xref: /openbmc/linux/fs/ubifs/super.c (revision 02d89917)
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  
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  	.scan_objects = ubifs_shrink_scan,
59  	.count_objects = ubifs_shrink_count,
60  	.seeks = DEFAULT_SEEKS,
61  };
62  
63  /**
64   * validate_inode - validate inode.
65   * @c: UBIFS file-system description object
66   * @inode: the inode to validate
67   *
68   * This is a helper function for 'ubifs_iget()' which validates various fields
69   * of a newly built inode to make sure they contain sane values and prevent
70   * possible vulnerabilities. Returns zero if the inode is all right and
71   * a non-zero error code if not.
72   */
73  static int validate_inode(struct ubifs_info *c, const struct inode *inode)
74  {
75  	int err;
76  	const struct ubifs_inode *ui = ubifs_inode(inode);
77  
78  	if (inode->i_size > c->max_inode_sz) {
79  		ubifs_err(c, "inode is too large (%lld)",
80  			  (long long)inode->i_size);
81  		return 1;
82  	}
83  
84  	if (ui->compr_type >= UBIFS_COMPR_TYPES_CNT) {
85  		ubifs_err(c, "unknown compression type %d", ui->compr_type);
86  		return 2;
87  	}
88  
89  	if (ui->xattr_names + ui->xattr_cnt > XATTR_LIST_MAX)
90  		return 3;
91  
92  	if (ui->data_len < 0 || ui->data_len > UBIFS_MAX_INO_DATA)
93  		return 4;
94  
95  	if (ui->xattr && !S_ISREG(inode->i_mode))
96  		return 5;
97  
98  	if (!ubifs_compr_present(c, ui->compr_type)) {
99  		ubifs_warn(c, "inode %lu uses '%s' compression, but it was not compiled in",
100  			   inode->i_ino, ubifs_compr_name(c, ui->compr_type));
101  	}
102  
103  	err = dbg_check_dir(c, inode);
104  	return err;
105  }
106  
107  struct inode *ubifs_iget(struct super_block *sb, unsigned long inum)
108  {
109  	int err;
110  	union ubifs_key key;
111  	struct ubifs_ino_node *ino;
112  	struct ubifs_info *c = sb->s_fs_info;
113  	struct inode *inode;
114  	struct ubifs_inode *ui;
115  
116  	dbg_gen("inode %lu", inum);
117  
118  	inode = iget_locked(sb, inum);
119  	if (!inode)
120  		return ERR_PTR(-ENOMEM);
121  	if (!(inode->i_state & I_NEW))
122  		return inode;
123  	ui = ubifs_inode(inode);
124  
125  	ino = kmalloc(UBIFS_MAX_INO_NODE_SZ, GFP_NOFS);
126  	if (!ino) {
127  		err = -ENOMEM;
128  		goto out;
129  	}
130  
131  	ino_key_init(c, &key, inode->i_ino);
132  
133  	err = ubifs_tnc_lookup(c, &key, ino);
134  	if (err)
135  		goto out_ino;
136  
137  	inode->i_flags |= S_NOCMTIME;
138  
139  	if (!IS_ENABLED(CONFIG_UBIFS_ATIME_SUPPORT))
140  		inode->i_flags |= S_NOATIME;
141  
142  	set_nlink(inode, le32_to_cpu(ino->nlink));
143  	i_uid_write(inode, le32_to_cpu(ino->uid));
144  	i_gid_write(inode, le32_to_cpu(ino->gid));
145  	inode->i_atime.tv_sec  = (int64_t)le64_to_cpu(ino->atime_sec);
146  	inode->i_atime.tv_nsec = le32_to_cpu(ino->atime_nsec);
147  	inode->i_mtime.tv_sec  = (int64_t)le64_to_cpu(ino->mtime_sec);
148  	inode->i_mtime.tv_nsec = le32_to_cpu(ino->mtime_nsec);
149  	inode_set_ctime(inode, (int64_t)le64_to_cpu(ino->ctime_sec),
150  			le32_to_cpu(ino->ctime_nsec));
151  	inode->i_mode = le32_to_cpu(ino->mode);
152  	inode->i_size = le64_to_cpu(ino->size);
153  
154  	ui->data_len    = le32_to_cpu(ino->data_len);
155  	ui->flags       = le32_to_cpu(ino->flags);
156  	ui->compr_type  = le16_to_cpu(ino->compr_type);
157  	ui->creat_sqnum = le64_to_cpu(ino->creat_sqnum);
158  	ui->xattr_cnt   = le32_to_cpu(ino->xattr_cnt);
159  	ui->xattr_size  = le32_to_cpu(ino->xattr_size);
160  	ui->xattr_names = le32_to_cpu(ino->xattr_names);
161  	ui->synced_i_size = ui->ui_size = inode->i_size;
162  
163  	ui->xattr = (ui->flags & UBIFS_XATTR_FL) ? 1 : 0;
164  
165  	err = validate_inode(c, inode);
166  	if (err)
167  		goto out_invalid;
168  
169  	switch (inode->i_mode & S_IFMT) {
170  	case S_IFREG:
171  		inode->i_mapping->a_ops = &ubifs_file_address_operations;
172  		inode->i_op = &ubifs_file_inode_operations;
173  		inode->i_fop = &ubifs_file_operations;
174  		if (ui->xattr) {
175  			ui->data = kmalloc(ui->data_len + 1, GFP_NOFS);
176  			if (!ui->data) {
177  				err = -ENOMEM;
178  				goto out_ino;
179  			}
180  			memcpy(ui->data, ino->data, ui->data_len);
181  			((char *)ui->data)[ui->data_len] = '\0';
182  		} else if (ui->data_len != 0) {
183  			err = 10;
184  			goto out_invalid;
185  		}
186  		break;
187  	case S_IFDIR:
188  		inode->i_op  = &ubifs_dir_inode_operations;
189  		inode->i_fop = &ubifs_dir_operations;
190  		if (ui->data_len != 0) {
191  			err = 11;
192  			goto out_invalid;
193  		}
194  		break;
195  	case S_IFLNK:
196  		inode->i_op = &ubifs_symlink_inode_operations;
197  		if (ui->data_len <= 0 || ui->data_len > UBIFS_MAX_INO_DATA) {
198  			err = 12;
199  			goto out_invalid;
200  		}
201  		ui->data = kmalloc(ui->data_len + 1, GFP_NOFS);
202  		if (!ui->data) {
203  			err = -ENOMEM;
204  			goto out_ino;
205  		}
206  		memcpy(ui->data, ino->data, ui->data_len);
207  		((char *)ui->data)[ui->data_len] = '\0';
208  		break;
209  	case S_IFBLK:
210  	case S_IFCHR:
211  	{
212  		dev_t rdev;
213  		union ubifs_dev_desc *dev;
214  
215  		ui->data = kmalloc(sizeof(union ubifs_dev_desc), GFP_NOFS);
216  		if (!ui->data) {
217  			err = -ENOMEM;
218  			goto out_ino;
219  		}
220  
221  		dev = (union ubifs_dev_desc *)ino->data;
222  		if (ui->data_len == sizeof(dev->new))
223  			rdev = new_decode_dev(le32_to_cpu(dev->new));
224  		else if (ui->data_len == sizeof(dev->huge))
225  			rdev = huge_decode_dev(le64_to_cpu(dev->huge));
226  		else {
227  			err = 13;
228  			goto out_invalid;
229  		}
230  		memcpy(ui->data, ino->data, ui->data_len);
231  		inode->i_op = &ubifs_file_inode_operations;
232  		init_special_inode(inode, inode->i_mode, rdev);
233  		break;
234  	}
235  	case S_IFSOCK:
236  	case S_IFIFO:
237  		inode->i_op = &ubifs_file_inode_operations;
238  		init_special_inode(inode, inode->i_mode, 0);
239  		if (ui->data_len != 0) {
240  			err = 14;
241  			goto out_invalid;
242  		}
243  		break;
244  	default:
245  		err = 15;
246  		goto out_invalid;
247  	}
248  
249  	kfree(ino);
250  	ubifs_set_inode_flags(inode);
251  	unlock_new_inode(inode);
252  	return inode;
253  
254  out_invalid:
255  	ubifs_err(c, "inode %lu validation failed, error %d", inode->i_ino, err);
256  	ubifs_dump_node(c, ino, UBIFS_MAX_INO_NODE_SZ);
257  	ubifs_dump_inode(c, inode);
258  	err = -EINVAL;
259  out_ino:
260  	kfree(ino);
261  out:
262  	ubifs_err(c, "failed to read inode %lu, error %d", inode->i_ino, err);
263  	iget_failed(inode);
264  	return ERR_PTR(err);
265  }
266  
267  static struct inode *ubifs_alloc_inode(struct super_block *sb)
268  {
269  	struct ubifs_inode *ui;
270  
271  	ui = alloc_inode_sb(sb, ubifs_inode_slab, GFP_NOFS);
272  	if (!ui)
273  		return NULL;
274  
275  	memset((void *)ui + sizeof(struct inode), 0,
276  	       sizeof(struct ubifs_inode) - sizeof(struct inode));
277  	mutex_init(&ui->ui_mutex);
278  	init_rwsem(&ui->xattr_sem);
279  	spin_lock_init(&ui->ui_lock);
280  	return &ui->vfs_inode;
281  };
282  
283  static void ubifs_free_inode(struct inode *inode)
284  {
285  	struct ubifs_inode *ui = ubifs_inode(inode);
286  
287  	kfree(ui->data);
288  	fscrypt_free_inode(inode);
289  
290  	kmem_cache_free(ubifs_inode_slab, ui);
291  }
292  
293  /*
294   * Note, Linux write-back code calls this without 'i_mutex'.
295   */
296  static int ubifs_write_inode(struct inode *inode, struct writeback_control *wbc)
297  {
298  	int err = 0;
299  	struct ubifs_info *c = inode->i_sb->s_fs_info;
300  	struct ubifs_inode *ui = ubifs_inode(inode);
301  
302  	ubifs_assert(c, !ui->xattr);
303  	if (is_bad_inode(inode))
304  		return 0;
305  
306  	mutex_lock(&ui->ui_mutex);
307  	/*
308  	 * Due to races between write-back forced by budgeting
309  	 * (see 'sync_some_inodes()') and background write-back, the inode may
310  	 * have already been synchronized, do not do this again. This might
311  	 * also happen if it was synchronized in an VFS operation, e.g.
312  	 * 'ubifs_link()'.
313  	 */
314  	if (!ui->dirty) {
315  		mutex_unlock(&ui->ui_mutex);
316  		return 0;
317  	}
318  
319  	/*
320  	 * As an optimization, do not write orphan inodes to the media just
321  	 * because this is not needed.
322  	 */
323  	dbg_gen("inode %lu, mode %#x, nlink %u",
324  		inode->i_ino, (int)inode->i_mode, inode->i_nlink);
325  	if (inode->i_nlink) {
326  		err = ubifs_jnl_write_inode(c, inode);
327  		if (err)
328  			ubifs_err(c, "can't write inode %lu, error %d",
329  				  inode->i_ino, err);
330  		else
331  			err = dbg_check_inode_size(c, inode, ui->ui_size);
332  	}
333  
334  	ui->dirty = 0;
335  	mutex_unlock(&ui->ui_mutex);
336  	ubifs_release_dirty_inode_budget(c, ui);
337  	return err;
338  }
339  
340  static int ubifs_drop_inode(struct inode *inode)
341  {
342  	int drop = generic_drop_inode(inode);
343  
344  	if (!drop)
345  		drop = fscrypt_drop_inode(inode);
346  
347  	return drop;
348  }
349  
350  static void ubifs_evict_inode(struct inode *inode)
351  {
352  	int err;
353  	struct ubifs_info *c = inode->i_sb->s_fs_info;
354  	struct ubifs_inode *ui = ubifs_inode(inode);
355  
356  	if (ui->xattr)
357  		/*
358  		 * Extended attribute inode deletions are fully handled in
359  		 * 'ubifs_removexattr()'. These inodes are special and have
360  		 * limited usage, so there is nothing to do here.
361  		 */
362  		goto out;
363  
364  	dbg_gen("inode %lu, mode %#x", inode->i_ino, (int)inode->i_mode);
365  	ubifs_assert(c, !atomic_read(&inode->i_count));
366  
367  	truncate_inode_pages_final(&inode->i_data);
368  
369  	if (inode->i_nlink)
370  		goto done;
371  
372  	if (is_bad_inode(inode))
373  		goto out;
374  
375  	ui->ui_size = inode->i_size = 0;
376  	err = ubifs_jnl_delete_inode(c, inode);
377  	if (err)
378  		/*
379  		 * Worst case we have a lost orphan inode wasting space, so a
380  		 * simple error message is OK here.
381  		 */
382  		ubifs_err(c, "can't delete inode %lu, error %d",
383  			  inode->i_ino, err);
384  
385  out:
386  	if (ui->dirty)
387  		ubifs_release_dirty_inode_budget(c, ui);
388  	else {
389  		/* We've deleted something - clean the "no space" flags */
390  		c->bi.nospace = c->bi.nospace_rp = 0;
391  		smp_wmb();
392  	}
393  done:
394  	clear_inode(inode);
395  	fscrypt_put_encryption_info(inode);
396  }
397  
398  static void ubifs_dirty_inode(struct inode *inode, int flags)
399  {
400  	struct ubifs_info *c = inode->i_sb->s_fs_info;
401  	struct ubifs_inode *ui = ubifs_inode(inode);
402  
403  	ubifs_assert(c, mutex_is_locked(&ui->ui_mutex));
404  	if (!ui->dirty) {
405  		ui->dirty = 1;
406  		dbg_gen("inode %lu",  inode->i_ino);
407  	}
408  }
409  
410  static int ubifs_statfs(struct dentry *dentry, struct kstatfs *buf)
411  {
412  	struct ubifs_info *c = dentry->d_sb->s_fs_info;
413  	unsigned long long free;
414  	__le32 *uuid = (__le32 *)c->uuid;
415  
416  	free = ubifs_get_free_space(c);
417  	dbg_gen("free space %lld bytes (%lld blocks)",
418  		free, free >> UBIFS_BLOCK_SHIFT);
419  
420  	buf->f_type = UBIFS_SUPER_MAGIC;
421  	buf->f_bsize = UBIFS_BLOCK_SIZE;
422  	buf->f_blocks = c->block_cnt;
423  	buf->f_bfree = free >> UBIFS_BLOCK_SHIFT;
424  	if (free > c->report_rp_size)
425  		buf->f_bavail = (free - c->report_rp_size) >> UBIFS_BLOCK_SHIFT;
426  	else
427  		buf->f_bavail = 0;
428  	buf->f_files = 0;
429  	buf->f_ffree = 0;
430  	buf->f_namelen = UBIFS_MAX_NLEN;
431  	buf->f_fsid.val[0] = le32_to_cpu(uuid[0]) ^ le32_to_cpu(uuid[2]);
432  	buf->f_fsid.val[1] = le32_to_cpu(uuid[1]) ^ le32_to_cpu(uuid[3]);
433  	ubifs_assert(c, buf->f_bfree <= c->block_cnt);
434  	return 0;
435  }
436  
437  static int ubifs_show_options(struct seq_file *s, struct dentry *root)
438  {
439  	struct ubifs_info *c = root->d_sb->s_fs_info;
440  
441  	if (c->mount_opts.unmount_mode == 2)
442  		seq_puts(s, ",fast_unmount");
443  	else if (c->mount_opts.unmount_mode == 1)
444  		seq_puts(s, ",norm_unmount");
445  
446  	if (c->mount_opts.bulk_read == 2)
447  		seq_puts(s, ",bulk_read");
448  	else if (c->mount_opts.bulk_read == 1)
449  		seq_puts(s, ",no_bulk_read");
450  
451  	if (c->mount_opts.chk_data_crc == 2)
452  		seq_puts(s, ",chk_data_crc");
453  	else if (c->mount_opts.chk_data_crc == 1)
454  		seq_puts(s, ",no_chk_data_crc");
455  
456  	if (c->mount_opts.override_compr) {
457  		seq_printf(s, ",compr=%s",
458  			   ubifs_compr_name(c, c->mount_opts.compr_type));
459  	}
460  
461  	seq_printf(s, ",assert=%s", ubifs_assert_action_name(c));
462  	seq_printf(s, ",ubi=%d,vol=%d", c->vi.ubi_num, c->vi.vol_id);
463  
464  	return 0;
465  }
466  
467  static int ubifs_sync_fs(struct super_block *sb, int wait)
468  {
469  	int i, err;
470  	struct ubifs_info *c = sb->s_fs_info;
471  
472  	/*
473  	 * Zero @wait is just an advisory thing to help the file system shove
474  	 * lots of data into the queues, and there will be the second
475  	 * '->sync_fs()' call, with non-zero @wait.
476  	 */
477  	if (!wait)
478  		return 0;
479  
480  	/*
481  	 * Synchronize write buffers, because 'ubifs_run_commit()' does not
482  	 * do this if it waits for an already running commit.
483  	 */
484  	for (i = 0; i < c->jhead_cnt; i++) {
485  		err = ubifs_wbuf_sync(&c->jheads[i].wbuf);
486  		if (err)
487  			return err;
488  	}
489  
490  	/*
491  	 * Strictly speaking, it is not necessary to commit the journal here,
492  	 * synchronizing write-buffers would be enough. But committing makes
493  	 * UBIFS free space predictions much more accurate, so we want to let
494  	 * the user be able to get more accurate results of 'statfs()' after
495  	 * they synchronize the file system.
496  	 */
497  	err = ubifs_run_commit(c);
498  	if (err)
499  		return err;
500  
501  	return ubi_sync(c->vi.ubi_num);
502  }
503  
504  /**
505   * init_constants_early - initialize UBIFS constants.
506   * @c: UBIFS file-system description object
507   *
508   * This function initialize UBIFS constants which do not need the superblock to
509   * be read. It also checks that the UBI volume satisfies basic UBIFS
510   * requirements. Returns zero in case of success and a negative error code in
511   * case of failure.
512   */
513  static int init_constants_early(struct ubifs_info *c)
514  {
515  	if (c->vi.corrupted) {
516  		ubifs_warn(c, "UBI volume is corrupted - read-only mode");
517  		c->ro_media = 1;
518  	}
519  
520  	if (c->di.ro_mode) {
521  		ubifs_msg(c, "read-only UBI device");
522  		c->ro_media = 1;
523  	}
524  
525  	if (c->vi.vol_type == UBI_STATIC_VOLUME) {
526  		ubifs_msg(c, "static UBI volume - read-only mode");
527  		c->ro_media = 1;
528  	}
529  
530  	c->leb_cnt = c->vi.size;
531  	c->leb_size = c->vi.usable_leb_size;
532  	c->leb_start = c->di.leb_start;
533  	c->half_leb_size = c->leb_size / 2;
534  	c->min_io_size = c->di.min_io_size;
535  	c->min_io_shift = fls(c->min_io_size) - 1;
536  	c->max_write_size = c->di.max_write_size;
537  	c->max_write_shift = fls(c->max_write_size) - 1;
538  
539  	if (c->leb_size < UBIFS_MIN_LEB_SZ) {
540  		ubifs_errc(c, "too small LEBs (%d bytes), min. is %d bytes",
541  			   c->leb_size, UBIFS_MIN_LEB_SZ);
542  		return -EINVAL;
543  	}
544  
545  	if (c->leb_cnt < UBIFS_MIN_LEB_CNT) {
546  		ubifs_errc(c, "too few LEBs (%d), min. is %d",
547  			   c->leb_cnt, UBIFS_MIN_LEB_CNT);
548  		return -EINVAL;
549  	}
550  
551  	if (!is_power_of_2(c->min_io_size)) {
552  		ubifs_errc(c, "bad min. I/O size %d", c->min_io_size);
553  		return -EINVAL;
554  	}
555  
556  	/*
557  	 * Maximum write size has to be greater or equivalent to min. I/O
558  	 * size, and be multiple of min. I/O size.
559  	 */
560  	if (c->max_write_size < c->min_io_size ||
561  	    c->max_write_size % c->min_io_size ||
562  	    !is_power_of_2(c->max_write_size)) {
563  		ubifs_errc(c, "bad write buffer size %d for %d min. I/O unit",
564  			   c->max_write_size, c->min_io_size);
565  		return -EINVAL;
566  	}
567  
568  	/*
569  	 * UBIFS aligns all node to 8-byte boundary, so to make function in
570  	 * io.c simpler, assume minimum I/O unit size to be 8 bytes if it is
571  	 * less than 8.
572  	 */
573  	if (c->min_io_size < 8) {
574  		c->min_io_size = 8;
575  		c->min_io_shift = 3;
576  		if (c->max_write_size < c->min_io_size) {
577  			c->max_write_size = c->min_io_size;
578  			c->max_write_shift = c->min_io_shift;
579  		}
580  	}
581  
582  	c->ref_node_alsz = ALIGN(UBIFS_REF_NODE_SZ, c->min_io_size);
583  	c->mst_node_alsz = ALIGN(UBIFS_MST_NODE_SZ, c->min_io_size);
584  
585  	/*
586  	 * Initialize node length ranges which are mostly needed for node
587  	 * length validation.
588  	 */
589  	c->ranges[UBIFS_PAD_NODE].len  = UBIFS_PAD_NODE_SZ;
590  	c->ranges[UBIFS_SB_NODE].len   = UBIFS_SB_NODE_SZ;
591  	c->ranges[UBIFS_MST_NODE].len  = UBIFS_MST_NODE_SZ;
592  	c->ranges[UBIFS_REF_NODE].len  = UBIFS_REF_NODE_SZ;
593  	c->ranges[UBIFS_TRUN_NODE].len = UBIFS_TRUN_NODE_SZ;
594  	c->ranges[UBIFS_CS_NODE].len   = UBIFS_CS_NODE_SZ;
595  	c->ranges[UBIFS_AUTH_NODE].min_len = UBIFS_AUTH_NODE_SZ;
596  	c->ranges[UBIFS_AUTH_NODE].max_len = UBIFS_AUTH_NODE_SZ +
597  				UBIFS_MAX_HMAC_LEN;
598  	c->ranges[UBIFS_SIG_NODE].min_len = UBIFS_SIG_NODE_SZ;
599  	c->ranges[UBIFS_SIG_NODE].max_len = c->leb_size - UBIFS_SB_NODE_SZ;
600  
601  	c->ranges[UBIFS_INO_NODE].min_len  = UBIFS_INO_NODE_SZ;
602  	c->ranges[UBIFS_INO_NODE].max_len  = UBIFS_MAX_INO_NODE_SZ;
603  	c->ranges[UBIFS_ORPH_NODE].min_len =
604  				UBIFS_ORPH_NODE_SZ + sizeof(__le64);
605  	c->ranges[UBIFS_ORPH_NODE].max_len = c->leb_size;
606  	c->ranges[UBIFS_DENT_NODE].min_len = UBIFS_DENT_NODE_SZ;
607  	c->ranges[UBIFS_DENT_NODE].max_len = UBIFS_MAX_DENT_NODE_SZ;
608  	c->ranges[UBIFS_XENT_NODE].min_len = UBIFS_XENT_NODE_SZ;
609  	c->ranges[UBIFS_XENT_NODE].max_len = UBIFS_MAX_XENT_NODE_SZ;
610  	c->ranges[UBIFS_DATA_NODE].min_len = UBIFS_DATA_NODE_SZ;
611  	c->ranges[UBIFS_DATA_NODE].max_len = UBIFS_MAX_DATA_NODE_SZ;
612  	/*
613  	 * Minimum indexing node size is amended later when superblock is
614  	 * read and the key length is known.
615  	 */
616  	c->ranges[UBIFS_IDX_NODE].min_len = UBIFS_IDX_NODE_SZ + UBIFS_BRANCH_SZ;
617  	/*
618  	 * Maximum indexing node size is amended later when superblock is
619  	 * read and the fanout is known.
620  	 */
621  	c->ranges[UBIFS_IDX_NODE].max_len = INT_MAX;
622  
623  	/*
624  	 * Initialize dead and dark LEB space watermarks. See gc.c for comments
625  	 * about these values.
626  	 */
627  	c->dead_wm = ALIGN(MIN_WRITE_SZ, c->min_io_size);
628  	c->dark_wm = ALIGN(UBIFS_MAX_NODE_SZ, c->min_io_size);
629  
630  	/*
631  	 * Calculate how many bytes would be wasted at the end of LEB if it was
632  	 * fully filled with data nodes of maximum size. This is used in
633  	 * calculations when reporting free space.
634  	 */
635  	c->leb_overhead = c->leb_size % UBIFS_MAX_DATA_NODE_SZ;
636  
637  	/* Buffer size for bulk-reads */
638  	c->max_bu_buf_len = UBIFS_MAX_BULK_READ * UBIFS_MAX_DATA_NODE_SZ;
639  	if (c->max_bu_buf_len > c->leb_size)
640  		c->max_bu_buf_len = c->leb_size;
641  
642  	/* Log is ready, preserve one LEB for commits. */
643  	c->min_log_bytes = c->leb_size;
644  
645  	return 0;
646  }
647  
648  /**
649   * bud_wbuf_callback - bud LEB write-buffer synchronization call-back.
650   * @c: UBIFS file-system description object
651   * @lnum: LEB the write-buffer was synchronized to
652   * @free: how many free bytes left in this LEB
653   * @pad: how many bytes were padded
654   *
655   * This is a callback function which is called by the I/O unit when the
656   * write-buffer is synchronized. We need this to correctly maintain space
657   * accounting in bud logical eraseblocks. This function returns zero in case of
658   * success and a negative error code in case of failure.
659   *
660   * This function actually belongs to the journal, but we keep it here because
661   * we want to keep it static.
662   */
663  static int bud_wbuf_callback(struct ubifs_info *c, int lnum, int free, int pad)
664  {
665  	return ubifs_update_one_lp(c, lnum, free, pad, 0, 0);
666  }
667  
668  /*
669   * init_constants_sb - initialize UBIFS constants.
670   * @c: UBIFS file-system description object
671   *
672   * This is a helper function which initializes various UBIFS constants after
673   * the superblock has been read. It also checks various UBIFS parameters and
674   * makes sure they are all right. Returns zero in case of success and a
675   * negative error code in case of failure.
676   */
677  static int init_constants_sb(struct ubifs_info *c)
678  {
679  	int tmp, err;
680  	long long tmp64;
681  
682  	c->main_bytes = (long long)c->main_lebs * c->leb_size;
683  	c->max_znode_sz = sizeof(struct ubifs_znode) +
684  				c->fanout * sizeof(struct ubifs_zbranch);
685  
686  	tmp = ubifs_idx_node_sz(c, 1);
687  	c->ranges[UBIFS_IDX_NODE].min_len = tmp;
688  	c->min_idx_node_sz = ALIGN(tmp, 8);
689  
690  	tmp = ubifs_idx_node_sz(c, c->fanout);
691  	c->ranges[UBIFS_IDX_NODE].max_len = tmp;
692  	c->max_idx_node_sz = ALIGN(tmp, 8);
693  
694  	/* Make sure LEB size is large enough to fit full commit */
695  	tmp = UBIFS_CS_NODE_SZ + UBIFS_REF_NODE_SZ * c->jhead_cnt;
696  	tmp = ALIGN(tmp, c->min_io_size);
697  	if (tmp > c->leb_size) {
698  		ubifs_err(c, "too small LEB size %d, at least %d needed",
699  			  c->leb_size, tmp);
700  		return -EINVAL;
701  	}
702  
703  	/*
704  	 * Make sure that the log is large enough to fit reference nodes for
705  	 * all buds plus one reserved LEB.
706  	 */
707  	tmp64 = c->max_bud_bytes + c->leb_size - 1;
708  	c->max_bud_cnt = div_u64(tmp64, c->leb_size);
709  	tmp = (c->ref_node_alsz * c->max_bud_cnt + c->leb_size - 1);
710  	tmp /= c->leb_size;
711  	tmp += 1;
712  	if (c->log_lebs < tmp) {
713  		ubifs_err(c, "too small log %d LEBs, required min. %d LEBs",
714  			  c->log_lebs, tmp);
715  		return -EINVAL;
716  	}
717  
718  	/*
719  	 * When budgeting we assume worst-case scenarios when the pages are not
720  	 * be compressed and direntries are of the maximum size.
721  	 *
722  	 * Note, data, which may be stored in inodes is budgeted separately, so
723  	 * it is not included into 'c->bi.inode_budget'.
724  	 */
725  	c->bi.page_budget = UBIFS_MAX_DATA_NODE_SZ * UBIFS_BLOCKS_PER_PAGE;
726  	c->bi.inode_budget = UBIFS_INO_NODE_SZ;
727  	c->bi.dent_budget = UBIFS_MAX_DENT_NODE_SZ;
728  
729  	/*
730  	 * When the amount of flash space used by buds becomes
731  	 * 'c->max_bud_bytes', UBIFS just blocks all writers and starts commit.
732  	 * The writers are unblocked when the commit is finished. To avoid
733  	 * writers to be blocked UBIFS initiates background commit in advance,
734  	 * when number of bud bytes becomes above the limit defined below.
735  	 */
736  	c->bg_bud_bytes = (c->max_bud_bytes * 13) >> 4;
737  
738  	/*
739  	 * Ensure minimum journal size. All the bytes in the journal heads are
740  	 * considered to be used, when calculating the current journal usage.
741  	 * Consequently, if the journal is too small, UBIFS will treat it as
742  	 * always full.
743  	 */
744  	tmp64 = (long long)(c->jhead_cnt + 1) * c->leb_size + 1;
745  	if (c->bg_bud_bytes < tmp64)
746  		c->bg_bud_bytes = tmp64;
747  	if (c->max_bud_bytes < tmp64 + c->leb_size)
748  		c->max_bud_bytes = tmp64 + c->leb_size;
749  
750  	err = ubifs_calc_lpt_geom(c);
751  	if (err)
752  		return err;
753  
754  	/* Initialize effective LEB size used in budgeting calculations */
755  	c->idx_leb_size = c->leb_size - c->max_idx_node_sz;
756  	return 0;
757  }
758  
759  /*
760   * init_constants_master - initialize UBIFS constants.
761   * @c: UBIFS file-system description object
762   *
763   * This is a helper function which initializes various UBIFS constants after
764   * the master node has been read. It also checks various UBIFS parameters and
765   * makes sure they are all right.
766   */
767  static void init_constants_master(struct ubifs_info *c)
768  {
769  	long long tmp64;
770  
771  	c->bi.min_idx_lebs = ubifs_calc_min_idx_lebs(c);
772  	c->report_rp_size = ubifs_reported_space(c, c->rp_size);
773  
774  	/*
775  	 * Calculate total amount of FS blocks. This number is not used
776  	 * internally because it does not make much sense for UBIFS, but it is
777  	 * necessary to report something for the 'statfs()' call.
778  	 *
779  	 * Subtract the LEB reserved for GC, the LEB which is reserved for
780  	 * deletions, minimum LEBs for the index, and assume only one journal
781  	 * head is available.
782  	 */
783  	tmp64 = c->main_lebs - 1 - 1 - MIN_INDEX_LEBS - c->jhead_cnt + 1;
784  	tmp64 *= (long long)c->leb_size - c->leb_overhead;
785  	tmp64 = ubifs_reported_space(c, tmp64);
786  	c->block_cnt = tmp64 >> UBIFS_BLOCK_SHIFT;
787  }
788  
789  /**
790   * take_gc_lnum - reserve GC LEB.
791   * @c: UBIFS file-system description object
792   *
793   * This function ensures that the LEB reserved for garbage collection is marked
794   * as "taken" in lprops. We also have to set free space to LEB size and dirty
795   * space to zero, because lprops may contain out-of-date information if the
796   * file-system was un-mounted before it has been committed. This function
797   * returns zero in case of success and a negative error code in case of
798   * failure.
799   */
800  static int take_gc_lnum(struct ubifs_info *c)
801  {
802  	int err;
803  
804  	if (c->gc_lnum == -1) {
805  		ubifs_err(c, "no LEB for GC");
806  		return -EINVAL;
807  	}
808  
809  	/* And we have to tell lprops that this LEB is taken */
810  	err = ubifs_change_one_lp(c, c->gc_lnum, c->leb_size, 0,
811  				  LPROPS_TAKEN, 0, 0);
812  	return err;
813  }
814  
815  /**
816   * alloc_wbufs - allocate write-buffers.
817   * @c: UBIFS file-system description object
818   *
819   * This helper function allocates and initializes UBIFS write-buffers. Returns
820   * zero in case of success and %-ENOMEM in case of failure.
821   */
822  static int alloc_wbufs(struct ubifs_info *c)
823  {
824  	int i, err;
825  
826  	c->jheads = kcalloc(c->jhead_cnt, sizeof(struct ubifs_jhead),
827  			    GFP_KERNEL);
828  	if (!c->jheads)
829  		return -ENOMEM;
830  
831  	/* Initialize journal heads */
832  	for (i = 0; i < c->jhead_cnt; i++) {
833  		INIT_LIST_HEAD(&c->jheads[i].buds_list);
834  		err = ubifs_wbuf_init(c, &c->jheads[i].wbuf);
835  		if (err)
836  			goto out_wbuf;
837  
838  		c->jheads[i].wbuf.sync_callback = &bud_wbuf_callback;
839  		c->jheads[i].wbuf.jhead = i;
840  		c->jheads[i].grouped = 1;
841  		c->jheads[i].log_hash = ubifs_hash_get_desc(c);
842  		if (IS_ERR(c->jheads[i].log_hash)) {
843  			err = PTR_ERR(c->jheads[i].log_hash);
844  			goto out_log_hash;
845  		}
846  	}
847  
848  	/*
849  	 * Garbage Collector head does not need to be synchronized by timer.
850  	 * Also GC head nodes are not grouped.
851  	 */
852  	c->jheads[GCHD].wbuf.no_timer = 1;
853  	c->jheads[GCHD].grouped = 0;
854  
855  	return 0;
856  
857  out_log_hash:
858  	kfree(c->jheads[i].wbuf.buf);
859  	kfree(c->jheads[i].wbuf.inodes);
860  
861  out_wbuf:
862  	while (i--) {
863  		kfree(c->jheads[i].wbuf.buf);
864  		kfree(c->jheads[i].wbuf.inodes);
865  		kfree(c->jheads[i].log_hash);
866  	}
867  	kfree(c->jheads);
868  	c->jheads = NULL;
869  
870  	return err;
871  }
872  
873  /**
874   * free_wbufs - free write-buffers.
875   * @c: UBIFS file-system description object
876   */
877  static void free_wbufs(struct ubifs_info *c)
878  {
879  	int i;
880  
881  	if (c->jheads) {
882  		for (i = 0; i < c->jhead_cnt; i++) {
883  			kfree(c->jheads[i].wbuf.buf);
884  			kfree(c->jheads[i].wbuf.inodes);
885  			kfree(c->jheads[i].log_hash);
886  		}
887  		kfree(c->jheads);
888  		c->jheads = NULL;
889  	}
890  }
891  
892  /**
893   * free_orphans - free orphans.
894   * @c: UBIFS file-system description object
895   */
896  static void free_orphans(struct ubifs_info *c)
897  {
898  	struct ubifs_orphan *orph;
899  
900  	while (c->orph_dnext) {
901  		orph = c->orph_dnext;
902  		c->orph_dnext = orph->dnext;
903  		list_del(&orph->list);
904  		kfree(orph);
905  	}
906  
907  	while (!list_empty(&c->orph_list)) {
908  		orph = list_entry(c->orph_list.next, struct ubifs_orphan, list);
909  		list_del(&orph->list);
910  		kfree(orph);
911  		ubifs_err(c, "orphan list not empty at unmount");
912  	}
913  
914  	vfree(c->orph_buf);
915  	c->orph_buf = NULL;
916  }
917  
918  /**
919   * free_buds - free per-bud objects.
920   * @c: UBIFS file-system description object
921   */
922  static void free_buds(struct ubifs_info *c)
923  {
924  	struct ubifs_bud *bud, *n;
925  
926  	rbtree_postorder_for_each_entry_safe(bud, n, &c->buds, rb)
927  		kfree(bud);
928  }
929  
930  /**
931   * check_volume_empty - check if the UBI volume is empty.
932   * @c: UBIFS file-system description object
933   *
934   * This function checks if the UBIFS volume is empty by looking if its LEBs are
935   * mapped or not. The result of checking is stored in the @c->empty variable.
936   * Returns zero in case of success and a negative error code in case of
937   * failure.
938   */
939  static int check_volume_empty(struct ubifs_info *c)
940  {
941  	int lnum, err;
942  
943  	c->empty = 1;
944  	for (lnum = 0; lnum < c->leb_cnt; lnum++) {
945  		err = ubifs_is_mapped(c, lnum);
946  		if (unlikely(err < 0))
947  			return err;
948  		if (err == 1) {
949  			c->empty = 0;
950  			break;
951  		}
952  
953  		cond_resched();
954  	}
955  
956  	return 0;
957  }
958  
959  /*
960   * UBIFS mount options.
961   *
962   * Opt_fast_unmount: do not run a journal commit before un-mounting
963   * Opt_norm_unmount: run a journal commit before un-mounting
964   * Opt_bulk_read: enable bulk-reads
965   * Opt_no_bulk_read: disable bulk-reads
966   * Opt_chk_data_crc: check CRCs when reading data nodes
967   * Opt_no_chk_data_crc: do not check CRCs when reading data nodes
968   * Opt_override_compr: override default compressor
969   * Opt_assert: set ubifs_assert() action
970   * Opt_auth_key: The key name used for authentication
971   * Opt_auth_hash_name: The hash type used for authentication
972   * Opt_err: just end of array marker
973   */
974  enum {
975  	Opt_fast_unmount,
976  	Opt_norm_unmount,
977  	Opt_bulk_read,
978  	Opt_no_bulk_read,
979  	Opt_chk_data_crc,
980  	Opt_no_chk_data_crc,
981  	Opt_override_compr,
982  	Opt_assert,
983  	Opt_auth_key,
984  	Opt_auth_hash_name,
985  	Opt_ignore,
986  	Opt_err,
987  };
988  
989  static const match_table_t tokens = {
990  	{Opt_fast_unmount, "fast_unmount"},
991  	{Opt_norm_unmount, "norm_unmount"},
992  	{Opt_bulk_read, "bulk_read"},
993  	{Opt_no_bulk_read, "no_bulk_read"},
994  	{Opt_chk_data_crc, "chk_data_crc"},
995  	{Opt_no_chk_data_crc, "no_chk_data_crc"},
996  	{Opt_override_compr, "compr=%s"},
997  	{Opt_auth_key, "auth_key=%s"},
998  	{Opt_auth_hash_name, "auth_hash_name=%s"},
999  	{Opt_ignore, "ubi=%s"},
1000  	{Opt_ignore, "vol=%s"},
1001  	{Opt_assert, "assert=%s"},
1002  	{Opt_err, NULL},
1003  };
1004  
1005  /**
1006   * parse_standard_option - parse a standard mount option.
1007   * @option: the option to parse
1008   *
1009   * Normally, standard mount options like "sync" are passed to file-systems as
1010   * flags. However, when a "rootflags=" kernel boot parameter is used, they may
1011   * be present in the options string. This function tries to deal with this
1012   * situation and parse standard options. Returns 0 if the option was not
1013   * recognized, and the corresponding integer flag if it was.
1014   *
1015   * UBIFS is only interested in the "sync" option, so do not check for anything
1016   * else.
1017   */
1018  static int parse_standard_option(const char *option)
1019  {
1020  
1021  	pr_notice("UBIFS: parse %s\n", option);
1022  	if (!strcmp(option, "sync"))
1023  		return SB_SYNCHRONOUS;
1024  	return 0;
1025  }
1026  
1027  /**
1028   * ubifs_parse_options - parse mount parameters.
1029   * @c: UBIFS file-system description object
1030   * @options: parameters to parse
1031   * @is_remount: non-zero if this is FS re-mount
1032   *
1033   * This function parses UBIFS mount options and returns zero in case success
1034   * and a negative error code in case of failure.
1035   */
1036  static int ubifs_parse_options(struct ubifs_info *c, char *options,
1037  			       int is_remount)
1038  {
1039  	char *p;
1040  	substring_t args[MAX_OPT_ARGS];
1041  
1042  	if (!options)
1043  		return 0;
1044  
1045  	while ((p = strsep(&options, ","))) {
1046  		int token;
1047  
1048  		if (!*p)
1049  			continue;
1050  
1051  		token = match_token(p, tokens, args);
1052  		switch (token) {
1053  		/*
1054  		 * %Opt_fast_unmount and %Opt_norm_unmount options are ignored.
1055  		 * We accept them in order to be backward-compatible. But this
1056  		 * should be removed at some point.
1057  		 */
1058  		case Opt_fast_unmount:
1059  			c->mount_opts.unmount_mode = 2;
1060  			break;
1061  		case Opt_norm_unmount:
1062  			c->mount_opts.unmount_mode = 1;
1063  			break;
1064  		case Opt_bulk_read:
1065  			c->mount_opts.bulk_read = 2;
1066  			c->bulk_read = 1;
1067  			break;
1068  		case Opt_no_bulk_read:
1069  			c->mount_opts.bulk_read = 1;
1070  			c->bulk_read = 0;
1071  			break;
1072  		case Opt_chk_data_crc:
1073  			c->mount_opts.chk_data_crc = 2;
1074  			c->no_chk_data_crc = 0;
1075  			break;
1076  		case Opt_no_chk_data_crc:
1077  			c->mount_opts.chk_data_crc = 1;
1078  			c->no_chk_data_crc = 1;
1079  			break;
1080  		case Opt_override_compr:
1081  		{
1082  			char *name = match_strdup(&args[0]);
1083  
1084  			if (!name)
1085  				return -ENOMEM;
1086  			if (!strcmp(name, "none"))
1087  				c->mount_opts.compr_type = UBIFS_COMPR_NONE;
1088  			else if (!strcmp(name, "lzo"))
1089  				c->mount_opts.compr_type = UBIFS_COMPR_LZO;
1090  			else if (!strcmp(name, "zlib"))
1091  				c->mount_opts.compr_type = UBIFS_COMPR_ZLIB;
1092  			else if (!strcmp(name, "zstd"))
1093  				c->mount_opts.compr_type = UBIFS_COMPR_ZSTD;
1094  			else {
1095  				ubifs_err(c, "unknown compressor \"%s\"", name); //FIXME: is c ready?
1096  				kfree(name);
1097  				return -EINVAL;
1098  			}
1099  			kfree(name);
1100  			c->mount_opts.override_compr = 1;
1101  			c->default_compr = c->mount_opts.compr_type;
1102  			break;
1103  		}
1104  		case Opt_assert:
1105  		{
1106  			char *act = match_strdup(&args[0]);
1107  
1108  			if (!act)
1109  				return -ENOMEM;
1110  			if (!strcmp(act, "report"))
1111  				c->assert_action = ASSACT_REPORT;
1112  			else if (!strcmp(act, "read-only"))
1113  				c->assert_action = ASSACT_RO;
1114  			else if (!strcmp(act, "panic"))
1115  				c->assert_action = ASSACT_PANIC;
1116  			else {
1117  				ubifs_err(c, "unknown assert action \"%s\"", act);
1118  				kfree(act);
1119  				return -EINVAL;
1120  			}
1121  			kfree(act);
1122  			break;
1123  		}
1124  		case Opt_auth_key:
1125  			if (!is_remount) {
1126  				c->auth_key_name = kstrdup(args[0].from,
1127  								GFP_KERNEL);
1128  				if (!c->auth_key_name)
1129  					return -ENOMEM;
1130  			}
1131  			break;
1132  		case Opt_auth_hash_name:
1133  			if (!is_remount) {
1134  				c->auth_hash_name = kstrdup(args[0].from,
1135  								GFP_KERNEL);
1136  				if (!c->auth_hash_name)
1137  					return -ENOMEM;
1138  			}
1139  			break;
1140  		case Opt_ignore:
1141  			break;
1142  		default:
1143  		{
1144  			unsigned long flag;
1145  			struct super_block *sb = c->vfs_sb;
1146  
1147  			flag = parse_standard_option(p);
1148  			if (!flag) {
1149  				ubifs_err(c, "unrecognized mount option \"%s\" or missing value",
1150  					  p);
1151  				return -EINVAL;
1152  			}
1153  			sb->s_flags |= flag;
1154  			break;
1155  		}
1156  		}
1157  	}
1158  
1159  	return 0;
1160  }
1161  
1162  /*
1163   * ubifs_release_options - release mount parameters which have been dumped.
1164   * @c: UBIFS file-system description object
1165   */
1166  static void ubifs_release_options(struct ubifs_info *c)
1167  {
1168  	kfree(c->auth_key_name);
1169  	c->auth_key_name = NULL;
1170  	kfree(c->auth_hash_name);
1171  	c->auth_hash_name = NULL;
1172  }
1173  
1174  /**
1175   * destroy_journal - destroy journal data structures.
1176   * @c: UBIFS file-system description object
1177   *
1178   * This function destroys journal data structures including those that may have
1179   * been created by recovery functions.
1180   */
1181  static void destroy_journal(struct ubifs_info *c)
1182  {
1183  	while (!list_empty(&c->unclean_leb_list)) {
1184  		struct ubifs_unclean_leb *ucleb;
1185  
1186  		ucleb = list_entry(c->unclean_leb_list.next,
1187  				   struct ubifs_unclean_leb, list);
1188  		list_del(&ucleb->list);
1189  		kfree(ucleb);
1190  	}
1191  	while (!list_empty(&c->old_buds)) {
1192  		struct ubifs_bud *bud;
1193  
1194  		bud = list_entry(c->old_buds.next, struct ubifs_bud, list);
1195  		list_del(&bud->list);
1196  		kfree(bud);
1197  	}
1198  	ubifs_destroy_idx_gc(c);
1199  	ubifs_destroy_size_tree(c);
1200  	ubifs_tnc_close(c);
1201  	free_buds(c);
1202  }
1203  
1204  /**
1205   * bu_init - initialize bulk-read information.
1206   * @c: UBIFS file-system description object
1207   */
1208  static void bu_init(struct ubifs_info *c)
1209  {
1210  	ubifs_assert(c, c->bulk_read == 1);
1211  
1212  	if (c->bu.buf)
1213  		return; /* Already initialized */
1214  
1215  again:
1216  	c->bu.buf = kmalloc(c->max_bu_buf_len, GFP_KERNEL | __GFP_NOWARN);
1217  	if (!c->bu.buf) {
1218  		if (c->max_bu_buf_len > UBIFS_KMALLOC_OK) {
1219  			c->max_bu_buf_len = UBIFS_KMALLOC_OK;
1220  			goto again;
1221  		}
1222  
1223  		/* Just disable bulk-read */
1224  		ubifs_warn(c, "cannot allocate %d bytes of memory for bulk-read, disabling it",
1225  			   c->max_bu_buf_len);
1226  		c->mount_opts.bulk_read = 1;
1227  		c->bulk_read = 0;
1228  		return;
1229  	}
1230  }
1231  
1232  /**
1233   * check_free_space - check if there is enough free space to mount.
1234   * @c: UBIFS file-system description object
1235   *
1236   * This function makes sure UBIFS has enough free space to be mounted in
1237   * read/write mode. UBIFS must always have some free space to allow deletions.
1238   */
1239  static int check_free_space(struct ubifs_info *c)
1240  {
1241  	ubifs_assert(c, c->dark_wm > 0);
1242  	if (c->lst.total_free + c->lst.total_dirty < c->dark_wm) {
1243  		ubifs_err(c, "insufficient free space to mount in R/W mode");
1244  		ubifs_dump_budg(c, &c->bi);
1245  		ubifs_dump_lprops(c);
1246  		return -ENOSPC;
1247  	}
1248  	return 0;
1249  }
1250  
1251  /**
1252   * mount_ubifs - mount UBIFS file-system.
1253   * @c: UBIFS file-system description object
1254   *
1255   * This function mounts UBIFS file system. Returns zero in case of success and
1256   * a negative error code in case of failure.
1257   */
1258  static int mount_ubifs(struct ubifs_info *c)
1259  {
1260  	int err;
1261  	long long x, y;
1262  	size_t sz;
1263  
1264  	c->ro_mount = !!sb_rdonly(c->vfs_sb);
1265  	/* Suppress error messages while probing if SB_SILENT is set */
1266  	c->probing = !!(c->vfs_sb->s_flags & SB_SILENT);
1267  
1268  	err = init_constants_early(c);
1269  	if (err)
1270  		return err;
1271  
1272  	err = ubifs_debugging_init(c);
1273  	if (err)
1274  		return err;
1275  
1276  	err = ubifs_sysfs_register(c);
1277  	if (err)
1278  		goto out_debugging;
1279  
1280  	err = check_volume_empty(c);
1281  	if (err)
1282  		goto out_free;
1283  
1284  	if (c->empty && (c->ro_mount || c->ro_media)) {
1285  		/*
1286  		 * This UBI volume is empty, and read-only, or the file system
1287  		 * is mounted read-only - we cannot format it.
1288  		 */
1289  		ubifs_err(c, "can't format empty UBI volume: read-only %s",
1290  			  c->ro_media ? "UBI volume" : "mount");
1291  		err = -EROFS;
1292  		goto out_free;
1293  	}
1294  
1295  	if (c->ro_media && !c->ro_mount) {
1296  		ubifs_err(c, "cannot mount read-write - read-only media");
1297  		err = -EROFS;
1298  		goto out_free;
1299  	}
1300  
1301  	/*
1302  	 * The requirement for the buffer is that it should fit indexing B-tree
1303  	 * height amount of integers. We assume the height if the TNC tree will
1304  	 * never exceed 64.
1305  	 */
1306  	err = -ENOMEM;
1307  	c->bottom_up_buf = kmalloc_array(BOTTOM_UP_HEIGHT, sizeof(int),
1308  					 GFP_KERNEL);
1309  	if (!c->bottom_up_buf)
1310  		goto out_free;
1311  
1312  	c->sbuf = vmalloc(c->leb_size);
1313  	if (!c->sbuf)
1314  		goto out_free;
1315  
1316  	if (!c->ro_mount) {
1317  		c->ileb_buf = vmalloc(c->leb_size);
1318  		if (!c->ileb_buf)
1319  			goto out_free;
1320  	}
1321  
1322  	if (c->bulk_read == 1)
1323  		bu_init(c);
1324  
1325  	if (!c->ro_mount) {
1326  		c->write_reserve_buf = kmalloc(COMPRESSED_DATA_NODE_BUF_SZ + \
1327  					       UBIFS_CIPHER_BLOCK_SIZE,
1328  					       GFP_KERNEL);
1329  		if (!c->write_reserve_buf)
1330  			goto out_free;
1331  	}
1332  
1333  	c->mounting = 1;
1334  
1335  	if (c->auth_key_name) {
1336  		if (IS_ENABLED(CONFIG_UBIFS_FS_AUTHENTICATION)) {
1337  			err = ubifs_init_authentication(c);
1338  			if (err)
1339  				goto out_free;
1340  		} else {
1341  			ubifs_err(c, "auth_key_name, but UBIFS is built without"
1342  				  " authentication support");
1343  			err = -EINVAL;
1344  			goto out_free;
1345  		}
1346  	}
1347  
1348  	err = ubifs_read_superblock(c);
1349  	if (err)
1350  		goto out_auth;
1351  
1352  	c->probing = 0;
1353  
1354  	/*
1355  	 * Make sure the compressor which is set as default in the superblock
1356  	 * or overridden by mount options is actually compiled in.
1357  	 */
1358  	if (!ubifs_compr_present(c, c->default_compr)) {
1359  		ubifs_err(c, "'compressor \"%s\" is not compiled in",
1360  			  ubifs_compr_name(c, c->default_compr));
1361  		err = -ENOTSUPP;
1362  		goto out_auth;
1363  	}
1364  
1365  	err = init_constants_sb(c);
1366  	if (err)
1367  		goto out_auth;
1368  
1369  	sz = ALIGN(c->max_idx_node_sz, c->min_io_size) * 2;
1370  	c->cbuf = kmalloc(sz, GFP_NOFS);
1371  	if (!c->cbuf) {
1372  		err = -ENOMEM;
1373  		goto out_auth;
1374  	}
1375  
1376  	err = alloc_wbufs(c);
1377  	if (err)
1378  		goto out_cbuf;
1379  
1380  	sprintf(c->bgt_name, BGT_NAME_PATTERN, c->vi.ubi_num, c->vi.vol_id);
1381  	if (!c->ro_mount) {
1382  		/* Create background thread */
1383  		c->bgt = kthread_run(ubifs_bg_thread, c, "%s", c->bgt_name);
1384  		if (IS_ERR(c->bgt)) {
1385  			err = PTR_ERR(c->bgt);
1386  			c->bgt = NULL;
1387  			ubifs_err(c, "cannot spawn \"%s\", error %d",
1388  				  c->bgt_name, err);
1389  			goto out_wbufs;
1390  		}
1391  	}
1392  
1393  	err = ubifs_read_master(c);
1394  	if (err)
1395  		goto out_master;
1396  
1397  	init_constants_master(c);
1398  
1399  	if ((c->mst_node->flags & cpu_to_le32(UBIFS_MST_DIRTY)) != 0) {
1400  		ubifs_msg(c, "recovery needed");
1401  		c->need_recovery = 1;
1402  	}
1403  
1404  	if (c->need_recovery && !c->ro_mount) {
1405  		err = ubifs_recover_inl_heads(c, c->sbuf);
1406  		if (err)
1407  			goto out_master;
1408  	}
1409  
1410  	err = ubifs_lpt_init(c, 1, !c->ro_mount);
1411  	if (err)
1412  		goto out_master;
1413  
1414  	if (!c->ro_mount && c->space_fixup) {
1415  		err = ubifs_fixup_free_space(c);
1416  		if (err)
1417  			goto out_lpt;
1418  	}
1419  
1420  	if (!c->ro_mount && !c->need_recovery) {
1421  		/*
1422  		 * Set the "dirty" flag so that if we reboot uncleanly we
1423  		 * will notice this immediately on the next mount.
1424  		 */
1425  		c->mst_node->flags |= cpu_to_le32(UBIFS_MST_DIRTY);
1426  		err = ubifs_write_master(c);
1427  		if (err)
1428  			goto out_lpt;
1429  	}
1430  
1431  	/*
1432  	 * Handle offline signed images: Now that the master node is
1433  	 * written and its validation no longer depends on the hash
1434  	 * in the superblock, we can update the offline signed
1435  	 * superblock with a HMAC version,
1436  	 */
1437  	if (ubifs_authenticated(c) && ubifs_hmac_zero(c, c->sup_node->hmac)) {
1438  		err = ubifs_hmac_wkm(c, c->sup_node->hmac_wkm);
1439  		if (err)
1440  			goto out_lpt;
1441  		c->superblock_need_write = 1;
1442  	}
1443  
1444  	if (!c->ro_mount && c->superblock_need_write) {
1445  		err = ubifs_write_sb_node(c, c->sup_node);
1446  		if (err)
1447  			goto out_lpt;
1448  		c->superblock_need_write = 0;
1449  	}
1450  
1451  	err = dbg_check_idx_size(c, c->bi.old_idx_sz);
1452  	if (err)
1453  		goto out_lpt;
1454  
1455  	err = ubifs_replay_journal(c);
1456  	if (err)
1457  		goto out_journal;
1458  
1459  	/* Calculate 'min_idx_lebs' after journal replay */
1460  	c->bi.min_idx_lebs = ubifs_calc_min_idx_lebs(c);
1461  
1462  	err = ubifs_mount_orphans(c, c->need_recovery, c->ro_mount);
1463  	if (err)
1464  		goto out_orphans;
1465  
1466  	if (!c->ro_mount) {
1467  		int lnum;
1468  
1469  		err = check_free_space(c);
1470  		if (err)
1471  			goto out_orphans;
1472  
1473  		/* Check for enough log space */
1474  		lnum = c->lhead_lnum + 1;
1475  		if (lnum >= UBIFS_LOG_LNUM + c->log_lebs)
1476  			lnum = UBIFS_LOG_LNUM;
1477  		if (lnum == c->ltail_lnum) {
1478  			err = ubifs_consolidate_log(c);
1479  			if (err)
1480  				goto out_orphans;
1481  		}
1482  
1483  		if (c->need_recovery) {
1484  			if (!ubifs_authenticated(c)) {
1485  				err = ubifs_recover_size(c, true);
1486  				if (err)
1487  					goto out_orphans;
1488  			}
1489  
1490  			err = ubifs_rcvry_gc_commit(c);
1491  			if (err)
1492  				goto out_orphans;
1493  
1494  			if (ubifs_authenticated(c)) {
1495  				err = ubifs_recover_size(c, false);
1496  				if (err)
1497  					goto out_orphans;
1498  			}
1499  		} else {
1500  			err = take_gc_lnum(c);
1501  			if (err)
1502  				goto out_orphans;
1503  
1504  			/*
1505  			 * GC LEB may contain garbage if there was an unclean
1506  			 * reboot, and it should be un-mapped.
1507  			 */
1508  			err = ubifs_leb_unmap(c, c->gc_lnum);
1509  			if (err)
1510  				goto out_orphans;
1511  		}
1512  
1513  		err = dbg_check_lprops(c);
1514  		if (err)
1515  			goto out_orphans;
1516  	} else if (c->need_recovery) {
1517  		err = ubifs_recover_size(c, false);
1518  		if (err)
1519  			goto out_orphans;
1520  	} else {
1521  		/*
1522  		 * Even if we mount read-only, we have to set space in GC LEB
1523  		 * to proper value because this affects UBIFS free space
1524  		 * reporting. We do not want to have a situation when
1525  		 * re-mounting from R/O to R/W changes amount of free space.
1526  		 */
1527  		err = take_gc_lnum(c);
1528  		if (err)
1529  			goto out_orphans;
1530  	}
1531  
1532  	spin_lock(&ubifs_infos_lock);
1533  	list_add_tail(&c->infos_list, &ubifs_infos);
1534  	spin_unlock(&ubifs_infos_lock);
1535  
1536  	if (c->need_recovery) {
1537  		if (c->ro_mount)
1538  			ubifs_msg(c, "recovery deferred");
1539  		else {
1540  			c->need_recovery = 0;
1541  			ubifs_msg(c, "recovery completed");
1542  			/*
1543  			 * GC LEB has to be empty and taken at this point. But
1544  			 * the journal head LEBs may also be accounted as
1545  			 * "empty taken" if they are empty.
1546  			 */
1547  			ubifs_assert(c, c->lst.taken_empty_lebs > 0);
1548  		}
1549  	} else
1550  		ubifs_assert(c, c->lst.taken_empty_lebs > 0);
1551  
1552  	err = dbg_check_filesystem(c);
1553  	if (err)
1554  		goto out_infos;
1555  
1556  	dbg_debugfs_init_fs(c);
1557  
1558  	c->mounting = 0;
1559  
1560  	ubifs_msg(c, "UBIFS: mounted UBI device %d, volume %d, name \"%s\"%s",
1561  		  c->vi.ubi_num, c->vi.vol_id, c->vi.name,
1562  		  c->ro_mount ? ", R/O mode" : "");
1563  	x = (long long)c->main_lebs * c->leb_size;
1564  	y = (long long)c->log_lebs * c->leb_size + c->max_bud_bytes;
1565  	ubifs_msg(c, "LEB size: %d bytes (%d KiB), min./max. I/O unit sizes: %d bytes/%d bytes",
1566  		  c->leb_size, c->leb_size >> 10, c->min_io_size,
1567  		  c->max_write_size);
1568  	ubifs_msg(c, "FS size: %lld bytes (%lld MiB, %d LEBs), max %d LEBs, journal size %lld bytes (%lld MiB, %d LEBs)",
1569  		  x, x >> 20, c->main_lebs, c->max_leb_cnt,
1570  		  y, y >> 20, c->log_lebs + c->max_bud_cnt);
1571  	ubifs_msg(c, "reserved for root: %llu bytes (%llu KiB)",
1572  		  c->report_rp_size, c->report_rp_size >> 10);
1573  	ubifs_msg(c, "media format: w%d/r%d (latest is w%d/r%d), UUID %pUB%s",
1574  		  c->fmt_version, c->ro_compat_version,
1575  		  UBIFS_FORMAT_VERSION, UBIFS_RO_COMPAT_VERSION, c->uuid,
1576  		  c->big_lpt ? ", big LPT model" : ", small LPT model");
1577  
1578  	dbg_gen("default compressor:  %s", ubifs_compr_name(c, c->default_compr));
1579  	dbg_gen("data journal heads:  %d",
1580  		c->jhead_cnt - NONDATA_JHEADS_CNT);
1581  	dbg_gen("log LEBs:            %d (%d - %d)",
1582  		c->log_lebs, UBIFS_LOG_LNUM, c->log_last);
1583  	dbg_gen("LPT area LEBs:       %d (%d - %d)",
1584  		c->lpt_lebs, c->lpt_first, c->lpt_last);
1585  	dbg_gen("orphan area LEBs:    %d (%d - %d)",
1586  		c->orph_lebs, c->orph_first, c->orph_last);
1587  	dbg_gen("main area LEBs:      %d (%d - %d)",
1588  		c->main_lebs, c->main_first, c->leb_cnt - 1);
1589  	dbg_gen("index LEBs:          %d", c->lst.idx_lebs);
1590  	dbg_gen("total index bytes:   %llu (%llu KiB, %llu MiB)",
1591  		c->bi.old_idx_sz, c->bi.old_idx_sz >> 10,
1592  		c->bi.old_idx_sz >> 20);
1593  	dbg_gen("key hash type:       %d", c->key_hash_type);
1594  	dbg_gen("tree fanout:         %d", c->fanout);
1595  	dbg_gen("reserved GC LEB:     %d", c->gc_lnum);
1596  	dbg_gen("max. znode size      %d", c->max_znode_sz);
1597  	dbg_gen("max. index node size %d", c->max_idx_node_sz);
1598  	dbg_gen("node sizes:          data %zu, inode %zu, dentry %zu",
1599  		UBIFS_DATA_NODE_SZ, UBIFS_INO_NODE_SZ, UBIFS_DENT_NODE_SZ);
1600  	dbg_gen("node sizes:          trun %zu, sb %zu, master %zu",
1601  		UBIFS_TRUN_NODE_SZ, UBIFS_SB_NODE_SZ, UBIFS_MST_NODE_SZ);
1602  	dbg_gen("node sizes:          ref %zu, cmt. start %zu, orph %zu",
1603  		UBIFS_REF_NODE_SZ, UBIFS_CS_NODE_SZ, UBIFS_ORPH_NODE_SZ);
1604  	dbg_gen("max. node sizes:     data %zu, inode %zu dentry %zu, idx %d",
1605  		UBIFS_MAX_DATA_NODE_SZ, UBIFS_MAX_INO_NODE_SZ,
1606  		UBIFS_MAX_DENT_NODE_SZ, ubifs_idx_node_sz(c, c->fanout));
1607  	dbg_gen("dead watermark:      %d", c->dead_wm);
1608  	dbg_gen("dark watermark:      %d", c->dark_wm);
1609  	dbg_gen("LEB overhead:        %d", c->leb_overhead);
1610  	x = (long long)c->main_lebs * c->dark_wm;
1611  	dbg_gen("max. dark space:     %lld (%lld KiB, %lld MiB)",
1612  		x, x >> 10, x >> 20);
1613  	dbg_gen("maximum bud bytes:   %lld (%lld KiB, %lld MiB)",
1614  		c->max_bud_bytes, c->max_bud_bytes >> 10,
1615  		c->max_bud_bytes >> 20);
1616  	dbg_gen("BG commit bud bytes: %lld (%lld KiB, %lld MiB)",
1617  		c->bg_bud_bytes, c->bg_bud_bytes >> 10,
1618  		c->bg_bud_bytes >> 20);
1619  	dbg_gen("current bud bytes    %lld (%lld KiB, %lld MiB)",
1620  		c->bud_bytes, c->bud_bytes >> 10, c->bud_bytes >> 20);
1621  	dbg_gen("max. seq. number:    %llu", c->max_sqnum);
1622  	dbg_gen("commit number:       %llu", c->cmt_no);
1623  	dbg_gen("max. xattrs per inode: %d", ubifs_xattr_max_cnt(c));
1624  	dbg_gen("max orphans:           %d", c->max_orphans);
1625  
1626  	return 0;
1627  
1628  out_infos:
1629  	spin_lock(&ubifs_infos_lock);
1630  	list_del(&c->infos_list);
1631  	spin_unlock(&ubifs_infos_lock);
1632  out_orphans:
1633  	free_orphans(c);
1634  out_journal:
1635  	destroy_journal(c);
1636  out_lpt:
1637  	ubifs_lpt_free(c, 0);
1638  out_master:
1639  	kfree(c->mst_node);
1640  	kfree(c->rcvrd_mst_node);
1641  	if (c->bgt)
1642  		kthread_stop(c->bgt);
1643  out_wbufs:
1644  	free_wbufs(c);
1645  out_cbuf:
1646  	kfree(c->cbuf);
1647  out_auth:
1648  	ubifs_exit_authentication(c);
1649  out_free:
1650  	kfree(c->write_reserve_buf);
1651  	kfree(c->bu.buf);
1652  	vfree(c->ileb_buf);
1653  	vfree(c->sbuf);
1654  	kfree(c->bottom_up_buf);
1655  	kfree(c->sup_node);
1656  	ubifs_sysfs_unregister(c);
1657  out_debugging:
1658  	ubifs_debugging_exit(c);
1659  	return err;
1660  }
1661  
1662  /**
1663   * ubifs_umount - un-mount UBIFS file-system.
1664   * @c: UBIFS file-system description object
1665   *
1666   * Note, this function is called to free allocated resourced when un-mounting,
1667   * as well as free resources when an error occurred while we were half way
1668   * through mounting (error path cleanup function). So it has to make sure the
1669   * resource was actually allocated before freeing it.
1670   */
1671  static void ubifs_umount(struct ubifs_info *c)
1672  {
1673  	dbg_gen("un-mounting UBI device %d, volume %d", c->vi.ubi_num,
1674  		c->vi.vol_id);
1675  
1676  	dbg_debugfs_exit_fs(c);
1677  	spin_lock(&ubifs_infos_lock);
1678  	list_del(&c->infos_list);
1679  	spin_unlock(&ubifs_infos_lock);
1680  
1681  	if (c->bgt)
1682  		kthread_stop(c->bgt);
1683  
1684  	destroy_journal(c);
1685  	free_wbufs(c);
1686  	free_orphans(c);
1687  	ubifs_lpt_free(c, 0);
1688  	ubifs_exit_authentication(c);
1689  
1690  	ubifs_release_options(c);
1691  	kfree(c->cbuf);
1692  	kfree(c->rcvrd_mst_node);
1693  	kfree(c->mst_node);
1694  	kfree(c->write_reserve_buf);
1695  	kfree(c->bu.buf);
1696  	vfree(c->ileb_buf);
1697  	vfree(c->sbuf);
1698  	kfree(c->bottom_up_buf);
1699  	kfree(c->sup_node);
1700  	ubifs_debugging_exit(c);
1701  	ubifs_sysfs_unregister(c);
1702  }
1703  
1704  /**
1705   * ubifs_remount_rw - re-mount in read-write mode.
1706   * @c: UBIFS file-system description object
1707   *
1708   * UBIFS avoids allocating many unnecessary resources when mounted in read-only
1709   * mode. This function allocates the needed resources and re-mounts UBIFS in
1710   * read-write mode.
1711   */
1712  static int ubifs_remount_rw(struct ubifs_info *c)
1713  {
1714  	int err, lnum;
1715  
1716  	if (c->rw_incompat) {
1717  		ubifs_err(c, "the file-system is not R/W-compatible");
1718  		ubifs_msg(c, "on-flash format version is w%d/r%d, but software only supports up to version w%d/r%d",
1719  			  c->fmt_version, c->ro_compat_version,
1720  			  UBIFS_FORMAT_VERSION, UBIFS_RO_COMPAT_VERSION);
1721  		return -EROFS;
1722  	}
1723  
1724  	mutex_lock(&c->umount_mutex);
1725  	dbg_save_space_info(c);
1726  	c->remounting_rw = 1;
1727  	c->ro_mount = 0;
1728  
1729  	if (c->space_fixup) {
1730  		err = ubifs_fixup_free_space(c);
1731  		if (err)
1732  			goto out;
1733  	}
1734  
1735  	err = check_free_space(c);
1736  	if (err)
1737  		goto out;
1738  
1739  	if (c->need_recovery) {
1740  		ubifs_msg(c, "completing deferred recovery");
1741  		err = ubifs_write_rcvrd_mst_node(c);
1742  		if (err)
1743  			goto out;
1744  		if (!ubifs_authenticated(c)) {
1745  			err = ubifs_recover_size(c, true);
1746  			if (err)
1747  				goto out;
1748  		}
1749  		err = ubifs_clean_lebs(c, c->sbuf);
1750  		if (err)
1751  			goto out;
1752  		err = ubifs_recover_inl_heads(c, c->sbuf);
1753  		if (err)
1754  			goto out;
1755  	} else {
1756  		/* A readonly mount is not allowed to have orphans */
1757  		ubifs_assert(c, c->tot_orphans == 0);
1758  		err = ubifs_clear_orphans(c);
1759  		if (err)
1760  			goto out;
1761  	}
1762  
1763  	if (!(c->mst_node->flags & cpu_to_le32(UBIFS_MST_DIRTY))) {
1764  		c->mst_node->flags |= cpu_to_le32(UBIFS_MST_DIRTY);
1765  		err = ubifs_write_master(c);
1766  		if (err)
1767  			goto out;
1768  	}
1769  
1770  	if (c->superblock_need_write) {
1771  		struct ubifs_sb_node *sup = c->sup_node;
1772  
1773  		err = ubifs_write_sb_node(c, sup);
1774  		if (err)
1775  			goto out;
1776  
1777  		c->superblock_need_write = 0;
1778  	}
1779  
1780  	c->ileb_buf = vmalloc(c->leb_size);
1781  	if (!c->ileb_buf) {
1782  		err = -ENOMEM;
1783  		goto out;
1784  	}
1785  
1786  	c->write_reserve_buf = kmalloc(COMPRESSED_DATA_NODE_BUF_SZ + \
1787  				       UBIFS_CIPHER_BLOCK_SIZE, GFP_KERNEL);
1788  	if (!c->write_reserve_buf) {
1789  		err = -ENOMEM;
1790  		goto out;
1791  	}
1792  
1793  	err = ubifs_lpt_init(c, 0, 1);
1794  	if (err)
1795  		goto out;
1796  
1797  	/* Create background thread */
1798  	c->bgt = kthread_run(ubifs_bg_thread, c, "%s", c->bgt_name);
1799  	if (IS_ERR(c->bgt)) {
1800  		err = PTR_ERR(c->bgt);
1801  		c->bgt = NULL;
1802  		ubifs_err(c, "cannot spawn \"%s\", error %d",
1803  			  c->bgt_name, err);
1804  		goto out;
1805  	}
1806  
1807  	c->orph_buf = vmalloc(c->leb_size);
1808  	if (!c->orph_buf) {
1809  		err = -ENOMEM;
1810  		goto out;
1811  	}
1812  
1813  	/* Check for enough log space */
1814  	lnum = c->lhead_lnum + 1;
1815  	if (lnum >= UBIFS_LOG_LNUM + c->log_lebs)
1816  		lnum = UBIFS_LOG_LNUM;
1817  	if (lnum == c->ltail_lnum) {
1818  		err = ubifs_consolidate_log(c);
1819  		if (err)
1820  			goto out;
1821  	}
1822  
1823  	if (c->need_recovery) {
1824  		err = ubifs_rcvry_gc_commit(c);
1825  		if (err)
1826  			goto out;
1827  
1828  		if (ubifs_authenticated(c)) {
1829  			err = ubifs_recover_size(c, false);
1830  			if (err)
1831  				goto out;
1832  		}
1833  	} else {
1834  		err = ubifs_leb_unmap(c, c->gc_lnum);
1835  	}
1836  	if (err)
1837  		goto out;
1838  
1839  	dbg_gen("re-mounted read-write");
1840  	c->remounting_rw = 0;
1841  
1842  	if (c->need_recovery) {
1843  		c->need_recovery = 0;
1844  		ubifs_msg(c, "deferred recovery completed");
1845  	} else {
1846  		/*
1847  		 * Do not run the debugging space check if the were doing
1848  		 * recovery, because when we saved the information we had the
1849  		 * file-system in a state where the TNC and lprops has been
1850  		 * modified in memory, but all the I/O operations (including a
1851  		 * commit) were deferred. So the file-system was in
1852  		 * "non-committed" state. Now the file-system is in committed
1853  		 * state, and of course the amount of free space will change
1854  		 * because, for example, the old index size was imprecise.
1855  		 */
1856  		err = dbg_check_space_info(c);
1857  	}
1858  
1859  	mutex_unlock(&c->umount_mutex);
1860  	return err;
1861  
1862  out:
1863  	c->ro_mount = 1;
1864  	vfree(c->orph_buf);
1865  	c->orph_buf = NULL;
1866  	if (c->bgt) {
1867  		kthread_stop(c->bgt);
1868  		c->bgt = NULL;
1869  	}
1870  	kfree(c->write_reserve_buf);
1871  	c->write_reserve_buf = NULL;
1872  	vfree(c->ileb_buf);
1873  	c->ileb_buf = NULL;
1874  	ubifs_lpt_free(c, 1);
1875  	c->remounting_rw = 0;
1876  	mutex_unlock(&c->umount_mutex);
1877  	return err;
1878  }
1879  
1880  /**
1881   * ubifs_remount_ro - re-mount in read-only mode.
1882   * @c: UBIFS file-system description object
1883   *
1884   * We assume VFS has stopped writing. Possibly the background thread could be
1885   * running a commit, however kthread_stop will wait in that case.
1886   */
1887  static void ubifs_remount_ro(struct ubifs_info *c)
1888  {
1889  	int i, err;
1890  
1891  	ubifs_assert(c, !c->need_recovery);
1892  	ubifs_assert(c, !c->ro_mount);
1893  
1894  	mutex_lock(&c->umount_mutex);
1895  	if (c->bgt) {
1896  		kthread_stop(c->bgt);
1897  		c->bgt = NULL;
1898  	}
1899  
1900  	dbg_save_space_info(c);
1901  
1902  	for (i = 0; i < c->jhead_cnt; i++) {
1903  		err = ubifs_wbuf_sync(&c->jheads[i].wbuf);
1904  		if (err)
1905  			ubifs_ro_mode(c, err);
1906  	}
1907  
1908  	c->mst_node->flags &= ~cpu_to_le32(UBIFS_MST_DIRTY);
1909  	c->mst_node->flags |= cpu_to_le32(UBIFS_MST_NO_ORPHS);
1910  	c->mst_node->gc_lnum = cpu_to_le32(c->gc_lnum);
1911  	err = ubifs_write_master(c);
1912  	if (err)
1913  		ubifs_ro_mode(c, err);
1914  
1915  	vfree(c->orph_buf);
1916  	c->orph_buf = NULL;
1917  	kfree(c->write_reserve_buf);
1918  	c->write_reserve_buf = NULL;
1919  	vfree(c->ileb_buf);
1920  	c->ileb_buf = NULL;
1921  	ubifs_lpt_free(c, 1);
1922  	c->ro_mount = 1;
1923  	err = dbg_check_space_info(c);
1924  	if (err)
1925  		ubifs_ro_mode(c, err);
1926  	mutex_unlock(&c->umount_mutex);
1927  }
1928  
1929  static void ubifs_put_super(struct super_block *sb)
1930  {
1931  	int i;
1932  	struct ubifs_info *c = sb->s_fs_info;
1933  
1934  	ubifs_msg(c, "un-mount UBI device %d", c->vi.ubi_num);
1935  
1936  	/*
1937  	 * The following asserts are only valid if there has not been a failure
1938  	 * of the media. For example, there will be dirty inodes if we failed
1939  	 * to write them back because of I/O errors.
1940  	 */
1941  	if (!c->ro_error) {
1942  		ubifs_assert(c, c->bi.idx_growth == 0);
1943  		ubifs_assert(c, c->bi.dd_growth == 0);
1944  		ubifs_assert(c, c->bi.data_growth == 0);
1945  	}
1946  
1947  	/*
1948  	 * The 'c->umount_lock' prevents races between UBIFS memory shrinker
1949  	 * and file system un-mount. Namely, it prevents the shrinker from
1950  	 * picking this superblock for shrinking - it will be just skipped if
1951  	 * the mutex is locked.
1952  	 */
1953  	mutex_lock(&c->umount_mutex);
1954  	if (!c->ro_mount) {
1955  		/*
1956  		 * First of all kill the background thread to make sure it does
1957  		 * not interfere with un-mounting and freeing resources.
1958  		 */
1959  		if (c->bgt) {
1960  			kthread_stop(c->bgt);
1961  			c->bgt = NULL;
1962  		}
1963  
1964  		/*
1965  		 * On fatal errors c->ro_error is set to 1, in which case we do
1966  		 * not write the master node.
1967  		 */
1968  		if (!c->ro_error) {
1969  			int err;
1970  
1971  			/* Synchronize write-buffers */
1972  			for (i = 0; i < c->jhead_cnt; i++) {
1973  				err = ubifs_wbuf_sync(&c->jheads[i].wbuf);
1974  				if (err)
1975  					ubifs_ro_mode(c, err);
1976  			}
1977  
1978  			/*
1979  			 * We are being cleanly unmounted which means the
1980  			 * orphans were killed - indicate this in the master
1981  			 * node. Also save the reserved GC LEB number.
1982  			 */
1983  			c->mst_node->flags &= ~cpu_to_le32(UBIFS_MST_DIRTY);
1984  			c->mst_node->flags |= cpu_to_le32(UBIFS_MST_NO_ORPHS);
1985  			c->mst_node->gc_lnum = cpu_to_le32(c->gc_lnum);
1986  			err = ubifs_write_master(c);
1987  			if (err)
1988  				/*
1989  				 * Recovery will attempt to fix the master area
1990  				 * next mount, so we just print a message and
1991  				 * continue to unmount normally.
1992  				 */
1993  				ubifs_err(c, "failed to write master node, error %d",
1994  					  err);
1995  		} else {
1996  			for (i = 0; i < c->jhead_cnt; i++)
1997  				/* Make sure write-buffer timers are canceled */
1998  				hrtimer_cancel(&c->jheads[i].wbuf.timer);
1999  		}
2000  	}
2001  
2002  	ubifs_umount(c);
2003  	ubi_close_volume(c->ubi);
2004  	mutex_unlock(&c->umount_mutex);
2005  }
2006  
2007  static int ubifs_remount_fs(struct super_block *sb, int *flags, char *data)
2008  {
2009  	int err;
2010  	struct ubifs_info *c = sb->s_fs_info;
2011  
2012  	sync_filesystem(sb);
2013  	dbg_gen("old flags %#lx, new flags %#x", sb->s_flags, *flags);
2014  
2015  	err = ubifs_parse_options(c, data, 1);
2016  	if (err) {
2017  		ubifs_err(c, "invalid or unknown remount parameter");
2018  		return err;
2019  	}
2020  
2021  	if (c->ro_mount && !(*flags & SB_RDONLY)) {
2022  		if (c->ro_error) {
2023  			ubifs_msg(c, "cannot re-mount R/W due to prior errors");
2024  			return -EROFS;
2025  		}
2026  		if (c->ro_media) {
2027  			ubifs_msg(c, "cannot re-mount R/W - UBI volume is R/O");
2028  			return -EROFS;
2029  		}
2030  		err = ubifs_remount_rw(c);
2031  		if (err)
2032  			return err;
2033  	} else if (!c->ro_mount && (*flags & SB_RDONLY)) {
2034  		if (c->ro_error) {
2035  			ubifs_msg(c, "cannot re-mount R/O due to prior errors");
2036  			return -EROFS;
2037  		}
2038  		ubifs_remount_ro(c);
2039  	}
2040  
2041  	if (c->bulk_read == 1)
2042  		bu_init(c);
2043  	else {
2044  		dbg_gen("disable bulk-read");
2045  		mutex_lock(&c->bu_mutex);
2046  		kfree(c->bu.buf);
2047  		c->bu.buf = NULL;
2048  		mutex_unlock(&c->bu_mutex);
2049  	}
2050  
2051  	if (!c->need_recovery)
2052  		ubifs_assert(c, c->lst.taken_empty_lebs > 0);
2053  
2054  	return 0;
2055  }
2056  
2057  const struct super_operations ubifs_super_operations = {
2058  	.alloc_inode   = ubifs_alloc_inode,
2059  	.free_inode    = ubifs_free_inode,
2060  	.put_super     = ubifs_put_super,
2061  	.write_inode   = ubifs_write_inode,
2062  	.drop_inode    = ubifs_drop_inode,
2063  	.evict_inode   = ubifs_evict_inode,
2064  	.statfs        = ubifs_statfs,
2065  	.dirty_inode   = ubifs_dirty_inode,
2066  	.remount_fs    = ubifs_remount_fs,
2067  	.show_options  = ubifs_show_options,
2068  	.sync_fs       = ubifs_sync_fs,
2069  };
2070  
2071  /**
2072   * open_ubi - parse UBI device name string and open the UBI device.
2073   * @name: UBI volume name
2074   * @mode: UBI volume open mode
2075   *
2076   * The primary method of mounting UBIFS is by specifying the UBI volume
2077   * character device node path. However, UBIFS may also be mounted without any
2078   * character device node using one of the following methods:
2079   *
2080   * o ubiX_Y    - mount UBI device number X, volume Y;
2081   * o ubiY      - mount UBI device number 0, volume Y;
2082   * o ubiX:NAME - mount UBI device X, volume with name NAME;
2083   * o ubi:NAME  - mount UBI device 0, volume with name NAME.
2084   *
2085   * Alternative '!' separator may be used instead of ':' (because some shells
2086   * like busybox may interpret ':' as an NFS host name separator). This function
2087   * returns UBI volume description object in case of success and a negative
2088   * error code in case of failure.
2089   */
2090  static struct ubi_volume_desc *open_ubi(const char *name, int mode)
2091  {
2092  	struct ubi_volume_desc *ubi;
2093  	int dev, vol;
2094  	char *endptr;
2095  
2096  	if (!name || !*name)
2097  		return ERR_PTR(-EINVAL);
2098  
2099  	/* First, try to open using the device node path method */
2100  	ubi = ubi_open_volume_path(name, mode);
2101  	if (!IS_ERR(ubi))
2102  		return ubi;
2103  
2104  	/* Try the "nodev" method */
2105  	if (name[0] != 'u' || name[1] != 'b' || name[2] != 'i')
2106  		return ERR_PTR(-EINVAL);
2107  
2108  	/* ubi:NAME method */
2109  	if ((name[3] == ':' || name[3] == '!') && name[4] != '\0')
2110  		return ubi_open_volume_nm(0, name + 4, mode);
2111  
2112  	if (!isdigit(name[3]))
2113  		return ERR_PTR(-EINVAL);
2114  
2115  	dev = simple_strtoul(name + 3, &endptr, 0);
2116  
2117  	/* ubiY method */
2118  	if (*endptr == '\0')
2119  		return ubi_open_volume(0, dev, mode);
2120  
2121  	/* ubiX_Y method */
2122  	if (*endptr == '_' && isdigit(endptr[1])) {
2123  		vol = simple_strtoul(endptr + 1, &endptr, 0);
2124  		if (*endptr != '\0')
2125  			return ERR_PTR(-EINVAL);
2126  		return ubi_open_volume(dev, vol, mode);
2127  	}
2128  
2129  	/* ubiX:NAME method */
2130  	if ((*endptr == ':' || *endptr == '!') && endptr[1] != '\0')
2131  		return ubi_open_volume_nm(dev, ++endptr, mode);
2132  
2133  	return ERR_PTR(-EINVAL);
2134  }
2135  
2136  static struct ubifs_info *alloc_ubifs_info(struct ubi_volume_desc *ubi)
2137  {
2138  	struct ubifs_info *c;
2139  
2140  	c = kzalloc(sizeof(struct ubifs_info), GFP_KERNEL);
2141  	if (c) {
2142  		spin_lock_init(&c->cnt_lock);
2143  		spin_lock_init(&c->cs_lock);
2144  		spin_lock_init(&c->buds_lock);
2145  		spin_lock_init(&c->space_lock);
2146  		spin_lock_init(&c->orphan_lock);
2147  		init_rwsem(&c->commit_sem);
2148  		mutex_init(&c->lp_mutex);
2149  		mutex_init(&c->tnc_mutex);
2150  		mutex_init(&c->log_mutex);
2151  		mutex_init(&c->umount_mutex);
2152  		mutex_init(&c->bu_mutex);
2153  		mutex_init(&c->write_reserve_mutex);
2154  		init_waitqueue_head(&c->cmt_wq);
2155  		c->buds = RB_ROOT;
2156  		c->old_idx = RB_ROOT;
2157  		c->size_tree = RB_ROOT;
2158  		c->orph_tree = RB_ROOT;
2159  		INIT_LIST_HEAD(&c->infos_list);
2160  		INIT_LIST_HEAD(&c->idx_gc);
2161  		INIT_LIST_HEAD(&c->replay_list);
2162  		INIT_LIST_HEAD(&c->replay_buds);
2163  		INIT_LIST_HEAD(&c->uncat_list);
2164  		INIT_LIST_HEAD(&c->empty_list);
2165  		INIT_LIST_HEAD(&c->freeable_list);
2166  		INIT_LIST_HEAD(&c->frdi_idx_list);
2167  		INIT_LIST_HEAD(&c->unclean_leb_list);
2168  		INIT_LIST_HEAD(&c->old_buds);
2169  		INIT_LIST_HEAD(&c->orph_list);
2170  		INIT_LIST_HEAD(&c->orph_new);
2171  		c->no_chk_data_crc = 1;
2172  		c->assert_action = ASSACT_RO;
2173  
2174  		c->highest_inum = UBIFS_FIRST_INO;
2175  		c->lhead_lnum = c->ltail_lnum = UBIFS_LOG_LNUM;
2176  
2177  		ubi_get_volume_info(ubi, &c->vi);
2178  		ubi_get_device_info(c->vi.ubi_num, &c->di);
2179  	}
2180  	return c;
2181  }
2182  
2183  static int ubifs_fill_super(struct super_block *sb, void *data, int silent)
2184  {
2185  	struct ubifs_info *c = sb->s_fs_info;
2186  	struct inode *root;
2187  	int err;
2188  
2189  	c->vfs_sb = sb;
2190  	/* Re-open the UBI device in read-write mode */
2191  	c->ubi = ubi_open_volume(c->vi.ubi_num, c->vi.vol_id, UBI_READWRITE);
2192  	if (IS_ERR(c->ubi)) {
2193  		err = PTR_ERR(c->ubi);
2194  		goto out;
2195  	}
2196  
2197  	err = ubifs_parse_options(c, data, 0);
2198  	if (err)
2199  		goto out_close;
2200  
2201  	/*
2202  	 * UBIFS provides 'backing_dev_info' in order to disable read-ahead. For
2203  	 * UBIFS, I/O is not deferred, it is done immediately in read_folio,
2204  	 * which means the user would have to wait not just for their own I/O
2205  	 * but the read-ahead I/O as well i.e. completely pointless.
2206  	 *
2207  	 * Read-ahead will be disabled because @sb->s_bdi->ra_pages is 0. Also
2208  	 * @sb->s_bdi->capabilities are initialized to 0 so there won't be any
2209  	 * writeback happening.
2210  	 */
2211  	err = super_setup_bdi_name(sb, "ubifs_%d_%d", c->vi.ubi_num,
2212  				   c->vi.vol_id);
2213  	if (err)
2214  		goto out_close;
2215  	sb->s_bdi->ra_pages = 0;
2216  	sb->s_bdi->io_pages = 0;
2217  
2218  	sb->s_fs_info = c;
2219  	sb->s_magic = UBIFS_SUPER_MAGIC;
2220  	sb->s_blocksize = UBIFS_BLOCK_SIZE;
2221  	sb->s_blocksize_bits = UBIFS_BLOCK_SHIFT;
2222  	sb->s_maxbytes = c->max_inode_sz = key_max_inode_size(c);
2223  	if (c->max_inode_sz > MAX_LFS_FILESIZE)
2224  		sb->s_maxbytes = c->max_inode_sz = MAX_LFS_FILESIZE;
2225  	sb->s_op = &ubifs_super_operations;
2226  	sb->s_xattr = ubifs_xattr_handlers;
2227  	fscrypt_set_ops(sb, &ubifs_crypt_operations);
2228  
2229  	mutex_lock(&c->umount_mutex);
2230  	err = mount_ubifs(c);
2231  	if (err) {
2232  		ubifs_assert(c, err < 0);
2233  		goto out_unlock;
2234  	}
2235  
2236  	/* Read the root inode */
2237  	root = ubifs_iget(sb, UBIFS_ROOT_INO);
2238  	if (IS_ERR(root)) {
2239  		err = PTR_ERR(root);
2240  		goto out_umount;
2241  	}
2242  
2243  	sb->s_root = d_make_root(root);
2244  	if (!sb->s_root) {
2245  		err = -ENOMEM;
2246  		goto out_umount;
2247  	}
2248  
2249  	import_uuid(&sb->s_uuid, c->uuid);
2250  
2251  	mutex_unlock(&c->umount_mutex);
2252  	return 0;
2253  
2254  out_umount:
2255  	ubifs_umount(c);
2256  out_unlock:
2257  	mutex_unlock(&c->umount_mutex);
2258  out_close:
2259  	ubifs_release_options(c);
2260  	ubi_close_volume(c->ubi);
2261  out:
2262  	return err;
2263  }
2264  
2265  static int sb_test(struct super_block *sb, void *data)
2266  {
2267  	struct ubifs_info *c1 = data;
2268  	struct ubifs_info *c = sb->s_fs_info;
2269  
2270  	return c->vi.cdev == c1->vi.cdev;
2271  }
2272  
2273  static int sb_set(struct super_block *sb, void *data)
2274  {
2275  	sb->s_fs_info = data;
2276  	return set_anon_super(sb, NULL);
2277  }
2278  
2279  static struct dentry *ubifs_mount(struct file_system_type *fs_type, int flags,
2280  			const char *name, void *data)
2281  {
2282  	struct ubi_volume_desc *ubi;
2283  	struct ubifs_info *c;
2284  	struct super_block *sb;
2285  	int err;
2286  
2287  	dbg_gen("name %s, flags %#x", name, flags);
2288  
2289  	/*
2290  	 * Get UBI device number and volume ID. Mount it read-only so far
2291  	 * because this might be a new mount point, and UBI allows only one
2292  	 * read-write user at a time.
2293  	 */
2294  	ubi = open_ubi(name, UBI_READONLY);
2295  	if (IS_ERR(ubi)) {
2296  		if (!(flags & SB_SILENT))
2297  			pr_err("UBIFS error (pid: %d): cannot open \"%s\", error %d",
2298  			       current->pid, name, (int)PTR_ERR(ubi));
2299  		return ERR_CAST(ubi);
2300  	}
2301  
2302  	c = alloc_ubifs_info(ubi);
2303  	if (!c) {
2304  		err = -ENOMEM;
2305  		goto out_close;
2306  	}
2307  
2308  	dbg_gen("opened ubi%d_%d", c->vi.ubi_num, c->vi.vol_id);
2309  
2310  	sb = sget(fs_type, sb_test, sb_set, flags, c);
2311  	if (IS_ERR(sb)) {
2312  		err = PTR_ERR(sb);
2313  		kfree(c);
2314  		goto out_close;
2315  	}
2316  
2317  	if (sb->s_root) {
2318  		struct ubifs_info *c1 = sb->s_fs_info;
2319  		kfree(c);
2320  		/* A new mount point for already mounted UBIFS */
2321  		dbg_gen("this ubi volume is already mounted");
2322  		if (!!(flags & SB_RDONLY) != c1->ro_mount) {
2323  			err = -EBUSY;
2324  			goto out_deact;
2325  		}
2326  	} else {
2327  		err = ubifs_fill_super(sb, data, flags & SB_SILENT ? 1 : 0);
2328  		if (err)
2329  			goto out_deact;
2330  		/* We do not support atime */
2331  		sb->s_flags |= SB_ACTIVE;
2332  		if (IS_ENABLED(CONFIG_UBIFS_ATIME_SUPPORT))
2333  			ubifs_msg(c, "full atime support is enabled.");
2334  		else
2335  			sb->s_flags |= SB_NOATIME;
2336  	}
2337  
2338  	/* 'fill_super()' opens ubi again so we must close it here */
2339  	ubi_close_volume(ubi);
2340  
2341  	return dget(sb->s_root);
2342  
2343  out_deact:
2344  	deactivate_locked_super(sb);
2345  out_close:
2346  	ubi_close_volume(ubi);
2347  	return ERR_PTR(err);
2348  }
2349  
2350  static void kill_ubifs_super(struct super_block *s)
2351  {
2352  	struct ubifs_info *c = s->s_fs_info;
2353  	kill_anon_super(s);
2354  	kfree(c);
2355  }
2356  
2357  static struct file_system_type ubifs_fs_type = {
2358  	.name    = "ubifs",
2359  	.owner   = THIS_MODULE,
2360  	.mount   = ubifs_mount,
2361  	.kill_sb = kill_ubifs_super,
2362  };
2363  MODULE_ALIAS_FS("ubifs");
2364  
2365  /*
2366   * Inode slab cache constructor.
2367   */
2368  static void inode_slab_ctor(void *obj)
2369  {
2370  	struct ubifs_inode *ui = obj;
2371  	inode_init_once(&ui->vfs_inode);
2372  }
2373  
2374  static int __init ubifs_init(void)
2375  {
2376  	int err;
2377  
2378  	BUILD_BUG_ON(sizeof(struct ubifs_ch) != 24);
2379  
2380  	/* Make sure node sizes are 8-byte aligned */
2381  	BUILD_BUG_ON(UBIFS_CH_SZ        & 7);
2382  	BUILD_BUG_ON(UBIFS_INO_NODE_SZ  & 7);
2383  	BUILD_BUG_ON(UBIFS_DENT_NODE_SZ & 7);
2384  	BUILD_BUG_ON(UBIFS_XENT_NODE_SZ & 7);
2385  	BUILD_BUG_ON(UBIFS_DATA_NODE_SZ & 7);
2386  	BUILD_BUG_ON(UBIFS_TRUN_NODE_SZ & 7);
2387  	BUILD_BUG_ON(UBIFS_SB_NODE_SZ   & 7);
2388  	BUILD_BUG_ON(UBIFS_MST_NODE_SZ  & 7);
2389  	BUILD_BUG_ON(UBIFS_REF_NODE_SZ  & 7);
2390  	BUILD_BUG_ON(UBIFS_CS_NODE_SZ   & 7);
2391  	BUILD_BUG_ON(UBIFS_ORPH_NODE_SZ & 7);
2392  
2393  	BUILD_BUG_ON(UBIFS_MAX_DENT_NODE_SZ & 7);
2394  	BUILD_BUG_ON(UBIFS_MAX_XENT_NODE_SZ & 7);
2395  	BUILD_BUG_ON(UBIFS_MAX_DATA_NODE_SZ & 7);
2396  	BUILD_BUG_ON(UBIFS_MAX_INO_NODE_SZ  & 7);
2397  	BUILD_BUG_ON(UBIFS_MAX_NODE_SZ      & 7);
2398  	BUILD_BUG_ON(MIN_WRITE_SZ           & 7);
2399  
2400  	/* Check min. node size */
2401  	BUILD_BUG_ON(UBIFS_INO_NODE_SZ  < MIN_WRITE_SZ);
2402  	BUILD_BUG_ON(UBIFS_DENT_NODE_SZ < MIN_WRITE_SZ);
2403  	BUILD_BUG_ON(UBIFS_XENT_NODE_SZ < MIN_WRITE_SZ);
2404  	BUILD_BUG_ON(UBIFS_TRUN_NODE_SZ < MIN_WRITE_SZ);
2405  
2406  	BUILD_BUG_ON(UBIFS_MAX_DENT_NODE_SZ > UBIFS_MAX_NODE_SZ);
2407  	BUILD_BUG_ON(UBIFS_MAX_XENT_NODE_SZ > UBIFS_MAX_NODE_SZ);
2408  	BUILD_BUG_ON(UBIFS_MAX_DATA_NODE_SZ > UBIFS_MAX_NODE_SZ);
2409  	BUILD_BUG_ON(UBIFS_MAX_INO_NODE_SZ  > UBIFS_MAX_NODE_SZ);
2410  
2411  	/* Defined node sizes */
2412  	BUILD_BUG_ON(UBIFS_SB_NODE_SZ  != 4096);
2413  	BUILD_BUG_ON(UBIFS_MST_NODE_SZ != 512);
2414  	BUILD_BUG_ON(UBIFS_INO_NODE_SZ != 160);
2415  	BUILD_BUG_ON(UBIFS_REF_NODE_SZ != 64);
2416  
2417  	/*
2418  	 * We use 2 bit wide bit-fields to store compression type, which should
2419  	 * be amended if more compressors are added. The bit-fields are:
2420  	 * @compr_type in 'struct ubifs_inode', @default_compr in
2421  	 * 'struct ubifs_info' and @compr_type in 'struct ubifs_mount_opts'.
2422  	 */
2423  	BUILD_BUG_ON(UBIFS_COMPR_TYPES_CNT > 4);
2424  
2425  	/*
2426  	 * We require that PAGE_SIZE is greater-than-or-equal-to
2427  	 * UBIFS_BLOCK_SIZE. It is assumed that both are powers of 2.
2428  	 */
2429  	if (PAGE_SIZE < UBIFS_BLOCK_SIZE) {
2430  		pr_err("UBIFS error (pid %d): VFS page cache size is %u bytes, but UBIFS requires at least 4096 bytes",
2431  		       current->pid, (unsigned int)PAGE_SIZE);
2432  		return -EINVAL;
2433  	}
2434  
2435  	ubifs_inode_slab = kmem_cache_create("ubifs_inode_slab",
2436  				sizeof(struct ubifs_inode), 0,
2437  				SLAB_MEM_SPREAD | SLAB_RECLAIM_ACCOUNT |
2438  				SLAB_ACCOUNT, &inode_slab_ctor);
2439  	if (!ubifs_inode_slab)
2440  		return -ENOMEM;
2441  
2442  	err = register_shrinker(&ubifs_shrinker_info, "ubifs-slab");
2443  	if (err)
2444  		goto out_slab;
2445  
2446  	err = ubifs_compressors_init();
2447  	if (err)
2448  		goto out_shrinker;
2449  
2450  	dbg_debugfs_init();
2451  
2452  	err = ubifs_sysfs_init();
2453  	if (err)
2454  		goto out_dbg;
2455  
2456  	err = register_filesystem(&ubifs_fs_type);
2457  	if (err) {
2458  		pr_err("UBIFS error (pid %d): cannot register file system, error %d",
2459  		       current->pid, err);
2460  		goto out_sysfs;
2461  	}
2462  	return 0;
2463  
2464  out_sysfs:
2465  	ubifs_sysfs_exit();
2466  out_dbg:
2467  	dbg_debugfs_exit();
2468  	ubifs_compressors_exit();
2469  out_shrinker:
2470  	unregister_shrinker(&ubifs_shrinker_info);
2471  out_slab:
2472  	kmem_cache_destroy(ubifs_inode_slab);
2473  	return err;
2474  }
2475  /* late_initcall to let compressors initialize first */
2476  late_initcall(ubifs_init);
2477  
2478  static void __exit ubifs_exit(void)
2479  {
2480  	WARN_ON(!list_empty(&ubifs_infos));
2481  	WARN_ON(atomic_long_read(&ubifs_clean_zn_cnt) != 0);
2482  
2483  	dbg_debugfs_exit();
2484  	ubifs_sysfs_exit();
2485  	ubifs_compressors_exit();
2486  	unregister_shrinker(&ubifs_shrinker_info);
2487  
2488  	/*
2489  	 * Make sure all delayed rcu free inodes are flushed before we
2490  	 * destroy cache.
2491  	 */
2492  	rcu_barrier();
2493  	kmem_cache_destroy(ubifs_inode_slab);
2494  	unregister_filesystem(&ubifs_fs_type);
2495  }
2496  module_exit(ubifs_exit);
2497  
2498  MODULE_LICENSE("GPL");
2499  MODULE_VERSION(__stringify(UBIFS_VERSION));
2500  MODULE_AUTHOR("Artem Bityutskiy, Adrian Hunter");
2501  MODULE_DESCRIPTION("UBIFS - UBI File System");
2502