kvm tools, setup: Create private directory
[linux-2.6/next.git] / fs / ubifs / super.c
blob529be058202938cf1226ec8644401951df8ab032
1 /*
2 * This file is part of UBIFS.
4 * Copyright (C) 2006-2008 Nokia Corporation.
6 * This program is free software; you can redistribute it and/or modify it
7 * under the terms of the GNU General Public License version 2 as published by
8 * the Free Software Foundation.
10 * This program is distributed in the hope that it will be useful, but WITHOUT
11 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
12 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
13 * more details.
15 * You should have received a copy of the GNU General Public License along with
16 * this program; if not, write to the Free Software Foundation, Inc., 51
17 * Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
19 * Authors: Artem Bityutskiy (Битюцкий Артём)
20 * Adrian Hunter
24 * This file implements UBIFS initialization and VFS superblock operations. Some
25 * initialization stuff which is rather large and complex is placed at
26 * corresponding subsystems, but most of it is here.
29 #include <linux/init.h>
30 #include <linux/slab.h>
31 #include <linux/module.h>
32 #include <linux/ctype.h>
33 #include <linux/kthread.h>
34 #include <linux/parser.h>
35 #include <linux/seq_file.h>
36 #include <linux/mount.h>
37 #include <linux/math64.h>
38 #include <linux/writeback.h>
39 #include "ubifs.h"
42 * Maximum amount of memory we may 'kmalloc()' without worrying that we are
43 * allocating too much.
45 #define UBIFS_KMALLOC_OK (128*1024)
47 /* Slab cache for UBIFS inodes */
48 struct kmem_cache *ubifs_inode_slab;
50 /* UBIFS TNC shrinker description */
51 static struct shrinker ubifs_shrinker_info = {
52 .shrink = ubifs_shrinker,
53 .seeks = DEFAULT_SEEKS,
56 /**
57 * validate_inode - validate inode.
58 * @c: UBIFS file-system description object
59 * @inode: the inode to validate
61 * This is a helper function for 'ubifs_iget()' which validates various fields
62 * of a newly built inode to make sure they contain sane values and prevent
63 * possible vulnerabilities. Returns zero if the inode is all right and
64 * a non-zero error code if not.
66 static int validate_inode(struct ubifs_info *c, const struct inode *inode)
68 int err;
69 const struct ubifs_inode *ui = ubifs_inode(inode);
71 if (inode->i_size > c->max_inode_sz) {
72 ubifs_err("inode is too large (%lld)",
73 (long long)inode->i_size);
74 return 1;
77 if (ui->compr_type < 0 || ui->compr_type >= UBIFS_COMPR_TYPES_CNT) {
78 ubifs_err("unknown compression type %d", ui->compr_type);
79 return 2;
82 if (ui->xattr_names + ui->xattr_cnt > XATTR_LIST_MAX)
83 return 3;
85 if (ui->data_len < 0 || ui->data_len > UBIFS_MAX_INO_DATA)
86 return 4;
88 if (ui->xattr && (inode->i_mode & S_IFMT) != S_IFREG)
89 return 5;
91 if (!ubifs_compr_present(ui->compr_type)) {
92 ubifs_warn("inode %lu uses '%s' compression, but it was not "
93 "compiled in", inode->i_ino,
94 ubifs_compr_name(ui->compr_type));
97 err = dbg_check_dir_size(c, inode);
98 return err;
101 struct inode *ubifs_iget(struct super_block *sb, unsigned long inum)
103 int err;
104 union ubifs_key key;
105 struct ubifs_ino_node *ino;
106 struct ubifs_info *c = sb->s_fs_info;
107 struct inode *inode;
108 struct ubifs_inode *ui;
110 dbg_gen("inode %lu", inum);
112 inode = iget_locked(sb, inum);
113 if (!inode)
114 return ERR_PTR(-ENOMEM);
115 if (!(inode->i_state & I_NEW))
116 return inode;
117 ui = ubifs_inode(inode);
119 ino = kmalloc(UBIFS_MAX_INO_NODE_SZ, GFP_NOFS);
120 if (!ino) {
121 err = -ENOMEM;
122 goto out;
125 ino_key_init(c, &key, inode->i_ino);
127 err = ubifs_tnc_lookup(c, &key, ino);
128 if (err)
129 goto out_ino;
131 inode->i_flags |= (S_NOCMTIME | S_NOATIME);
132 inode->i_nlink = le32_to_cpu(ino->nlink);
133 inode->i_uid = le32_to_cpu(ino->uid);
134 inode->i_gid = le32_to_cpu(ino->gid);
135 inode->i_atime.tv_sec = (int64_t)le64_to_cpu(ino->atime_sec);
136 inode->i_atime.tv_nsec = le32_to_cpu(ino->atime_nsec);
137 inode->i_mtime.tv_sec = (int64_t)le64_to_cpu(ino->mtime_sec);
138 inode->i_mtime.tv_nsec = le32_to_cpu(ino->mtime_nsec);
139 inode->i_ctime.tv_sec = (int64_t)le64_to_cpu(ino->ctime_sec);
140 inode->i_ctime.tv_nsec = le32_to_cpu(ino->ctime_nsec);
141 inode->i_mode = le32_to_cpu(ino->mode);
142 inode->i_size = le64_to_cpu(ino->size);
144 ui->data_len = le32_to_cpu(ino->data_len);
145 ui->flags = le32_to_cpu(ino->flags);
146 ui->compr_type = le16_to_cpu(ino->compr_type);
147 ui->creat_sqnum = le64_to_cpu(ino->creat_sqnum);
148 ui->xattr_cnt = le32_to_cpu(ino->xattr_cnt);
149 ui->xattr_size = le32_to_cpu(ino->xattr_size);
150 ui->xattr_names = le32_to_cpu(ino->xattr_names);
151 ui->synced_i_size = ui->ui_size = inode->i_size;
153 ui->xattr = (ui->flags & UBIFS_XATTR_FL) ? 1 : 0;
155 err = validate_inode(c, inode);
156 if (err)
157 goto out_invalid;
159 /* Disable read-ahead */
160 inode->i_mapping->backing_dev_info = &c->bdi;
162 switch (inode->i_mode & S_IFMT) {
163 case S_IFREG:
164 inode->i_mapping->a_ops = &ubifs_file_address_operations;
165 inode->i_op = &ubifs_file_inode_operations;
166 inode->i_fop = &ubifs_file_operations;
167 if (ui->xattr) {
168 ui->data = kmalloc(ui->data_len + 1, GFP_NOFS);
169 if (!ui->data) {
170 err = -ENOMEM;
171 goto out_ino;
173 memcpy(ui->data, ino->data, ui->data_len);
174 ((char *)ui->data)[ui->data_len] = '\0';
175 } else if (ui->data_len != 0) {
176 err = 10;
177 goto out_invalid;
179 break;
180 case S_IFDIR:
181 inode->i_op = &ubifs_dir_inode_operations;
182 inode->i_fop = &ubifs_dir_operations;
183 if (ui->data_len != 0) {
184 err = 11;
185 goto out_invalid;
187 break;
188 case S_IFLNK:
189 inode->i_op = &ubifs_symlink_inode_operations;
190 if (ui->data_len <= 0 || ui->data_len > UBIFS_MAX_INO_DATA) {
191 err = 12;
192 goto out_invalid;
194 ui->data = kmalloc(ui->data_len + 1, GFP_NOFS);
195 if (!ui->data) {
196 err = -ENOMEM;
197 goto out_ino;
199 memcpy(ui->data, ino->data, ui->data_len);
200 ((char *)ui->data)[ui->data_len] = '\0';
201 break;
202 case S_IFBLK:
203 case S_IFCHR:
205 dev_t rdev;
206 union ubifs_dev_desc *dev;
208 ui->data = kmalloc(sizeof(union ubifs_dev_desc), GFP_NOFS);
209 if (!ui->data) {
210 err = -ENOMEM;
211 goto out_ino;
214 dev = (union ubifs_dev_desc *)ino->data;
215 if (ui->data_len == sizeof(dev->new))
216 rdev = new_decode_dev(le32_to_cpu(dev->new));
217 else if (ui->data_len == sizeof(dev->huge))
218 rdev = huge_decode_dev(le64_to_cpu(dev->huge));
219 else {
220 err = 13;
221 goto out_invalid;
223 memcpy(ui->data, ino->data, ui->data_len);
224 inode->i_op = &ubifs_file_inode_operations;
225 init_special_inode(inode, inode->i_mode, rdev);
226 break;
228 case S_IFSOCK:
229 case S_IFIFO:
230 inode->i_op = &ubifs_file_inode_operations;
231 init_special_inode(inode, inode->i_mode, 0);
232 if (ui->data_len != 0) {
233 err = 14;
234 goto out_invalid;
236 break;
237 default:
238 err = 15;
239 goto out_invalid;
242 kfree(ino);
243 ubifs_set_inode_flags(inode);
244 unlock_new_inode(inode);
245 return inode;
247 out_invalid:
248 ubifs_err("inode %lu validation failed, error %d", inode->i_ino, err);
249 dbg_dump_node(c, ino);
250 dbg_dump_inode(c, inode);
251 err = -EINVAL;
252 out_ino:
253 kfree(ino);
254 out:
255 ubifs_err("failed to read inode %lu, error %d", inode->i_ino, err);
256 iget_failed(inode);
257 return ERR_PTR(err);
260 static struct inode *ubifs_alloc_inode(struct super_block *sb)
262 struct ubifs_inode *ui;
264 ui = kmem_cache_alloc(ubifs_inode_slab, GFP_NOFS);
265 if (!ui)
266 return NULL;
268 memset((void *)ui + sizeof(struct inode), 0,
269 sizeof(struct ubifs_inode) - sizeof(struct inode));
270 mutex_init(&ui->ui_mutex);
271 spin_lock_init(&ui->ui_lock);
272 return &ui->vfs_inode;
275 static void ubifs_i_callback(struct rcu_head *head)
277 struct inode *inode = container_of(head, struct inode, i_rcu);
278 struct ubifs_inode *ui = ubifs_inode(inode);
279 INIT_LIST_HEAD(&inode->i_dentry);
280 kmem_cache_free(ubifs_inode_slab, ui);
283 static void ubifs_destroy_inode(struct inode *inode)
285 struct ubifs_inode *ui = ubifs_inode(inode);
287 kfree(ui->data);
288 call_rcu(&inode->i_rcu, ubifs_i_callback);
292 * Note, Linux write-back code calls this without 'i_mutex'.
294 static int ubifs_write_inode(struct inode *inode, struct writeback_control *wbc)
296 int err = 0;
297 struct ubifs_info *c = inode->i_sb->s_fs_info;
298 struct ubifs_inode *ui = ubifs_inode(inode);
300 ubifs_assert(!ui->xattr);
301 if (is_bad_inode(inode))
302 return 0;
304 mutex_lock(&ui->ui_mutex);
306 * Due to races between write-back forced by budgeting
307 * (see 'sync_some_inodes()') and pdflush write-back, the inode may
308 * have already been synchronized, do not do this again. This might
309 * also happen if it was synchronized in an VFS operation, e.g.
310 * 'ubifs_link()'.
312 if (!ui->dirty) {
313 mutex_unlock(&ui->ui_mutex);
314 return 0;
318 * As an optimization, do not write orphan inodes to the media just
319 * because this is not needed.
321 dbg_gen("inode %lu, mode %#x, nlink %u",
322 inode->i_ino, (int)inode->i_mode, inode->i_nlink);
323 if (inode->i_nlink) {
324 err = ubifs_jnl_write_inode(c, inode);
325 if (err)
326 ubifs_err("can't write inode %lu, error %d",
327 inode->i_ino, err);
328 else
329 err = dbg_check_inode_size(c, inode, ui->ui_size);
332 ui->dirty = 0;
333 mutex_unlock(&ui->ui_mutex);
334 ubifs_release_dirty_inode_budget(c, ui);
335 return err;
338 static void ubifs_evict_inode(struct inode *inode)
340 int err;
341 struct ubifs_info *c = inode->i_sb->s_fs_info;
342 struct ubifs_inode *ui = ubifs_inode(inode);
344 if (ui->xattr)
346 * Extended attribute inode deletions are fully handled in
347 * 'ubifs_removexattr()'. These inodes are special and have
348 * limited usage, so there is nothing to do here.
350 goto out;
352 dbg_gen("inode %lu, mode %#x", inode->i_ino, (int)inode->i_mode);
353 ubifs_assert(!atomic_read(&inode->i_count));
355 truncate_inode_pages(&inode->i_data, 0);
357 if (inode->i_nlink)
358 goto done;
360 if (is_bad_inode(inode))
361 goto out;
363 ui->ui_size = inode->i_size = 0;
364 err = ubifs_jnl_delete_inode(c, inode);
365 if (err)
367 * Worst case we have a lost orphan inode wasting space, so a
368 * simple error message is OK here.
370 ubifs_err("can't delete inode %lu, error %d",
371 inode->i_ino, err);
373 out:
374 if (ui->dirty)
375 ubifs_release_dirty_inode_budget(c, ui);
376 else {
377 /* We've deleted something - clean the "no space" flags */
378 c->bi.nospace = c->bi.nospace_rp = 0;
379 smp_wmb();
381 done:
382 end_writeback(inode);
385 static void ubifs_dirty_inode(struct inode *inode, int flags)
387 struct ubifs_inode *ui = ubifs_inode(inode);
389 ubifs_assert(mutex_is_locked(&ui->ui_mutex));
390 if (!ui->dirty) {
391 ui->dirty = 1;
392 dbg_gen("inode %lu", inode->i_ino);
396 static int ubifs_statfs(struct dentry *dentry, struct kstatfs *buf)
398 struct ubifs_info *c = dentry->d_sb->s_fs_info;
399 unsigned long long free;
400 __le32 *uuid = (__le32 *)c->uuid;
402 free = ubifs_get_free_space(c);
403 dbg_gen("free space %lld bytes (%lld blocks)",
404 free, free >> UBIFS_BLOCK_SHIFT);
406 buf->f_type = UBIFS_SUPER_MAGIC;
407 buf->f_bsize = UBIFS_BLOCK_SIZE;
408 buf->f_blocks = c->block_cnt;
409 buf->f_bfree = free >> UBIFS_BLOCK_SHIFT;
410 if (free > c->report_rp_size)
411 buf->f_bavail = (free - c->report_rp_size) >> UBIFS_BLOCK_SHIFT;
412 else
413 buf->f_bavail = 0;
414 buf->f_files = 0;
415 buf->f_ffree = 0;
416 buf->f_namelen = UBIFS_MAX_NLEN;
417 buf->f_fsid.val[0] = le32_to_cpu(uuid[0]) ^ le32_to_cpu(uuid[2]);
418 buf->f_fsid.val[1] = le32_to_cpu(uuid[1]) ^ le32_to_cpu(uuid[3]);
419 ubifs_assert(buf->f_bfree <= c->block_cnt);
420 return 0;
423 static int ubifs_show_options(struct seq_file *s, struct vfsmount *mnt)
425 struct ubifs_info *c = mnt->mnt_sb->s_fs_info;
427 if (c->mount_opts.unmount_mode == 2)
428 seq_printf(s, ",fast_unmount");
429 else if (c->mount_opts.unmount_mode == 1)
430 seq_printf(s, ",norm_unmount");
432 if (c->mount_opts.bulk_read == 2)
433 seq_printf(s, ",bulk_read");
434 else if (c->mount_opts.bulk_read == 1)
435 seq_printf(s, ",no_bulk_read");
437 if (c->mount_opts.chk_data_crc == 2)
438 seq_printf(s, ",chk_data_crc");
439 else if (c->mount_opts.chk_data_crc == 1)
440 seq_printf(s, ",no_chk_data_crc");
442 if (c->mount_opts.override_compr) {
443 seq_printf(s, ",compr=%s",
444 ubifs_compr_name(c->mount_opts.compr_type));
447 return 0;
450 static int ubifs_sync_fs(struct super_block *sb, int wait)
452 int i, err;
453 struct ubifs_info *c = sb->s_fs_info;
456 * Zero @wait is just an advisory thing to help the file system shove
457 * lots of data into the queues, and there will be the second
458 * '->sync_fs()' call, with non-zero @wait.
460 if (!wait)
461 return 0;
464 * Synchronize write buffers, because 'ubifs_run_commit()' does not
465 * do this if it waits for an already running commit.
467 for (i = 0; i < c->jhead_cnt; i++) {
468 err = ubifs_wbuf_sync(&c->jheads[i].wbuf);
469 if (err)
470 return err;
474 * Strictly speaking, it is not necessary to commit the journal here,
475 * synchronizing write-buffers would be enough. But committing makes
476 * UBIFS free space predictions much more accurate, so we want to let
477 * the user be able to get more accurate results of 'statfs()' after
478 * they synchronize the file system.
480 err = ubifs_run_commit(c);
481 if (err)
482 return err;
484 return ubi_sync(c->vi.ubi_num);
488 * init_constants_early - initialize UBIFS constants.
489 * @c: UBIFS file-system description object
491 * This function initialize UBIFS constants which do not need the superblock to
492 * be read. It also checks that the UBI volume satisfies basic UBIFS
493 * requirements. Returns zero in case of success and a negative error code in
494 * case of failure.
496 static int init_constants_early(struct ubifs_info *c)
498 if (c->vi.corrupted) {
499 ubifs_warn("UBI volume is corrupted - read-only mode");
500 c->ro_media = 1;
503 if (c->di.ro_mode) {
504 ubifs_msg("read-only UBI device");
505 c->ro_media = 1;
508 if (c->vi.vol_type == UBI_STATIC_VOLUME) {
509 ubifs_msg("static UBI volume - read-only mode");
510 c->ro_media = 1;
513 c->leb_cnt = c->vi.size;
514 c->leb_size = c->vi.usable_leb_size;
515 c->leb_start = c->di.leb_start;
516 c->half_leb_size = c->leb_size / 2;
517 c->min_io_size = c->di.min_io_size;
518 c->min_io_shift = fls(c->min_io_size) - 1;
519 c->max_write_size = c->di.max_write_size;
520 c->max_write_shift = fls(c->max_write_size) - 1;
522 if (c->leb_size < UBIFS_MIN_LEB_SZ) {
523 ubifs_err("too small LEBs (%d bytes), min. is %d bytes",
524 c->leb_size, UBIFS_MIN_LEB_SZ);
525 return -EINVAL;
528 if (c->leb_cnt < UBIFS_MIN_LEB_CNT) {
529 ubifs_err("too few LEBs (%d), min. is %d",
530 c->leb_cnt, UBIFS_MIN_LEB_CNT);
531 return -EINVAL;
534 if (!is_power_of_2(c->min_io_size)) {
535 ubifs_err("bad min. I/O size %d", c->min_io_size);
536 return -EINVAL;
540 * Maximum write size has to be greater or equivalent to min. I/O
541 * size, and be multiple of min. I/O size.
543 if (c->max_write_size < c->min_io_size ||
544 c->max_write_size % c->min_io_size ||
545 !is_power_of_2(c->max_write_size)) {
546 ubifs_err("bad write buffer size %d for %d min. I/O unit",
547 c->max_write_size, c->min_io_size);
548 return -EINVAL;
552 * UBIFS aligns all node to 8-byte boundary, so to make function in
553 * io.c simpler, assume minimum I/O unit size to be 8 bytes if it is
554 * less than 8.
556 if (c->min_io_size < 8) {
557 c->min_io_size = 8;
558 c->min_io_shift = 3;
559 if (c->max_write_size < c->min_io_size) {
560 c->max_write_size = c->min_io_size;
561 c->max_write_shift = c->min_io_shift;
565 c->ref_node_alsz = ALIGN(UBIFS_REF_NODE_SZ, c->min_io_size);
566 c->mst_node_alsz = ALIGN(UBIFS_MST_NODE_SZ, c->min_io_size);
569 * Initialize node length ranges which are mostly needed for node
570 * length validation.
572 c->ranges[UBIFS_PAD_NODE].len = UBIFS_PAD_NODE_SZ;
573 c->ranges[UBIFS_SB_NODE].len = UBIFS_SB_NODE_SZ;
574 c->ranges[UBIFS_MST_NODE].len = UBIFS_MST_NODE_SZ;
575 c->ranges[UBIFS_REF_NODE].len = UBIFS_REF_NODE_SZ;
576 c->ranges[UBIFS_TRUN_NODE].len = UBIFS_TRUN_NODE_SZ;
577 c->ranges[UBIFS_CS_NODE].len = UBIFS_CS_NODE_SZ;
579 c->ranges[UBIFS_INO_NODE].min_len = UBIFS_INO_NODE_SZ;
580 c->ranges[UBIFS_INO_NODE].max_len = UBIFS_MAX_INO_NODE_SZ;
581 c->ranges[UBIFS_ORPH_NODE].min_len =
582 UBIFS_ORPH_NODE_SZ + sizeof(__le64);
583 c->ranges[UBIFS_ORPH_NODE].max_len = c->leb_size;
584 c->ranges[UBIFS_DENT_NODE].min_len = UBIFS_DENT_NODE_SZ;
585 c->ranges[UBIFS_DENT_NODE].max_len = UBIFS_MAX_DENT_NODE_SZ;
586 c->ranges[UBIFS_XENT_NODE].min_len = UBIFS_XENT_NODE_SZ;
587 c->ranges[UBIFS_XENT_NODE].max_len = UBIFS_MAX_XENT_NODE_SZ;
588 c->ranges[UBIFS_DATA_NODE].min_len = UBIFS_DATA_NODE_SZ;
589 c->ranges[UBIFS_DATA_NODE].max_len = UBIFS_MAX_DATA_NODE_SZ;
591 * Minimum indexing node size is amended later when superblock is
592 * read and the key length is known.
594 c->ranges[UBIFS_IDX_NODE].min_len = UBIFS_IDX_NODE_SZ + UBIFS_BRANCH_SZ;
596 * Maximum indexing node size is amended later when superblock is
597 * read and the fanout is known.
599 c->ranges[UBIFS_IDX_NODE].max_len = INT_MAX;
602 * Initialize dead and dark LEB space watermarks. See gc.c for comments
603 * about these values.
605 c->dead_wm = ALIGN(MIN_WRITE_SZ, c->min_io_size);
606 c->dark_wm = ALIGN(UBIFS_MAX_NODE_SZ, c->min_io_size);
609 * Calculate how many bytes would be wasted at the end of LEB if it was
610 * fully filled with data nodes of maximum size. This is used in
611 * calculations when reporting free space.
613 c->leb_overhead = c->leb_size % UBIFS_MAX_DATA_NODE_SZ;
615 /* Buffer size for bulk-reads */
616 c->max_bu_buf_len = UBIFS_MAX_BULK_READ * UBIFS_MAX_DATA_NODE_SZ;
617 if (c->max_bu_buf_len > c->leb_size)
618 c->max_bu_buf_len = c->leb_size;
619 return 0;
623 * bud_wbuf_callback - bud LEB write-buffer synchronization call-back.
624 * @c: UBIFS file-system description object
625 * @lnum: LEB the write-buffer was synchronized to
626 * @free: how many free bytes left in this LEB
627 * @pad: how many bytes were padded
629 * This is a callback function which is called by the I/O unit when the
630 * write-buffer is synchronized. We need this to correctly maintain space
631 * accounting in bud logical eraseblocks. This function returns zero in case of
632 * success and a negative error code in case of failure.
634 * This function actually belongs to the journal, but we keep it here because
635 * we want to keep it static.
637 static int bud_wbuf_callback(struct ubifs_info *c, int lnum, int free, int pad)
639 return ubifs_update_one_lp(c, lnum, free, pad, 0, 0);
643 * init_constants_sb - initialize UBIFS constants.
644 * @c: UBIFS file-system description object
646 * This is a helper function which initializes various UBIFS constants after
647 * the superblock has been read. It also checks various UBIFS parameters and
648 * makes sure they are all right. Returns zero in case of success and a
649 * negative error code in case of failure.
651 static int init_constants_sb(struct ubifs_info *c)
653 int tmp, err;
654 long long tmp64;
656 c->main_bytes = (long long)c->main_lebs * c->leb_size;
657 c->max_znode_sz = sizeof(struct ubifs_znode) +
658 c->fanout * sizeof(struct ubifs_zbranch);
660 tmp = ubifs_idx_node_sz(c, 1);
661 c->ranges[UBIFS_IDX_NODE].min_len = tmp;
662 c->min_idx_node_sz = ALIGN(tmp, 8);
664 tmp = ubifs_idx_node_sz(c, c->fanout);
665 c->ranges[UBIFS_IDX_NODE].max_len = tmp;
666 c->max_idx_node_sz = ALIGN(tmp, 8);
668 /* Make sure LEB size is large enough to fit full commit */
669 tmp = UBIFS_CS_NODE_SZ + UBIFS_REF_NODE_SZ * c->jhead_cnt;
670 tmp = ALIGN(tmp, c->min_io_size);
671 if (tmp > c->leb_size) {
672 dbg_err("too small LEB size %d, at least %d needed",
673 c->leb_size, tmp);
674 return -EINVAL;
678 * Make sure that the log is large enough to fit reference nodes for
679 * all buds plus one reserved LEB.
681 tmp64 = c->max_bud_bytes + c->leb_size - 1;
682 c->max_bud_cnt = div_u64(tmp64, c->leb_size);
683 tmp = (c->ref_node_alsz * c->max_bud_cnt + c->leb_size - 1);
684 tmp /= c->leb_size;
685 tmp += 1;
686 if (c->log_lebs < tmp) {
687 dbg_err("too small log %d LEBs, required min. %d LEBs",
688 c->log_lebs, tmp);
689 return -EINVAL;
693 * When budgeting we assume worst-case scenarios when the pages are not
694 * be compressed and direntries are of the maximum size.
696 * Note, data, which may be stored in inodes is budgeted separately, so
697 * it is not included into 'c->bi.inode_budget'.
699 c->bi.page_budget = UBIFS_MAX_DATA_NODE_SZ * UBIFS_BLOCKS_PER_PAGE;
700 c->bi.inode_budget = UBIFS_INO_NODE_SZ;
701 c->bi.dent_budget = UBIFS_MAX_DENT_NODE_SZ;
704 * When the amount of flash space used by buds becomes
705 * 'c->max_bud_bytes', UBIFS just blocks all writers and starts commit.
706 * The writers are unblocked when the commit is finished. To avoid
707 * writers to be blocked UBIFS initiates background commit in advance,
708 * when number of bud bytes becomes above the limit defined below.
710 c->bg_bud_bytes = (c->max_bud_bytes * 13) >> 4;
713 * Ensure minimum journal size. All the bytes in the journal heads are
714 * considered to be used, when calculating the current journal usage.
715 * Consequently, if the journal is too small, UBIFS will treat it as
716 * always full.
718 tmp64 = (long long)(c->jhead_cnt + 1) * c->leb_size + 1;
719 if (c->bg_bud_bytes < tmp64)
720 c->bg_bud_bytes = tmp64;
721 if (c->max_bud_bytes < tmp64 + c->leb_size)
722 c->max_bud_bytes = tmp64 + c->leb_size;
724 err = ubifs_calc_lpt_geom(c);
725 if (err)
726 return err;
728 /* Initialize effective LEB size used in budgeting calculations */
729 c->idx_leb_size = c->leb_size - c->max_idx_node_sz;
730 return 0;
734 * init_constants_master - initialize UBIFS constants.
735 * @c: UBIFS file-system description object
737 * This is a helper function which initializes various UBIFS constants after
738 * the master node has been read. It also checks various UBIFS parameters and
739 * makes sure they are all right.
741 static void init_constants_master(struct ubifs_info *c)
743 long long tmp64;
745 c->bi.min_idx_lebs = ubifs_calc_min_idx_lebs(c);
746 c->report_rp_size = ubifs_reported_space(c, c->rp_size);
749 * Calculate total amount of FS blocks. This number is not used
750 * internally because it does not make much sense for UBIFS, but it is
751 * necessary to report something for the 'statfs()' call.
753 * Subtract the LEB reserved for GC, the LEB which is reserved for
754 * deletions, minimum LEBs for the index, and assume only one journal
755 * head is available.
757 tmp64 = c->main_lebs - 1 - 1 - MIN_INDEX_LEBS - c->jhead_cnt + 1;
758 tmp64 *= (long long)c->leb_size - c->leb_overhead;
759 tmp64 = ubifs_reported_space(c, tmp64);
760 c->block_cnt = tmp64 >> UBIFS_BLOCK_SHIFT;
764 * take_gc_lnum - reserve GC LEB.
765 * @c: UBIFS file-system description object
767 * This function ensures that the LEB reserved for garbage collection is marked
768 * as "taken" in lprops. We also have to set free space to LEB size and dirty
769 * space to zero, because lprops may contain out-of-date information if the
770 * file-system was un-mounted before it has been committed. This function
771 * returns zero in case of success and a negative error code in case of
772 * failure.
774 static int take_gc_lnum(struct ubifs_info *c)
776 int err;
778 if (c->gc_lnum == -1) {
779 ubifs_err("no LEB for GC");
780 return -EINVAL;
783 /* And we have to tell lprops that this LEB is taken */
784 err = ubifs_change_one_lp(c, c->gc_lnum, c->leb_size, 0,
785 LPROPS_TAKEN, 0, 0);
786 return err;
790 * alloc_wbufs - allocate write-buffers.
791 * @c: UBIFS file-system description object
793 * This helper function allocates and initializes UBIFS write-buffers. Returns
794 * zero in case of success and %-ENOMEM in case of failure.
796 static int alloc_wbufs(struct ubifs_info *c)
798 int i, err;
800 c->jheads = kzalloc(c->jhead_cnt * sizeof(struct ubifs_jhead),
801 GFP_KERNEL);
802 if (!c->jheads)
803 return -ENOMEM;
805 /* Initialize journal heads */
806 for (i = 0; i < c->jhead_cnt; i++) {
807 INIT_LIST_HEAD(&c->jheads[i].buds_list);
808 err = ubifs_wbuf_init(c, &c->jheads[i].wbuf);
809 if (err)
810 return err;
812 c->jheads[i].wbuf.sync_callback = &bud_wbuf_callback;
813 c->jheads[i].wbuf.jhead = i;
814 c->jheads[i].grouped = 1;
817 c->jheads[BASEHD].wbuf.dtype = UBI_SHORTTERM;
819 * Garbage Collector head likely contains long-term data and
820 * does not need to be synchronized by timer. Also GC head nodes are
821 * not grouped.
823 c->jheads[GCHD].wbuf.dtype = UBI_LONGTERM;
824 c->jheads[GCHD].wbuf.no_timer = 1;
825 c->jheads[GCHD].grouped = 0;
827 return 0;
831 * free_wbufs - free write-buffers.
832 * @c: UBIFS file-system description object
834 static void free_wbufs(struct ubifs_info *c)
836 int i;
838 if (c->jheads) {
839 for (i = 0; i < c->jhead_cnt; i++) {
840 kfree(c->jheads[i].wbuf.buf);
841 kfree(c->jheads[i].wbuf.inodes);
843 kfree(c->jheads);
844 c->jheads = NULL;
849 * free_orphans - free orphans.
850 * @c: UBIFS file-system description object
852 static void free_orphans(struct ubifs_info *c)
854 struct ubifs_orphan *orph;
856 while (c->orph_dnext) {
857 orph = c->orph_dnext;
858 c->orph_dnext = orph->dnext;
859 list_del(&orph->list);
860 kfree(orph);
863 while (!list_empty(&c->orph_list)) {
864 orph = list_entry(c->orph_list.next, struct ubifs_orphan, list);
865 list_del(&orph->list);
866 kfree(orph);
867 dbg_err("orphan list not empty at unmount");
870 vfree(c->orph_buf);
871 c->orph_buf = NULL;
875 * free_buds - free per-bud objects.
876 * @c: UBIFS file-system description object
878 static void free_buds(struct ubifs_info *c)
880 struct rb_node *this = c->buds.rb_node;
881 struct ubifs_bud *bud;
883 while (this) {
884 if (this->rb_left)
885 this = this->rb_left;
886 else if (this->rb_right)
887 this = this->rb_right;
888 else {
889 bud = rb_entry(this, struct ubifs_bud, rb);
890 this = rb_parent(this);
891 if (this) {
892 if (this->rb_left == &bud->rb)
893 this->rb_left = NULL;
894 else
895 this->rb_right = NULL;
897 kfree(bud);
903 * check_volume_empty - check if the UBI volume is empty.
904 * @c: UBIFS file-system description object
906 * This function checks if the UBIFS volume is empty by looking if its LEBs are
907 * mapped or not. The result of checking is stored in the @c->empty variable.
908 * Returns zero in case of success and a negative error code in case of
909 * failure.
911 static int check_volume_empty(struct ubifs_info *c)
913 int lnum, err;
915 c->empty = 1;
916 for (lnum = 0; lnum < c->leb_cnt; lnum++) {
917 err = ubi_is_mapped(c->ubi, lnum);
918 if (unlikely(err < 0))
919 return err;
920 if (err == 1) {
921 c->empty = 0;
922 break;
925 cond_resched();
928 return 0;
932 * UBIFS mount options.
934 * Opt_fast_unmount: do not run a journal commit before un-mounting
935 * Opt_norm_unmount: run a journal commit before un-mounting
936 * Opt_bulk_read: enable bulk-reads
937 * Opt_no_bulk_read: disable bulk-reads
938 * Opt_chk_data_crc: check CRCs when reading data nodes
939 * Opt_no_chk_data_crc: do not check CRCs when reading data nodes
940 * Opt_override_compr: override default compressor
941 * Opt_err: just end of array marker
943 enum {
944 Opt_fast_unmount,
945 Opt_norm_unmount,
946 Opt_bulk_read,
947 Opt_no_bulk_read,
948 Opt_chk_data_crc,
949 Opt_no_chk_data_crc,
950 Opt_override_compr,
951 Opt_err,
954 static const match_table_t tokens = {
955 {Opt_fast_unmount, "fast_unmount"},
956 {Opt_norm_unmount, "norm_unmount"},
957 {Opt_bulk_read, "bulk_read"},
958 {Opt_no_bulk_read, "no_bulk_read"},
959 {Opt_chk_data_crc, "chk_data_crc"},
960 {Opt_no_chk_data_crc, "no_chk_data_crc"},
961 {Opt_override_compr, "compr=%s"},
962 {Opt_err, NULL},
966 * parse_standard_option - parse a standard mount option.
967 * @option: the option to parse
969 * Normally, standard mount options like "sync" are passed to file-systems as
970 * flags. However, when a "rootflags=" kernel boot parameter is used, they may
971 * be present in the options string. This function tries to deal with this
972 * situation and parse standard options. Returns 0 if the option was not
973 * recognized, and the corresponding integer flag if it was.
975 * UBIFS is only interested in the "sync" option, so do not check for anything
976 * else.
978 static int parse_standard_option(const char *option)
980 ubifs_msg("parse %s", option);
981 if (!strcmp(option, "sync"))
982 return MS_SYNCHRONOUS;
983 return 0;
987 * ubifs_parse_options - parse mount parameters.
988 * @c: UBIFS file-system description object
989 * @options: parameters to parse
990 * @is_remount: non-zero if this is FS re-mount
992 * This function parses UBIFS mount options and returns zero in case success
993 * and a negative error code in case of failure.
995 static int ubifs_parse_options(struct ubifs_info *c, char *options,
996 int is_remount)
998 char *p;
999 substring_t args[MAX_OPT_ARGS];
1001 if (!options)
1002 return 0;
1004 while ((p = strsep(&options, ","))) {
1005 int token;
1007 if (!*p)
1008 continue;
1010 token = match_token(p, tokens, args);
1011 switch (token) {
1013 * %Opt_fast_unmount and %Opt_norm_unmount options are ignored.
1014 * We accept them in order to be backward-compatible. But this
1015 * should be removed at some point.
1017 case Opt_fast_unmount:
1018 c->mount_opts.unmount_mode = 2;
1019 break;
1020 case Opt_norm_unmount:
1021 c->mount_opts.unmount_mode = 1;
1022 break;
1023 case Opt_bulk_read:
1024 c->mount_opts.bulk_read = 2;
1025 c->bulk_read = 1;
1026 break;
1027 case Opt_no_bulk_read:
1028 c->mount_opts.bulk_read = 1;
1029 c->bulk_read = 0;
1030 break;
1031 case Opt_chk_data_crc:
1032 c->mount_opts.chk_data_crc = 2;
1033 c->no_chk_data_crc = 0;
1034 break;
1035 case Opt_no_chk_data_crc:
1036 c->mount_opts.chk_data_crc = 1;
1037 c->no_chk_data_crc = 1;
1038 break;
1039 case Opt_override_compr:
1041 char *name = match_strdup(&args[0]);
1043 if (!name)
1044 return -ENOMEM;
1045 if (!strcmp(name, "none"))
1046 c->mount_opts.compr_type = UBIFS_COMPR_NONE;
1047 else if (!strcmp(name, "lzo"))
1048 c->mount_opts.compr_type = UBIFS_COMPR_LZO;
1049 else if (!strcmp(name, "zlib"))
1050 c->mount_opts.compr_type = UBIFS_COMPR_ZLIB;
1051 else {
1052 ubifs_err("unknown compressor \"%s\"", name);
1053 kfree(name);
1054 return -EINVAL;
1056 kfree(name);
1057 c->mount_opts.override_compr = 1;
1058 c->default_compr = c->mount_opts.compr_type;
1059 break;
1061 default:
1063 unsigned long flag;
1064 struct super_block *sb = c->vfs_sb;
1066 flag = parse_standard_option(p);
1067 if (!flag) {
1068 ubifs_err("unrecognized mount option \"%s\" "
1069 "or missing value", p);
1070 return -EINVAL;
1072 sb->s_flags |= flag;
1073 break;
1078 return 0;
1082 * destroy_journal - destroy journal data structures.
1083 * @c: UBIFS file-system description object
1085 * This function destroys journal data structures including those that may have
1086 * been created by recovery functions.
1088 static void destroy_journal(struct ubifs_info *c)
1090 while (!list_empty(&c->unclean_leb_list)) {
1091 struct ubifs_unclean_leb *ucleb;
1093 ucleb = list_entry(c->unclean_leb_list.next,
1094 struct ubifs_unclean_leb, list);
1095 list_del(&ucleb->list);
1096 kfree(ucleb);
1098 while (!list_empty(&c->old_buds)) {
1099 struct ubifs_bud *bud;
1101 bud = list_entry(c->old_buds.next, struct ubifs_bud, list);
1102 list_del(&bud->list);
1103 kfree(bud);
1105 ubifs_destroy_idx_gc(c);
1106 ubifs_destroy_size_tree(c);
1107 ubifs_tnc_close(c);
1108 free_buds(c);
1112 * bu_init - initialize bulk-read information.
1113 * @c: UBIFS file-system description object
1115 static void bu_init(struct ubifs_info *c)
1117 ubifs_assert(c->bulk_read == 1);
1119 if (c->bu.buf)
1120 return; /* Already initialized */
1122 again:
1123 c->bu.buf = kmalloc(c->max_bu_buf_len, GFP_KERNEL | __GFP_NOWARN);
1124 if (!c->bu.buf) {
1125 if (c->max_bu_buf_len > UBIFS_KMALLOC_OK) {
1126 c->max_bu_buf_len = UBIFS_KMALLOC_OK;
1127 goto again;
1130 /* Just disable bulk-read */
1131 ubifs_warn("Cannot allocate %d bytes of memory for bulk-read, "
1132 "disabling it", c->max_bu_buf_len);
1133 c->mount_opts.bulk_read = 1;
1134 c->bulk_read = 0;
1135 return;
1140 * check_free_space - check if there is enough free space to mount.
1141 * @c: UBIFS file-system description object
1143 * This function makes sure UBIFS has enough free space to be mounted in
1144 * read/write mode. UBIFS must always have some free space to allow deletions.
1146 static int check_free_space(struct ubifs_info *c)
1148 ubifs_assert(c->dark_wm > 0);
1149 if (c->lst.total_free + c->lst.total_dirty < c->dark_wm) {
1150 ubifs_err("insufficient free space to mount in R/W mode");
1151 dbg_dump_budg(c, &c->bi);
1152 dbg_dump_lprops(c);
1153 return -ENOSPC;
1155 return 0;
1159 * mount_ubifs - mount UBIFS file-system.
1160 * @c: UBIFS file-system description object
1162 * This function mounts UBIFS file system. Returns zero in case of success and
1163 * a negative error code in case of failure.
1165 * Note, the function does not de-allocate resources it it fails half way
1166 * through, and the caller has to do this instead.
1168 static int mount_ubifs(struct ubifs_info *c)
1170 int err;
1171 long long x;
1172 size_t sz;
1174 c->ro_mount = !!(c->vfs_sb->s_flags & MS_RDONLY);
1175 err = init_constants_early(c);
1176 if (err)
1177 return err;
1179 err = ubifs_debugging_init(c);
1180 if (err)
1181 return err;
1183 err = check_volume_empty(c);
1184 if (err)
1185 goto out_free;
1187 if (c->empty && (c->ro_mount || c->ro_media)) {
1189 * This UBI volume is empty, and read-only, or the file system
1190 * is mounted read-only - we cannot format it.
1192 ubifs_err("can't format empty UBI volume: read-only %s",
1193 c->ro_media ? "UBI volume" : "mount");
1194 err = -EROFS;
1195 goto out_free;
1198 if (c->ro_media && !c->ro_mount) {
1199 ubifs_err("cannot mount read-write - read-only media");
1200 err = -EROFS;
1201 goto out_free;
1205 * The requirement for the buffer is that it should fit indexing B-tree
1206 * height amount of integers. We assume the height if the TNC tree will
1207 * never exceed 64.
1209 err = -ENOMEM;
1210 c->bottom_up_buf = kmalloc(BOTTOM_UP_HEIGHT * sizeof(int), GFP_KERNEL);
1211 if (!c->bottom_up_buf)
1212 goto out_free;
1214 c->sbuf = vmalloc(c->leb_size);
1215 if (!c->sbuf)
1216 goto out_free;
1218 if (!c->ro_mount) {
1219 c->ileb_buf = vmalloc(c->leb_size);
1220 if (!c->ileb_buf)
1221 goto out_free;
1224 if (c->bulk_read == 1)
1225 bu_init(c);
1227 if (!c->ro_mount) {
1228 c->write_reserve_buf = kmalloc(COMPRESSED_DATA_NODE_BUF_SZ,
1229 GFP_KERNEL);
1230 if (!c->write_reserve_buf)
1231 goto out_free;
1234 c->mounting = 1;
1236 err = ubifs_read_superblock(c);
1237 if (err)
1238 goto out_free;
1241 * Make sure the compressor which is set as default in the superblock
1242 * or overridden by mount options is actually compiled in.
1244 if (!ubifs_compr_present(c->default_compr)) {
1245 ubifs_err("'compressor \"%s\" is not compiled in",
1246 ubifs_compr_name(c->default_compr));
1247 err = -ENOTSUPP;
1248 goto out_free;
1251 err = init_constants_sb(c);
1252 if (err)
1253 goto out_free;
1255 sz = ALIGN(c->max_idx_node_sz, c->min_io_size);
1256 sz = ALIGN(sz + c->max_idx_node_sz, c->min_io_size);
1257 c->cbuf = kmalloc(sz, GFP_NOFS);
1258 if (!c->cbuf) {
1259 err = -ENOMEM;
1260 goto out_free;
1263 err = alloc_wbufs(c);
1264 if (err)
1265 goto out_cbuf;
1267 sprintf(c->bgt_name, BGT_NAME_PATTERN, c->vi.ubi_num, c->vi.vol_id);
1268 if (!c->ro_mount) {
1269 /* Create background thread */
1270 c->bgt = kthread_create(ubifs_bg_thread, c, "%s", c->bgt_name);
1271 if (IS_ERR(c->bgt)) {
1272 err = PTR_ERR(c->bgt);
1273 c->bgt = NULL;
1274 ubifs_err("cannot spawn \"%s\", error %d",
1275 c->bgt_name, err);
1276 goto out_wbufs;
1278 wake_up_process(c->bgt);
1281 err = ubifs_read_master(c);
1282 if (err)
1283 goto out_master;
1285 init_constants_master(c);
1287 if ((c->mst_node->flags & cpu_to_le32(UBIFS_MST_DIRTY)) != 0) {
1288 ubifs_msg("recovery needed");
1289 c->need_recovery = 1;
1292 if (c->need_recovery && !c->ro_mount) {
1293 err = ubifs_recover_inl_heads(c, c->sbuf);
1294 if (err)
1295 goto out_master;
1298 err = ubifs_lpt_init(c, 1, !c->ro_mount);
1299 if (err)
1300 goto out_master;
1302 if (!c->ro_mount && c->space_fixup) {
1303 err = ubifs_fixup_free_space(c);
1304 if (err)
1305 goto out_master;
1308 if (!c->ro_mount) {
1310 * Set the "dirty" flag so that if we reboot uncleanly we
1311 * will notice this immediately on the next mount.
1313 c->mst_node->flags |= cpu_to_le32(UBIFS_MST_DIRTY);
1314 err = ubifs_write_master(c);
1315 if (err)
1316 goto out_lpt;
1319 err = dbg_check_idx_size(c, c->bi.old_idx_sz);
1320 if (err)
1321 goto out_lpt;
1323 err = ubifs_replay_journal(c);
1324 if (err)
1325 goto out_journal;
1327 /* Calculate 'min_idx_lebs' after journal replay */
1328 c->bi.min_idx_lebs = ubifs_calc_min_idx_lebs(c);
1330 err = ubifs_mount_orphans(c, c->need_recovery, c->ro_mount);
1331 if (err)
1332 goto out_orphans;
1334 if (!c->ro_mount) {
1335 int lnum;
1337 err = check_free_space(c);
1338 if (err)
1339 goto out_orphans;
1341 /* Check for enough log space */
1342 lnum = c->lhead_lnum + 1;
1343 if (lnum >= UBIFS_LOG_LNUM + c->log_lebs)
1344 lnum = UBIFS_LOG_LNUM;
1345 if (lnum == c->ltail_lnum) {
1346 err = ubifs_consolidate_log(c);
1347 if (err)
1348 goto out_orphans;
1351 if (c->need_recovery) {
1352 err = ubifs_recover_size(c);
1353 if (err)
1354 goto out_orphans;
1355 err = ubifs_rcvry_gc_commit(c);
1356 if (err)
1357 goto out_orphans;
1358 } else {
1359 err = take_gc_lnum(c);
1360 if (err)
1361 goto out_orphans;
1364 * GC LEB may contain garbage if there was an unclean
1365 * reboot, and it should be un-mapped.
1367 err = ubifs_leb_unmap(c, c->gc_lnum);
1368 if (err)
1369 goto out_orphans;
1372 err = dbg_check_lprops(c);
1373 if (err)
1374 goto out_orphans;
1375 } else if (c->need_recovery) {
1376 err = ubifs_recover_size(c);
1377 if (err)
1378 goto out_orphans;
1379 } else {
1381 * Even if we mount read-only, we have to set space in GC LEB
1382 * to proper value because this affects UBIFS free space
1383 * reporting. We do not want to have a situation when
1384 * re-mounting from R/O to R/W changes amount of free space.
1386 err = take_gc_lnum(c);
1387 if (err)
1388 goto out_orphans;
1391 spin_lock(&ubifs_infos_lock);
1392 list_add_tail(&c->infos_list, &ubifs_infos);
1393 spin_unlock(&ubifs_infos_lock);
1395 if (c->need_recovery) {
1396 if (c->ro_mount)
1397 ubifs_msg("recovery deferred");
1398 else {
1399 c->need_recovery = 0;
1400 ubifs_msg("recovery completed");
1402 * GC LEB has to be empty and taken at this point. But
1403 * the journal head LEBs may also be accounted as
1404 * "empty taken" if they are empty.
1406 ubifs_assert(c->lst.taken_empty_lebs > 0);
1408 } else
1409 ubifs_assert(c->lst.taken_empty_lebs > 0);
1411 err = dbg_check_filesystem(c);
1412 if (err)
1413 goto out_infos;
1415 err = dbg_debugfs_init_fs(c);
1416 if (err)
1417 goto out_infos;
1419 c->mounting = 0;
1421 ubifs_msg("mounted UBI device %d, volume %d, name \"%s\"",
1422 c->vi.ubi_num, c->vi.vol_id, c->vi.name);
1423 if (c->ro_mount)
1424 ubifs_msg("mounted read-only");
1425 x = (long long)c->main_lebs * c->leb_size;
1426 ubifs_msg("file system size: %lld bytes (%lld KiB, %lld MiB, %d "
1427 "LEBs)", x, x >> 10, x >> 20, c->main_lebs);
1428 x = (long long)c->log_lebs * c->leb_size + c->max_bud_bytes;
1429 ubifs_msg("journal size: %lld bytes (%lld KiB, %lld MiB, %d "
1430 "LEBs)", x, x >> 10, x >> 20, c->log_lebs + c->max_bud_cnt);
1431 ubifs_msg("media format: w%d/r%d (latest is w%d/r%d)",
1432 c->fmt_version, c->ro_compat_version,
1433 UBIFS_FORMAT_VERSION, UBIFS_RO_COMPAT_VERSION);
1434 ubifs_msg("default compressor: %s", ubifs_compr_name(c->default_compr));
1435 ubifs_msg("reserved for root: %llu bytes (%llu KiB)",
1436 c->report_rp_size, c->report_rp_size >> 10);
1438 dbg_msg("compiled on: " __DATE__ " at " __TIME__);
1439 dbg_msg("min. I/O unit size: %d bytes", c->min_io_size);
1440 dbg_msg("max. write size: %d bytes", c->max_write_size);
1441 dbg_msg("LEB size: %d bytes (%d KiB)",
1442 c->leb_size, c->leb_size >> 10);
1443 dbg_msg("data journal heads: %d",
1444 c->jhead_cnt - NONDATA_JHEADS_CNT);
1445 dbg_msg("UUID: %pUB", c->uuid);
1446 dbg_msg("big_lpt %d", c->big_lpt);
1447 dbg_msg("log LEBs: %d (%d - %d)",
1448 c->log_lebs, UBIFS_LOG_LNUM, c->log_last);
1449 dbg_msg("LPT area LEBs: %d (%d - %d)",
1450 c->lpt_lebs, c->lpt_first, c->lpt_last);
1451 dbg_msg("orphan area LEBs: %d (%d - %d)",
1452 c->orph_lebs, c->orph_first, c->orph_last);
1453 dbg_msg("main area LEBs: %d (%d - %d)",
1454 c->main_lebs, c->main_first, c->leb_cnt - 1);
1455 dbg_msg("index LEBs: %d", c->lst.idx_lebs);
1456 dbg_msg("total index bytes: %lld (%lld KiB, %lld MiB)",
1457 c->bi.old_idx_sz, c->bi.old_idx_sz >> 10,
1458 c->bi.old_idx_sz >> 20);
1459 dbg_msg("key hash type: %d", c->key_hash_type);
1460 dbg_msg("tree fanout: %d", c->fanout);
1461 dbg_msg("reserved GC LEB: %d", c->gc_lnum);
1462 dbg_msg("first main LEB: %d", c->main_first);
1463 dbg_msg("max. znode size %d", c->max_znode_sz);
1464 dbg_msg("max. index node size %d", c->max_idx_node_sz);
1465 dbg_msg("node sizes: data %zu, inode %zu, dentry %zu",
1466 UBIFS_DATA_NODE_SZ, UBIFS_INO_NODE_SZ, UBIFS_DENT_NODE_SZ);
1467 dbg_msg("node sizes: trun %zu, sb %zu, master %zu",
1468 UBIFS_TRUN_NODE_SZ, UBIFS_SB_NODE_SZ, UBIFS_MST_NODE_SZ);
1469 dbg_msg("node sizes: ref %zu, cmt. start %zu, orph %zu",
1470 UBIFS_REF_NODE_SZ, UBIFS_CS_NODE_SZ, UBIFS_ORPH_NODE_SZ);
1471 dbg_msg("max. node sizes: data %zu, inode %zu dentry %zu, idx %d",
1472 UBIFS_MAX_DATA_NODE_SZ, UBIFS_MAX_INO_NODE_SZ,
1473 UBIFS_MAX_DENT_NODE_SZ, ubifs_idx_node_sz(c, c->fanout));
1474 dbg_msg("dead watermark: %d", c->dead_wm);
1475 dbg_msg("dark watermark: %d", c->dark_wm);
1476 dbg_msg("LEB overhead: %d", c->leb_overhead);
1477 x = (long long)c->main_lebs * c->dark_wm;
1478 dbg_msg("max. dark space: %lld (%lld KiB, %lld MiB)",
1479 x, x >> 10, x >> 20);
1480 dbg_msg("maximum bud bytes: %lld (%lld KiB, %lld MiB)",
1481 c->max_bud_bytes, c->max_bud_bytes >> 10,
1482 c->max_bud_bytes >> 20);
1483 dbg_msg("BG commit bud bytes: %lld (%lld KiB, %lld MiB)",
1484 c->bg_bud_bytes, c->bg_bud_bytes >> 10,
1485 c->bg_bud_bytes >> 20);
1486 dbg_msg("current bud bytes %lld (%lld KiB, %lld MiB)",
1487 c->bud_bytes, c->bud_bytes >> 10, c->bud_bytes >> 20);
1488 dbg_msg("max. seq. number: %llu", c->max_sqnum);
1489 dbg_msg("commit number: %llu", c->cmt_no);
1491 return 0;
1493 out_infos:
1494 spin_lock(&ubifs_infos_lock);
1495 list_del(&c->infos_list);
1496 spin_unlock(&ubifs_infos_lock);
1497 out_orphans:
1498 free_orphans(c);
1499 out_journal:
1500 destroy_journal(c);
1501 out_lpt:
1502 ubifs_lpt_free(c, 0);
1503 out_master:
1504 kfree(c->mst_node);
1505 kfree(c->rcvrd_mst_node);
1506 if (c->bgt)
1507 kthread_stop(c->bgt);
1508 out_wbufs:
1509 free_wbufs(c);
1510 out_cbuf:
1511 kfree(c->cbuf);
1512 out_free:
1513 kfree(c->write_reserve_buf);
1514 kfree(c->bu.buf);
1515 vfree(c->ileb_buf);
1516 vfree(c->sbuf);
1517 kfree(c->bottom_up_buf);
1518 ubifs_debugging_exit(c);
1519 return err;
1523 * ubifs_umount - un-mount UBIFS file-system.
1524 * @c: UBIFS file-system description object
1526 * Note, this function is called to free allocated resourced when un-mounting,
1527 * as well as free resources when an error occurred while we were half way
1528 * through mounting (error path cleanup function). So it has to make sure the
1529 * resource was actually allocated before freeing it.
1531 static void ubifs_umount(struct ubifs_info *c)
1533 dbg_gen("un-mounting UBI device %d, volume %d", c->vi.ubi_num,
1534 c->vi.vol_id);
1536 dbg_debugfs_exit_fs(c);
1537 spin_lock(&ubifs_infos_lock);
1538 list_del(&c->infos_list);
1539 spin_unlock(&ubifs_infos_lock);
1541 if (c->bgt)
1542 kthread_stop(c->bgt);
1544 destroy_journal(c);
1545 free_wbufs(c);
1546 free_orphans(c);
1547 ubifs_lpt_free(c, 0);
1549 kfree(c->cbuf);
1550 kfree(c->rcvrd_mst_node);
1551 kfree(c->mst_node);
1552 kfree(c->write_reserve_buf);
1553 kfree(c->bu.buf);
1554 vfree(c->ileb_buf);
1555 vfree(c->sbuf);
1556 kfree(c->bottom_up_buf);
1557 ubifs_debugging_exit(c);
1561 * ubifs_remount_rw - re-mount in read-write mode.
1562 * @c: UBIFS file-system description object
1564 * UBIFS avoids allocating many unnecessary resources when mounted in read-only
1565 * mode. This function allocates the needed resources and re-mounts UBIFS in
1566 * read-write mode.
1568 static int ubifs_remount_rw(struct ubifs_info *c)
1570 int err, lnum;
1572 if (c->rw_incompat) {
1573 ubifs_err("the file-system is not R/W-compatible");
1574 ubifs_msg("on-flash format version is w%d/r%d, but software "
1575 "only supports up to version w%d/r%d", c->fmt_version,
1576 c->ro_compat_version, UBIFS_FORMAT_VERSION,
1577 UBIFS_RO_COMPAT_VERSION);
1578 return -EROFS;
1581 mutex_lock(&c->umount_mutex);
1582 dbg_save_space_info(c);
1583 c->remounting_rw = 1;
1584 c->ro_mount = 0;
1586 err = check_free_space(c);
1587 if (err)
1588 goto out;
1590 if (c->old_leb_cnt != c->leb_cnt) {
1591 struct ubifs_sb_node *sup;
1593 sup = ubifs_read_sb_node(c);
1594 if (IS_ERR(sup)) {
1595 err = PTR_ERR(sup);
1596 goto out;
1598 sup->leb_cnt = cpu_to_le32(c->leb_cnt);
1599 err = ubifs_write_sb_node(c, sup);
1600 kfree(sup);
1601 if (err)
1602 goto out;
1605 if (c->need_recovery) {
1606 ubifs_msg("completing deferred recovery");
1607 err = ubifs_write_rcvrd_mst_node(c);
1608 if (err)
1609 goto out;
1610 err = ubifs_recover_size(c);
1611 if (err)
1612 goto out;
1613 err = ubifs_clean_lebs(c, c->sbuf);
1614 if (err)
1615 goto out;
1616 err = ubifs_recover_inl_heads(c, c->sbuf);
1617 if (err)
1618 goto out;
1619 } else {
1620 /* A readonly mount is not allowed to have orphans */
1621 ubifs_assert(c->tot_orphans == 0);
1622 err = ubifs_clear_orphans(c);
1623 if (err)
1624 goto out;
1627 if (!(c->mst_node->flags & cpu_to_le32(UBIFS_MST_DIRTY))) {
1628 c->mst_node->flags |= cpu_to_le32(UBIFS_MST_DIRTY);
1629 err = ubifs_write_master(c);
1630 if (err)
1631 goto out;
1634 c->ileb_buf = vmalloc(c->leb_size);
1635 if (!c->ileb_buf) {
1636 err = -ENOMEM;
1637 goto out;
1640 c->write_reserve_buf = kmalloc(COMPRESSED_DATA_NODE_BUF_SZ, GFP_KERNEL);
1641 if (!c->write_reserve_buf)
1642 goto out;
1644 err = ubifs_lpt_init(c, 0, 1);
1645 if (err)
1646 goto out;
1648 /* Create background thread */
1649 c->bgt = kthread_create(ubifs_bg_thread, c, "%s", c->bgt_name);
1650 if (IS_ERR(c->bgt)) {
1651 err = PTR_ERR(c->bgt);
1652 c->bgt = NULL;
1653 ubifs_err("cannot spawn \"%s\", error %d",
1654 c->bgt_name, err);
1655 goto out;
1657 wake_up_process(c->bgt);
1659 c->orph_buf = vmalloc(c->leb_size);
1660 if (!c->orph_buf) {
1661 err = -ENOMEM;
1662 goto out;
1665 /* Check for enough log space */
1666 lnum = c->lhead_lnum + 1;
1667 if (lnum >= UBIFS_LOG_LNUM + c->log_lebs)
1668 lnum = UBIFS_LOG_LNUM;
1669 if (lnum == c->ltail_lnum) {
1670 err = ubifs_consolidate_log(c);
1671 if (err)
1672 goto out;
1675 if (c->need_recovery)
1676 err = ubifs_rcvry_gc_commit(c);
1677 else
1678 err = ubifs_leb_unmap(c, c->gc_lnum);
1679 if (err)
1680 goto out;
1682 dbg_gen("re-mounted read-write");
1683 c->remounting_rw = 0;
1685 if (c->need_recovery) {
1686 c->need_recovery = 0;
1687 ubifs_msg("deferred recovery completed");
1688 } else {
1690 * Do not run the debugging space check if the were doing
1691 * recovery, because when we saved the information we had the
1692 * file-system in a state where the TNC and lprops has been
1693 * modified in memory, but all the I/O operations (including a
1694 * commit) were deferred. So the file-system was in
1695 * "non-committed" state. Now the file-system is in committed
1696 * state, and of course the amount of free space will change
1697 * because, for example, the old index size was imprecise.
1699 err = dbg_check_space_info(c);
1702 if (c->space_fixup) {
1703 err = ubifs_fixup_free_space(c);
1704 if (err)
1705 goto out;
1708 mutex_unlock(&c->umount_mutex);
1709 return err;
1711 out:
1712 c->ro_mount = 1;
1713 vfree(c->orph_buf);
1714 c->orph_buf = NULL;
1715 if (c->bgt) {
1716 kthread_stop(c->bgt);
1717 c->bgt = NULL;
1719 free_wbufs(c);
1720 kfree(c->write_reserve_buf);
1721 c->write_reserve_buf = NULL;
1722 vfree(c->ileb_buf);
1723 c->ileb_buf = NULL;
1724 ubifs_lpt_free(c, 1);
1725 c->remounting_rw = 0;
1726 mutex_unlock(&c->umount_mutex);
1727 return err;
1731 * ubifs_remount_ro - re-mount in read-only mode.
1732 * @c: UBIFS file-system description object
1734 * We assume VFS has stopped writing. Possibly the background thread could be
1735 * running a commit, however kthread_stop will wait in that case.
1737 static void ubifs_remount_ro(struct ubifs_info *c)
1739 int i, err;
1741 ubifs_assert(!c->need_recovery);
1742 ubifs_assert(!c->ro_mount);
1744 mutex_lock(&c->umount_mutex);
1745 if (c->bgt) {
1746 kthread_stop(c->bgt);
1747 c->bgt = NULL;
1750 dbg_save_space_info(c);
1752 for (i = 0; i < c->jhead_cnt; i++)
1753 ubifs_wbuf_sync(&c->jheads[i].wbuf);
1755 c->mst_node->flags &= ~cpu_to_le32(UBIFS_MST_DIRTY);
1756 c->mst_node->flags |= cpu_to_le32(UBIFS_MST_NO_ORPHS);
1757 c->mst_node->gc_lnum = cpu_to_le32(c->gc_lnum);
1758 err = ubifs_write_master(c);
1759 if (err)
1760 ubifs_ro_mode(c, err);
1762 vfree(c->orph_buf);
1763 c->orph_buf = NULL;
1764 kfree(c->write_reserve_buf);
1765 c->write_reserve_buf = NULL;
1766 vfree(c->ileb_buf);
1767 c->ileb_buf = NULL;
1768 ubifs_lpt_free(c, 1);
1769 c->ro_mount = 1;
1770 err = dbg_check_space_info(c);
1771 if (err)
1772 ubifs_ro_mode(c, err);
1773 mutex_unlock(&c->umount_mutex);
1776 static void ubifs_put_super(struct super_block *sb)
1778 int i;
1779 struct ubifs_info *c = sb->s_fs_info;
1781 ubifs_msg("un-mount UBI device %d, volume %d", c->vi.ubi_num,
1782 c->vi.vol_id);
1785 * The following asserts are only valid if there has not been a failure
1786 * of the media. For example, there will be dirty inodes if we failed
1787 * to write them back because of I/O errors.
1789 if (!c->ro_error) {
1790 ubifs_assert(c->bi.idx_growth == 0);
1791 ubifs_assert(c->bi.dd_growth == 0);
1792 ubifs_assert(c->bi.data_growth == 0);
1796 * The 'c->umount_lock' prevents races between UBIFS memory shrinker
1797 * and file system un-mount. Namely, it prevents the shrinker from
1798 * picking this superblock for shrinking - it will be just skipped if
1799 * the mutex is locked.
1801 mutex_lock(&c->umount_mutex);
1802 if (!c->ro_mount) {
1804 * First of all kill the background thread to make sure it does
1805 * not interfere with un-mounting and freeing resources.
1807 if (c->bgt) {
1808 kthread_stop(c->bgt);
1809 c->bgt = NULL;
1813 * On fatal errors c->ro_error is set to 1, in which case we do
1814 * not write the master node.
1816 if (!c->ro_error) {
1817 int err;
1819 /* Synchronize write-buffers */
1820 for (i = 0; i < c->jhead_cnt; i++)
1821 ubifs_wbuf_sync(&c->jheads[i].wbuf);
1824 * We are being cleanly unmounted which means the
1825 * orphans were killed - indicate this in the master
1826 * node. Also save the reserved GC LEB number.
1828 c->mst_node->flags &= ~cpu_to_le32(UBIFS_MST_DIRTY);
1829 c->mst_node->flags |= cpu_to_le32(UBIFS_MST_NO_ORPHS);
1830 c->mst_node->gc_lnum = cpu_to_le32(c->gc_lnum);
1831 err = ubifs_write_master(c);
1832 if (err)
1834 * Recovery will attempt to fix the master area
1835 * next mount, so we just print a message and
1836 * continue to unmount normally.
1838 ubifs_err("failed to write master node, "
1839 "error %d", err);
1840 } else {
1841 for (i = 0; i < c->jhead_cnt; i++)
1842 /* Make sure write-buffer timers are canceled */
1843 hrtimer_cancel(&c->jheads[i].wbuf.timer);
1847 ubifs_umount(c);
1848 bdi_destroy(&c->bdi);
1849 ubi_close_volume(c->ubi);
1850 mutex_unlock(&c->umount_mutex);
1853 static int ubifs_remount_fs(struct super_block *sb, int *flags, char *data)
1855 int err;
1856 struct ubifs_info *c = sb->s_fs_info;
1858 dbg_gen("old flags %#lx, new flags %#x", sb->s_flags, *flags);
1860 err = ubifs_parse_options(c, data, 1);
1861 if (err) {
1862 ubifs_err("invalid or unknown remount parameter");
1863 return err;
1866 if (c->ro_mount && !(*flags & MS_RDONLY)) {
1867 if (c->ro_error) {
1868 ubifs_msg("cannot re-mount R/W due to prior errors");
1869 return -EROFS;
1871 if (c->ro_media) {
1872 ubifs_msg("cannot re-mount R/W - UBI volume is R/O");
1873 return -EROFS;
1875 err = ubifs_remount_rw(c);
1876 if (err)
1877 return err;
1878 } else if (!c->ro_mount && (*flags & MS_RDONLY)) {
1879 if (c->ro_error) {
1880 ubifs_msg("cannot re-mount R/O due to prior errors");
1881 return -EROFS;
1883 ubifs_remount_ro(c);
1886 if (c->bulk_read == 1)
1887 bu_init(c);
1888 else {
1889 dbg_gen("disable bulk-read");
1890 kfree(c->bu.buf);
1891 c->bu.buf = NULL;
1894 ubifs_assert(c->lst.taken_empty_lebs > 0);
1895 return 0;
1898 const struct super_operations ubifs_super_operations = {
1899 .alloc_inode = ubifs_alloc_inode,
1900 .destroy_inode = ubifs_destroy_inode,
1901 .put_super = ubifs_put_super,
1902 .write_inode = ubifs_write_inode,
1903 .evict_inode = ubifs_evict_inode,
1904 .statfs = ubifs_statfs,
1905 .dirty_inode = ubifs_dirty_inode,
1906 .remount_fs = ubifs_remount_fs,
1907 .show_options = ubifs_show_options,
1908 .sync_fs = ubifs_sync_fs,
1912 * open_ubi - parse UBI device name string and open the UBI device.
1913 * @name: UBI volume name
1914 * @mode: UBI volume open mode
1916 * The primary method of mounting UBIFS is by specifying the UBI volume
1917 * character device node path. However, UBIFS may also be mounted withoug any
1918 * character device node using one of the following methods:
1920 * o ubiX_Y - mount UBI device number X, volume Y;
1921 * o ubiY - mount UBI device number 0, volume Y;
1922 * o ubiX:NAME - mount UBI device X, volume with name NAME;
1923 * o ubi:NAME - mount UBI device 0, volume with name NAME.
1925 * Alternative '!' separator may be used instead of ':' (because some shells
1926 * like busybox may interpret ':' as an NFS host name separator). This function
1927 * returns UBI volume description object in case of success and a negative
1928 * error code in case of failure.
1930 static struct ubi_volume_desc *open_ubi(const char *name, int mode)
1932 struct ubi_volume_desc *ubi;
1933 int dev, vol;
1934 char *endptr;
1936 /* First, try to open using the device node path method */
1937 ubi = ubi_open_volume_path(name, mode);
1938 if (!IS_ERR(ubi))
1939 return ubi;
1941 /* Try the "nodev" method */
1942 if (name[0] != 'u' || name[1] != 'b' || name[2] != 'i')
1943 return ERR_PTR(-EINVAL);
1945 /* ubi:NAME method */
1946 if ((name[3] == ':' || name[3] == '!') && name[4] != '\0')
1947 return ubi_open_volume_nm(0, name + 4, mode);
1949 if (!isdigit(name[3]))
1950 return ERR_PTR(-EINVAL);
1952 dev = simple_strtoul(name + 3, &endptr, 0);
1954 /* ubiY method */
1955 if (*endptr == '\0')
1956 return ubi_open_volume(0, dev, mode);
1958 /* ubiX_Y method */
1959 if (*endptr == '_' && isdigit(endptr[1])) {
1960 vol = simple_strtoul(endptr + 1, &endptr, 0);
1961 if (*endptr != '\0')
1962 return ERR_PTR(-EINVAL);
1963 return ubi_open_volume(dev, vol, mode);
1966 /* ubiX:NAME method */
1967 if ((*endptr == ':' || *endptr == '!') && endptr[1] != '\0')
1968 return ubi_open_volume_nm(dev, ++endptr, mode);
1970 return ERR_PTR(-EINVAL);
1973 static struct ubifs_info *alloc_ubifs_info(struct ubi_volume_desc *ubi)
1975 struct ubifs_info *c;
1977 c = kzalloc(sizeof(struct ubifs_info), GFP_KERNEL);
1978 if (c) {
1979 spin_lock_init(&c->cnt_lock);
1980 spin_lock_init(&c->cs_lock);
1981 spin_lock_init(&c->buds_lock);
1982 spin_lock_init(&c->space_lock);
1983 spin_lock_init(&c->orphan_lock);
1984 init_rwsem(&c->commit_sem);
1985 mutex_init(&c->lp_mutex);
1986 mutex_init(&c->tnc_mutex);
1987 mutex_init(&c->log_mutex);
1988 mutex_init(&c->mst_mutex);
1989 mutex_init(&c->umount_mutex);
1990 mutex_init(&c->bu_mutex);
1991 mutex_init(&c->write_reserve_mutex);
1992 init_waitqueue_head(&c->cmt_wq);
1993 c->buds = RB_ROOT;
1994 c->old_idx = RB_ROOT;
1995 c->size_tree = RB_ROOT;
1996 c->orph_tree = RB_ROOT;
1997 INIT_LIST_HEAD(&c->infos_list);
1998 INIT_LIST_HEAD(&c->idx_gc);
1999 INIT_LIST_HEAD(&c->replay_list);
2000 INIT_LIST_HEAD(&c->replay_buds);
2001 INIT_LIST_HEAD(&c->uncat_list);
2002 INIT_LIST_HEAD(&c->empty_list);
2003 INIT_LIST_HEAD(&c->freeable_list);
2004 INIT_LIST_HEAD(&c->frdi_idx_list);
2005 INIT_LIST_HEAD(&c->unclean_leb_list);
2006 INIT_LIST_HEAD(&c->old_buds);
2007 INIT_LIST_HEAD(&c->orph_list);
2008 INIT_LIST_HEAD(&c->orph_new);
2009 c->no_chk_data_crc = 1;
2011 c->highest_inum = UBIFS_FIRST_INO;
2012 c->lhead_lnum = c->ltail_lnum = UBIFS_LOG_LNUM;
2014 ubi_get_volume_info(ubi, &c->vi);
2015 ubi_get_device_info(c->vi.ubi_num, &c->di);
2017 return c;
2020 static int ubifs_fill_super(struct super_block *sb, void *data, int silent)
2022 struct ubifs_info *c = sb->s_fs_info;
2023 struct inode *root;
2024 int err;
2026 c->vfs_sb = sb;
2027 /* Re-open the UBI device in read-write mode */
2028 c->ubi = ubi_open_volume(c->vi.ubi_num, c->vi.vol_id, UBI_READWRITE);
2029 if (IS_ERR(c->ubi)) {
2030 err = PTR_ERR(c->ubi);
2031 goto out;
2035 * UBIFS provides 'backing_dev_info' in order to disable read-ahead. For
2036 * UBIFS, I/O is not deferred, it is done immediately in readpage,
2037 * which means the user would have to wait not just for their own I/O
2038 * but the read-ahead I/O as well i.e. completely pointless.
2040 * Read-ahead will be disabled because @c->bdi.ra_pages is 0.
2042 c->bdi.name = "ubifs",
2043 c->bdi.capabilities = BDI_CAP_MAP_COPY;
2044 err = bdi_init(&c->bdi);
2045 if (err)
2046 goto out_close;
2047 err = bdi_register(&c->bdi, NULL, "ubifs_%d_%d",
2048 c->vi.ubi_num, c->vi.vol_id);
2049 if (err)
2050 goto out_bdi;
2052 err = ubifs_parse_options(c, data, 0);
2053 if (err)
2054 goto out_bdi;
2056 sb->s_bdi = &c->bdi;
2057 sb->s_fs_info = c;
2058 sb->s_magic = UBIFS_SUPER_MAGIC;
2059 sb->s_blocksize = UBIFS_BLOCK_SIZE;
2060 sb->s_blocksize_bits = UBIFS_BLOCK_SHIFT;
2061 sb->s_maxbytes = c->max_inode_sz = key_max_inode_size(c);
2062 if (c->max_inode_sz > MAX_LFS_FILESIZE)
2063 sb->s_maxbytes = c->max_inode_sz = MAX_LFS_FILESIZE;
2064 sb->s_op = &ubifs_super_operations;
2066 mutex_lock(&c->umount_mutex);
2067 err = mount_ubifs(c);
2068 if (err) {
2069 ubifs_assert(err < 0);
2070 goto out_unlock;
2073 /* Read the root inode */
2074 root = ubifs_iget(sb, UBIFS_ROOT_INO);
2075 if (IS_ERR(root)) {
2076 err = PTR_ERR(root);
2077 goto out_umount;
2080 sb->s_root = d_alloc_root(root);
2081 if (!sb->s_root)
2082 goto out_iput;
2084 mutex_unlock(&c->umount_mutex);
2085 return 0;
2087 out_iput:
2088 iput(root);
2089 out_umount:
2090 ubifs_umount(c);
2091 out_unlock:
2092 mutex_unlock(&c->umount_mutex);
2093 out_bdi:
2094 bdi_destroy(&c->bdi);
2095 out_close:
2096 ubi_close_volume(c->ubi);
2097 out:
2098 return err;
2101 static int sb_test(struct super_block *sb, void *data)
2103 struct ubifs_info *c1 = data;
2104 struct ubifs_info *c = sb->s_fs_info;
2106 return c->vi.cdev == c1->vi.cdev;
2109 static int sb_set(struct super_block *sb, void *data)
2111 sb->s_fs_info = data;
2112 return set_anon_super(sb, NULL);
2115 static struct dentry *ubifs_mount(struct file_system_type *fs_type, int flags,
2116 const char *name, void *data)
2118 struct ubi_volume_desc *ubi;
2119 struct ubifs_info *c;
2120 struct super_block *sb;
2121 int err;
2123 dbg_gen("name %s, flags %#x", name, flags);
2126 * Get UBI device number and volume ID. Mount it read-only so far
2127 * because this might be a new mount point, and UBI allows only one
2128 * read-write user at a time.
2130 ubi = open_ubi(name, UBI_READONLY);
2131 if (IS_ERR(ubi)) {
2132 dbg_err("cannot open \"%s\", error %d",
2133 name, (int)PTR_ERR(ubi));
2134 return ERR_CAST(ubi);
2137 c = alloc_ubifs_info(ubi);
2138 if (!c) {
2139 err = -ENOMEM;
2140 goto out_close;
2143 dbg_gen("opened ubi%d_%d", c->vi.ubi_num, c->vi.vol_id);
2145 sb = sget(fs_type, sb_test, sb_set, c);
2146 if (IS_ERR(sb)) {
2147 err = PTR_ERR(sb);
2148 kfree(c);
2149 goto out_close;
2152 if (sb->s_root) {
2153 struct ubifs_info *c1 = sb->s_fs_info;
2154 kfree(c);
2155 /* A new mount point for already mounted UBIFS */
2156 dbg_gen("this ubi volume is already mounted");
2157 if (!!(flags & MS_RDONLY) != c1->ro_mount) {
2158 err = -EBUSY;
2159 goto out_deact;
2161 } else {
2162 sb->s_flags = flags;
2163 err = ubifs_fill_super(sb, data, flags & MS_SILENT ? 1 : 0);
2164 if (err)
2165 goto out_deact;
2166 /* We do not support atime */
2167 sb->s_flags |= MS_ACTIVE | MS_NOATIME;
2170 /* 'fill_super()' opens ubi again so we must close it here */
2171 ubi_close_volume(ubi);
2173 return dget(sb->s_root);
2175 out_deact:
2176 deactivate_locked_super(sb);
2177 out_close:
2178 ubi_close_volume(ubi);
2179 return ERR_PTR(err);
2182 static void kill_ubifs_super(struct super_block *s)
2184 struct ubifs_info *c = s->s_fs_info;
2185 kill_anon_super(s);
2186 kfree(c);
2189 static struct file_system_type ubifs_fs_type = {
2190 .name = "ubifs",
2191 .owner = THIS_MODULE,
2192 .mount = ubifs_mount,
2193 .kill_sb = kill_ubifs_super,
2197 * Inode slab cache constructor.
2199 static void inode_slab_ctor(void *obj)
2201 struct ubifs_inode *ui = obj;
2202 inode_init_once(&ui->vfs_inode);
2205 static int __init ubifs_init(void)
2207 int err;
2209 BUILD_BUG_ON(sizeof(struct ubifs_ch) != 24);
2211 /* Make sure node sizes are 8-byte aligned */
2212 BUILD_BUG_ON(UBIFS_CH_SZ & 7);
2213 BUILD_BUG_ON(UBIFS_INO_NODE_SZ & 7);
2214 BUILD_BUG_ON(UBIFS_DENT_NODE_SZ & 7);
2215 BUILD_BUG_ON(UBIFS_XENT_NODE_SZ & 7);
2216 BUILD_BUG_ON(UBIFS_DATA_NODE_SZ & 7);
2217 BUILD_BUG_ON(UBIFS_TRUN_NODE_SZ & 7);
2218 BUILD_BUG_ON(UBIFS_SB_NODE_SZ & 7);
2219 BUILD_BUG_ON(UBIFS_MST_NODE_SZ & 7);
2220 BUILD_BUG_ON(UBIFS_REF_NODE_SZ & 7);
2221 BUILD_BUG_ON(UBIFS_CS_NODE_SZ & 7);
2222 BUILD_BUG_ON(UBIFS_ORPH_NODE_SZ & 7);
2224 BUILD_BUG_ON(UBIFS_MAX_DENT_NODE_SZ & 7);
2225 BUILD_BUG_ON(UBIFS_MAX_XENT_NODE_SZ & 7);
2226 BUILD_BUG_ON(UBIFS_MAX_DATA_NODE_SZ & 7);
2227 BUILD_BUG_ON(UBIFS_MAX_INO_NODE_SZ & 7);
2228 BUILD_BUG_ON(UBIFS_MAX_NODE_SZ & 7);
2229 BUILD_BUG_ON(MIN_WRITE_SZ & 7);
2231 /* Check min. node size */
2232 BUILD_BUG_ON(UBIFS_INO_NODE_SZ < MIN_WRITE_SZ);
2233 BUILD_BUG_ON(UBIFS_DENT_NODE_SZ < MIN_WRITE_SZ);
2234 BUILD_BUG_ON(UBIFS_XENT_NODE_SZ < MIN_WRITE_SZ);
2235 BUILD_BUG_ON(UBIFS_TRUN_NODE_SZ < MIN_WRITE_SZ);
2237 BUILD_BUG_ON(UBIFS_MAX_DENT_NODE_SZ > UBIFS_MAX_NODE_SZ);
2238 BUILD_BUG_ON(UBIFS_MAX_XENT_NODE_SZ > UBIFS_MAX_NODE_SZ);
2239 BUILD_BUG_ON(UBIFS_MAX_DATA_NODE_SZ > UBIFS_MAX_NODE_SZ);
2240 BUILD_BUG_ON(UBIFS_MAX_INO_NODE_SZ > UBIFS_MAX_NODE_SZ);
2242 /* Defined node sizes */
2243 BUILD_BUG_ON(UBIFS_SB_NODE_SZ != 4096);
2244 BUILD_BUG_ON(UBIFS_MST_NODE_SZ != 512);
2245 BUILD_BUG_ON(UBIFS_INO_NODE_SZ != 160);
2246 BUILD_BUG_ON(UBIFS_REF_NODE_SZ != 64);
2249 * We use 2 bit wide bit-fields to store compression type, which should
2250 * be amended if more compressors are added. The bit-fields are:
2251 * @compr_type in 'struct ubifs_inode', @default_compr in
2252 * 'struct ubifs_info' and @compr_type in 'struct ubifs_mount_opts'.
2254 BUILD_BUG_ON(UBIFS_COMPR_TYPES_CNT > 4);
2257 * We require that PAGE_CACHE_SIZE is greater-than-or-equal-to
2258 * UBIFS_BLOCK_SIZE. It is assumed that both are powers of 2.
2260 if (PAGE_CACHE_SIZE < UBIFS_BLOCK_SIZE) {
2261 ubifs_err("VFS page cache size is %u bytes, but UBIFS requires"
2262 " at least 4096 bytes",
2263 (unsigned int)PAGE_CACHE_SIZE);
2264 return -EINVAL;
2267 err = register_filesystem(&ubifs_fs_type);
2268 if (err) {
2269 ubifs_err("cannot register file system, error %d", err);
2270 return err;
2273 err = -ENOMEM;
2274 ubifs_inode_slab = kmem_cache_create("ubifs_inode_slab",
2275 sizeof(struct ubifs_inode), 0,
2276 SLAB_MEM_SPREAD | SLAB_RECLAIM_ACCOUNT,
2277 &inode_slab_ctor);
2278 if (!ubifs_inode_slab)
2279 goto out_reg;
2281 register_shrinker(&ubifs_shrinker_info);
2283 err = ubifs_compressors_init();
2284 if (err)
2285 goto out_shrinker;
2287 err = dbg_debugfs_init();
2288 if (err)
2289 goto out_compr;
2291 return 0;
2293 out_compr:
2294 ubifs_compressors_exit();
2295 out_shrinker:
2296 unregister_shrinker(&ubifs_shrinker_info);
2297 kmem_cache_destroy(ubifs_inode_slab);
2298 out_reg:
2299 unregister_filesystem(&ubifs_fs_type);
2300 return err;
2302 /* late_initcall to let compressors initialize first */
2303 late_initcall(ubifs_init);
2305 static void __exit ubifs_exit(void)
2307 ubifs_assert(list_empty(&ubifs_infos));
2308 ubifs_assert(atomic_long_read(&ubifs_clean_zn_cnt) == 0);
2310 dbg_debugfs_exit();
2311 ubifs_compressors_exit();
2312 unregister_shrinker(&ubifs_shrinker_info);
2313 kmem_cache_destroy(ubifs_inode_slab);
2314 unregister_filesystem(&ubifs_fs_type);
2316 module_exit(ubifs_exit);
2318 MODULE_LICENSE("GPL");
2319 MODULE_VERSION(__stringify(UBIFS_VERSION));
2320 MODULE_AUTHOR("Artem Bityutskiy, Adrian Hunter");
2321 MODULE_DESCRIPTION("UBIFS - UBI File System");