when
1524 		 * re-mounting from R/O to R/W changes amount of free space.
1525 		 */
1526 		err = take_gc_lnum(c);
1527 		if (err)
1528 			goto out_orphans;
1529 	}
1530 
1531 	spin_lock(&ubifs_infos_lock);
1532 	list_add_tail(&c->infos_list, &ubifs_infos);
1533 	spin_unlock(&ubifs_infos_lock);
1534 
1535 	if (c->need_recovery) {
1536 		if (c->ro_mount)
1537 			ubifs_msg(c, "recovery deferred");
1538 		else {
1539 			c->need_recovery = 0;
1540 			ubifs_msg(c, "recovery completed");
1541 			/*
1542 			 * GC LEB has to be empty and taken at this point. But
1543 			 * the journal head LEBs may also be accounted as
1544 			 * "empty taken" if they are empty.
1545 			 */
1546 			ubifs_assert(c, c->lst.taken_empty_lebs > 0);
1547 		}
1548 	} else
1549 		ubifs_assert(c, c->lst.taken_empty_lebs > 0);
1550 
1551 	err = dbg_check_filesystem(c);
1552 	if (err)
1553 		goto out_infos;
1554 
1555 	dbg_debugfs_init_fs(c);
1556 
1557 	c->mounting = 0;
1558 
1559 	ubifs_msg(c, "UBIFS: mounted UBI device %d, volume %d, name \"%s\"%s",
1560 		  c->vi.ubi_num, c->vi.vol_id, c->vi.name,
1561 		  c->ro_mount ? ", R/O mode" : "");
1562 	x = (long long)c->main_lebs * c->leb_size;
1563 	y = (long long)c->log_lebs * c->leb_size + c->max_bud_bytes;
1564 	ubifs_msg(c, "LEB size: %d bytes (%d KiB), min./max. I/O unit sizes: %d bytes/%d bytes",
1565 		  c->leb_size, c->leb_size >> 10, c->min_io_size,
1566 		  c->max_write_size);
1567 	ubifs_msg(c, "FS size: %lld bytes (%lld MiB, %d LEBs), max %d LEBs, journal size %lld bytes (%lld MiB, %d LEBs)",
1568 		  x, x >> 20, c->main_lebs, c->max_leb_cnt,
1569 		  y, y >> 20, c->log_lebs + c->max_bud_cnt);
1570 	ubifs_msg(c, "reserved for root: %llu bytes (%llu KiB)",
1571 		  c->report_rp_size, c->report_rp_size >> 10);
1572 	ubifs_msg(c, "media format: w%d/r%d (latest is w%d/r%d), UUID %pUB%s",
1573 		  c->fmt_version, c->ro_compat_version,
1574 		  UBIFS_FORMAT_VERSION, UBIFS_RO_COMPAT_VERSION, c->uuid,
1575 		  c->big_lpt ? ", big LPT model" : ", small LPT model");
1576 
1577 	dbg_gen("default compressor:  %s", ubifs_compr_name(c, c->default_compr));
1578 	dbg_gen("data journal heads:  %d",
1579 		c->jhead_cnt - NONDATA_JHEADS_CNT);
1580 	dbg_gen("log LEBs:            %d (%d - %d)",
1581 		c->log_lebs, UBIFS_LOG_LNUM, c->log_last);
1582 	dbg_gen("LPT area LEBs:       %d (%d - %d)",
1583 		c->lpt_lebs, c->lpt_first, c->lpt_last);
1584 	dbg_gen("orphan area LEBs:    %d (%d - %d)",
1585 		c->orph_lebs, c->orph_first, c->orph_last);
1586 	dbg_gen("main area LEBs:      %d (%d - %d)",
1587 		c->main_lebs, c->main_first, c->leb_cnt - 1);
1588 	dbg_gen("index LEBs:          %d", c->lst.idx_lebs);
1589 	dbg_gen("total index bytes:   %llu (%llu KiB, %llu MiB)",
1590 		c->bi.old_idx_sz, c->bi.old_idx_sz >> 10,
1591 		c->bi.old_idx_sz >> 20);
1592 	dbg_gen("key hash type:       %d", c->key_hash_type);
1593 	dbg_gen("tree fanout:         %d", c->fanout);
1594 	dbg_gen("reserved GC LEB:     %d", c->gc_lnum);
1595 	dbg_gen("max. znode size      %d", c->max_znode_sz);
1596 	dbg_gen("max. index node size %d", c->max_idx_node_sz);
1597 	dbg_gen("node sizes:          data %zu, inode %zu, dentry %zu",
1598 		UBIFS_DATA_NODE_SZ, UBIFS_INO_NODE_SZ, UBIFS_DENT_NODE_SZ);
1599 	dbg_gen("node sizes:          trun %zu, sb %zu, master %zu",
1600 		UBIFS_TRUN_NODE_SZ, UBIFS_SB_NODE_SZ, UBIFS_MST_NODE_SZ);
1601 	dbg_gen("node sizes:          ref %zu, cmt. start %zu, orph %zu",
1602 		UBIFS_REF_NODE_SZ, UBIFS_CS_NODE_SZ, UBIFS_ORPH_NODE_SZ);
1603 	dbg_gen("max. node sizes:     data %zu, inode %zu dentry %zu, idx %d",
1604 		UBIFS_MAX_DATA_NODE_SZ, UBIFS_MAX_INO_NODE_SZ,
1605 		UBIFS_MAX_DENT_NODE_SZ, ubifs_idx_node_sz(c, c->fanout));
1606 	dbg_gen("dead watermark:      %d", c->dead_wm);
1607 	dbg_gen("dark watermark:      %d", c->dark_wm);
1608 	dbg_gen("LEB overhead:        %d", c->leb_overhead);
1609 	x = (long long)c->main_lebs * c->dark_wm;
1610 	dbg_gen("max. dark space:     %lld (%lld KiB, %lld MiB)",
1611 		x, x >> 10, x >> 20);
1612 	dbg_gen("maximum bud bytes:   %lld (%lld KiB, %lld MiB)",
1613 		c->max_bud_bytes, c->max_bud_bytes >> 10,
1614 		c->max_bud_bytes >> 20);
1615 	dbg_gen("BG commit bud bytes: %lld (%lld KiB, %lld MiB)",
1616 		c->bg_bud_bytes, c->bg_bud_bytes >> 10,
1617 		c->bg_bud_bytes >> 20);
1618 	dbg_gen("current bud bytes    %lld (%lld KiB, %lld MiB)",
1619 		c->bud_bytes, c->bud_bytes >> 10, c->bud_bytes >> 20);
1620 	dbg_gen("max. seq. number:    %llu", c->max_sqnum);
1621 	dbg_gen("commit number:       %llu", c->cmt_no);
1622 	dbg_gen("max. xattrs per inode: %d", ubifs_xattr_max_cnt(c));
1623 	dbg_gen("max orphans:           %d", c->max_orphans);
1624 
1625 	return 0;
1626 
1627 out_infos:
1628 	spin_lock(&ubifs_infos_lock);
1629 	list_del(&c->infos_list);
1630 	spin_unlock(&ubifs_infos_lock);
1631 out_orphans:
1632 	free_orphans(c);
1633 out_journal:
1634 	destroy_journal(c);
1635 out_lpt:
1636 	ubifs_lpt_free(c, 0);
1637 out_master:
1638 	kfree(c->mst_node);
1639 	kfree(c->rcvrd_mst_node);
1640 	if (c->bgt)
1641 		kthread_stop(c->bgt);
1642 out_wbufs:
1643 	free_wbufs(c);
1644 out_cbuf:
1645 	kfree(c->cbuf);
1646 out_auth:
1647 	ubifs_exit_authentication(c);
1648 out_free:
1649 	kfree(c->write_reserve_buf);
1650 	kfree(c->bu.buf);
1651 	vfree(c->ileb_buf);
1652 	vfree(c->sbuf);
1653 	kfree(c->bottom_up_buf);
1654 	kfree(c->sup_node);
1655 	ubifs_sysfs_unregister(c);
1656 out_debugging:
1657 	ubifs_debugging_exit(c);
1658 	return err;
1659 }
1660 
1661 /**
1662  * ubifs_umount - un-mount UBIFS file-system.
1663  * @c: UBIFS file-system description object
1664  *
1665  * Note, this function is called to free allocated resourced when un-mounting,
1666  * as well as free resources when an error occurred while we were half way
1667  * through mounting (error path cleanup function). So it has to make sure the
1668  * resource was actually allocated before freeing it.
1669  */
ubifs_umount(struct ubifs_info * c)1670 static void ubifs_umount(struct ubifs_info *c)
1671 {
1672 	dbg_gen("un-mounting UBI device %d, volume %d", c->vi.ubi_num,
1673 		c->vi.vol_id);
1674 
1675 	dbg_debugfs_exit_fs(c);
1676 	spin_lock(&ubifs_infos_lock);
1677 	list_del(&c->infos_list);
1678 	spin_unlock(&ubifs_infos_lock);
1679 
1680 	if (c->bgt)
1681 		kthread_stop(c->bgt);
1682 
1683 	destroy_journal(c);
1684 	free_wbufs(c);
1685 	free_orphans(c);
1686 	ubifs_lpt_free(c, 0);
1687 	ubifs_exit_authentication(c);
1688 
1689 	ubifs_release_options(c);
1690 	kfree(c->cbuf);
1691 	kfree(c->rcvrd_mst_node);
1692 	kfree(c->mst_node);
1693 	kfree(c->write_reserve_buf);
1694 	kfree(c->bu.buf);
1695 	vfree(c->ileb_buf);
1696 	vfree(c->sbuf);
1697 	kfree(c->bottom_up_buf);
1698 	kfree(c->sup_node);
1699 	ubifs_debugging_exit(c);
1700 	ubifs_sysfs_unregister(c);
1701 }
1702 
1703 /**
1704  * ubifs_remount_rw - re-mount in read-write mode.
1705  * @c: UBIFS file-system description object
1706  *
1707  * UBIFS avoids allocating many unnecessary resources when mounted in read-only
1708  * mode. This function allocates the needed resources and re-mounts UBIFS in
1709  * read-write mode.
1710  */
ubifs_remount_rw(struct ubifs_info * c)1711 static int ubifs_remount_rw(struct ubifs_info *c)
1712 {
1713 	int err, lnum;
1714 
1715 	if (c->rw_incompat) {
1716 		ubifs_err(c, "the file-system is not R/W-compatible");
1717 		ubifs_msg(c, "on-flash format version is w%d/r%d, but software only supports up to version w%d/r%d",
1718 			  c->fmt_version, c->ro_compat_version,
1719 			  UBIFS_FORMAT_VERSION, UBIFS_RO_COMPAT_VERSION);
1720 		return -EROFS;
1721 	}
1722 
1723 	mutex_lock(&c->umount_mutex);
1724 	dbg_save_space_info(c);
1725 	c->remounting_rw = 1;
1726 	c->ro_mount = 0;
1727 
1728 	if (c->space_fixup) {
1729 		err = ubifs_fixup_free_space(c);
1730 		if (err)
1731 			goto out;
1732 	}
1733 
1734 	err = check_free_space(c);
1735 	if (err)
1736 		goto out;
1737 
1738 	if (c->need_recovery) {
1739 		ubifs_msg(c, "completing deferred recovery");
1740 		err = ubifs_write_rcvrd_mst_node(c);
1741 		if (err)
1742 			goto out;
1743 		if (!ubifs_authenticated(c)) {
1744 			err = ubifs_recover_size(c, true);
1745 			if (err)
1746 				goto out;
1747 		}
1748 		err = ubifs_clean_lebs(c, c->sbuf);
1749 		if (err)
1750 			goto out;
1751 		err = ubifs_recover_inl_heads(c, c->sbuf);
1752 		if (err)
1753 			goto out;
1754 	} else {
1755 		/* A readonly mount is not allowed to have orphans */
1756 		ubifs_assert(c, c->tot_orphans == 0);
1757 		err = ubifs_clear_orphans(c);
1758 		if (err)
1759 			goto out;
1760 	}
1761 
1762 	if (!(c->mst_node->flags & cpu_to_le32(UBIFS_MST_DIRTY))) {
1763 		c->mst_node->flags |= cpu_to_le32(UBIFS_MST_DIRTY);
1764 		err = ubifs_write_master(c);
1765 		if (err)
1766 			goto out;
1767 	}
1768 
1769 	if (c->superblock_need_write) {
1770 		struct ubifs_sb_node *sup = c->sup_node;
1771 
1772 		err = ubifs_write_sb_node(c, sup);
1773 		if (err)
1774 			goto out;
1775 
1776 		c->superblock_need_write = 0;
1777 	}
1778 
1779 	c->ileb_buf = vmalloc(c->leb_size);
1780 	if (!c->ileb_buf) {
1781 		err = -ENOMEM;
1782 		goto out;
1783 	}
1784 
1785 	c->write_reserve_buf = kmalloc(COMPRESSED_DATA_NODE_BUF_SZ + \
1786 				       UBIFS_CIPHER_BLOCK_SIZE, GFP_KERNEL);
1787 	if (!c->write_reserve_buf) {
1788 		err = -ENOMEM;
1789 		goto out;
1790 	}
1791 
1792 	err = ubifs_lpt_init(c, 0, 1);
1793 	if (err)
1794 		goto out;
1795 
1796 	/* Create background thread */
1797 	c->bgt = kthread_run(ubifs_bg_thread, c, "%s", c->bgt_name);
1798 	if (IS_ERR(c->bgt)) {
1799 		err = PTR_ERR(c->bgt);
1800 		c->bgt = NULL;
1801 		ubifs_err(c, "cannot spawn \"%s\", error %d",
1802 			  c->bgt_name, err);
1803 		goto out;
1804 	}
1805 
1806 	c->orph_buf = vmalloc(c->leb_size);
1807 	if (!c->orph_buf) {
1808 		err = -ENOMEM;
1809 		goto out;
1810 	}
1811 
1812 	/* Check for enough log space */
1813 	lnum = c->lhead_lnum + 1;
1814 	if (lnum >= UBIFS_LOG_LNUM + c->log_lebs)
1815 		lnum = UBIFS_LOG_LNUM;
1816 	if (lnum == c->ltail_lnum) {
1817 		err = ubifs_consolidate_log(c);
1818 		if (err)
1819 			goto out;
1820 	}
1821 
1822 	if (c->need_recovery) {
1823 		err = ubifs_rcvry_gc_commit(c);
1824 		if (err)
1825 			goto out;
1826 
1827 		if (ubifs_authenticated(c)) {
1828 			err = ubifs_recover_size(c, false);
1829 			if (err)
1830 				goto out;
1831 		}
1832 	} else {
1833 		err = ubifs_leb_unmap(c, c->gc_lnum);
1834 	}
1835 	if (err)
1836 		goto out;
1837 
1838 	dbg_gen("re-mounted read-write");
1839 	c->remounting_rw = 0;
1840 
1841 	if (c->need_recovery) {
1842 		c->need_recovery = 0;
1843 		ubifs_msg(c, "deferred recovery completed");
1844 	} else {
1845 		/*
1846 		 * Do not run the debugging space check if the were doing
1847 		 * recovery, because when we saved the information we had the
1848 		 * file-system in a state where the TNC and lprops has been
1849 		 * modified in memory, but all the I/O operations (including a
1850 		 * commit) were deferred. So the file-system was in
1851 		 * "non-committed" state. Now the file-system is in committed
1852 		 * state, and of course the amount of free space will change
1853 		 * because, for example, the old index size was imprecise.
1854 		 */
1855 		err = dbg_check_space_info(c);
1856 	}
1857 
1858 	mutex_unlock(&c->umount_mutex);
1859 	return err;
1860 
1861 out:
1862 	c->ro_mount = 1;
1863 	vfree(c->orph_buf);
1864 	c->orph_buf = NULL;
1865 	if (c->bgt) {
1866 		kthread_stop(c->bgt);
1867 		c->bgt = NULL;
1868 	}
1869 	kfree(c->write_reserve_buf);
1870 	c->write_reserve_buf = NULL;
1871 	vfree(c->ileb_buf);
1872 	c->ileb_buf = NULL;
1873 	ubifs_lpt_free(c, 1);
1874 	c->remounting_rw = 0;
1875 	mutex_unlock(&c->umount_mutex);
1876 	return err;
1877 }
1878 
1879 /**
1880  * ubifs_remount_ro - re-mount in read-only mode.
1881  * @c: UBIFS file-system description object
1882  *
1883  * We assume VFS has stopped writing. Possibly the background thread could be
1884  * running a commit, however kthread_stop will wait in that case.
1885  */
ubifs_remount_ro(struct ubifs_info * c)1886 static void ubifs_remount_ro(struct ubifs_info *c)
1887 {
1888 	int i, err;
1889 
1890 	ubifs_assert(c, !c->need_recovery);
1891 	ubifs_assert(c, !c->ro_mount);
1892 
1893 	mutex_lock(&c->umount_mutex);
1894 	if (c->bgt) {
1895 		kthread_stop(c->bgt);
1896 		c->bgt = NULL;
1897 	}
1898 
1899 	dbg_save_space_info(c);
1900 
1901 	for (i = 0; i < c->jhead_cnt; i++) {
1902 		err = ubifs_wbuf_sync(&c->jheads[i].wbuf);
1903 		if (err)
1904 			ubifs_ro_mode(c, err);
1905 	}
1906 
1907 	c->mst_node->flags &= ~cpu_to_le32(UBIFS_MST_DIRTY);
1908 	c->mst_node->flags |= cpu_to_le32(UBIFS_MST_NO_ORPHS);
1909 	c->mst_node->gc_lnum = cpu_to_le32(c->gc_lnum);
1910 	err = ubifs_write_master(c);
1911 	if (err)
1912 		ubifs_ro_mode(c, err);
1913 
1914 	vfree(c->orph_buf);
1915 	c->orph_buf = NULL;
1916 	kfree(c->write_reserve_buf);
1917 	c->write_reserve_buf = NULL;
1918 	vfree(c->ileb_buf);
1919 	c->ileb_buf = NULL;
1920 	ubifs_lpt_free(c, 1);
1921 	c->ro_mount = 1;
1922 	err = dbg_check_space_info(c);
1923 	if (err)
1924 		ubifs_ro_mode(c, err);
1925 	mutex_unlock(&c->umount_mutex);
1926 }
1927 
ubifs_put_super(struct super_block * sb)1928 static void ubifs_put_super(struct super_block *sb)
1929 {
1930 	int i;
1931 	struct ubifs_info *c = sb->s_fs_info;
1932 
1933 	ubifs_msg(c, "un-mount UBI device %d", c->vi.ubi_num);
1934 
1935 	/*
1936 	 * The following asserts are only valid if there has not been a failure
1937 	 * of the media. For example, there will be dirty inodes if we failed
1938 	 * to write them back because of I/O errors.
1939 	 */
1940 	if (!c->ro_error) {
1941 		ubifs_assert(c, c->bi.idx_growth == 0);
1942 		ubifs_assert(c, c->bi.dd_growth == 0);
1943 		ubifs_assert(c, c->bi.data_growth == 0);
1944 	}
1945 
1946 	/*
1947 	 * The 'c->umount_lock' prevents races between UBIFS memory shrinker
1948 	 * and file system un-mount. Namely, it prevents the shrinker from
1949 	 * picking this superblock for shrinking - it will be just skipped if
1950 	 * the mutex is locked.
1951 	 */
1952 	mutex_lock(&c->umount_mutex);
1953 	if (!c->ro_mount) {
1954 		/*
1955 		 * First of all kill the background thread to make sure it does
1956 		 * not interfere with un-mounting and freeing resources.
1957 		 */
1958 		if (c->bgt) {
1959 			kthread_stop(c->bgt);
1960 			c->bgt = NULL;
1961 		}
1962 
1963 		/*
1964 		 * On fatal errors c->ro_error is set to 1, in which case we do
1965 		 * not write the master node.
1966 		 */
1967 		if (!c->ro_error) {
1968 			int err;
1969 
1970 			/* Synchronize write-buffers */
1971 			for (i = 0; i < c->jhead_cnt; i++) {
1972 				err = ubifs_wbuf_sync(&c->jheads[i].wbuf);
1973 				if (err)
1974 					ubifs_ro_mode(c, err);
1975 			}
1976 
1977 			/*
1978 			 * We are being cleanly unmounted which means the
1979 			 * orphans were killed - indicate this in the master
1980 			 * node. Also save the reserved GC LEB number.
1981 			 */
1982 			c->mst_node->flags &= ~cpu_to_le32(UBIFS_MST_DIRTY);
1983 			c->mst_node->flags |= cpu_to_le32(UBIFS_MST_NO_ORPHS);
1984 			c->mst_node->gc_lnum = cpu_to_le32(c->gc_lnum);
1985 			err = ubifs_write_master(c);
1986 			if (err)
1987 				/*
1988 				 * Recovery will attempt to fix the master area
1989 				 * next mount, so we just print a message and
1990 				 * continue to unmount normally.
1991 				 */
1992 				ubifs_err(c, "failed to write master node, error %d",
1993 					  err);
1994 		} else {
1995 			for (i = 0; i < c->jhead_cnt; i++)
1996 				/* Make sure write-buffer timers are canceled */
1997 				hrtimer_cancel(&c->jheads[i].wbuf.timer);
1998 		}
1999 	}
2000 
2001 	ubifs_umount(c);
2002 	ubi_close_volume(c->ubi);
2003 	mutex_unlock(&c->umount_mutex);
2004 }
2005 
ubifs_remount_fs(struct super_block * sb,int * flags,char * data)2006 static int ubifs_remount_fs(struct super_block *sb, int *flags, char *data)
2007 {
2008 	int err;
2009 	struct ubifs_info *c = sb->s_fs_info;
2010 
2011 	sync_filesystem(sb);
2012 	dbg_gen("old flags %#lx, new flags %#x", sb->s_flags, *flags);
2013 
2014 	err = ubifs_parse_options(c, data, 1);
2015 	if (err) {
2016 		ubifs_err(c, "invalid or unknown remount parameter");
2017 		return err;
2018 	}
2019 
2020 	if (c->ro_mount && !(*flags & SB_RDONLY)) {
2021 		if (c->ro_error) {
2022 			ubifs_msg(c, "cannot re-mount R/W due to prior errors");
2023 			return -EROFS;
2024 		}
2025 		if (c->ro_media) {
2026 			ubifs_msg(c, "cannot re-mount R/W - UBI volume is R/O");
2027 			return -EROFS;
2028 		}
2029 		err = ubifs_remount_rw(c);
2030 		if (err)
2031 			return err;
2032 	} else if (!c->ro_mount && (*flags & SB_RDONLY)) {
2033 		if (c->ro_error) {
2034 			ubifs_msg(c, "cannot re-mount R/O due to prior errors");
2035 			return -EROFS;
2036 		}
2037 		ubifs_remount_ro(c);
2038 	}
2039 
2040 	if (c->bulk_read == 1)
2041 		bu_init(c);
2042 	else {
2043 		dbg_gen("disable bulk-read");
2044 		mutex_lock(&c->bu_mutex);
2045 		kfree(c->bu.buf);
2046 		c->bu.buf = NULL;
2047 		mutex_unlock(&c->bu_mutex);
2048 	}
2049 
2050 	if (!c->need_recovery)
2051 		ubifs_assert(c, c->lst.taken_empty_lebs > 0);
2052 
2053 	return 0;
2054 }
2055 
2056 const struct super_operations ubifs_super_operations = {
2057 	.alloc_inode   = ubifs_alloc_inode,
2058 	.free_inode    = ubifs_free_inode,
2059 	.put_super     = ubifs_put_super,
2060 	.write_inode   = ubifs_write_inode,
2061 	.drop_inode    = ubifs_drop_inode,
2062 	.evict_inode   = ubifs_evict_inode,
2063 	.statfs        = ubifs_statfs,
2064 	.dirty_inode   = ubifs_dirty_inode,
2065 	.remount_fs    = ubifs_remount_fs,
2066 	.show_options  = ubifs_show_options,
2067 	.sync_fs       = ubifs_sync_fs,
2068 };
2069 
2070 /**
2071  * open_ubi - parse UBI device name string and open the UBI device.
2072  * @name: UBI volume name
2073  * @mode: UBI volume open mode
2074  *
2075  * The primary method of mounting UBIFS is by specifying the UBI volume
2076  * character device node path. However, UBIFS may also be mounted without any
2077  * character device node using one of the following methods:
2078  *
2079  * o ubiX_Y    - mount UBI device number X, volume Y;
2080  * o ubiY      - mount UBI device number 0, volume Y;
2081  * o ubiX:NAME - mount UBI device X, volume with name NAME;
2082  * o ubi:NAME  - mount UBI device 0, volume with name NAME.
2083  *
2084  * Alternative '!' separator may be used instead of ':' (because some shells
2085  * like busybox may interpret ':' as an NFS host name separator). This function
2086  * returns UBI volume description object in case of success and a negative
2087  * error code in case of failure.
2088  */
open_ubi(const char * name,int mode)2089 static struct ubi_volume_desc *open_ubi(const char *name, int mode)
2090 {
2091 	struct ubi_volume_desc *ubi;
2092 	int dev, vol;
2093 	char *endptr;
2094 
2095 	if (!name || !*name)
2096 		return ERR_PTR(-EINVAL);
2097 
2098 	/* First, try to open using the device node path method */
2099 	ubi = ubi_open_volume_path(name, mode);
2100 	if (!IS_ERR(ubi))
2101 		return ubi;
2102 
2103 	/* Try the "nodev" method */
2104 	if (name[0] != 'u' || name[1] != 'b' || name[2] != 'i')
2105 		return ERR_PTR(-EINVAL);
2106 
2107 	/* ubi:NAME method */
2108 	if ((name[3] == ':' || name[3] == '!') && name[4] != '\0')
2109 		return ubi_open_volume_nm(0, name + 4, mode);
2110 
2111 	if (!isdigit(name[3]))
2112 		return ERR_PTR(-EINVAL);
2113 
2114 	dev = simple_strtoul(name + 3, &endptr, 0);
2115 
2116 	/* ubiY method */
2117 	if (*endptr == '\0')
2118 		return ubi_open_volume(0, dev, mode);
2119 
2120 	/* ubiX_Y method */
2121 	if (*endptr == '_' && isdigit(endptr[1])) {
2122 		vol = simple_strtoul(endptr + 1, &endptr, 0);
2123 		if (*endptr != '\0')
2124 			return ERR_PTR(-EINVAL);
2125 		return ubi_open_volume(dev, vol, mode);
2126 	}
2127 
2128 	/* ubiX:NAME method */
2129 	if ((*endptr == ':' || *endptr == '!') && endptr[1] != '\0')
2130 		return ubi_open_volume_nm(dev, ++endptr, mode);
2131 
2132 	return ERR_PTR(-EINVAL);
2133 }
2134 
alloc_ubifs_info(struct ubi_volume_desc * ubi)2135 static struct ubifs_info *alloc_ubifs_info(struct ubi_volume_desc *ubi)
2136 {
2137 	struct ubifs_info *c;
2138 
2139 	c = kzalloc(sizeof(struct ubifs_info), GFP_KERNEL);
2140 	if (c) {
2141 		spin_lock_init(&c->cnt_lock);
2142 		spin_lock_init(&c->cs_lock);
2143 		spin_lock_init(&c->buds_lock);
2144 		spin_lock_init(&c->space_lock);
2145 		spin_lock_init(&c->orphan_lock);
2146 		init_rwsem(&c->commit_sem);
2147 		mutex_init(&c->lp_mutex);
2148 		mutex_init(&c->tnc_mutex);
2149 		mutex_init(&c->log_mutex);
2150 		mutex_init(&c->umount_mutex);
2151 		mutex_init(&c->bu_mutex);
2152 		mutex_init(&c->write_reserve_mutex);
2153 		init_waitqueue_head(&c->cmt_wq);
2154 		init_waitqueue_head(&c->reserve_space_wq);
2155 		atomic_set(&c->need_wait_space, 0);
2156 		c->buds = RB_ROOT;
2157 		c->old_idx = RB_ROOT;
2158 		c->size_tree = RB_ROOT;
2159 		c->orph_tree = RB_ROOT;
2160 		INIT_LIST_HEAD(&c->infos_list);
2161 		INIT_LIST_HEAD(&c->idx_gc);
2162 		INIT_LIST_HEAD(&c->replay_list);
2163 		INIT_LIST_HEAD(&c->replay_buds);
2164 		INIT_LIST_HEAD(&c->uncat_list);
2165 		INIT_LIST_HEAD(&c->empty_list);
2166 		INIT_LIST_HEAD(&c->freeable_list);
2167 		INIT_LIST_HEAD(&c->frdi_idx_list);
2168 		INIT_LIST_HEAD(&c->unclean_leb_list);
2169 		INIT_LIST_HEAD(&c->old_buds);
2170 		INIT_LIST_HEAD(&c->orph_list);
2171 		INIT_LIST_HEAD(&c->orph_new);
2172 		c->no_chk_data_crc = 1;
2173 		c->assert_action = ASSACT_RO;
2174 
2175 		c->highest_inum = UBIFS_FIRST_INO;
2176 		c->lhead_lnum = c->ltail_lnum = UBIFS_LOG_LNUM;
2177 
2178 		ubi_get_volume_info(ubi, &c->vi);
2179 		ubi_get_device_info(c->vi.ubi_num, &c->di);
2180 	}
2181 	return c;
2182 }
2183 
ubifs_fill_super(struct super_block * sb,void * data,int silent)2184 static int ubifs_fill_super(struct super_block *sb, void *data, int silent)
2185 {
2186 	struct ubifs_info *c = sb->s_fs_info;
2187 	struct inode *root;
2188 	int err;
2189 
2190 	c->vfs_sb = sb;
2191 	/* Re-open the UBI device in read-write mode */
2192 	c->ubi = ubi_open_volume(c->vi.ubi_num, c->vi.vol_id, UBI_READWRITE);
2193 	if (IS_ERR(c->ubi)) {
2194 		err = PTR_ERR(c->ubi);
2195 		goto out;
2196 	}
2197 
2198 	err = ubifs_parse_options(c, data, 0);
2199 	if (err)
2200 		goto out_close;
2201 
2202 	/*
2203 	 * UBIFS provides 'backing_dev_info' in order to disable read-ahead. For
2204 	 * UBIFS, I/O is not deferred, it is done immediately in read_folio,
2205 	 * which means the user would have to wait not just for their own I/O
2206 	 * but the read-ahead I/O as well i.e. completely pointless.
2207 	 *
2208 	 * Read-ahead will be disabled because @sb->s_bdi->ra_pages is 0. Also
2209 	 * @sb->s_bdi->capabilities are initialized to 0 so there won't be any
2210 	 * writeback happening.
2211 	 */
2212 	err = super_setup_bdi_name(sb, "ubifs_%d_%d", c->vi.ubi_num,
2213 				   c->vi.vol_id);
2214 	if (err)
2215 		goto out_close;
2216 	sb->s_bdi->ra_pages = 0;
2217 	sb->s_bdi->io_pages = 0;
2218 
2219 	sb->s_fs_info = c;
2220 	sb->s_magic = UBIFS_SUPER_MAGIC;
2221 	sb->s_blocksize = UBIFS_BLOCK_SIZE;
2222 	sb->s_blocksize_bits = UBIFS_BLOCK_SHIFT;
2223 	sb->s_maxbytes = c->max_inode_sz = key_max_inode_size(c);
2224 	if (c->max_inode_sz > MAX_LFS_FILESIZE)
2225 		sb->s_maxbytes = c->max_inode_sz = MAX_LFS_FILESIZE;
2226 	sb->s_op = &ubifs_super_operations;
2227 	sb->s_xattr = ubifs_xattr_handlers;
2228 	fscrypt_set_ops(sb, &ubifs_crypt_operations);
2229 
2230 	mutex_lock(&c->umount_mutex);
2231 	err = mount_ubifs(c);
2232 	if (err) {
2233 		ubifs_assert(c, err < 0);
2234 		goto out_unlock;
2235 	}
2236 
2237 	/* Read the root inode */
2238 	root = ubifs_iget(sb, UBIFS_ROOT_INO);
2239 	if (IS_ERR(root)) {
2240 		err = PTR_ERR(root);
2241 		goto out_umount;
2242 	}
2243 
2244 	generic_set_sb_d_ops(sb);
2245 	sb->s_root = d_make_root(root);
2246 	if (!sb->s_root) {
2247 		err = -ENOMEM;
2248 		goto out_umount;
2249 	}
2250 
2251 	super_set_uuid(sb, c->uuid, sizeof(c->uuid));
2252 
2253 	mutex_unlock(&c->umount_mutex);
2254 	return 0;
2255 
2256 out_umount:
2257 	ubifs_umount(c);
2258 out_unlock:
2259 	mutex_unlock(&c->umount_mutex);
2260 out_close:
2261 	ubifs_release_options(c);
2262 	ubi_close_volume(c->ubi);
2263 out:
2264 	return err;
2265 }
2266 
sb_test(struct super_block * sb,void * data)2267 static int sb_test(struct super_block *sb, void *data)
2268 {
2269 	struct ubifs_info *c1 = data;
2270 	struct ubifs_info *c = sb->s_fs_info;
2271 
2272 	return c->vi.cdev == c1->vi.cdev;
2273 }
2274 
sb_set(struct super_block * sb,void * data)2275 static int sb_set(struct super_block *sb, void *data)
2276 {
2277 	sb->s_fs_info = data;
2278 	return set_anon_super(sb, NULL);
2279 }
2280 
ubifs_mount(struct file_system_type * fs_type,int flags,const char * name,void * data)2281 static struct dentry *ubifs_mount(struct file_system_type *fs_type, int flags,
2282 			const char *name, void *data)
2283 {
2284 	struct ubi_volume_desc *ubi;
2285 	struct ubifs_info *c;
2286 	struct super_block *sb;
2287 	int err;
2288 
2289 	dbg_gen("name %s, flags %#x", name, flags);
2290 
2291 	/*
2292 	 * Get UBI device number and volume ID. Mount it read-only so far
2293 	 * because this might be a new mount point, and UBI allows only one
2294 	 * read-write user at a time.
2295 	 */
2296 	ubi = open_ubi(name, UBI_READONLY);
2297 	if (IS_ERR(ubi)) {
2298 		if (!(flags & SB_SILENT))
2299 			pr_err("UBIFS error (pid: %d): cannot open \"%s\", error %d",
2300 			       current->pid, name, (int)PTR_ERR(ubi));
2301 		return ERR_CAST(ubi);
2302 	}
2303 
2304 	c = alloc_ubifs_info(ubi);
2305 	if (!c) {
2306 		err = -ENOMEM;
2307 		goto out_close;
2308 	}
2309 
2310 	dbg_gen("opened ubi%d_%d", c->vi.ubi_num, c->vi.vol_id);
2311 
2312 	sb = sget(fs_type, sb_test, sb_set, flags, c);
2313 	if (IS_ERR(sb)) {
2314 		err = PTR_ERR(sb);
2315 		kfree(c);
2316 		goto out_close;
2317 	}
2318 
2319 	if (sb->s_root) {
2320 		struct ubifs_info *c1 = sb->s_fs_info;
2321 		kfree(c);
2322 		/* A new mount point for already mounted UBIFS */
2323 		dbg_gen("this ubi volume is already mounted");
2324 		if (!!(flags & SB_RDONLY) != c1->ro_mount) {
2325 			err = -EBUSY;
2326 			goto out_deact;
2327 		}
2328 	} else {
2329 		err = ubifs_fill_super(sb, data, flags & SB_SILENT ? 1 : 0);
2330 		if (err)
2331 			goto out_deact;
2332 		/* We do not support atime */
2333 		sb->s_flags |= SB_ACTIVE;
2334 		if (IS_ENABLED(CONFIG_UBIFS_ATIME_SUPPORT))
2335 			ubifs_msg(c, "full atime support is enabled.");
2336 		else
2337 			sb->s_flags |= SB_NOATIME;
2338 	}
2339 
2340 	/* 'fill_super()' opens ubi again so we must close it here */
2341 	ubi_close_volume(ubi);
2342 
2343 	return dget(sb->s_root);
2344 
2345 out_deact:
2346 	deactivate_locked_super(sb);
2347 out_close:
2348 	ubi_close_volume(ubi);
2349 	return ERR_PTR(err);
2350 }
2351 
kill_ubifs_super(struct super_block * s)2352 static void kill_ubifs_super(struct super_block *s)
2353 {
2354 	struct ubifs_info *c = s->s_fs_info;
2355 	kill_anon_super(s);
2356 	kfree(c);
2357 }
2358 
2359 static struct file_system_type ubifs_fs_type = {
2360 	.name    = "ubifs",
2361 	.owner   = THIS_MODULE,
2362 	.mount   = ubifs_mount,
2363 	.kill_sb = kill_ubifs_super,
2364 };
2365 MODULE_ALIAS_FS("ubifs");
2366 
2367 /*
2368  * Inode slab cache constructor.
2369  */
inode_slab_ctor(void * obj)2370 static void inode_slab_ctor(void *obj)
2371 {
2372 	struct ubifs_inode *ui = obj;
2373 	inode_init_once(&ui->vfs_inode);
2374 }
2375 
ubifs_init(void)2376 static int __init ubifs_init(void)
2377 {
2378 	int err = -ENOMEM;
2379 
2380 	BUILD_BUG_ON(sizeof(struct ubifs_ch) != 24);
2381 
2382 	/* Make sure node sizes are 8-byte aligned */
2383 	BUILD_BUG_ON(UBIFS_CH_SZ        & 7);
2384 	BUILD_BUG_ON(UBIFS_INO_NODE_SZ  & 7);
2385 	BUILD_BUG_ON(UBIFS_DENT_NODE_SZ & 7);
2386 	BUILD_BUG_ON(UBIFS_XENT_NODE_SZ & 7);
2387 	BUILD_BUG_ON(UBIFS_DATA_NODE_SZ & 7);
2388 	BUILD_BUG_ON(UBIFS_TRUN_NODE_SZ & 7);
2389 	BUILD_BUG_ON(UBIFS_SB_NODE_SZ   & 7);
2390 	BUILD_BUG_ON(UBIFS_MST_NODE_SZ  & 7);
2391 	BUILD_BUG_ON(UBIFS_REF_NODE_SZ  & 7);
2392 	BUILD_BUG_ON(UBIFS_CS_NODE_SZ   & 7);
2393 	BUILD_BUG_ON(UBIFS_ORPH_NODE_SZ & 7);
2394 
2395 	BUILD_BUG_ON(UBIFS_MAX_DENT_NODE_SZ & 7);
2396 	BUILD_BUG_ON(UBIFS_MAX_XENT_NODE_SZ & 7);
2397 	BUILD_BUG_ON(UBIFS_MAX_DATA_NODE_SZ & 7);
2398 	BUILD_BUG_ON(UBIFS_MAX_INO_NODE_SZ  & 7);
2399 	BUILD_BUG_ON(UBIFS_MAX_NODE_SZ      & 7);
2400 	BUILD_BUG_ON(MIN_WRITE_SZ           & 7);
2401 
2402 	/* Check min. node size */
2403 	BUILD_BUG_ON(UBIFS_INO_NODE_SZ  < MIN_WRITE_SZ);
2404 	BUILD_BUG_ON(UBIFS_DENT_NODE_SZ < MIN_WRITE_SZ);
2405 	BUILD_BUG_ON(UBIFS_XENT_NODE_SZ < MIN_WRITE_SZ);
2406 	BUILD_BUG_ON(UBIFS_TRUN_NODE_SZ < MIN_WRITE_SZ);
2407 
2408 	BUILD_BUG_ON(UBIFS_MAX_DENT_NODE_SZ > UBIFS_MAX_NODE_SZ);
2409 	BUILD_BUG_ON(UBIFS_MAX_XENT_NODE_SZ > UBIFS_MAX_NODE_SZ);
2410 	BUILD_BUG_ON(UBIFS_MAX_DATA_NODE_SZ > UBIFS_MAX_NODE_SZ);
2411 	BUILD_BUG_ON(UBIFS_MAX_INO_NODE_SZ  > UBIFS_MAX_NODE_SZ);
2412 
2413 	/* Defined node sizes */
2414 	BUILD_BUG_ON(UBIFS_SB_NODE_SZ  != 4096);
2415 	BUILD_BUG_ON(UBIFS_MST_NODE_SZ != 512);
2416 	BUILD_BUG_ON(UBIFS_INO_NODE_SZ != 160);
2417 	BUILD_BUG_ON(UBIFS_REF_NODE_SZ != 64);
2418 
2419 	/*
2420 	 * We use 2 bit wide bit-fields to store compression type, which should
2421 	 * be amended if more compressors are added. The bit-fields are:
2422 	 * @compr_type in 'struct ubifs_inode', @default_compr in
2423 	 * 'struct ubifs_info' and @compr_type in 'struct ubifs_mount_opts'.
2424 	 */
2425 	BUILD_BUG_ON(UBIFS_COMPR_TYPES_CNT > 4);
2426 
2427 	/*
2428 	 * We require that PAGE_SIZE is greater-than-or-equal-to
2429 	 * UBIFS_BLOCK_SIZE. It is assumed that both are powers of 2.
2430 	 */
2431 	if (PAGE_SIZE < UBIFS_BLOCK_SIZE) {
2432 		pr_err("UBIFS error (pid %d): VFS page cache size is %u bytes, but UBIFS requires at least 4096 bytes",
2433 		       current->pid, (unsigned int)PAGE_SIZE);
2434 		return -EINVAL;
2435 	}
2436 
2437 	ubifs_inode_slab = kmem_cache_create("ubifs_inode_slab",
2438 				sizeof(struct ubifs_inode), 0,
2439 				SLAB_RECLAIM_ACCOUNT | SLAB_ACCOUNT,
2440 				&inode_slab_ctor);
2441 	if (!ubifs_inode_slab)
2442 		return -ENOMEM;
2443 
2444 	ubifs_shrinker_info = shrinker_alloc(0, "ubifs-slab");
2445 	if (!ubifs_shrinker_info)
2446 		goto out_slab;
2447 
2448 	ubifs_shrinker_info->count_objects = ubifs_shrink_count;
2449 	ubifs_shrinker_info->scan_objects = ubifs_shrink_scan;
2450 
2451 	shrinker_register(ubifs_shrinker_info);
2452 
2453 	err = ubifs_compressors_init();
2454 	if (err)
2455 		goto out_shrinker;
2456 
2457 	dbg_debugfs_init();
2458 
2459 	err = ubifs_sysfs_init();
2460 	if (err)
2461 		goto out_dbg;
2462 
2463 	err = register_filesystem(&ubifs_fs_type);
2464 	if (err) {
2465 		pr_err("UBIFS error (pid %d): cannot register file system, error %d",
2466 		       current->pid, err);
2467 		goto out_sysfs;
2468 	}
2469 	return 0;
2470 
2471 out_sysfs:
2472 	ubifs_sysfs_exit();
2473 out_dbg:
2474 	dbg_debugfs_exit();
2475 	ubifs_compressors_exit();
2476 out_shrinker:
2477 	shrinker_free(ubifs_shrinker_info);
2478 out_slab:
2479 	kmem_cache_destroy(ubifs_inode_slab);
2480 	return err;
2481 }
2482 /* late_initcall to let compressors initialize first */
2483 late_initcall(ubifs_init);
2484 
ubifs_exit(void)2485 static void __exit ubifs_exit(void)
2486 {
2487 	WARN_ON(!list_empty(&ubifs_infos));
2488 	WARN_ON(atomic_long_read(&ubifs_clean_zn_cnt) != 0);
2489 
2490 	dbg_debugfs_exit();
2491 	ubifs_sysfs_exit();
2492 	ubifs_compressors_exit();
2493 	shrinker_free(ubifs_shrinker_info);
2494 
2495 	/*
2496 	 * Make sure all delayed rcu free inodes are flushed before we
2497 	 * destroy cache.
2498 	 */
2499 	rcu_barrier();
2500 	kmem_cache_destroy(ubifs_inode_slab);
2501 	unregister_filesystem(&ubifs_fs_type);
2502 }
2503 module_exit(ubifs_exit);
2504 
2505 MODULE_LICENSE("GPL");
2506 MODULE_VERSION(__stringify(UBIFS_VERSION));
2507 MODULE_AUTHOR("Artem Bityutskiy, Adrian Hunter");
2508 MODULE_DESCRIPTION("UBIFS - UBI File System");
2509