2 * the_nilfs.c - the_nilfs shared structure.
4 * Copyright (C) 2005-2008 Nippon Telegraph and Telephone Corporation.
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by
8 * the Free Software Foundation; either version 2 of the License, or
9 * (at your option) any later version.
11 * This program is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU General Public License for more details.
16 * You should have received a copy of the GNU General Public License
17 * along with this program; if not, write to the Free Software
18 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
20 * Written by Ryusuke Konishi <ryusuke@osrg.net>
24 #include <linux/buffer_head.h>
25 #include <linux/slab.h>
26 #include <linux/blkdev.h>
27 #include <linux/backing-dev.h>
28 #include <linux/random.h>
29 #include <linux/crc32.h>
39 static int nilfs_valid_sb(struct nilfs_super_block *sbp);
41 void nilfs_set_last_segment(struct the_nilfs *nilfs,
42 sector_t start_blocknr, u64 seq, __u64 cno)
44 spin_lock(&nilfs->ns_last_segment_lock);
45 nilfs->ns_last_pseg = start_blocknr;
46 nilfs->ns_last_seq = seq;
47 nilfs->ns_last_cno = cno;
49 if (!nilfs_sb_dirty(nilfs)) {
50 if (nilfs->ns_prev_seq == nilfs->ns_last_seq)
53 set_nilfs_sb_dirty(nilfs);
55 nilfs->ns_prev_seq = nilfs->ns_last_seq;
58 spin_unlock(&nilfs->ns_last_segment_lock);
62 * alloc_nilfs - allocate a nilfs object
63 * @bdev: block device to which the_nilfs is related
65 * Return Value: On success, pointer to the_nilfs is returned.
66 * On error, NULL is returned.
68 struct the_nilfs *alloc_nilfs(struct block_device *bdev)
70 struct the_nilfs *nilfs;
72 nilfs = kzalloc(sizeof(*nilfs), GFP_KERNEL);
76 nilfs->ns_bdev = bdev;
77 atomic_set(&nilfs->ns_ndirtyblks, 0);
78 init_rwsem(&nilfs->ns_sem);
79 mutex_init(&nilfs->ns_snapshot_mount_mutex);
80 INIT_LIST_HEAD(&nilfs->ns_dirty_files);
81 INIT_LIST_HEAD(&nilfs->ns_gc_inodes);
82 spin_lock_init(&nilfs->ns_inode_lock);
83 spin_lock_init(&nilfs->ns_next_gen_lock);
84 spin_lock_init(&nilfs->ns_last_segment_lock);
85 nilfs->ns_cptree = RB_ROOT;
86 spin_lock_init(&nilfs->ns_cptree_lock);
87 init_rwsem(&nilfs->ns_segctor_sem);
93 * destroy_nilfs - destroy nilfs object
94 * @nilfs: nilfs object to be released
96 void destroy_nilfs(struct the_nilfs *nilfs)
99 if (nilfs_init(nilfs)) {
100 brelse(nilfs->ns_sbh[0]);
101 brelse(nilfs->ns_sbh[1]);
106 static int nilfs_load_super_root(struct the_nilfs *nilfs,
107 struct super_block *sb, sector_t sr_block)
109 struct buffer_head *bh_sr;
110 struct nilfs_super_root *raw_sr;
111 struct nilfs_super_block **sbp = nilfs->ns_sbp;
112 struct nilfs_inode *rawi;
113 unsigned dat_entry_size, segment_usage_size, checkpoint_size;
117 err = nilfs_read_super_root_block(nilfs, sr_block, &bh_sr, 1);
121 down_read(&nilfs->ns_sem);
122 dat_entry_size = le16_to_cpu(sbp[0]->s_dat_entry_size);
123 checkpoint_size = le16_to_cpu(sbp[0]->s_checkpoint_size);
124 segment_usage_size = le16_to_cpu(sbp[0]->s_segment_usage_size);
125 up_read(&nilfs->ns_sem);
127 inode_size = nilfs->ns_inode_size;
129 rawi = (void *)bh_sr->b_data + NILFS_SR_DAT_OFFSET(inode_size);
130 err = nilfs_dat_read(sb, dat_entry_size, rawi, &nilfs->ns_dat);
134 rawi = (void *)bh_sr->b_data + NILFS_SR_CPFILE_OFFSET(inode_size);
135 err = nilfs_cpfile_read(sb, checkpoint_size, rawi, &nilfs->ns_cpfile);
139 rawi = (void *)bh_sr->b_data + NILFS_SR_SUFILE_OFFSET(inode_size);
140 err = nilfs_sufile_read(sb, segment_usage_size, rawi,
145 raw_sr = (struct nilfs_super_root *)bh_sr->b_data;
146 nilfs->ns_nongc_ctime = le64_to_cpu(raw_sr->sr_nongc_ctime);
153 iput(nilfs->ns_cpfile);
160 static void nilfs_init_recovery_info(struct nilfs_recovery_info *ri)
162 memset(ri, 0, sizeof(*ri));
163 INIT_LIST_HEAD(&ri->ri_used_segments);
166 static void nilfs_clear_recovery_info(struct nilfs_recovery_info *ri)
168 nilfs_dispose_segment_list(&ri->ri_used_segments);
172 * nilfs_store_log_cursor - load log cursor from a super block
173 * @nilfs: nilfs object
174 * @sbp: buffer storing super block to be read
176 * nilfs_store_log_cursor() reads the last position of the log
177 * containing a super root from a given super block, and initializes
178 * relevant information on the nilfs object preparatory for log
179 * scanning and recovery.
181 static int nilfs_store_log_cursor(struct the_nilfs *nilfs,
182 struct nilfs_super_block *sbp)
186 nilfs->ns_last_pseg = le64_to_cpu(sbp->s_last_pseg);
187 nilfs->ns_last_cno = le64_to_cpu(sbp->s_last_cno);
188 nilfs->ns_last_seq = le64_to_cpu(sbp->s_last_seq);
190 nilfs->ns_prev_seq = nilfs->ns_last_seq;
191 nilfs->ns_seg_seq = nilfs->ns_last_seq;
193 nilfs_get_segnum_of_block(nilfs, nilfs->ns_last_pseg);
194 nilfs->ns_cno = nilfs->ns_last_cno + 1;
195 if (nilfs->ns_segnum >= nilfs->ns_nsegments) {
196 printk(KERN_ERR "NILFS invalid last segment number.\n");
203 * load_nilfs - load and recover the nilfs
204 * @nilfs: the_nilfs structure to be released
205 * @sb: super block isntance used to recover past segment
207 * load_nilfs() searches and load the latest super root,
208 * attaches the last segment, and does recovery if needed.
209 * The caller must call this exclusively for simultaneous mounts.
211 int load_nilfs(struct the_nilfs *nilfs, struct super_block *sb)
213 struct nilfs_recovery_info ri;
214 unsigned int s_flags = sb->s_flags;
215 int really_read_only = bdev_read_only(nilfs->ns_bdev);
216 int valid_fs = nilfs_valid_fs(nilfs);
220 printk(KERN_WARNING "NILFS warning: mounting unchecked fs\n");
221 if (s_flags & MS_RDONLY) {
222 printk(KERN_INFO "NILFS: INFO: recovery "
223 "required for readonly filesystem.\n");
224 printk(KERN_INFO "NILFS: write access will "
225 "be enabled during recovery.\n");
229 nilfs_init_recovery_info(&ri);
231 err = nilfs_search_super_root(nilfs, &ri);
233 struct nilfs_super_block **sbp = nilfs->ns_sbp;
239 if (!nilfs_valid_sb(sbp[1])) {
241 "NILFS warning: unable to fall back to spare"
246 "NILFS: try rollback from an earlier position\n");
249 * restore super block with its spare and reconfigure
250 * relevant states of the nilfs object.
252 memcpy(sbp[0], sbp[1], nilfs->ns_sbsize);
253 nilfs->ns_crc_seed = le32_to_cpu(sbp[0]->s_crc_seed);
254 nilfs->ns_sbwtime = le64_to_cpu(sbp[0]->s_wtime);
256 /* verify consistency between two super blocks */
257 blocksize = BLOCK_SIZE << le32_to_cpu(sbp[0]->s_log_block_size);
258 if (blocksize != nilfs->ns_blocksize) {
260 "NILFS warning: blocksize differs between "
261 "two super blocks (%d != %d)\n",
262 blocksize, nilfs->ns_blocksize);
266 err = nilfs_store_log_cursor(nilfs, sbp[0]);
270 /* drop clean flag to allow roll-forward and recovery */
271 nilfs->ns_mount_state &= ~NILFS_VALID_FS;
274 err = nilfs_search_super_root(nilfs, &ri);
279 err = nilfs_load_super_root(nilfs, sb, ri.ri_super_root);
281 printk(KERN_ERR "NILFS: error loading super root.\n");
288 if (s_flags & MS_RDONLY) {
291 if (nilfs_test_opt(nilfs, NORECOVERY)) {
292 printk(KERN_INFO "NILFS: norecovery option specified. "
293 "skipping roll-forward recovery\n");
296 features = le64_to_cpu(nilfs->ns_sbp[0]->s_feature_compat_ro) &
297 ~NILFS_FEATURE_COMPAT_RO_SUPP;
299 printk(KERN_ERR "NILFS: couldn't proceed with "
300 "recovery because of unsupported optional "
302 (unsigned long long)features);
306 if (really_read_only) {
307 printk(KERN_ERR "NILFS: write access "
308 "unavailable, cannot proceed.\n");
312 sb->s_flags &= ~MS_RDONLY;
313 } else if (nilfs_test_opt(nilfs, NORECOVERY)) {
314 printk(KERN_ERR "NILFS: recovery cancelled because norecovery "
315 "option was specified for a read/write mount\n");
320 err = nilfs_salvage_orphan_logs(nilfs, sb, &ri);
324 down_write(&nilfs->ns_sem);
325 nilfs->ns_mount_state |= NILFS_VALID_FS; /* set "clean" flag */
326 err = nilfs_cleanup_super(sb);
327 up_write(&nilfs->ns_sem);
330 printk(KERN_ERR "NILFS: failed to update super block. "
331 "recovery unfinished.\n");
334 printk(KERN_INFO "NILFS: recovery complete.\n");
337 nilfs_clear_recovery_info(&ri);
338 sb->s_flags = s_flags;
342 printk(KERN_ERR "NILFS: error searching super root.\n");
346 iput(nilfs->ns_cpfile);
347 iput(nilfs->ns_sufile);
351 nilfs_clear_recovery_info(&ri);
352 sb->s_flags = s_flags;
356 static unsigned long long nilfs_max_size(unsigned int blkbits)
358 unsigned int max_bits;
359 unsigned long long res = MAX_LFS_FILESIZE; /* page cache limit */
361 max_bits = blkbits + NILFS_BMAP_KEY_BIT; /* bmap size limit */
363 res = min_t(unsigned long long, res, (1ULL << max_bits) - 1);
368 * nilfs_nrsvsegs - calculate the number of reserved segments
369 * @nilfs: nilfs object
370 * @nsegs: total number of segments
372 unsigned long nilfs_nrsvsegs(struct the_nilfs *nilfs, unsigned long nsegs)
374 return max_t(unsigned long, NILFS_MIN_NRSVSEGS,
375 DIV_ROUND_UP(nsegs * nilfs->ns_r_segments_percentage,
379 void nilfs_set_nsegments(struct the_nilfs *nilfs, unsigned long nsegs)
381 nilfs->ns_nsegments = nsegs;
382 nilfs->ns_nrsvsegs = nilfs_nrsvsegs(nilfs, nsegs);
385 static int nilfs_store_disk_layout(struct the_nilfs *nilfs,
386 struct nilfs_super_block *sbp)
388 if (le32_to_cpu(sbp->s_rev_level) < NILFS_MIN_SUPP_REV) {
389 printk(KERN_ERR "NILFS: unsupported revision "
390 "(superblock rev.=%d.%d, current rev.=%d.%d). "
391 "Please check the version of mkfs.nilfs.\n",
392 le32_to_cpu(sbp->s_rev_level),
393 le16_to_cpu(sbp->s_minor_rev_level),
394 NILFS_CURRENT_REV, NILFS_MINOR_REV);
397 nilfs->ns_sbsize = le16_to_cpu(sbp->s_bytes);
398 if (nilfs->ns_sbsize > BLOCK_SIZE)
401 nilfs->ns_inode_size = le16_to_cpu(sbp->s_inode_size);
402 if (nilfs->ns_inode_size > nilfs->ns_blocksize) {
403 printk(KERN_ERR "NILFS: too large inode size: %d bytes.\n",
404 nilfs->ns_inode_size);
406 } else if (nilfs->ns_inode_size < NILFS_MIN_INODE_SIZE) {
407 printk(KERN_ERR "NILFS: too small inode size: %d bytes.\n",
408 nilfs->ns_inode_size);
412 nilfs->ns_first_ino = le32_to_cpu(sbp->s_first_ino);
414 nilfs->ns_blocks_per_segment = le32_to_cpu(sbp->s_blocks_per_segment);
415 if (nilfs->ns_blocks_per_segment < NILFS_SEG_MIN_BLOCKS) {
416 printk(KERN_ERR "NILFS: too short segment.\n");
420 nilfs->ns_first_data_block = le64_to_cpu(sbp->s_first_data_block);
421 nilfs->ns_r_segments_percentage =
422 le32_to_cpu(sbp->s_r_segments_percentage);
423 if (nilfs->ns_r_segments_percentage < 1 ||
424 nilfs->ns_r_segments_percentage > 99) {
425 printk(KERN_ERR "NILFS: invalid reserved segments percentage.\n");
429 nilfs_set_nsegments(nilfs, le64_to_cpu(sbp->s_nsegments));
430 nilfs->ns_crc_seed = le32_to_cpu(sbp->s_crc_seed);
434 static int nilfs_valid_sb(struct nilfs_super_block *sbp)
436 static unsigned char sum[4];
437 const int sumoff = offsetof(struct nilfs_super_block, s_sum);
441 if (!sbp || le16_to_cpu(sbp->s_magic) != NILFS_SUPER_MAGIC)
443 bytes = le16_to_cpu(sbp->s_bytes);
444 if (bytes > BLOCK_SIZE)
446 crc = crc32_le(le32_to_cpu(sbp->s_crc_seed), (unsigned char *)sbp,
448 crc = crc32_le(crc, sum, 4);
449 crc = crc32_le(crc, (unsigned char *)sbp + sumoff + 4,
451 return crc == le32_to_cpu(sbp->s_sum);
454 static int nilfs_sb2_bad_offset(struct nilfs_super_block *sbp, u64 offset)
456 return offset < ((le64_to_cpu(sbp->s_nsegments) *
457 le32_to_cpu(sbp->s_blocks_per_segment)) <<
458 (le32_to_cpu(sbp->s_log_block_size) + 10));
461 static void nilfs_release_super_block(struct the_nilfs *nilfs)
465 for (i = 0; i < 2; i++) {
466 if (nilfs->ns_sbp[i]) {
467 brelse(nilfs->ns_sbh[i]);
468 nilfs->ns_sbh[i] = NULL;
469 nilfs->ns_sbp[i] = NULL;
474 void nilfs_fall_back_super_block(struct the_nilfs *nilfs)
476 brelse(nilfs->ns_sbh[0]);
477 nilfs->ns_sbh[0] = nilfs->ns_sbh[1];
478 nilfs->ns_sbp[0] = nilfs->ns_sbp[1];
479 nilfs->ns_sbh[1] = NULL;
480 nilfs->ns_sbp[1] = NULL;
483 void nilfs_swap_super_block(struct the_nilfs *nilfs)
485 struct buffer_head *tsbh = nilfs->ns_sbh[0];
486 struct nilfs_super_block *tsbp = nilfs->ns_sbp[0];
488 nilfs->ns_sbh[0] = nilfs->ns_sbh[1];
489 nilfs->ns_sbp[0] = nilfs->ns_sbp[1];
490 nilfs->ns_sbh[1] = tsbh;
491 nilfs->ns_sbp[1] = tsbp;
494 static int nilfs_load_super_block(struct the_nilfs *nilfs,
495 struct super_block *sb, int blocksize,
496 struct nilfs_super_block **sbpp)
498 struct nilfs_super_block **sbp = nilfs->ns_sbp;
499 struct buffer_head **sbh = nilfs->ns_sbh;
500 u64 sb2off = NILFS_SB2_OFFSET_BYTES(nilfs->ns_bdev->bd_inode->i_size);
501 int valid[2], swp = 0;
503 sbp[0] = nilfs_read_super_block(sb, NILFS_SB_OFFSET_BYTES, blocksize,
505 sbp[1] = nilfs_read_super_block(sb, sb2off, blocksize, &sbh[1]);
509 printk(KERN_ERR "NILFS: unable to read superblock\n");
513 "NILFS warning: unable to read primary superblock "
514 "(blocksize = %d)\n", blocksize);
515 } else if (!sbp[1]) {
517 "NILFS warning: unable to read secondary superblock "
518 "(blocksize = %d)\n", blocksize);
522 * Compare two super blocks and set 1 in swp if the secondary
523 * super block is valid and newer. Otherwise, set 0 in swp.
525 valid[0] = nilfs_valid_sb(sbp[0]);
526 valid[1] = nilfs_valid_sb(sbp[1]);
527 swp = valid[1] && (!valid[0] ||
528 le64_to_cpu(sbp[1]->s_last_cno) >
529 le64_to_cpu(sbp[0]->s_last_cno));
531 if (valid[swp] && nilfs_sb2_bad_offset(sbp[swp], sb2off)) {
539 nilfs_release_super_block(nilfs);
540 printk(KERN_ERR "NILFS: Can't find nilfs on dev %s.\n",
546 printk(KERN_WARNING "NILFS warning: broken superblock. "
547 "using spare superblock (blocksize = %d).\n", blocksize);
549 nilfs_swap_super_block(nilfs);
551 nilfs->ns_sbwcount = 0;
552 nilfs->ns_sbwtime = le64_to_cpu(sbp[0]->s_wtime);
553 nilfs->ns_prot_seq = le64_to_cpu(sbp[valid[1] & !swp]->s_last_seq);
559 * init_nilfs - initialize a NILFS instance.
560 * @nilfs: the_nilfs structure
562 * @data: mount options
564 * init_nilfs() performs common initialization per block device (e.g.
565 * reading the super block, getting disk layout information, initializing
566 * shared fields in the_nilfs).
568 * Return Value: On success, 0 is returned. On error, a negative error
571 int init_nilfs(struct the_nilfs *nilfs, struct super_block *sb, char *data)
573 struct nilfs_super_block *sbp;
577 down_write(&nilfs->ns_sem);
579 blocksize = sb_min_blocksize(sb, NILFS_MIN_BLOCK_SIZE);
581 printk(KERN_ERR "NILFS: unable to set blocksize\n");
585 err = nilfs_load_super_block(nilfs, sb, blocksize, &sbp);
589 err = nilfs_store_magic_and_option(sb, sbp, data);
593 err = nilfs_check_feature_compatibility(sb, sbp);
597 blocksize = BLOCK_SIZE << le32_to_cpu(sbp->s_log_block_size);
598 if (blocksize < NILFS_MIN_BLOCK_SIZE ||
599 blocksize > NILFS_MAX_BLOCK_SIZE) {
600 printk(KERN_ERR "NILFS: couldn't mount because of unsupported "
601 "filesystem blocksize %d\n", blocksize);
605 if (sb->s_blocksize != blocksize) {
606 int hw_blocksize = bdev_logical_block_size(sb->s_bdev);
608 if (blocksize < hw_blocksize) {
610 "NILFS: blocksize %d too small for device "
611 "(sector-size = %d).\n",
612 blocksize, hw_blocksize);
616 nilfs_release_super_block(nilfs);
617 sb_set_blocksize(sb, blocksize);
619 err = nilfs_load_super_block(nilfs, sb, blocksize, &sbp);
622 /* not failed_sbh; sbh is released automatically
623 when reloading fails. */
625 nilfs->ns_blocksize_bits = sb->s_blocksize_bits;
626 nilfs->ns_blocksize = blocksize;
628 get_random_bytes(&nilfs->ns_next_generation,
629 sizeof(nilfs->ns_next_generation));
631 err = nilfs_store_disk_layout(nilfs, sbp);
635 sb->s_maxbytes = nilfs_max_size(sb->s_blocksize_bits);
637 nilfs->ns_mount_state = le16_to_cpu(sbp->s_state);
639 err = nilfs_store_log_cursor(nilfs, sbp);
643 set_nilfs_init(nilfs);
646 up_write(&nilfs->ns_sem);
650 nilfs_release_super_block(nilfs);
654 int nilfs_discard_segments(struct the_nilfs *nilfs, __u64 *segnump,
657 sector_t seg_start, seg_end;
658 sector_t start = 0, nblocks = 0;
659 unsigned int sects_per_block;
663 sects_per_block = (1 << nilfs->ns_blocksize_bits) /
664 bdev_logical_block_size(nilfs->ns_bdev);
665 for (sn = segnump; sn < segnump + nsegs; sn++) {
666 nilfs_get_segment_range(nilfs, *sn, &seg_start, &seg_end);
670 nblocks = seg_end - seg_start + 1;
671 } else if (start + nblocks == seg_start) {
672 nblocks += seg_end - seg_start + 1;
674 ret = blkdev_issue_discard(nilfs->ns_bdev,
675 start * sects_per_block,
676 nblocks * sects_per_block,
684 ret = blkdev_issue_discard(nilfs->ns_bdev,
685 start * sects_per_block,
686 nblocks * sects_per_block,
691 int nilfs_count_free_blocks(struct the_nilfs *nilfs, sector_t *nblocks)
693 unsigned long ncleansegs;
695 down_read(&NILFS_MDT(nilfs->ns_dat)->mi_sem);
696 ncleansegs = nilfs_sufile_get_ncleansegs(nilfs->ns_sufile);
697 up_read(&NILFS_MDT(nilfs->ns_dat)->mi_sem);
698 *nblocks = (sector_t)ncleansegs * nilfs->ns_blocks_per_segment;
702 int nilfs_near_disk_full(struct the_nilfs *nilfs)
704 unsigned long ncleansegs, nincsegs;
706 ncleansegs = nilfs_sufile_get_ncleansegs(nilfs->ns_sufile);
707 nincsegs = atomic_read(&nilfs->ns_ndirtyblks) /
708 nilfs->ns_blocks_per_segment + 1;
710 return ncleansegs <= nilfs->ns_nrsvsegs + nincsegs;
713 struct nilfs_root *nilfs_lookup_root(struct the_nilfs *nilfs, __u64 cno)
716 struct nilfs_root *root;
718 spin_lock(&nilfs->ns_cptree_lock);
719 n = nilfs->ns_cptree.rb_node;
721 root = rb_entry(n, struct nilfs_root, rb_node);
723 if (cno < root->cno) {
725 } else if (cno > root->cno) {
728 atomic_inc(&root->count);
729 spin_unlock(&nilfs->ns_cptree_lock);
733 spin_unlock(&nilfs->ns_cptree_lock);
739 nilfs_find_or_create_root(struct the_nilfs *nilfs, __u64 cno)
741 struct rb_node **p, *parent;
742 struct nilfs_root *root, *new;
744 root = nilfs_lookup_root(nilfs, cno);
748 new = kmalloc(sizeof(*root), GFP_KERNEL);
752 spin_lock(&nilfs->ns_cptree_lock);
754 p = &nilfs->ns_cptree.rb_node;
759 root = rb_entry(parent, struct nilfs_root, rb_node);
761 if (cno < root->cno) {
763 } else if (cno > root->cno) {
766 atomic_inc(&root->count);
767 spin_unlock(&nilfs->ns_cptree_lock);
776 atomic_set(&new->count, 1);
777 atomic64_set(&new->inodes_count, 0);
778 atomic64_set(&new->blocks_count, 0);
780 rb_link_node(&new->rb_node, parent, p);
781 rb_insert_color(&new->rb_node, &nilfs->ns_cptree);
783 spin_unlock(&nilfs->ns_cptree_lock);
788 void nilfs_put_root(struct nilfs_root *root)
790 if (atomic_dec_and_test(&root->count)) {
791 struct the_nilfs *nilfs = root->nilfs;
793 spin_lock(&nilfs->ns_cptree_lock);
794 rb_erase(&root->rb_node, &nilfs->ns_cptree);
795 spin_unlock(&nilfs->ns_cptree_lock);