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1 // SPDX-License-Identifier: GPL-2.0+
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 #ifndef __UBOOT__
18 #include <linux/init.h>
19 #include <linux/slab.h>
20 #include <linux/module.h>
21 #include <linux/ctype.h>
22 #include <linux/kthread.h>
23 #include <linux/parser.h>
24 #include <linux/seq_file.h>
25 #include <linux/mount.h>
26 #include <linux/math64.h>
27 #include <linux/writeback.h>
28 #else
29 
30 #include <common.h>
31 #include <malloc.h>
32 #include <memalign.h>
33 #include <linux/bug.h>
34 #include <linux/log2.h>
35 #include <linux/stat.h>
36 #include <linux/err.h>
37 #include "ubifs.h"
38 #include <ubi_uboot.h>
39 #include <mtd/ubi-user.h>
40 
41 struct dentry;
42 struct file;
43 struct iattr;
44 struct kstat;
45 struct vfsmount;
46 
47 #define INODE_LOCKED_MAX	64
48 
49 struct super_block *ubifs_sb;
50 
51 static struct inode *inodes_locked_down[INODE_LOCKED_MAX];
52 
set_anon_super(struct super_block * s,void * data)53 int set_anon_super(struct super_block *s, void *data)
54 {
55 	return 0;
56 }
57 
iget_locked(struct super_block * sb,unsigned long ino)58 struct inode *iget_locked(struct super_block *sb, unsigned long ino)
59 {
60 	struct inode *inode;
61 
62 	inode = (struct inode *)malloc_cache_aligned(
63 			sizeof(struct ubifs_inode));
64 	if (inode) {
65 		inode->i_ino = ino;
66 		inode->i_sb = sb;
67 		list_add(&inode->i_sb_list, &sb->s_inodes);
68 		inode->i_state = I_LOCK | I_NEW;
69 	}
70 
71 	return inode;
72 }
73 
iget_failed(struct inode * inode)74 void iget_failed(struct inode *inode)
75 {
76 }
77 
ubifs_iput(struct inode * inode)78 int ubifs_iput(struct inode *inode)
79 {
80 	list_del_init(&inode->i_sb_list);
81 
82 	free(inode);
83 	return 0;
84 }
85 
86 /*
87  * Lock (save) inode in inode array for readback after recovery
88  */
iput(struct inode * inode)89 void iput(struct inode *inode)
90 {
91 	int i;
92 	struct inode *ino;
93 
94 	/*
95 	 * Search end of list
96 	 */
97 	for (i = 0; i < INODE_LOCKED_MAX; i++) {
98 		if (inodes_locked_down[i] == NULL)
99 			break;
100 	}
101 
102 	if (i >= INODE_LOCKED_MAX) {
103 		dbg_gen("Error, can't lock (save) more inodes while recovery!!!");
104 		return;
105 	}
106 
107 	/*
108 	 * Allocate and use new inode
109 	 */
110 	ino = (struct inode *)malloc_cache_aligned(sizeof(struct ubifs_inode));
111 	memcpy(ino, inode, sizeof(struct ubifs_inode));
112 
113 	/*
114 	 * Finally save inode in array
115 	 */
116 	inodes_locked_down[i] = ino;
117 }
118 
119 /* from fs/inode.c */
120 /**
121  * clear_nlink - directly zero an inode's link count
122  * @inode: inode
123  *
124  * This is a low-level filesystem helper to replace any
125  * direct filesystem manipulation of i_nlink.  See
126  * drop_nlink() for why we care about i_nlink hitting zero.
127  */
clear_nlink(struct inode * inode)128 void clear_nlink(struct inode *inode)
129 {
130 	if (inode->i_nlink) {
131 		inode->__i_nlink = 0;
132 		atomic_long_inc(&inode->i_sb->s_remove_count);
133 	}
134 }
135 EXPORT_SYMBOL(clear_nlink);
136 
137 /**
138  * set_nlink - directly set an inode's link count
139  * @inode: inode
140  * @nlink: new nlink (should be non-zero)
141  *
142  * This is a low-level filesystem helper to replace any
143  * direct filesystem manipulation of i_nlink.
144  */
set_nlink(struct inode * inode,unsigned int nlink)145 void set_nlink(struct inode *inode, unsigned int nlink)
146 {
147 	if (!nlink) {
148 		clear_nlink(inode);
149 	} else {
150 		/* Yes, some filesystems do change nlink from zero to one */
151 		if (inode->i_nlink == 0)
152 			atomic_long_dec(&inode->i_sb->s_remove_count);
153 
154 		inode->__i_nlink = nlink;
155 	}
156 }
157 EXPORT_SYMBOL(set_nlink);
158 
159 /* from include/linux/fs.h */
i_uid_write(struct inode * inode,uid_t uid)160 static inline void i_uid_write(struct inode *inode, uid_t uid)
161 {
162 	inode->i_uid.val = uid;
163 }
164 
i_gid_write(struct inode * inode,gid_t gid)165 static inline void i_gid_write(struct inode *inode, gid_t gid)
166 {
167 	inode->i_gid.val = gid;
168 }
169 
unlock_new_inode(struct inode * inode)170 void unlock_new_inode(struct inode *inode)
171 {
172 	return;
173 }
174 #endif
175 
176 /*
177  * Maximum amount of memory we may 'kmalloc()' without worrying that we are
178  * allocating too much.
179  */
180 #define UBIFS_KMALLOC_OK (128*1024)
181 
182 /* Slab cache for UBIFS inodes */
183 struct kmem_cache *ubifs_inode_slab;
184 
185 #ifndef __UBOOT__
186 /* UBIFS TNC shrinker description */
187 static struct shrinker ubifs_shrinker_info = {
188 	.scan_objects = ubifs_shrink_scan,
189 	.count_objects = ubifs_shrink_count,
190 	.seeks = DEFAULT_SEEKS,
191 };
192 #endif
193 
194 /**
195  * validate_inode - validate inode.
196  * @c: UBIFS file-system description object
197  * @inode: the inode to validate
198  *
199  * This is a helper function for 'ubifs_iget()' which validates various fields
200  * of a newly built inode to make sure they contain sane values and prevent
201  * possible vulnerabilities. Returns zero if the inode is all right and
202  * a non-zero error code if not.
203  */
validate_inode(struct ubifs_info * c,const struct inode * inode)204 static int validate_inode(struct ubifs_info *c, const struct inode *inode)
205 {
206 	int err;
207 	const struct ubifs_inode *ui = ubifs_inode(inode);
208 
209 	if (inode->i_size > c->max_inode_sz) {
210 		ubifs_err(c, "inode is too large (%lld)",
211 			  (long long)inode->i_size);
212 		return 1;
213 	}
214 
215 	if (ui->compr_type >= UBIFS_COMPR_TYPES_CNT) {
216 		ubifs_err(c, "unknown compression type %d", ui->compr_type);
217 		return 2;
218 	}
219 
220 	if (ui->xattr_names + ui->xattr_cnt > XATTR_LIST_MAX)
221 		return 3;
222 
223 	if (ui->data_len < 0 || ui->data_len > UBIFS_MAX_INO_DATA)
224 		return 4;
225 
226 	if (ui->xattr && !S_ISREG(inode->i_mode))
227 		return 5;
228 
229 	if (!ubifs_compr_present(ui->compr_type)) {
230 		ubifs_warn(c, "inode %lu uses '%s' compression, but it was not compiled in",
231 			   inode->i_ino, ubifs_compr_name(ui->compr_type));
232 	}
233 
234 	err = dbg_check_dir(c, inode);
235 	return err;
236 }
237 
ubifs_iget(struct super_block * sb,unsigned long inum)238 struct inode *ubifs_iget(struct super_block *sb, unsigned long inum)
239 {
240 	int err;
241 	union ubifs_key key;
242 	struct ubifs_ino_node *ino;
243 	struct ubifs_info *c = sb->s_fs_info;
244 	struct inode *inode;
245 	struct ubifs_inode *ui;
246 #ifdef __UBOOT__
247 	int i;
248 #endif
249 
250 	dbg_gen("inode %lu", inum);
251 
252 #ifdef __UBOOT__
253 	/*
254 	 * U-Boot special handling of locked down inodes via recovery
255 	 * e.g. ubifs_recover_size()
256 	 */
257 	for (i = 0; i < INODE_LOCKED_MAX; i++) {
258 		/*
259 		 * Exit on last entry (NULL), inode not found in list
260 		 */
261 		if (inodes_locked_down[i] == NULL)
262 			break;
263 
264 		if (inodes_locked_down[i]->i_ino == inum) {
265 			/*
266 			 * We found the locked down inode in our array,
267 			 * so just return this pointer instead of creating
268 			 * a new one.
269 			 */
270 			return inodes_locked_down[i];
271 		}
272 	}
273 #endif
274 
275 	inode = iget_locked(sb, inum);
276 	if (!inode)
277 		return ERR_PTR(-ENOMEM);
278 	if (!(inode->i_state & I_NEW))
279 		return inode;
280 	ui = ubifs_inode(inode);
281 
282 	ino = kmalloc(UBIFS_MAX_INO_NODE_SZ, GFP_NOFS);
283 	if (!ino) {
284 		err = -ENOMEM;
285 		goto out;
286 	}
287 
288 	ino_key_init(c, &key, inode->i_ino);
289 
290 	err = ubifs_tnc_lookup(c, &key, ino);
291 	if (err)
292 		goto out_ino;
293 
294 	inode->i_flags |= (S_NOCMTIME | S_NOATIME);
295 	set_nlink(inode, le32_to_cpu(ino->nlink));
296 	i_uid_write(inode, le32_to_cpu(ino->uid));
297 	i_gid_write(inode, le32_to_cpu(ino->gid));
298 	inode->i_atime.tv_sec  = (int64_t)le64_to_cpu(ino->atime_sec);
299 	inode->i_atime.tv_nsec = le32_to_cpu(ino->atime_nsec);
300 	inode->i_mtime.tv_sec  = (int64_t)le64_to_cpu(ino->mtime_sec);
301 	inode->i_mtime.tv_nsec = le32_to_cpu(ino->mtime_nsec);
302 	inode->i_ctime.tv_sec  = (int64_t)le64_to_cpu(ino->ctime_sec);
303 	inode->i_ctime.tv_nsec = le32_to_cpu(ino->ctime_nsec);
304 	inode->i_mode = le32_to_cpu(ino->mode);
305 	inode->i_size = le64_to_cpu(ino->size);
306 
307 	ui->data_len    = le32_to_cpu(ino->data_len);
308 	ui->flags       = le32_to_cpu(ino->flags);
309 	ui->compr_type  = le16_to_cpu(ino->compr_type);
310 	ui->creat_sqnum = le64_to_cpu(ino->creat_sqnum);
311 	ui->xattr_cnt   = le32_to_cpu(ino->xattr_cnt);
312 	ui->xattr_size  = le32_to_cpu(ino->xattr_size);
313 	ui->xattr_names = le32_to_cpu(ino->xattr_names);
314 	ui->synced_i_size = ui->ui_size = inode->i_size;
315 
316 	ui->xattr = (ui->flags & UBIFS_XATTR_FL) ? 1 : 0;
317 
318 	err = validate_inode(c, inode);
319 	if (err)
320 		goto out_invalid;
321 
322 #ifndef __UBOOT__
323 	switch (inode->i_mode & S_IFMT) {
324 	case S_IFREG:
325 		inode->i_mapping->a_ops = &ubifs_file_address_operations;
326 		inode->i_op = &ubifs_file_inode_operations;
327 		inode->i_fop = &ubifs_file_operations;
328 		if (ui->xattr) {
329 			ui->data = kmalloc(ui->data_len + 1, GFP_NOFS);
330 			if (!ui->data) {
331 				err = -ENOMEM;
332 				goto out_ino;
333 			}
334 			memcpy(ui->data, ino->data, ui->data_len);
335 			((char *)ui->data)[ui->data_len] = '\0';
336 		} else if (ui->data_len != 0) {
337 			err = 10;
338 			goto out_invalid;
339 		}
340 		break;
341 	case S_IFDIR:
342 		inode->i_op  = &ubifs_dir_inode_operations;
343 		inode->i_fop = &ubifs_dir_operations;
344 		if (ui->data_len != 0) {
345 			err = 11;
346 			goto out_invalid;
347 		}
348 		break;
349 	case S_IFLNK:
350 		inode->i_op = &ubifs_symlink_inode_operations;
351 		if (ui->data_len <= 0 || ui->data_len > UBIFS_MAX_INO_DATA) {
352 			err = 12;
353 			goto out_invalid;
354 		}
355 		ui->data = kmalloc(ui->data_len + 1, GFP_NOFS);
356 		if (!ui->data) {
357 			err = -ENOMEM;
358 			goto out_ino;
359 		}
360 		memcpy(ui->data, ino->data, ui->data_len);
361 		((char *)ui->data)[ui->data_len] = '\0';
362 		inode->i_link = ui->data;
363 		break;
364 	case S_IFBLK:
365 	case S_IFCHR:
366 	{
367 		dev_t rdev;
368 		union ubifs_dev_desc *dev;
369 
370 		ui->data = kmalloc(sizeof(union ubifs_dev_desc), GFP_NOFS);
371 		if (!ui->data) {
372 			err = -ENOMEM;
373 			goto out_ino;
374 		}
375 
376 		dev = (union ubifs_dev_desc *)ino->data;
377 		if (ui->data_len == sizeof(dev->new))
378 			rdev = new_decode_dev(le32_to_cpu(dev->new));
379 		else if (ui->data_len == sizeof(dev->huge))
380 			rdev = huge_decode_dev(le64_to_cpu(dev->huge));
381 		else {
382 			err = 13;
383 			goto out_invalid;
384 		}
385 		memcpy(ui->data, ino->data, ui->data_len);
386 		inode->i_op = &ubifs_file_inode_operations;
387 		init_special_inode(inode, inode->i_mode, rdev);
388 		break;
389 	}
390 	case S_IFSOCK:
391 	case S_IFIFO:
392 		inode->i_op = &ubifs_file_inode_operations;
393 		init_special_inode(inode, inode->i_mode, 0);
394 		if (ui->data_len != 0) {
395 			err = 14;
396 			goto out_invalid;
397 		}
398 		break;
399 	default:
400 		err = 15;
401 		goto out_invalid;
402 	}
403 #else
404 	if ((inode->i_mode & S_IFMT) == S_IFLNK) {
405 		if (ui->data_len <= 0 || ui->data_len > UBIFS_MAX_INO_DATA) {
406 			err = 12;
407 			goto out_invalid;
408 		}
409 		ui->data = kmalloc(ui->data_len + 1, GFP_NOFS);
410 		if (!ui->data) {
411 			err = -ENOMEM;
412 			goto out_ino;
413 		}
414 		memcpy(ui->data, ino->data, ui->data_len);
415 		((char *)ui->data)[ui->data_len] = '\0';
416 	}
417 #endif
418 
419 	kfree(ino);
420 #ifndef __UBOOT__
421 	ubifs_set_inode_flags(inode);
422 #endif
423 	unlock_new_inode(inode);
424 	return inode;
425 
426 out_invalid:
427 	ubifs_err(c, "inode %lu validation failed, error %d", inode->i_ino, err);
428 	ubifs_dump_node(c, ino);
429 	ubifs_dump_inode(c, inode);
430 	err = -EINVAL;
431 out_ino:
432 	kfree(ino);
433 out:
434 	ubifs_err(c, "failed to read inode %lu, error %d", inode->i_ino, err);
435 	iget_failed(inode);
436 	return ERR_PTR(err);
437 }
438 
ubifs_alloc_inode(struct super_block * sb)439 static struct inode *ubifs_alloc_inode(struct super_block *sb)
440 {
441 	struct ubifs_inode *ui;
442 
443 	ui = kmem_cache_alloc(ubifs_inode_slab, GFP_NOFS);
444 	if (!ui)
445 		return NULL;
446 
447 	memset((void *)ui + sizeof(struct inode), 0,
448 	       sizeof(struct ubifs_inode) - sizeof(struct inode));
449 	mutex_init(&ui->ui_mutex);
450 	spin_lock_init(&ui->ui_lock);
451 	return &ui->vfs_inode;
452 };
453 
454 #ifndef __UBOOT__
ubifs_i_callback(struct rcu_head * head)455 static void ubifs_i_callback(struct rcu_head *head)
456 {
457 	struct inode *inode = container_of(head, struct inode, i_rcu);
458 	struct ubifs_inode *ui = ubifs_inode(inode);
459 	kmem_cache_free(ubifs_inode_slab, ui);
460 }
461 
ubifs_destroy_inode(struct inode * inode)462 static void ubifs_destroy_inode(struct inode *inode)
463 {
464 	struct ubifs_inode *ui = ubifs_inode(inode);
465 
466 	kfree(ui->data);
467 	call_rcu(&inode->i_rcu, ubifs_i_callback);
468 }
469 
470 /*
471  * Note, Linux write-back code calls this without 'i_mutex'.
472  */
ubifs_write_inode(struct inode * inode,struct writeback_control * wbc)473 static int ubifs_write_inode(struct inode *inode, struct writeback_control *wbc)
474 {
475 	int err = 0;
476 	struct ubifs_info *c = inode->i_sb->s_fs_info;
477 	struct ubifs_inode *ui = ubifs_inode(inode);
478 
479 	ubifs_assert(!ui->xattr);
480 	if (is_bad_inode(inode))
481 		return 0;
482 
483 	mutex_lock(&ui->ui_mutex);
484 	/*
485 	 * Due to races between write-back forced by budgeting
486 	 * (see 'sync_some_inodes()') and background write-back, the inode may
487 	 * have already been synchronized, do not do this again. This might
488 	 * also happen if it was synchronized in an VFS operation, e.g.
489 	 * 'ubifs_link()'.
490 	 */
491 	if (!ui->dirty) {
492 		mutex_unlock(&ui->ui_mutex);
493 		return 0;
494 	}
495 
496 	/*
497 	 * As an optimization, do not write orphan inodes to the media just
498 	 * because this is not needed.
499 	 */
500 	dbg_gen("inode %lu, mode %#x, nlink %u",
501 		inode->i_ino, (int)inode->i_mode, inode->i_nlink);
502 	if (inode->i_nlink) {
503 		err = ubifs_jnl_write_inode(c, inode);
504 		if (err)
505 			ubifs_err(c, "can't write inode %lu, error %d",
506 				  inode->i_ino, err);
507 		else
508 			err = dbg_check_inode_size(c, inode, ui->ui_size);
509 	}
510 
511 	ui->dirty = 0;
512 	mutex_unlock(&ui->ui_mutex);
513 	ubifs_release_dirty_inode_budget(c, ui);
514 	return err;
515 }
516 
ubifs_evict_inode(struct inode * inode)517 static void ubifs_evict_inode(struct inode *inode)
518 {
519 	int err;
520 	struct ubifs_info *c = inode->i_sb->s_fs_info;
521 	struct ubifs_inode *ui = ubifs_inode(inode);
522 
523 	if (ui->xattr)
524 		/*
525 		 * Extended attribute inode deletions are fully handled in
526 		 * 'ubifs_removexattr()'. These inodes are special and have
527 		 * limited usage, so there is nothing to do here.
528 		 */
529 		goto out;
530 
531 	dbg_gen("inode %lu, mode %#x", inode->i_ino, (int)inode->i_mode);
532 	ubifs_assert(!atomic_read(&inode->i_count));
533 
534 	truncate_inode_pages_final(&inode->i_data);
535 
536 	if (inode->i_nlink)
537 		goto done;
538 
539 	if (is_bad_inode(inode))
540 		goto out;
541 
542 	ui->ui_size = inode->i_size = 0;
543 	err = ubifs_jnl_delete_inode(c, inode);
544 	if (err)
545 		/*
546 		 * Worst case we have a lost orphan inode wasting space, so a
547 		 * simple error message is OK here.
548 		 */
549 		ubifs_err(c, "can't delete inode %lu, error %d",
550 			  inode->i_ino, err);
551 
552 out:
553 	if (ui->dirty)
554 		ubifs_release_dirty_inode_budget(c, ui);
555 	else {
556 		/* We've deleted something - clean the "no space" flags */
557 		c->bi.nospace = c->bi.nospace_rp = 0;
558 		smp_wmb();
559 	}
560 done:
561 	clear_inode(inode);
562 }
563 #endif
564 
ubifs_dirty_inode(struct inode * inode,int flags)565 static void ubifs_dirty_inode(struct inode *inode, int flags)
566 {
567 	struct ubifs_inode *ui = ubifs_inode(inode);
568 
569 	ubifs_assert(mutex_is_locked(&ui->ui_mutex));
570 	if (!ui->dirty) {
571 		ui->dirty = 1;
572 		dbg_gen("inode %lu",  inode->i_ino);
573 	}
574 }
575 
576 #ifndef __UBOOT__
ubifs_statfs(struct dentry * dentry,struct kstatfs * buf)577 static int ubifs_statfs(struct dentry *dentry, struct kstatfs *buf)
578 {
579 	struct ubifs_info *c = dentry->d_sb->s_fs_info;
580 	unsigned long long free;
581 	__le32 *uuid = (__le32 *)c->uuid;
582 
583 	free = ubifs_get_free_space(c);
584 	dbg_gen("free space %lld bytes (%lld blocks)",
585 		free, free >> UBIFS_BLOCK_SHIFT);
586 
587 	buf->f_type = UBIFS_SUPER_MAGIC;
588 	buf->f_bsize = UBIFS_BLOCK_SIZE;
589 	buf->f_blocks = c->block_cnt;
590 	buf->f_bfree = free >> UBIFS_BLOCK_SHIFT;
591 	if (free > c->report_rp_size)
592 		buf->f_bavail = (free - c->report_rp_size) >> UBIFS_BLOCK_SHIFT;
593 	else
594 		buf->f_bavail = 0;
595 	buf->f_files = 0;
596 	buf->f_ffree = 0;
597 	buf->f_namelen = UBIFS_MAX_NLEN;
598 	buf->f_fsid.val[0] = le32_to_cpu(uuid[0]) ^ le32_to_cpu(uuid[2]);
599 	buf->f_fsid.val[1] = le32_to_cpu(uuid[1]) ^ le32_to_cpu(uuid[3]);
600 	ubifs_assert(buf->f_bfree <= c->block_cnt);
601 	return 0;
602 }
603 
ubifs_show_options(struct seq_file * s,struct dentry * root)604 static int ubifs_show_options(struct seq_file *s, struct dentry *root)
605 {
606 	struct ubifs_info *c = root->d_sb->s_fs_info;
607 
608 	if (c->mount_opts.unmount_mode == 2)
609 		seq_puts(s, ",fast_unmount");
610 	else if (c->mount_opts.unmount_mode == 1)
611 		seq_puts(s, ",norm_unmount");
612 
613 	if (c->mount_opts.bulk_read == 2)
614 		seq_puts(s, ",bulk_read");
615 	else if (c->mount_opts.bulk_read == 1)
616 		seq_puts(s, ",no_bulk_read");
617 
618 	if (c->mount_opts.chk_data_crc == 2)
619 		seq_puts(s, ",chk_data_crc");
620 	else if (c->mount_opts.chk_data_crc == 1)
621 		seq_puts(s, ",no_chk_data_crc");
622 
623 	if (c->mount_opts.override_compr) {
624 		seq_printf(s, ",compr=%s",
625 			   ubifs_compr_name(c->mount_opts.compr_type));
626 	}
627 
628 	return 0;
629 }
630 
ubifs_sync_fs(struct super_block * sb,int wait)631 static int ubifs_sync_fs(struct super_block *sb, int wait)
632 {
633 	int i, err;
634 	struct ubifs_info *c = sb->s_fs_info;
635 
636 	/*
637 	 * Zero @wait is just an advisory thing to help the file system shove
638 	 * lots of data into the queues, and there will be the second
639 	 * '->sync_fs()' call, with non-zero @wait.
640 	 */
641 	if (!wait)
642 		return 0;
643 
644 	/*
645 	 * Synchronize write buffers, because 'ubifs_run_commit()' does not
646 	 * do this if it waits for an already running commit.
647 	 */
648 	for (i = 0; i < c->jhead_cnt; i++) {
649 		err = ubifs_wbuf_sync(&c->jheads[i].wbuf);
650 		if (err)
651 			return err;
652 	}
653 
654 	/*
655 	 * Strictly speaking, it is not necessary to commit the journal here,
656 	 * synchronizing write-buffers would be enough. But committing makes
657 	 * UBIFS free space predictions much more accurate, so we want to let
658 	 * the user be able to get more accurate results of 'statfs()' after
659 	 * they synchronize the file system.
660 	 */
661 	err = ubifs_run_commit(c);
662 	if (err)
663 		return err;
664 
665 	return ubi_sync(c->vi.ubi_num);
666 }
667 #endif
668 
669 /**
670  * init_constants_early - initialize UBIFS constants.
671  * @c: UBIFS file-system description object
672  *
673  * This function initialize UBIFS constants which do not need the superblock to
674  * be read. It also checks that the UBI volume satisfies basic UBIFS
675  * requirements. Returns zero in case of success and a negative error code in
676  * case of failure.
677  */
init_constants_early(struct ubifs_info * c)678 static int init_constants_early(struct ubifs_info *c)
679 {
680 	if (c->vi.corrupted) {
681 		ubifs_warn(c, "UBI volume is corrupted - read-only mode");
682 		c->ro_media = 1;
683 	}
684 
685 	if (c->di.ro_mode) {
686 		ubifs_msg(c, "read-only UBI device");
687 		c->ro_media = 1;
688 	}
689 
690 	if (c->vi.vol_type == UBI_STATIC_VOLUME) {
691 		ubifs_msg(c, "static UBI volume - read-only mode");
692 		c->ro_media = 1;
693 	}
694 
695 	c->leb_cnt = c->vi.size;
696 	c->leb_size = c->vi.usable_leb_size;
697 	c->leb_start = c->di.leb_start;
698 	c->half_leb_size = c->leb_size / 2;
699 	c->min_io_size = c->di.min_io_size;
700 	c->min_io_shift = fls(c->min_io_size) - 1;
701 	c->max_write_size = c->di.max_write_size;
702 	c->max_write_shift = fls(c->max_write_size) - 1;
703 
704 	if (c->leb_size < UBIFS_MIN_LEB_SZ) {
705 		ubifs_err(c, "too small LEBs (%d bytes), min. is %d bytes",
706 			  c->leb_size, UBIFS_MIN_LEB_SZ);
707 		return -EINVAL;
708 	}
709 
710 	if (c->leb_cnt < UBIFS_MIN_LEB_CNT) {
711 		ubifs_err(c, "too few LEBs (%d), min. is %d",
712 			  c->leb_cnt, UBIFS_MIN_LEB_CNT);
713 		return -EINVAL;
714 	}
715 
716 	if (!is_power_of_2(c->min_io_size)) {
717 		ubifs_err(c, "bad min. I/O size %d", c->min_io_size);
718 		return -EINVAL;
719 	}
720 
721 	/*
722 	 * Maximum write size has to be greater or equivalent to min. I/O
723 	 * size, and be multiple of min. I/O size.
724 	 */
725 	if (c->max_write_size < c->min_io_size ||
726 	    c->max_write_size % c->min_io_size ||
727 	    !is_power_of_2(c->max_write_size)) {
728 		ubifs_err(c, "bad write buffer size %d for %d min. I/O unit",
729 			  c->max_write_size, c->min_io_size);
730 		return -EINVAL;
731 	}
732 
733 	/*
734 	 * UBIFS aligns all node to 8-byte boundary, so to make function in
735 	 * io.c simpler, assume minimum I/O unit size to be 8 bytes if it is
736 	 * less than 8.
737 	 */
738 	if (c->min_io_size < 8) {
739 		c->min_io_size = 8;
740 		c->min_io_shift = 3;
741 		if (c->max_write_size < c->min_io_size) {
742 			c->max_write_size = c->min_io_size;
743 			c->max_write_shift = c->min_io_shift;
744 		}
745 	}
746 
747 	c->ref_node_alsz = ALIGN(UBIFS_REF_NODE_SZ, c->min_io_size);
748 	c->mst_node_alsz = ALIGN(UBIFS_MST_NODE_SZ, c->min_io_size);
749 
750 	/*
751 	 * Initialize node length ranges which are mostly needed for node
752 	 * length validation.
753 	 */
754 	c->ranges[UBIFS_PAD_NODE].len  = UBIFS_PAD_NODE_SZ;
755 	c->ranges[UBIFS_SB_NODE].len   = UBIFS_SB_NODE_SZ;
756 	c->ranges[UBIFS_MST_NODE].len  = UBIFS_MST_NODE_SZ;
757 	c->ranges[UBIFS_REF_NODE].len  = UBIFS_REF_NODE_SZ;
758 	c->ranges[UBIFS_TRUN_NODE].len = UBIFS_TRUN_NODE_SZ;
759 	c->ranges[UBIFS_CS_NODE].len   = UBIFS_CS_NODE_SZ;
760 
761 	c->ranges[UBIFS_INO_NODE].min_len  = UBIFS_INO_NODE_SZ;
762 	c->ranges[UBIFS_INO_NODE].max_len  = UBIFS_MAX_INO_NODE_SZ;
763 	c->ranges[UBIFS_ORPH_NODE].min_len =
764 				UBIFS_ORPH_NODE_SZ + sizeof(__le64);
765 	c->ranges[UBIFS_ORPH_NODE].max_len = c->leb_size;
766 	c->ranges[UBIFS_DENT_NODE].min_len = UBIFS_DENT_NODE_SZ;
767 	c->ranges[UBIFS_DENT_NODE].max_len = UBIFS_MAX_DENT_NODE_SZ;
768 	c->ranges[UBIFS_XENT_NODE].min_len = UBIFS_XENT_NODE_SZ;
769 	c->ranges[UBIFS_XENT_NODE].max_len = UBIFS_MAX_XENT_NODE_SZ;
770 	c->ranges[UBIFS_DATA_NODE].min_len = UBIFS_DATA_NODE_SZ;
771 	c->ranges[UBIFS_DATA_NODE].max_len = UBIFS_MAX_DATA_NODE_SZ;
772 	/*
773 	 * Minimum indexing node size is amended later when superblock is
774 	 * read and the key length is known.
775 	 */
776 	c->ranges[UBIFS_IDX_NODE].min_len = UBIFS_IDX_NODE_SZ + UBIFS_BRANCH_SZ;
777 	/*
778 	 * Maximum indexing node size is amended later when superblock is
779 	 * read and the fanout is known.
780 	 */
781 	c->ranges[UBIFS_IDX_NODE].max_len = INT_MAX;
782 
783 	/*
784 	 * Initialize dead and dark LEB space watermarks. See gc.c for comments
785 	 * about these values.
786 	 */
787 	c->dead_wm = ALIGN(MIN_WRITE_SZ, c->min_io_size);
788 	c->dark_wm = ALIGN(UBIFS_MAX_NODE_SZ, c->min_io_size);
789 
790 	/*
791 	 * Calculate how many bytes would be wasted at the end of LEB if it was
792 	 * fully filled with data nodes of maximum size. This is used in
793 	 * calculations when reporting free space.
794 	 */
795 	c->leb_overhead = c->leb_size % UBIFS_MAX_DATA_NODE_SZ;
796 
797 	/* Buffer size for bulk-reads */
798 	c->max_bu_buf_len = UBIFS_MAX_BULK_READ * UBIFS_MAX_DATA_NODE_SZ;
799 	if (c->max_bu_buf_len > c->leb_size)
800 		c->max_bu_buf_len = c->leb_size;
801 	return 0;
802 }
803 
804 /**
805  * bud_wbuf_callback - bud LEB write-buffer synchronization call-back.
806  * @c: UBIFS file-system description object
807  * @lnum: LEB the write-buffer was synchronized to
808  * @free: how many free bytes left in this LEB
809  * @pad: how many bytes were padded
810  *
811  * This is a callback function which is called by the I/O unit when the
812  * write-buffer is synchronized. We need this to correctly maintain space
813  * accounting in bud logical eraseblocks. This function returns zero in case of
814  * success and a negative error code in case of failure.
815  *
816  * This function actually belongs to the journal, but we keep it here because
817  * we want to keep it static.
818  */
bud_wbuf_callback(struct ubifs_info * c,int lnum,int free,int pad)819 static int bud_wbuf_callback(struct ubifs_info *c, int lnum, int free, int pad)
820 {
821 	return ubifs_update_one_lp(c, lnum, free, pad, 0, 0);
822 }
823 
824 /*
825  * init_constants_sb - initialize UBIFS constants.
826  * @c: UBIFS file-system description object
827  *
828  * This is a helper function which initializes various UBIFS constants after
829  * the superblock has been read. It also checks various UBIFS parameters and
830  * makes sure they are all right. Returns zero in case of success and a
831  * negative error code in case of failure.
832  */
init_constants_sb(struct ubifs_info * c)833 static int init_constants_sb(struct ubifs_info *c)
834 {
835 	int tmp, err;
836 	long long tmp64;
837 
838 	c->main_bytes = (long long)c->main_lebs * c->leb_size;
839 	c->max_znode_sz = sizeof(struct ubifs_znode) +
840 				c->fanout * sizeof(struct ubifs_zbranch);
841 
842 	tmp = ubifs_idx_node_sz(c, 1);
843 	c->ranges[UBIFS_IDX_NODE].min_len = tmp;
844 	c->min_idx_node_sz = ALIGN(tmp, 8);
845 
846 	tmp = ubifs_idx_node_sz(c, c->fanout);
847 	c->ranges[UBIFS_IDX_NODE].max_len = tmp;
848 	c->max_idx_node_sz = ALIGN(tmp, 8);
849 
850 	/* Make sure LEB size is large enough to fit full commit */
851 	tmp = UBIFS_CS_NODE_SZ + UBIFS_REF_NODE_SZ * c->jhead_cnt;
852 	tmp = ALIGN(tmp, c->min_io_size);
853 	if (tmp > c->leb_size) {
854 		ubifs_err(c, "too small LEB size %d, at least %d needed",
855 			  c->leb_size, tmp);
856 		return -EINVAL;
857 	}
858 
859 	/*
860 	 * Make sure that the log is large enough to fit reference nodes for
861 	 * all buds plus one reserved LEB.
862 	 */
863 	tmp64 = c->max_bud_bytes + c->leb_size - 1;
864 	c->max_bud_cnt = div_u64(tmp64, c->leb_size);
865 	tmp = (c->ref_node_alsz * c->max_bud_cnt + c->leb_size - 1);
866 	tmp /= c->leb_size;
867 	tmp += 1;
868 	if (c->log_lebs < tmp) {
869 		ubifs_err(c, "too small log %d LEBs, required min. %d LEBs",
870 			  c->log_lebs, tmp);
871 		return -EINVAL;
872 	}
873 
874 	/*
875 	 * When budgeting we assume worst-case scenarios when the pages are not
876 	 * be compressed and direntries are of the maximum size.
877 	 *
878 	 * Note, data, which may be stored in inodes is budgeted separately, so
879 	 * it is not included into 'c->bi.inode_budget'.
880 	 */
881 	c->bi.page_budget = UBIFS_MAX_DATA_NODE_SZ * UBIFS_BLOCKS_PER_PAGE;
882 	c->bi.inode_budget = UBIFS_INO_NODE_SZ;
883 	c->bi.dent_budget = UBIFS_MAX_DENT_NODE_SZ;
884 
885 	/*
886 	 * When the amount of flash space used by buds becomes
887 	 * 'c->max_bud_bytes', UBIFS just blocks all writers and starts commit.
888 	 * The writers are unblocked when the commit is finished. To avoid
889 	 * writers to be blocked UBIFS initiates background commit in advance,
890 	 * when number of bud bytes becomes above the limit defined below.
891 	 */
892 	c->bg_bud_bytes = (c->max_bud_bytes * 13) >> 4;
893 
894 	/*
895 	 * Ensure minimum journal size. All the bytes in the journal heads are
896 	 * considered to be used, when calculating the current journal usage.
897 	 * Consequently, if the journal is too small, UBIFS will treat it as
898 	 * always full.
899 	 */
900 	tmp64 = (long long)(c->jhead_cnt + 1) * c->leb_size + 1;
901 	if (c->bg_bud_bytes < tmp64)
902 		c->bg_bud_bytes = tmp64;
903 	if (c->max_bud_bytes < tmp64 + c->leb_size)
904 		c->max_bud_bytes = tmp64 + c->leb_size;
905 
906 	err = ubifs_calc_lpt_geom(c);
907 	if (err)
908 		return err;
909 
910 	/* Initialize effective LEB size used in budgeting calculations */
911 	c->idx_leb_size = c->leb_size - c->max_idx_node_sz;
912 	return 0;
913 }
914 
915 /*
916  * init_constants_master - initialize UBIFS constants.
917  * @c: UBIFS file-system description object
918  *
919  * This is a helper function which initializes various UBIFS constants after
920  * the master node has been read. It also checks various UBIFS parameters and
921  * makes sure they are all right.
922  */
init_constants_master(struct ubifs_info * c)923 static void init_constants_master(struct ubifs_info *c)
924 {
925 	long long tmp64;
926 
927 	c->bi.min_idx_lebs = ubifs_calc_min_idx_lebs(c);
928 	c->report_rp_size = ubifs_reported_space(c, c->rp_size);
929 
930 	/*
931 	 * Calculate total amount of FS blocks. This number is not used
932 	 * internally because it does not make much sense for UBIFS, but it is
933 	 * necessary to report something for the 'statfs()' call.
934 	 *
935 	 * Subtract the LEB reserved for GC, the LEB which is reserved for
936 	 * deletions, minimum LEBs for the index, and assume only one journal
937 	 * head is available.
938 	 */
939 	tmp64 = c->main_lebs - 1 - 1 - MIN_INDEX_LEBS - c->jhead_cnt + 1;
940 	tmp64 *= (long long)c->leb_size - c->leb_overhead;
941 	tmp64 = ubifs_reported_space(c, tmp64);
942 	c->block_cnt = tmp64 >> UBIFS_BLOCK_SHIFT;
943 }
944 
945 /**
946  * take_gc_lnum - reserve GC LEB.
947  * @c: UBIFS file-system description object
948  *
949  * This function ensures that the LEB reserved for garbage collection is marked
950  * as "taken" in lprops. We also have to set free space to LEB size and dirty
951  * space to zero, because lprops may contain out-of-date information if the
952  * file-system was un-mounted before it has been committed. This function
953  * returns zero in case of success and a negative error code in case of
954  * failure.
955  */
take_gc_lnum(struct ubifs_info * c)956 static int take_gc_lnum(struct ubifs_info *c)
957 {
958 	int err;
959 
960 	if (c->gc_lnum == -1) {
961 		ubifs_err(c, "no LEB for GC");
962 		return -EINVAL;
963 	}
964 
965 	/* And we have to tell lprops that this LEB is taken */
966 	err = ubifs_change_one_lp(c, c->gc_lnum, c->leb_size, 0,
967 				  LPROPS_TAKEN, 0, 0);
968 	return err;
969 }
970 
971 /**
972  * alloc_wbufs - allocate write-buffers.
973  * @c: UBIFS file-system description object
974  *
975  * This helper function allocates and initializes UBIFS write-buffers. Returns
976  * zero in case of success and %-ENOMEM in case of failure.
977  */
alloc_wbufs(struct ubifs_info * c)978 static int alloc_wbufs(struct ubifs_info *c)
979 {
980 	int i, err;
981 
982 	c->jheads = kcalloc(c->jhead_cnt, sizeof(struct ubifs_jhead),
983 			    GFP_KERNEL);
984 	if (!c->jheads)
985 		return -ENOMEM;
986 
987 	/* Initialize journal heads */
988 	for (i = 0; i < c->jhead_cnt; i++) {
989 		INIT_LIST_HEAD(&c->jheads[i].buds_list);
990 		err = ubifs_wbuf_init(c, &c->jheads[i].wbuf);
991 		if (err)
992 			return err;
993 
994 		c->jheads[i].wbuf.sync_callback = &bud_wbuf_callback;
995 		c->jheads[i].wbuf.jhead = i;
996 		c->jheads[i].grouped = 1;
997 	}
998 
999 	/*
1000 	 * Garbage Collector head does not need to be synchronized by timer.
1001 	 * Also GC head nodes are not grouped.
1002 	 */
1003 	c->jheads[GCHD].wbuf.no_timer = 1;
1004 	c->jheads[GCHD].grouped = 0;
1005 
1006 	return 0;
1007 }
1008 
1009 /**
1010  * free_wbufs - free write-buffers.
1011  * @c: UBIFS file-system description object
1012  */
free_wbufs(struct ubifs_info * c)1013 static void free_wbufs(struct ubifs_info *c)
1014 {
1015 	int i;
1016 
1017 	if (c->jheads) {
1018 		for (i = 0; i < c->jhead_cnt; i++) {
1019 			kfree(c->jheads[i].wbuf.buf);
1020 			kfree(c->jheads[i].wbuf.inodes);
1021 		}
1022 		kfree(c->jheads);
1023 		c->jheads = NULL;
1024 	}
1025 }
1026 
1027 /**
1028  * free_orphans - free orphans.
1029  * @c: UBIFS file-system description object
1030  */
free_orphans(struct ubifs_info * c)1031 static void free_orphans(struct ubifs_info *c)
1032 {
1033 	struct ubifs_orphan *orph;
1034 
1035 	while (c->orph_dnext) {
1036 		orph = c->orph_dnext;
1037 		c->orph_dnext = orph->dnext;
1038 		list_del(&orph->list);
1039 		kfree(orph);
1040 	}
1041 
1042 	while (!list_empty(&c->orph_list)) {
1043 		orph = list_entry(c->orph_list.next, struct ubifs_orphan, list);
1044 		list_del(&orph->list);
1045 		kfree(orph);
1046 		ubifs_err(c, "orphan list not empty at unmount");
1047 	}
1048 
1049 	vfree(c->orph_buf);
1050 	c->orph_buf = NULL;
1051 }
1052 
1053 /**
1054  * free_buds - free per-bud objects.
1055  * @c: UBIFS file-system description object
1056  */
free_buds(struct ubifs_info * c)1057 static void free_buds(struct ubifs_info *c)
1058 {
1059 	struct ubifs_bud *bud, *n;
1060 
1061 	rbtree_postorder_for_each_entry_safe(bud, n, &c->buds, rb)
1062 		kfree(bud);
1063 }
1064 
1065 /**
1066  * check_volume_empty - check if the UBI volume is empty.
1067  * @c: UBIFS file-system description object
1068  *
1069  * This function checks if the UBIFS volume is empty by looking if its LEBs are
1070  * mapped or not. The result of checking is stored in the @c->empty variable.
1071  * Returns zero in case of success and a negative error code in case of
1072  * failure.
1073  */
check_volume_empty(struct ubifs_info * c)1074 static int check_volume_empty(struct ubifs_info *c)
1075 {
1076 	int lnum, err;
1077 
1078 	c->empty = 1;
1079 	for (lnum = 0; lnum < c->leb_cnt; lnum++) {
1080 		err = ubifs_is_mapped(c, lnum);
1081 		if (unlikely(err < 0))
1082 			return err;
1083 		if (err == 1) {
1084 			c->empty = 0;
1085 			break;
1086 		}
1087 
1088 		cond_resched();
1089 	}
1090 
1091 	return 0;
1092 }
1093 
1094 /*
1095  * UBIFS mount options.
1096  *
1097  * Opt_fast_unmount: do not run a journal commit before un-mounting
1098  * Opt_norm_unmount: run a journal commit before un-mounting
1099  * Opt_bulk_read: enable bulk-reads
1100  * Opt_no_bulk_read: disable bulk-reads
1101  * Opt_chk_data_crc: check CRCs when reading data nodes
1102  * Opt_no_chk_data_crc: do not check CRCs when reading data nodes
1103  * Opt_override_compr: override default compressor
1104  * Opt_err: just end of array marker
1105  */
1106 enum {
1107 	Opt_fast_unmount,
1108 	Opt_norm_unmount,
1109 	Opt_bulk_read,
1110 	Opt_no_bulk_read,
1111 	Opt_chk_data_crc,
1112 	Opt_no_chk_data_crc,
1113 	Opt_override_compr,
1114 	Opt_err,
1115 };
1116 
1117 #ifndef __UBOOT__
1118 static const match_table_t tokens = {
1119 	{Opt_fast_unmount, "fast_unmount"},
1120 	{Opt_norm_unmount, "norm_unmount"},
1121 	{Opt_bulk_read, "bulk_read"},
1122 	{Opt_no_bulk_read, "no_bulk_read"},
1123 	{Opt_chk_data_crc, "chk_data_crc"},
1124 	{Opt_no_chk_data_crc, "no_chk_data_crc"},
1125 	{Opt_override_compr, "compr=%s"},
1126 	{Opt_err, NULL},
1127 };
1128 
1129 /**
1130  * parse_standard_option - parse a standard mount option.
1131  * @option: the option to parse
1132  *
1133  * Normally, standard mount options like "sync" are passed to file-systems as
1134  * flags. However, when a "rootflags=" kernel boot parameter is used, they may
1135  * be present in the options string. This function tries to deal with this
1136  * situation and parse standard options. Returns 0 if the option was not
1137  * recognized, and the corresponding integer flag if it was.
1138  *
1139  * UBIFS is only interested in the "sync" option, so do not check for anything
1140  * else.
1141  */
parse_standard_option(const char * option)1142 static int parse_standard_option(const char *option)
1143 {
1144 
1145 	pr_notice("UBIFS: parse %s\n", option);
1146 	if (!strcmp(option, "sync"))
1147 		return MS_SYNCHRONOUS;
1148 	return 0;
1149 }
1150 
1151 /**
1152  * ubifs_parse_options - parse mount parameters.
1153  * @c: UBIFS file-system description object
1154  * @options: parameters to parse
1155  * @is_remount: non-zero if this is FS re-mount
1156  *
1157  * This function parses UBIFS mount options and returns zero in case success
1158  * and a negative error code in case of failure.
1159  */
ubifs_parse_options(struct ubifs_info * c,char * options,int is_remount)1160 static int ubifs_parse_options(struct ubifs_info *c, char *options,
1161 			       int is_remount)
1162 {
1163 	char *p;
1164 	substring_t args[MAX_OPT_ARGS];
1165 
1166 	if (!options)
1167 		return 0;
1168 
1169 	while ((p = strsep(&options, ","))) {
1170 		int token;
1171 
1172 		if (!*p)
1173 			continue;
1174 
1175 		token = match_token(p, tokens, args);
1176 		switch (token) {
1177 		/*
1178 		 * %Opt_fast_unmount and %Opt_norm_unmount options are ignored.
1179 		 * We accept them in order to be backward-compatible. But this
1180 		 * should be removed at some point.
1181 		 */
1182 		case Opt_fast_unmount:
1183 			c->mount_opts.unmount_mode = 2;
1184 			break;
1185 		case Opt_norm_unmount:
1186 			c->mount_opts.unmount_mode = 1;
1187 			break;
1188 		case Opt_bulk_read:
1189 			c->mount_opts.bulk_read = 2;
1190 			c->bulk_read = 1;
1191 			break;
1192 		case Opt_no_bulk_read:
1193 			c->mount_opts.bulk_read = 1;
1194 			c->bulk_read = 0;
1195 			break;
1196 		case Opt_chk_data_crc:
1197 			c->mount_opts.chk_data_crc = 2;
1198 			c->no_chk_data_crc = 0;
1199 			break;
1200 		case Opt_no_chk_data_crc:
1201 			c->mount_opts.chk_data_crc = 1;
1202 			c->no_chk_data_crc = 1;
1203 			break;
1204 		case Opt_override_compr:
1205 		{
1206 			char *name = match_strdup(&args[0]);
1207 
1208 			if (!name)
1209 				return -ENOMEM;
1210 			if (!strcmp(name, "none"))
1211 				c->mount_opts.compr_type = UBIFS_COMPR_NONE;
1212 			else if (!strcmp(name, "lzo"))
1213 				c->mount_opts.compr_type = UBIFS_COMPR_LZO;
1214 			else if (!strcmp(name, "zlib"))
1215 				c->mount_opts.compr_type = UBIFS_COMPR_ZLIB;
1216 			else {
1217 				ubifs_err(c, "unknown compressor \"%s\"", name); //FIXME: is c ready?
1218 				kfree(name);
1219 				return -EINVAL;
1220 			}
1221 			kfree(name);
1222 			c->mount_opts.override_compr = 1;
1223 			c->default_compr = c->mount_opts.compr_type;
1224 			break;
1225 		}
1226 		default:
1227 		{
1228 			unsigned long flag;
1229 			struct super_block *sb = c->vfs_sb;
1230 
1231 			flag = parse_standard_option(p);
1232 			if (!flag) {
1233 				ubifs_err(c, "unrecognized mount option \"%s\" or missing value",
1234 					  p);
1235 				return -EINVAL;
1236 			}
1237 			sb->s_flags |= flag;
1238 			break;
1239 		}
1240 		}
1241 	}
1242 
1243 	return 0;
1244 }
1245 #endif
1246 
1247 /**
1248  * destroy_journal - destroy journal data structures.
1249  * @c: UBIFS file-system description object
1250  *
1251  * This function destroys journal data structures including those that may have
1252  * been created by recovery functions.
1253  */
destroy_journal(struct ubifs_info * c)1254 static void destroy_journal(struct ubifs_info *c)
1255 {
1256 	while (!list_empty(&c->unclean_leb_list)) {
1257 		struct ubifs_unclean_leb *ucleb;
1258 
1259 		ucleb = list_entry(c->unclean_leb_list.next,
1260 				   struct ubifs_unclean_leb, list);
1261 		list_del(&ucleb->list);
1262 		kfree(ucleb);
1263 	}
1264 	while (!list_empty(&c->old_buds)) {
1265 		struct ubifs_bud *bud;
1266 
1267 		bud = list_entry(c->old_buds.next, struct ubifs_bud, list);
1268 		list_del(&bud->list);
1269 		kfree(bud);
1270 	}
1271 	ubifs_destroy_idx_gc(c);
1272 	ubifs_destroy_size_tree(c);
1273 	ubifs_tnc_close(c);
1274 	free_buds(c);
1275 }
1276 
1277 /**
1278  * bu_init - initialize bulk-read information.
1279  * @c: UBIFS file-system description object
1280  */
bu_init(struct ubifs_info * c)1281 static void bu_init(struct ubifs_info *c)
1282 {
1283 	ubifs_assert(c->bulk_read == 1);
1284 
1285 	if (c->bu.buf)
1286 		return; /* Already initialized */
1287 
1288 again:
1289 	c->bu.buf = kmalloc(c->max_bu_buf_len, GFP_KERNEL | __GFP_NOWARN);
1290 	if (!c->bu.buf) {
1291 		if (c->max_bu_buf_len > UBIFS_KMALLOC_OK) {
1292 			c->max_bu_buf_len = UBIFS_KMALLOC_OK;
1293 			goto again;
1294 		}
1295 
1296 		/* Just disable bulk-read */
1297 		ubifs_warn(c, "cannot allocate %d bytes of memory for bulk-read, disabling it",
1298 			   c->max_bu_buf_len);
1299 		c->mount_opts.bulk_read = 1;
1300 		c->bulk_read = 0;
1301 		return;
1302 	}
1303 }
1304 
1305 #ifndef __UBOOT__
1306 /**
1307  * check_free_space - check if there is enough free space to mount.
1308  * @c: UBIFS file-system description object
1309  *
1310  * This function makes sure UBIFS has enough free space to be mounted in
1311  * read/write mode. UBIFS must always have some free space to allow deletions.
1312  */
check_free_space(struct ubifs_info * c)1313 static int check_free_space(struct ubifs_info *c)
1314 {
1315 	ubifs_assert(c->dark_wm > 0);
1316 	if (c->lst.total_free + c->lst.total_dirty < c->dark_wm) {
1317 		ubifs_err(c, "insufficient free space to mount in R/W mode");
1318 		ubifs_dump_budg(c, &c->bi);
1319 		ubifs_dump_lprops(c);
1320 		return -ENOSPC;
1321 	}
1322 	return 0;
1323 }
1324 #endif
1325 
1326 /**
1327  * mount_ubifs - mount UBIFS file-system.
1328  * @c: UBIFS file-system description object
1329  *
1330  * This function mounts UBIFS file system. Returns zero in case of success and
1331  * a negative error code in case of failure.
1332  */
mount_ubifs(struct ubifs_info * c)1333 static int mount_ubifs(struct ubifs_info *c)
1334 {
1335 	int err;
1336 	long long x;
1337 #ifndef CONFIG_UBIFS_SILENCE_MSG
1338 	long long y;
1339 #endif
1340 	size_t sz;
1341 
1342 	c->ro_mount = !!(c->vfs_sb->s_flags & MS_RDONLY);
1343 	/* Suppress error messages while probing if MS_SILENT is set */
1344 	c->probing = !!(c->vfs_sb->s_flags & MS_SILENT);
1345 #ifdef __UBOOT__
1346 	if (!c->ro_mount) {
1347 		printf("UBIFS: only ro mode in U-Boot allowed.\n");
1348 		return -EACCES;
1349 	}
1350 #endif
1351 
1352 	err = init_constants_early(c);
1353 	if (err)
1354 		return err;
1355 
1356 	err = ubifs_debugging_init(c);
1357 	if (err)
1358 		return err;
1359 
1360 	err = check_volume_empty(c);
1361 	if (err)
1362 		goto out_free;
1363 
1364 	if (c->empty && (c->ro_mount || c->ro_media)) {
1365 		/*
1366 		 * This UBI volume is empty, and read-only, or the file system
1367 		 * is mounted read-only - we cannot format it.
1368 		 */
1369 		ubifs_err(c, "can't format empty UBI volume: read-only %s",
1370 			  c->ro_media ? "UBI volume" : "mount");
1371 		err = -EROFS;
1372 		goto out_free;
1373 	}
1374 
1375 	if (c->ro_media && !c->ro_mount) {
1376 		ubifs_err(c, "cannot mount read-write - read-only media");
1377 		err = -EROFS;
1378 		goto out_free;
1379 	}
1380 
1381 	/*
1382 	 * The requirement for the buffer is that it should fit indexing B-tree
1383 	 * height amount of integers. We assume the height if the TNC tree will
1384 	 * never exceed 64.
1385 	 */
1386 	err = -ENOMEM;
1387 	c->bottom_up_buf = kmalloc(BOTTOM_UP_HEIGHT * sizeof(int), GFP_KERNEL);
1388 	if (!c->bottom_up_buf)
1389 		goto out_free;
1390 
1391 	c->sbuf = vmalloc(c->leb_size);
1392 	if (!c->sbuf)
1393 		goto out_free;
1394 
1395 #ifndef __UBOOT__
1396 	if (!c->ro_mount) {
1397 		c->ileb_buf = vmalloc(c->leb_size);
1398 		if (!c->ileb_buf)
1399 			goto out_free;
1400 	}
1401 #endif
1402 
1403 	if (c->bulk_read == 1)
1404 		bu_init(c);
1405 
1406 #ifndef __UBOOT__
1407 	if (!c->ro_mount) {
1408 		c->write_reserve_buf = kmalloc(COMPRESSED_DATA_NODE_BUF_SZ,
1409 					       GFP_KERNEL);
1410 		if (!c->write_reserve_buf)
1411 			goto out_free;
1412 	}
1413 #endif
1414 
1415 	c->mounting = 1;
1416 
1417 	err = ubifs_read_superblock(c);
1418 	if (err)
1419 		goto out_free;
1420 
1421 	c->probing = 0;
1422 
1423 	/*
1424 	 * Make sure the compressor which is set as default in the superblock
1425 	 * or overridden by mount options is actually compiled in.
1426 	 */
1427 	if (!ubifs_compr_present(c->default_compr)) {
1428 		ubifs_err(c, "'compressor \"%s\" is not compiled in",
1429 			  ubifs_compr_name(c->default_compr));
1430 		err = -ENOTSUPP;
1431 		goto out_free;
1432 	}
1433 
1434 	err = init_constants_sb(c);
1435 	if (err)
1436 		goto out_free;
1437 
1438 	sz = ALIGN(c->max_idx_node_sz, c->min_io_size);
1439 	sz = ALIGN(sz + c->max_idx_node_sz, c->min_io_size);
1440 	c->cbuf = kmalloc(sz, GFP_NOFS);
1441 	if (!c->cbuf) {
1442 		err = -ENOMEM;
1443 		goto out_free;
1444 	}
1445 
1446 	err = alloc_wbufs(c);
1447 	if (err)
1448 		goto out_cbuf;
1449 
1450 	sprintf(c->bgt_name, BGT_NAME_PATTERN, c->vi.ubi_num, c->vi.vol_id);
1451 #ifndef __UBOOT__
1452 	if (!c->ro_mount) {
1453 		/* Create background thread */
1454 		c->bgt = kthread_create(ubifs_bg_thread, c, "%s", c->bgt_name);
1455 		if (IS_ERR(c->bgt)) {
1456 			err = PTR_ERR(c->bgt);
1457 			c->bgt = NULL;
1458 			ubifs_err(c, "cannot spawn \"%s\", error %d",
1459 				  c->bgt_name, err);
1460 			goto out_wbufs;
1461 		}
1462 		wake_up_process(c->bgt);
1463 	}
1464 #endif
1465 
1466 	err = ubifs_read_master(c);
1467 	if (err)
1468 		goto out_master;
1469 
1470 	init_constants_master(c);
1471 
1472 	if ((c->mst_node->flags & cpu_to_le32(UBIFS_MST_DIRTY)) != 0) {
1473 		ubifs_msg(c, "recovery needed");
1474 		c->need_recovery = 1;
1475 	}
1476 
1477 #ifndef __UBOOT__
1478 	if (c->need_recovery && !c->ro_mount) {
1479 		err = ubifs_recover_inl_heads(c, c->sbuf);
1480 		if (err)
1481 			goto out_master;
1482 	}
1483 #endif
1484 
1485 	err = ubifs_lpt_init(c, 1, !c->ro_mount);
1486 	if (err)
1487 		goto out_master;
1488 
1489 #ifndef __UBOOT__
1490 	if (!c->ro_mount && c->space_fixup) {
1491 		err = ubifs_fixup_free_space(c);
1492 		if (err)
1493 			goto out_lpt;
1494 	}
1495 
1496 	if (!c->ro_mount && !c->need_recovery) {
1497 		/*
1498 		 * Set the "dirty" flag so that if we reboot uncleanly we
1499 		 * will notice this immediately on the next mount.
1500 		 */
1501 		c->mst_node->flags |= cpu_to_le32(UBIFS_MST_DIRTY);
1502 		err = ubifs_write_master(c);
1503 		if (err)
1504 			goto out_lpt;
1505 	}
1506 #endif
1507 
1508 	err = dbg_check_idx_size(c, c->bi.old_idx_sz);
1509 	if (err)
1510 		goto out_lpt;
1511 
1512 	err = ubifs_replay_journal(c);
1513 	if (err)
1514 		goto out_journal;
1515 
1516 	/* Calculate 'min_idx_lebs' after journal replay */
1517 	c->bi.min_idx_lebs = ubifs_calc_min_idx_lebs(c);
1518 
1519 	err = ubifs_mount_orphans(c, c->need_recovery, c->ro_mount);
1520 	if (err)
1521 		goto out_orphans;
1522 
1523 	if (!c->ro_mount) {
1524 #ifndef __UBOOT__
1525 		int lnum;
1526 
1527 		err = check_free_space(c);
1528 		if (err)
1529 			goto out_orphans;
1530 
1531 		/* Check for enough log space */
1532 		lnum = c->lhead_lnum + 1;
1533 		if (lnum >= UBIFS_LOG_LNUM + c->log_lebs)
1534 			lnum = UBIFS_LOG_LNUM;
1535 		if (lnum == c->ltail_lnum) {
1536 			err = ubifs_consolidate_log(c);
1537 			if (err)
1538 				goto out_orphans;
1539 		}
1540 
1541 		if (c->need_recovery) {
1542 			err = ubifs_recover_size(c);
1543 			if (err)
1544 				goto out_orphans;
1545 			err = ubifs_rcvry_gc_commit(c);
1546 			if (err)
1547 				goto out_orphans;
1548 		} else {
1549 			err = take_gc_lnum(c);
1550 			if (err)
1551 				goto out_orphans;
1552 
1553 			/*
1554 			 * GC LEB may contain garbage if there was an unclean
1555 			 * reboot, and it should be un-mapped.
1556 			 */
1557 			err = ubifs_leb_unmap(c, c->gc_lnum);
1558 			if (err)
1559 				goto out_orphans;
1560 		}
1561 
1562 		err = dbg_check_lprops(c);
1563 		if (err)
1564 			goto out_orphans;
1565 #endif
1566 	} else if (c->need_recovery) {
1567 		err = ubifs_recover_size(c);
1568 		if (err)
1569 			goto out_orphans;
1570 	} else {
1571 		/*
1572 		 * Even if we mount read-only, we have to set space in GC LEB
1573 		 * to proper value because this affects UBIFS free space
1574 		 * reporting. We do not want to have a situation when
1575 		 * re-mounting from R/O to R/W changes amount of free space.
1576 		 */
1577 		err = take_gc_lnum(c);
1578 		if (err)
1579 			goto out_orphans;
1580 	}
1581 
1582 #ifndef __UBOOT__
1583 	spin_lock(&ubifs_infos_lock);
1584 	list_add_tail(&c->infos_list, &ubifs_infos);
1585 	spin_unlock(&ubifs_infos_lock);
1586 #endif
1587 
1588 	if (c->need_recovery) {
1589 		if (c->ro_mount)
1590 			ubifs_msg(c, "recovery deferred");
1591 		else {
1592 			c->need_recovery = 0;
1593 			ubifs_msg(c, "recovery completed");
1594 			/*
1595 			 * GC LEB has to be empty and taken at this point. But
1596 			 * the journal head LEBs may also be accounted as
1597 			 * "empty taken" if they are empty.
1598 			 */
1599 			ubifs_assert(c->lst.taken_empty_lebs > 0);
1600 		}
1601 	} else
1602 		ubifs_assert(c->lst.taken_empty_lebs > 0);
1603 
1604 	err = dbg_check_filesystem(c);
1605 	if (err)
1606 		goto out_infos;
1607 
1608 	err = dbg_debugfs_init_fs(c);
1609 	if (err)
1610 		goto out_infos;
1611 
1612 	c->mounting = 0;
1613 
1614 	ubifs_msg(c, "UBIFS: mounted UBI device %d, volume %d, name \"%s\"%s",
1615 		  c->vi.ubi_num, c->vi.vol_id, c->vi.name,
1616 		  c->ro_mount ? ", R/O mode" : "");
1617 	x = (long long)c->main_lebs * c->leb_size;
1618 #ifndef CONFIG_UBIFS_SILENCE_MSG
1619 	y = (long long)c->log_lebs * c->leb_size + c->max_bud_bytes;
1620 #endif
1621 	ubifs_msg(c, "LEB size: %d bytes (%d KiB), min./max. I/O unit sizes: %d bytes/%d bytes",
1622 		  c->leb_size, c->leb_size >> 10, c->min_io_size,
1623 		  c->max_write_size);
1624 	ubifs_msg(c, "FS size: %lld bytes (%lld MiB, %d LEBs), journal size %lld bytes (%lld MiB, %d LEBs)",
1625 		  x, x >> 20, c->main_lebs,
1626 		  y, y >> 20, c->log_lebs + c->max_bud_cnt);
1627 	ubifs_msg(c, "reserved for root: %llu bytes (%llu KiB)",
1628 		  c->report_rp_size, c->report_rp_size >> 10);
1629 	ubifs_msg(c, "media format: w%d/r%d (latest is w%d/r%d), UUID %pUB%s",
1630 		  c->fmt_version, c->ro_compat_version,
1631 		  UBIFS_FORMAT_VERSION, UBIFS_RO_COMPAT_VERSION, c->uuid,
1632 		  c->big_lpt ? ", big LPT model" : ", small LPT model");
1633 
1634 	dbg_gen("default compressor:  %s", ubifs_compr_name(c->default_compr));
1635 	dbg_gen("data journal heads:  %d",
1636 		c->jhead_cnt - NONDATA_JHEADS_CNT);
1637 	dbg_gen("log LEBs:            %d (%d - %d)",
1638 		c->log_lebs, UBIFS_LOG_LNUM, c->log_last);
1639 	dbg_gen("LPT area LEBs:       %d (%d - %d)",
1640 		c->lpt_lebs, c->lpt_first, c->lpt_last);
1641 	dbg_gen("orphan area LEBs:    %d (%d - %d)",
1642 		c->orph_lebs, c->orph_first, c->orph_last);
1643 	dbg_gen("main area LEBs:      %d (%d - %d)",
1644 		c->main_lebs, c->main_first, c->leb_cnt - 1);
1645 	dbg_gen("index LEBs:          %d", c->lst.idx_lebs);
1646 	dbg_gen("total index bytes:   %lld (%lld KiB, %lld MiB)",
1647 		c->bi.old_idx_sz, c->bi.old_idx_sz >> 10,
1648 		c->bi.old_idx_sz >> 20);
1649 	dbg_gen("key hash type:       %d", c->key_hash_type);
1650 	dbg_gen("tree fanout:         %d", c->fanout);
1651 	dbg_gen("reserved GC LEB:     %d", c->gc_lnum);
1652 	dbg_gen("max. znode size      %d", c->max_znode_sz);
1653 	dbg_gen("max. index node size %d", c->max_idx_node_sz);
1654 	dbg_gen("node sizes:          data %zu, inode %zu, dentry %zu",
1655 		UBIFS_DATA_NODE_SZ, UBIFS_INO_NODE_SZ, UBIFS_DENT_NODE_SZ);
1656 	dbg_gen("node sizes:          trun %zu, sb %zu, master %zu",
1657 		UBIFS_TRUN_NODE_SZ, UBIFS_SB_NODE_SZ, UBIFS_MST_NODE_SZ);
1658 	dbg_gen("node sizes:          ref %zu, cmt. start %zu, orph %zu",
1659 		UBIFS_REF_NODE_SZ, UBIFS_CS_NODE_SZ, UBIFS_ORPH_NODE_SZ);
1660 	dbg_gen("max. node sizes:     data %zu, inode %zu dentry %zu, idx %d",
1661 		UBIFS_MAX_DATA_NODE_SZ, UBIFS_MAX_INO_NODE_SZ,
1662 		UBIFS_MAX_DENT_NODE_SZ, ubifs_idx_node_sz(c, c->fanout));
1663 	dbg_gen("dead watermark:      %d", c->dead_wm);
1664 	dbg_gen("dark watermark:      %d", c->dark_wm);
1665 	dbg_gen("LEB overhead:        %d", c->leb_overhead);
1666 	x = (long long)c->main_lebs * c->dark_wm;
1667 	dbg_gen("max. dark space:     %lld (%lld KiB, %lld MiB)",
1668 		x, x >> 10, x >> 20);
1669 	dbg_gen("maximum bud bytes:   %lld (%lld KiB, %lld MiB)",
1670 		c->max_bud_bytes, c->max_bud_bytes >> 10,
1671 		c->max_bud_bytes >> 20);
1672 	dbg_gen("BG commit bud bytes: %lld (%lld KiB, %lld MiB)",
1673 		c->bg_bud_bytes, c->bg_bud_bytes >> 10,
1674 		c->bg_bud_bytes >> 20);
1675 	dbg_gen("current bud bytes    %lld (%lld KiB, %lld MiB)",
1676 		c->bud_bytes, c->bud_bytes >> 10, c->bud_bytes >> 20);
1677 	dbg_gen("max. seq. number:    %llu", c->max_sqnum);
1678 	dbg_gen("commit number:       %llu", c->cmt_no);
1679 
1680 	return 0;
1681 
1682 out_infos:
1683 	spin_lock(&ubifs_infos_lock);
1684 	list_del(&c->infos_list);
1685 	spin_unlock(&ubifs_infos_lock);
1686 out_orphans:
1687 	free_orphans(c);
1688 out_journal:
1689 	destroy_journal(c);
1690 out_lpt:
1691 	ubifs_lpt_free(c, 0);
1692 out_master:
1693 	kfree(c->mst_node);
1694 	kfree(c->rcvrd_mst_node);
1695 	if (c->bgt)
1696 		kthread_stop(c->bgt);
1697 #ifndef __UBOOT__
1698 out_wbufs:
1699 #endif
1700 	free_wbufs(c);
1701 out_cbuf:
1702 	kfree(c->cbuf);
1703 out_free:
1704 	kfree(c->write_reserve_buf);
1705 	kfree(c->bu.buf);
1706 	vfree(c->ileb_buf);
1707 	vfree(c->sbuf);
1708 	kfree(c->bottom_up_buf);
1709 	ubifs_debugging_exit(c);
1710 	return err;
1711 }
1712 
1713 /**
1714  * ubifs_umount - un-mount UBIFS file-system.
1715  * @c: UBIFS file-system description object
1716  *
1717  * Note, this function is called to free allocated resourced when un-mounting,
1718  * as well as free resources when an error occurred while we were half way
1719  * through mounting (error path cleanup function). So it has to make sure the
1720  * resource was actually allocated before freeing it.
1721  */
1722 #ifndef __UBOOT__
ubifs_umount(struct ubifs_info * c)1723 static void ubifs_umount(struct ubifs_info *c)
1724 #else
1725 void ubifs_umount(struct ubifs_info *c)
1726 #endif
1727 {
1728 	dbg_gen("un-mounting UBI device %d, volume %d", c->vi.ubi_num,
1729 		c->vi.vol_id);
1730 
1731 	dbg_debugfs_exit_fs(c);
1732 	spin_lock(&ubifs_infos_lock);
1733 	list_del(&c->infos_list);
1734 	spin_unlock(&ubifs_infos_lock);
1735 
1736 #ifndef __UBOOT__
1737 	if (c->bgt)
1738 		kthread_stop(c->bgt);
1739 
1740 	destroy_journal(c);
1741 #endif
1742 	free_wbufs(c);
1743 	free_orphans(c);
1744 	ubifs_lpt_free(c, 0);
1745 
1746 	kfree(c->cbuf);
1747 	kfree(c->rcvrd_mst_node);
1748 	kfree(c->mst_node);
1749 	kfree(c->write_reserve_buf);
1750 	kfree(c->bu.buf);
1751 	vfree(c->ileb_buf);
1752 	vfree(c->sbuf);
1753 	kfree(c->bottom_up_buf);
1754 	ubifs_debugging_exit(c);
1755 #ifdef __UBOOT__
1756 	/* Finally free U-Boot's global copy of superblock */
1757 	if (ubifs_sb != NULL) {
1758 		free(ubifs_sb->s_fs_info);
1759 		free(ubifs_sb);
1760 	}
1761 #endif
1762 }
1763 
1764 #ifndef __UBOOT__
1765 /**
1766  * ubifs_remount_rw - re-mount in read-write mode.
1767  * @c: UBIFS file-system description object
1768  *
1769  * UBIFS avoids allocating many unnecessary resources when mounted in read-only
1770  * mode. This function allocates the needed resources and re-mounts UBIFS in
1771  * read-write mode.
1772  */
ubifs_remount_rw(struct ubifs_info * c)1773 static int ubifs_remount_rw(struct ubifs_info *c)
1774 {
1775 	int err, lnum;
1776 
1777 	if (c->rw_incompat) {
1778 		ubifs_err(c, "the file-system is not R/W-compatible");
1779 		ubifs_msg(c, "on-flash format version is w%d/r%d, but software only supports up to version w%d/r%d",
1780 			  c->fmt_version, c->ro_compat_version,
1781 			  UBIFS_FORMAT_VERSION, UBIFS_RO_COMPAT_VERSION);
1782 		return -EROFS;
1783 	}
1784 
1785 	mutex_lock(&c->umount_mutex);
1786 	dbg_save_space_info(c);
1787 	c->remounting_rw = 1;
1788 	c->ro_mount = 0;
1789 
1790 	if (c->space_fixup) {
1791 		err = ubifs_fixup_free_space(c);
1792 		if (err)
1793 			goto out;
1794 	}
1795 
1796 	err = check_free_space(c);
1797 	if (err)
1798 		goto out;
1799 
1800 	if (c->old_leb_cnt != c->leb_cnt) {
1801 		struct ubifs_sb_node *sup;
1802 
1803 		sup = ubifs_read_sb_node(c);
1804 		if (IS_ERR(sup)) {
1805 			err = PTR_ERR(sup);
1806 			goto out;
1807 		}
1808 		sup->leb_cnt = cpu_to_le32(c->leb_cnt);
1809 		err = ubifs_write_sb_node(c, sup);
1810 		kfree(sup);
1811 		if (err)
1812 			goto out;
1813 	}
1814 
1815 	if (c->need_recovery) {
1816 		ubifs_msg(c, "completing deferred recovery");
1817 		err = ubifs_write_rcvrd_mst_node(c);
1818 		if (err)
1819 			goto out;
1820 		err = ubifs_recover_size(c);
1821 		if (err)
1822 			goto out;
1823 		err = ubifs_clean_lebs(c, c->sbuf);
1824 		if (err)
1825 			goto out;
1826 		err = ubifs_recover_inl_heads(c, c->sbuf);
1827 		if (err)
1828 			goto out;
1829 	} else {
1830 		/* A readonly mount is not allowed to have orphans */
1831 		ubifs_assert(c->tot_orphans == 0);
1832 		err = ubifs_clear_orphans(c);
1833 		if (err)
1834 			goto out;
1835 	}
1836 
1837 	if (!(c->mst_node->flags & cpu_to_le32(UBIFS_MST_DIRTY))) {
1838 		c->mst_node->flags |= cpu_to_le32(UBIFS_MST_DIRTY);
1839 		err = ubifs_write_master(c);
1840 		if (err)
1841 			goto out;
1842 	}
1843 
1844 	c->ileb_buf = vmalloc(c->leb_size);
1845 	if (!c->ileb_buf) {
1846 		err = -ENOMEM;
1847 		goto out;
1848 	}
1849 
1850 	c->write_reserve_buf = kmalloc(COMPRESSED_DATA_NODE_BUF_SZ, GFP_KERNEL);
1851 	if (!c->write_reserve_buf) {
1852 		err = -ENOMEM;
1853 		goto out;
1854 	}
1855 
1856 	err = ubifs_lpt_init(c, 0, 1);
1857 	if (err)
1858 		goto out;
1859 
1860 	/* Create background thread */
1861 	c->bgt = kthread_create(ubifs_bg_thread, c, "%s", c->bgt_name);
1862 	if (IS_ERR(c->bgt)) {
1863 		err = PTR_ERR(c->bgt);
1864 		c->bgt = NULL;
1865 		ubifs_err(c, "cannot spawn \"%s\", error %d",
1866 			  c->bgt_name, err);
1867 		goto out;
1868 	}
1869 	wake_up_process(c->bgt);
1870 
1871 	c->orph_buf = vmalloc(c->leb_size);
1872 	if (!c->orph_buf) {
1873 		err = -ENOMEM;
1874 		goto out;
1875 	}
1876 
1877 	/* Check for enough log space */
1878 	lnum = c->lhead_lnum + 1;
1879 	if (lnum >= UBIFS_LOG_LNUM + c->log_lebs)
1880 		lnum = UBIFS_LOG_LNUM;
1881 	if (lnum == c->ltail_lnum) {
1882 		err = ubifs_consolidate_log(c);
1883 		if (err)
1884 			goto out;
1885 	}
1886 
1887 	if (c->need_recovery)
1888 		err = ubifs_rcvry_gc_commit(c);
1889 	else
1890 		err = ubifs_leb_unmap(c, c->gc_lnum);
1891 	if (err)
1892 		goto out;
1893 
1894 	dbg_gen("re-mounted read-write");
1895 	c->remounting_rw = 0;
1896 
1897 	if (c->need_recovery) {
1898 		c->need_recovery = 0;
1899 		ubifs_msg(c, "deferred recovery completed");
1900 	} else {
1901 		/*
1902 		 * Do not run the debugging space check if the were doing
1903 		 * recovery, because when we saved the information we had the
1904 		 * file-system in a state where the TNC and lprops has been
1905 		 * modified in memory, but all the I/O operations (including a
1906 		 * commit) were deferred. So the file-system was in
1907 		 * "non-committed" state. Now the file-system is in committed
1908 		 * state, and of course the amount of free space will change
1909 		 * because, for example, the old index size was imprecise.
1910 		 */
1911 		err = dbg_check_space_info(c);
1912 	}
1913 
1914 	mutex_unlock(&c->umount_mutex);
1915 	return err;
1916 
1917 out:
1918 	c->ro_mount = 1;
1919 	vfree(c->orph_buf);
1920 	c->orph_buf = NULL;
1921 	if (c->bgt) {
1922 		kthread_stop(c->bgt);
1923 		c->bgt = NULL;
1924 	}
1925 	free_wbufs(c);
1926 	kfree(c->write_reserve_buf);
1927 	c->write_reserve_buf = NULL;
1928 	vfree(c->ileb_buf);
1929 	c->ileb_buf = NULL;
1930 	ubifs_lpt_free(c, 1);
1931 	c->remounting_rw = 0;
1932 	mutex_unlock(&c->umount_mutex);
1933 	return err;
1934 }
1935 
1936 /**
1937  * ubifs_remount_ro - re-mount in read-only mode.
1938  * @c: UBIFS file-system description object
1939  *
1940  * We assume VFS has stopped writing. Possibly the background thread could be
1941  * running a commit, however kthread_stop will wait in that case.
1942  */
ubifs_remount_ro(struct ubifs_info * c)1943 static void ubifs_remount_ro(struct ubifs_info *c)
1944 {
1945 	int i, err;
1946 
1947 	ubifs_assert(!c->need_recovery);
1948 	ubifs_assert(!c->ro_mount);
1949 
1950 	mutex_lock(&c->umount_mutex);
1951 	if (c->bgt) {
1952 		kthread_stop(c->bgt);
1953 		c->bgt = NULL;
1954 	}
1955 
1956 	dbg_save_space_info(c);
1957 
1958 	for (i = 0; i < c->jhead_cnt; i++)
1959 		ubifs_wbuf_sync(&c->jheads[i].wbuf);
1960 
1961 	c->mst_node->flags &= ~cpu_to_le32(UBIFS_MST_DIRTY);
1962 	c->mst_node->flags |= cpu_to_le32(UBIFS_MST_NO_ORPHS);
1963 	c->mst_node->gc_lnum = cpu_to_le32(c->gc_lnum);
1964 	err = ubifs_write_master(c);
1965 	if (err)
1966 		ubifs_ro_mode(c, err);
1967 
1968 	vfree(c->orph_buf);
1969 	c->orph_buf = NULL;
1970 	kfree(c->write_reserve_buf);
1971 	c->write_reserve_buf = NULL;
1972 	vfree(c->ileb_buf);
1973 	c->ileb_buf = NULL;
1974 	ubifs_lpt_free(c, 1);
1975 	c->ro_mount = 1;
1976 	err = dbg_check_space_info(c);
1977 	if (err)
1978 		ubifs_ro_mode(c, err);
1979 	mutex_unlock(&c->umount_mutex);
1980 }
1981 
ubifs_put_super(struct super_block * sb)1982 static void ubifs_put_super(struct super_block *sb)
1983 {
1984 	int i;
1985 	struct ubifs_info *c = sb->s_fs_info;
1986 
1987 	ubifs_msg(c, "un-mount UBI device %d", c->vi.ubi_num);
1988 
1989 	/*
1990 	 * The following asserts are only valid if there has not been a failure
1991 	 * of the media. For example, there will be dirty inodes if we failed
1992 	 * to write them back because of I/O errors.
1993 	 */
1994 	if (!c->ro_error) {
1995 		ubifs_assert(c->bi.idx_growth == 0);
1996 		ubifs_assert(c->bi.dd_growth == 0);
1997 		ubifs_assert(c->bi.data_growth == 0);
1998 	}
1999 
2000 	/*
2001 	 * The 'c->umount_lock' prevents races between UBIFS memory shrinker
2002 	 * and file system un-mount. Namely, it prevents the shrinker from
2003 	 * picking this superblock for shrinking - it will be just skipped if
2004 	 * the mutex is locked.
2005 	 */
2006 	mutex_lock(&c->umount_mutex);
2007 	if (!c->ro_mount) {
2008 		/*
2009 		 * First of all kill the background thread to make sure it does
2010 		 * not interfere with un-mounting and freeing resources.
2011 		 */
2012 		if (c->bgt) {
2013 			kthread_stop(c->bgt);
2014 			c->bgt = NULL;
2015 		}
2016 
2017 		/*
2018 		 * On fatal errors c->ro_error is set to 1, in which case we do
2019 		 * not write the master node.
2020 		 */
2021 		if (!c->ro_error) {
2022 			int err;
2023 
2024 			/* Synchronize write-buffers */
2025 			for (i = 0; i < c->jhead_cnt; i++)
2026 				ubifs_wbuf_sync(&c->jheads[i].wbuf);
2027 
2028 			/*
2029 			 * We are being cleanly unmounted which means the
2030 			 * orphans were killed - indicate this in the master
2031 			 * node. Also save the reserved GC LEB number.
2032 			 */
2033 			c->mst_node->flags &= ~cpu_to_le32(UBIFS_MST_DIRTY);
2034 			c->mst_node->flags |= cpu_to_le32(UBIFS_MST_NO_ORPHS);
2035 			c->mst_node->gc_lnum = cpu_to_le32(c->gc_lnum);
2036 			err = ubifs_write_master(c);
2037 			if (err)
2038 				/*
2039 				 * Recovery will attempt to fix the master area
2040 				 * next mount, so we just print a message and
2041 				 * continue to unmount normally.
2042 				 */
2043 				ubifs_err(c, "failed to write master node, error %d",
2044 					  err);
2045 		} else {
2046 #ifndef __UBOOT__
2047 			for (i = 0; i < c->jhead_cnt; i++)
2048 				/* Make sure write-buffer timers are canceled */
2049 				hrtimer_cancel(&c->jheads[i].wbuf.timer);
2050 #endif
2051 		}
2052 	}
2053 
2054 	ubifs_umount(c);
2055 #ifndef __UBOOT__
2056 	bdi_destroy(&c->bdi);
2057 #endif
2058 	ubi_close_volume(c->ubi);
2059 	mutex_unlock(&c->umount_mutex);
2060 }
2061 #endif
2062 
2063 #ifndef __UBOOT__
ubifs_remount_fs(struct super_block * sb,int * flags,char * data)2064 static int ubifs_remount_fs(struct super_block *sb, int *flags, char *data)
2065 {
2066 	int err;
2067 	struct ubifs_info *c = sb->s_fs_info;
2068 
2069 	sync_filesystem(sb);
2070 	dbg_gen("old flags %#lx, new flags %#x", sb->s_flags, *flags);
2071 
2072 	err = ubifs_parse_options(c, data, 1);
2073 	if (err) {
2074 		ubifs_err(c, "invalid or unknown remount parameter");
2075 		return err;
2076 	}
2077 
2078 	if (c->ro_mount && !(*flags & MS_RDONLY)) {
2079 		if (c->ro_error) {
2080 			ubifs_msg(c, "cannot re-mount R/W due to prior errors");
2081 			return -EROFS;
2082 		}
2083 		if (c->ro_media) {
2084 			ubifs_msg(c, "cannot re-mount R/W - UBI volume is R/O");
2085 			return -EROFS;
2086 		}
2087 		err = ubifs_remount_rw(c);
2088 		if (err)
2089 			return err;
2090 	} else if (!c->ro_mount && (*flags & MS_RDONLY)) {
2091 		if (c->ro_error) {
2092 			ubifs_msg(c, "cannot re-mount R/O due to prior errors");
2093 			return -EROFS;
2094 		}
2095 		ubifs_remount_ro(c);
2096 	}
2097 
2098 	if (c->bulk_read == 1)
2099 		bu_init(c);
2100 	else {
2101 		dbg_gen("disable bulk-read");
2102 		kfree(c->bu.buf);
2103 		c->bu.buf = NULL;
2104 	}
2105 
2106 	ubifs_assert(c->lst.taken_empty_lebs > 0);
2107 	return 0;
2108 }
2109 #endif
2110 
2111 const struct super_operations ubifs_super_operations = {
2112 	.alloc_inode   = ubifs_alloc_inode,
2113 #ifndef __UBOOT__
2114 	.destroy_inode = ubifs_destroy_inode,
2115 	.put_super     = ubifs_put_super,
2116 	.write_inode   = ubifs_write_inode,
2117 	.evict_inode   = ubifs_evict_inode,
2118 	.statfs        = ubifs_statfs,
2119 #endif
2120 	.dirty_inode   = ubifs_dirty_inode,
2121 #ifndef __UBOOT__
2122 	.remount_fs    = ubifs_remount_fs,
2123 	.show_options  = ubifs_show_options,
2124 	.sync_fs       = ubifs_sync_fs,
2125 #endif
2126 };
2127 
2128 /**
2129  * open_ubi - parse UBI device name string and open the UBI device.
2130  * @name: UBI volume name
2131  * @mode: UBI volume open mode
2132  *
2133  * The primary method of mounting UBIFS is by specifying the UBI volume
2134  * character device node path. However, UBIFS may also be mounted withoug any
2135  * character device node using one of the following methods:
2136  *
2137  * o ubiX_Y    - mount UBI device number X, volume Y;
2138  * o ubiY      - mount UBI device number 0, volume Y;
2139  * o ubiX:NAME - mount UBI device X, volume with name NAME;
2140  * o ubi:NAME  - mount UBI device 0, volume with name NAME.
2141  *
2142  * Alternative '!' separator may be used instead of ':' (because some shells
2143  * like busybox may interpret ':' as an NFS host name separator). This function
2144  * returns UBI volume description object in case of success and a negative
2145  * error code in case of failure.
2146  */
open_ubi(const char * name,int mode)2147 static struct ubi_volume_desc *open_ubi(const char *name, int mode)
2148 {
2149 #ifndef __UBOOT__
2150 	struct ubi_volume_desc *ubi;
2151 #endif
2152 	int dev, vol;
2153 	char *endptr;
2154 
2155 #ifndef __UBOOT__
2156 	/* First, try to open using the device node path method */
2157 	ubi = ubi_open_volume_path(name, mode);
2158 	if (!IS_ERR(ubi))
2159 		return ubi;
2160 #endif
2161 
2162 	/* Try the "nodev" method */
2163 	if (name[0] != 'u' || name[1] != 'b' || name[2] != 'i')
2164 		return ERR_PTR(-EINVAL);
2165 
2166 	/* ubi:NAME method */
2167 	if ((name[3] == ':' || name[3] == '!') && name[4] != '\0')
2168 		return ubi_open_volume_nm(0, name + 4, mode);
2169 
2170 	if (!isdigit(name[3]))
2171 		return ERR_PTR(-EINVAL);
2172 
2173 	dev = simple_strtoul(name + 3, &endptr, 0);
2174 
2175 	/* ubiY method */
2176 	if (*endptr == '\0')
2177 		return ubi_open_volume(0, dev, mode);
2178 
2179 	/* ubiX_Y method */
2180 	if (*endptr == '_' && isdigit(endptr[1])) {
2181 		vol = simple_strtoul(endptr + 1, &endptr, 0);
2182 		if (*endptr != '\0')
2183 			return ERR_PTR(-EINVAL);
2184 		return ubi_open_volume(dev, vol, mode);
2185 	}
2186 
2187 	/* ubiX:NAME method */
2188 	if ((*endptr == ':' || *endptr == '!') && endptr[1] != '\0')
2189 		return ubi_open_volume_nm(dev, ++endptr, mode);
2190 
2191 	return ERR_PTR(-EINVAL);
2192 }
2193 
alloc_ubifs_info(struct ubi_volume_desc * ubi)2194 static struct ubifs_info *alloc_ubifs_info(struct ubi_volume_desc *ubi)
2195 {
2196 	struct ubifs_info *c;
2197 
2198 	c = kzalloc(sizeof(struct ubifs_info), GFP_KERNEL);
2199 	if (c) {
2200 		spin_lock_init(&c->cnt_lock);
2201 		spin_lock_init(&c->cs_lock);
2202 		spin_lock_init(&c->buds_lock);
2203 		spin_lock_init(&c->space_lock);
2204 		spin_lock_init(&c->orphan_lock);
2205 		init_rwsem(&c->commit_sem);
2206 		mutex_init(&c->lp_mutex);
2207 		mutex_init(&c->tnc_mutex);
2208 		mutex_init(&c->log_mutex);
2209 		mutex_init(&c->umount_mutex);
2210 		mutex_init(&c->bu_mutex);
2211 		mutex_init(&c->write_reserve_mutex);
2212 		init_waitqueue_head(&c->cmt_wq);
2213 		c->buds = RB_ROOT;
2214 		c->old_idx = RB_ROOT;
2215 		c->size_tree = RB_ROOT;
2216 		c->orph_tree = RB_ROOT;
2217 		INIT_LIST_HEAD(&c->infos_list);
2218 		INIT_LIST_HEAD(&c->idx_gc);
2219 		INIT_LIST_HEAD(&c->replay_list);
2220 		INIT_LIST_HEAD(&c->replay_buds);
2221 		INIT_LIST_HEAD(&c->uncat_list);
2222 		INIT_LIST_HEAD(&c->empty_list);
2223 		INIT_LIST_HEAD(&c->freeable_list);
2224 		INIT_LIST_HEAD(&c->frdi_idx_list);
2225 		INIT_LIST_HEAD(&c->unclean_leb_list);
2226 		INIT_LIST_HEAD(&c->old_buds);
2227 		INIT_LIST_HEAD(&c->orph_list);
2228 		INIT_LIST_HEAD(&c->orph_new);
2229 		c->no_chk_data_crc = 1;
2230 
2231 		c->highest_inum = UBIFS_FIRST_INO;
2232 		c->lhead_lnum = c->ltail_lnum = UBIFS_LOG_LNUM;
2233 
2234 		ubi_get_volume_info(ubi, &c->vi);
2235 		ubi_get_device_info(c->vi.ubi_num, &c->di);
2236 	}
2237 	return c;
2238 }
2239 
ubifs_fill_super(struct super_block * sb,void * data,int silent)2240 static int ubifs_fill_super(struct super_block *sb, void *data, int silent)
2241 {
2242 	struct ubifs_info *c = sb->s_fs_info;
2243 	struct inode *root;
2244 	int err;
2245 
2246 	c->vfs_sb = sb;
2247 #ifndef __UBOOT__
2248 	/* Re-open the UBI device in read-write mode */
2249 	c->ubi = ubi_open_volume(c->vi.ubi_num, c->vi.vol_id, UBI_READWRITE);
2250 #else
2251 	/* U-Boot read only mode */
2252 	c->ubi = ubi_open_volume(c->vi.ubi_num, c->vi.vol_id, UBI_READONLY);
2253 #endif
2254 
2255 	if (IS_ERR(c->ubi)) {
2256 		err = PTR_ERR(c->ubi);
2257 		goto out;
2258 	}
2259 
2260 #ifndef __UBOOT__
2261 	/*
2262 	 * UBIFS provides 'backing_dev_info' in order to disable read-ahead. For
2263 	 * UBIFS, I/O is not deferred, it is done immediately in readpage,
2264 	 * which means the user would have to wait not just for their own I/O
2265 	 * but the read-ahead I/O as well i.e. completely pointless.
2266 	 *
2267 	 * Read-ahead will be disabled because @c->bdi.ra_pages is 0.
2268 	 */
2269 	c->bdi.name = "ubifs",
2270 	c->bdi.capabilities = 0;
2271 	err  = bdi_init(&c->bdi);
2272 	if (err)
2273 		goto out_close;
2274 	err = bdi_register(&c->bdi, NULL, "ubifs_%d_%d",
2275 			   c->vi.ubi_num, c->vi.vol_id);
2276 	if (err)
2277 		goto out_bdi;
2278 
2279 	err = ubifs_parse_options(c, data, 0);
2280 	if (err)
2281 		goto out_bdi;
2282 
2283 	sb->s_bdi = &c->bdi;
2284 #endif
2285 	sb->s_fs_info = c;
2286 	sb->s_magic = UBIFS_SUPER_MAGIC;
2287 	sb->s_blocksize = UBIFS_BLOCK_SIZE;
2288 	sb->s_blocksize_bits = UBIFS_BLOCK_SHIFT;
2289 	sb->s_maxbytes = c->max_inode_sz = key_max_inode_size(c);
2290 	if (c->max_inode_sz > MAX_LFS_FILESIZE)
2291 		sb->s_maxbytes = c->max_inode_sz = MAX_LFS_FILESIZE;
2292 	sb->s_op = &ubifs_super_operations;
2293 #ifndef __UBOOT__
2294 	sb->s_xattr = ubifs_xattr_handlers;
2295 #endif
2296 
2297 	mutex_lock(&c->umount_mutex);
2298 	err = mount_ubifs(c);
2299 	if (err) {
2300 		ubifs_assert(err < 0);
2301 		goto out_unlock;
2302 	}
2303 
2304 	/* Read the root inode */
2305 	root = ubifs_iget(sb, UBIFS_ROOT_INO);
2306 	if (IS_ERR(root)) {
2307 		err = PTR_ERR(root);
2308 		goto out_umount;
2309 	}
2310 
2311 #ifndef __UBOOT__
2312 	sb->s_root = d_make_root(root);
2313 	if (!sb->s_root) {
2314 		err = -ENOMEM;
2315 		goto out_umount;
2316 	}
2317 #else
2318 	sb->s_root = NULL;
2319 #endif
2320 
2321 	mutex_unlock(&c->umount_mutex);
2322 	return 0;
2323 
2324 out_umount:
2325 	ubifs_umount(c);
2326 out_unlock:
2327 	mutex_unlock(&c->umount_mutex);
2328 #ifndef __UBOOT__
2329 out_bdi:
2330 	bdi_destroy(&c->bdi);
2331 out_close:
2332 #endif
2333 	ubi_close_volume(c->ubi);
2334 out:
2335 	return err;
2336 }
2337 
sb_test(struct super_block * sb,void * data)2338 static int sb_test(struct super_block *sb, void *data)
2339 {
2340 	struct ubifs_info *c1 = data;
2341 	struct ubifs_info *c = sb->s_fs_info;
2342 
2343 	return c->vi.cdev == c1->vi.cdev;
2344 }
2345 
sb_set(struct super_block * sb,void * data)2346 static int sb_set(struct super_block *sb, void *data)
2347 {
2348 	sb->s_fs_info = data;
2349 	return set_anon_super(sb, NULL);
2350 }
2351 
alloc_super(struct file_system_type * type,int flags)2352 static struct super_block *alloc_super(struct file_system_type *type, int flags)
2353 {
2354 	struct super_block *s;
2355 	int err;
2356 
2357 	s = kzalloc(sizeof(struct super_block),  GFP_USER);
2358 	if (!s) {
2359 		err = -ENOMEM;
2360 		return ERR_PTR(err);
2361 	}
2362 
2363 	INIT_HLIST_NODE(&s->s_instances);
2364 	INIT_LIST_HEAD(&s->s_inodes);
2365 	s->s_time_gran = 1000000000;
2366 	s->s_flags = flags;
2367 
2368 	return s;
2369 }
2370 
2371 /**
2372  *	sget	-	find or create a superblock
2373  *	@type:	filesystem type superblock should belong to
2374  *	@test:	comparison callback
2375  *	@set:	setup callback
2376  *	@flags:	mount flags
2377  *	@data:	argument to each of them
2378  */
sget(struct file_system_type * type,int (* test)(struct super_block *,void *),int (* set)(struct super_block *,void *),int flags,void * data)2379 struct super_block *sget(struct file_system_type *type,
2380 			int (*test)(struct super_block *,void *),
2381 			int (*set)(struct super_block *,void *),
2382 			int flags,
2383 			void *data)
2384 {
2385 	struct super_block *s = NULL;
2386 #ifndef __UBOOT__
2387 	struct super_block *old;
2388 #endif
2389 	int err;
2390 
2391 #ifndef __UBOOT__
2392 retry:
2393 	spin_lock(&sb_lock);
2394 	if (test) {
2395 		hlist_for_each_entry(old, &type->fs_supers, s_instances) {
2396 			if (!test(old, data))
2397 				continue;
2398 			if (!grab_super(old))
2399 				goto retry;
2400 			if (s) {
2401 				up_write(&s->s_umount);
2402 				destroy_super(s);
2403 				s = NULL;
2404 			}
2405 			return old;
2406 		}
2407 	}
2408 #endif
2409 	if (!s) {
2410 		spin_unlock(&sb_lock);
2411 		s = alloc_super(type, flags);
2412 		if (!s)
2413 			return ERR_PTR(-ENOMEM);
2414 #ifndef __UBOOT__
2415 		goto retry;
2416 #endif
2417 	}
2418 
2419 	err = set(s, data);
2420 	if (err) {
2421 #ifndef __UBOOT__
2422 		spin_unlock(&sb_lock);
2423 		up_write(&s->s_umount);
2424 		destroy_super(s);
2425 #endif
2426 		return ERR_PTR(err);
2427 	}
2428 	s->s_type = type;
2429 #ifndef __UBOOT__
2430 	strlcpy(s->s_id, type->name, sizeof(s->s_id));
2431 	list_add_tail(&s->s_list, &super_blocks);
2432 #else
2433 	strncpy(s->s_id, type->name, sizeof(s->s_id));
2434 #endif
2435 	hlist_add_head(&s->s_instances, &type->fs_supers);
2436 #ifndef __UBOOT__
2437 	spin_unlock(&sb_lock);
2438 	get_filesystem(type);
2439 	register_shrinker(&s->s_shrink);
2440 #endif
2441 	return s;
2442 }
2443 
2444 EXPORT_SYMBOL(sget);
2445 
2446 
ubifs_mount(struct file_system_type * fs_type,int flags,const char * name,void * data)2447 static struct dentry *ubifs_mount(struct file_system_type *fs_type, int flags,
2448 			const char *name, void *data)
2449 {
2450 	struct ubi_volume_desc *ubi;
2451 	struct ubifs_info *c;
2452 	struct super_block *sb;
2453 	int err;
2454 
2455 	dbg_gen("name %s, flags %#x", name, flags);
2456 
2457 	/*
2458 	 * Get UBI device number and volume ID. Mount it read-only so far
2459 	 * because this might be a new mount point, and UBI allows only one
2460 	 * read-write user at a time.
2461 	 */
2462 	ubi = open_ubi(name, UBI_READONLY);
2463 	if (IS_ERR(ubi)) {
2464 		pr_err("UBIFS error (pid: %d): cannot open \"%s\", error %d",
2465 		       current->pid, name, (int)PTR_ERR(ubi));
2466 		return ERR_CAST(ubi);
2467 	}
2468 
2469 	c = alloc_ubifs_info(ubi);
2470 	if (!c) {
2471 		err = -ENOMEM;
2472 		goto out_close;
2473 	}
2474 
2475 	dbg_gen("opened ubi%d_%d", c->vi.ubi_num, c->vi.vol_id);
2476 
2477 	sb = sget(fs_type, sb_test, sb_set, flags, c);
2478 	if (IS_ERR(sb)) {
2479 		err = PTR_ERR(sb);
2480 		kfree(c);
2481 		goto out_close;
2482 	}
2483 
2484 	if (sb->s_root) {
2485 		struct ubifs_info *c1 = sb->s_fs_info;
2486 		kfree(c);
2487 		/* A new mount point for already mounted UBIFS */
2488 		dbg_gen("this ubi volume is already mounted");
2489 		if (!!(flags & MS_RDONLY) != c1->ro_mount) {
2490 			err = -EBUSY;
2491 			goto out_deact;
2492 		}
2493 	} else {
2494 		err = ubifs_fill_super(sb, data, flags & MS_SILENT ? 1 : 0);
2495 		if (err)
2496 			goto out_deact;
2497 		/* We do not support atime */
2498 		sb->s_flags |= MS_ACTIVE | MS_NOATIME;
2499 	}
2500 
2501 	/* 'fill_super()' opens ubi again so we must close it here */
2502 	ubi_close_volume(ubi);
2503 
2504 #ifdef __UBOOT__
2505 	ubifs_sb = sb;
2506 	return 0;
2507 #else
2508 	return dget(sb->s_root);
2509 #endif
2510 
2511 out_deact:
2512 #ifndef __UBOOT__
2513 	deactivate_locked_super(sb);
2514 #endif
2515 out_close:
2516 	ubi_close_volume(ubi);
2517 	return ERR_PTR(err);
2518 }
2519 
kill_ubifs_super(struct super_block * s)2520 static void kill_ubifs_super(struct super_block *s)
2521 {
2522 	struct ubifs_info *c = s->s_fs_info;
2523 #ifndef __UBOOT__
2524 	kill_anon_super(s);
2525 #endif
2526 	kfree(c);
2527 }
2528 
2529 static struct file_system_type ubifs_fs_type = {
2530 	.name    = "ubifs",
2531 	.owner   = THIS_MODULE,
2532 	.mount   = ubifs_mount,
2533 	.kill_sb = kill_ubifs_super,
2534 };
2535 #ifndef __UBOOT__
2536 MODULE_ALIAS_FS("ubifs");
2537 
2538 /*
2539  * Inode slab cache constructor.
2540  */
inode_slab_ctor(void * obj)2541 static void inode_slab_ctor(void *obj)
2542 {
2543 	struct ubifs_inode *ui = obj;
2544 	inode_init_once(&ui->vfs_inode);
2545 }
2546 
ubifs_init(void)2547 static int __init ubifs_init(void)
2548 #else
2549 int ubifs_init(void)
2550 #endif
2551 {
2552 	int err;
2553 
2554 	BUILD_BUG_ON(sizeof(struct ubifs_ch) != 24);
2555 
2556 	/* Make sure node sizes are 8-byte aligned */
2557 	BUILD_BUG_ON(UBIFS_CH_SZ        & 7);
2558 	BUILD_BUG_ON(UBIFS_INO_NODE_SZ  & 7);
2559 	BUILD_BUG_ON(UBIFS_DENT_NODE_SZ & 7);
2560 	BUILD_BUG_ON(UBIFS_XENT_NODE_SZ & 7);
2561 	BUILD_BUG_ON(UBIFS_DATA_NODE_SZ & 7);
2562 	BUILD_BUG_ON(UBIFS_TRUN_NODE_SZ & 7);
2563 	BUILD_BUG_ON(UBIFS_SB_NODE_SZ   & 7);
2564 	BUILD_BUG_ON(UBIFS_MST_NODE_SZ  & 7);
2565 	BUILD_BUG_ON(UBIFS_REF_NODE_SZ  & 7);
2566 	BUILD_BUG_ON(UBIFS_CS_NODE_SZ   & 7);
2567 	BUILD_BUG_ON(UBIFS_ORPH_NODE_SZ & 7);
2568 
2569 	BUILD_BUG_ON(UBIFS_MAX_DENT_NODE_SZ & 7);
2570 	BUILD_BUG_ON(UBIFS_MAX_XENT_NODE_SZ & 7);
2571 	BUILD_BUG_ON(UBIFS_MAX_DATA_NODE_SZ & 7);
2572 	BUILD_BUG_ON(UBIFS_MAX_INO_NODE_SZ  & 7);
2573 	BUILD_BUG_ON(UBIFS_MAX_NODE_SZ      & 7);
2574 	BUILD_BUG_ON(MIN_WRITE_SZ           & 7);
2575 
2576 	/* Check min. node size */
2577 	BUILD_BUG_ON(UBIFS_INO_NODE_SZ  < MIN_WRITE_SZ);
2578 	BUILD_BUG_ON(UBIFS_DENT_NODE_SZ < MIN_WRITE_SZ);
2579 	BUILD_BUG_ON(UBIFS_XENT_NODE_SZ < MIN_WRITE_SZ);
2580 	BUILD_BUG_ON(UBIFS_TRUN_NODE_SZ < MIN_WRITE_SZ);
2581 
2582 	BUILD_BUG_ON(UBIFS_MAX_DENT_NODE_SZ > UBIFS_MAX_NODE_SZ);
2583 	BUILD_BUG_ON(UBIFS_MAX_XENT_NODE_SZ > UBIFS_MAX_NODE_SZ);
2584 	BUILD_BUG_ON(UBIFS_MAX_DATA_NODE_SZ > UBIFS_MAX_NODE_SZ);
2585 	BUILD_BUG_ON(UBIFS_MAX_INO_NODE_SZ  > UBIFS_MAX_NODE_SZ);
2586 
2587 	/* Defined node sizes */
2588 	BUILD_BUG_ON(UBIFS_SB_NODE_SZ  != 4096);
2589 	BUILD_BUG_ON(UBIFS_MST_NODE_SZ != 512);
2590 	BUILD_BUG_ON(UBIFS_INO_NODE_SZ != 160);
2591 	BUILD_BUG_ON(UBIFS_REF_NODE_SZ != 64);
2592 
2593 	/*
2594 	 * We use 2 bit wide bit-fields to store compression type, which should
2595 	 * be amended if more compressors are added. The bit-fields are:
2596 	 * @compr_type in 'struct ubifs_inode', @default_compr in
2597 	 * 'struct ubifs_info' and @compr_type in 'struct ubifs_mount_opts'.
2598 	 */
2599 	BUILD_BUG_ON(UBIFS_COMPR_TYPES_CNT > 4);
2600 
2601 	/*
2602 	 * We require that PAGE_CACHE_SIZE is greater-than-or-equal-to
2603 	 * UBIFS_BLOCK_SIZE. It is assumed that both are powers of 2.
2604 	 */
2605 	if (PAGE_CACHE_SIZE < UBIFS_BLOCK_SIZE) {
2606 		pr_err("UBIFS error (pid %d): VFS page cache size is %u bytes, but UBIFS requires at least 4096 bytes",
2607 		       current->pid, (unsigned int)PAGE_CACHE_SIZE);
2608 		return -EINVAL;
2609 	}
2610 
2611 #ifndef __UBOOT__
2612 	ubifs_inode_slab = kmem_cache_create("ubifs_inode_slab",
2613 				sizeof(struct ubifs_inode), 0,
2614 				SLAB_MEM_SPREAD | SLAB_RECLAIM_ACCOUNT,
2615 				&inode_slab_ctor);
2616 	if (!ubifs_inode_slab)
2617 		return -ENOMEM;
2618 
2619 	err = register_shrinker(&ubifs_shrinker_info);
2620 	if (err)
2621 		goto out_slab;
2622 #endif
2623 
2624 	err = ubifs_compressors_init();
2625 	if (err)
2626 		goto out_shrinker;
2627 
2628 #ifndef __UBOOT__
2629 	err = dbg_debugfs_init();
2630 	if (err)
2631 		goto out_compr;
2632 
2633 	err = register_filesystem(&ubifs_fs_type);
2634 	if (err) {
2635 		pr_err("UBIFS error (pid %d): cannot register file system, error %d",
2636 		       current->pid, err);
2637 		goto out_dbg;
2638 	}
2639 #endif
2640 	return 0;
2641 
2642 #ifndef __UBOOT__
2643 out_dbg:
2644 	dbg_debugfs_exit();
2645 out_compr:
2646 	ubifs_compressors_exit();
2647 #endif
2648 out_shrinker:
2649 #ifndef __UBOOT__
2650 	unregister_shrinker(&ubifs_shrinker_info);
2651 out_slab:
2652 #endif
2653 	kmem_cache_destroy(ubifs_inode_slab);
2654 	return err;
2655 }
2656 /* late_initcall to let compressors initialize first */
2657 late_initcall(ubifs_init);
2658 
2659 #ifndef __UBOOT__
ubifs_exit(void)2660 static void __exit ubifs_exit(void)
2661 {
2662 	ubifs_assert(list_empty(&ubifs_infos));
2663 	ubifs_assert(atomic_long_read(&ubifs_clean_zn_cnt) == 0);
2664 
2665 	dbg_debugfs_exit();
2666 	ubifs_compressors_exit();
2667 	unregister_shrinker(&ubifs_shrinker_info);
2668 
2669 	/*
2670 	 * Make sure all delayed rcu free inodes are flushed before we
2671 	 * destroy cache.
2672 	 */
2673 	rcu_barrier();
2674 	kmem_cache_destroy(ubifs_inode_slab);
2675 	unregister_filesystem(&ubifs_fs_type);
2676 }
2677 module_exit(ubifs_exit);
2678 
2679 MODULE_LICENSE("GPL");
2680 MODULE_VERSION(__stringify(UBIFS_VERSION));
2681 MODULE_AUTHOR("Artem Bityutskiy, Adrian Hunter");
2682 MODULE_DESCRIPTION("UBIFS - UBI File System");
2683 #else
uboot_ubifs_mount(char * vol_name)2684 int uboot_ubifs_mount(char *vol_name)
2685 {
2686 	struct dentry *ret;
2687 	int flags;
2688 
2689 	/*
2690 	 * First unmount if allready mounted
2691 	 */
2692 	if (ubifs_sb)
2693 		ubifs_umount(ubifs_sb->s_fs_info);
2694 
2695 	/*
2696 	 * Mount in read-only mode
2697 	 */
2698 	flags = MS_RDONLY;
2699 	ret = ubifs_mount(&ubifs_fs_type, flags, vol_name, NULL);
2700 	if (IS_ERR(ret)) {
2701 		printf("Error reading superblock on volume '%s' " \
2702 			"errno=%d!\n", vol_name, (int)PTR_ERR(ret));
2703 		return -1;
2704 	}
2705 
2706 	return 0;
2707 }
2708 #endif
2709