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/crc32.h>
37 void nilfs_set_last_segment(struct the_nilfs
*nilfs
,
38 sector_t start_blocknr
, u64 seq
, __u64 cno
)
40 spin_lock(&nilfs
->ns_last_segment_lock
);
41 nilfs
->ns_last_pseg
= start_blocknr
;
42 nilfs
->ns_last_seq
= seq
;
43 nilfs
->ns_last_cno
= cno
;
44 spin_unlock(&nilfs
->ns_last_segment_lock
);
48 * alloc_nilfs - allocate the_nilfs structure
49 * @bdev: block device to which the_nilfs is related
51 * alloc_nilfs() allocates memory for the_nilfs and
52 * initializes its reference count and locks.
54 * Return Value: On success, pointer to the_nilfs is returned.
55 * On error, NULL is returned.
57 struct the_nilfs
*alloc_nilfs(struct block_device
*bdev
)
59 struct the_nilfs
*nilfs
;
61 nilfs
= kzalloc(sizeof(*nilfs
), GFP_KERNEL
);
65 nilfs
->ns_bdev
= bdev
;
66 atomic_set(&nilfs
->ns_count
, 1);
67 atomic_set(&nilfs
->ns_writer_refcount
, -1);
68 atomic_set(&nilfs
->ns_ndirtyblks
, 0);
69 init_rwsem(&nilfs
->ns_sem
);
70 mutex_init(&nilfs
->ns_writer_mutex
);
71 INIT_LIST_HEAD(&nilfs
->ns_supers
);
72 spin_lock_init(&nilfs
->ns_last_segment_lock
);
73 nilfs
->ns_gc_inodes_h
= NULL
;
74 init_rwsem(&nilfs
->ns_segctor_sem
);
80 * put_nilfs - release a reference to the_nilfs
81 * @nilfs: the_nilfs structure to be released
83 * put_nilfs() decrements a reference counter of the_nilfs.
84 * If the reference count reaches zero, the_nilfs is freed.
86 void put_nilfs(struct the_nilfs
*nilfs
)
88 if (!atomic_dec_and_test(&nilfs
->ns_count
))
91 * Increment of ns_count never occur below because the caller
92 * of get_nilfs() holds at least one reference to the_nilfs.
93 * Thus its exclusion control is not required here.
96 if (nilfs_loaded(nilfs
)) {
97 nilfs_mdt_clear(nilfs
->ns_sufile
);
98 nilfs_mdt_destroy(nilfs
->ns_sufile
);
99 nilfs_mdt_clear(nilfs
->ns_cpfile
);
100 nilfs_mdt_destroy(nilfs
->ns_cpfile
);
101 nilfs_mdt_clear(nilfs
->ns_dat
);
102 nilfs_mdt_destroy(nilfs
->ns_dat
);
103 /* XXX: how and when to clear nilfs->ns_gc_dat? */
104 nilfs_mdt_destroy(nilfs
->ns_gc_dat
);
106 if (nilfs_init(nilfs
)) {
107 nilfs_destroy_gccache(nilfs
);
108 brelse(nilfs
->ns_sbh
[0]);
109 brelse(nilfs
->ns_sbh
[1]);
114 static int nilfs_load_super_root(struct the_nilfs
*nilfs
,
115 struct nilfs_sb_info
*sbi
, sector_t sr_block
)
117 static struct lock_class_key dat_lock_key
;
118 struct buffer_head
*bh_sr
;
119 struct nilfs_super_root
*raw_sr
;
120 struct nilfs_super_block
**sbp
= nilfs
->ns_sbp
;
121 unsigned dat_entry_size
, segment_usage_size
, checkpoint_size
;
125 err
= nilfs_read_super_root_block(sbi
->s_super
, sr_block
, &bh_sr
, 1);
129 down_read(&nilfs
->ns_sem
);
130 dat_entry_size
= le16_to_cpu(sbp
[0]->s_dat_entry_size
);
131 checkpoint_size
= le16_to_cpu(sbp
[0]->s_checkpoint_size
);
132 segment_usage_size
= le16_to_cpu(sbp
[0]->s_segment_usage_size
);
133 up_read(&nilfs
->ns_sem
);
135 inode_size
= nilfs
->ns_inode_size
;
138 nilfs
->ns_dat
= nilfs_mdt_new(
139 nilfs
, NULL
, NILFS_DAT_INO
, NILFS_DAT_GFP
);
140 if (unlikely(!nilfs
->ns_dat
))
143 nilfs
->ns_gc_dat
= nilfs_mdt_new(
144 nilfs
, NULL
, NILFS_DAT_INO
, NILFS_DAT_GFP
);
145 if (unlikely(!nilfs
->ns_gc_dat
))
148 nilfs
->ns_cpfile
= nilfs_mdt_new(
149 nilfs
, NULL
, NILFS_CPFILE_INO
, NILFS_CPFILE_GFP
);
150 if (unlikely(!nilfs
->ns_cpfile
))
153 nilfs
->ns_sufile
= nilfs_mdt_new(
154 nilfs
, NULL
, NILFS_SUFILE_INO
, NILFS_SUFILE_GFP
);
155 if (unlikely(!nilfs
->ns_sufile
))
158 err
= nilfs_palloc_init_blockgroup(nilfs
->ns_dat
, dat_entry_size
);
162 err
= nilfs_palloc_init_blockgroup(nilfs
->ns_gc_dat
, dat_entry_size
);
166 lockdep_set_class(&NILFS_MDT(nilfs
->ns_dat
)->mi_sem
, &dat_lock_key
);
167 lockdep_set_class(&NILFS_MDT(nilfs
->ns_gc_dat
)->mi_sem
, &dat_lock_key
);
169 nilfs_mdt_set_shadow(nilfs
->ns_dat
, nilfs
->ns_gc_dat
);
170 nilfs_mdt_set_entry_size(nilfs
->ns_cpfile
, checkpoint_size
,
171 sizeof(struct nilfs_cpfile_header
));
172 nilfs_mdt_set_entry_size(nilfs
->ns_sufile
, segment_usage_size
,
173 sizeof(struct nilfs_sufile_header
));
175 err
= nilfs_mdt_read_inode_direct(
176 nilfs
->ns_dat
, bh_sr
, NILFS_SR_DAT_OFFSET(inode_size
));
180 err
= nilfs_mdt_read_inode_direct(
181 nilfs
->ns_cpfile
, bh_sr
, NILFS_SR_CPFILE_OFFSET(inode_size
));
185 err
= nilfs_mdt_read_inode_direct(
186 nilfs
->ns_sufile
, bh_sr
, NILFS_SR_SUFILE_OFFSET(inode_size
));
190 raw_sr
= (struct nilfs_super_root
*)bh_sr
->b_data
;
191 nilfs
->ns_nongc_ctime
= le64_to_cpu(raw_sr
->sr_nongc_ctime
);
198 nilfs_mdt_destroy(nilfs
->ns_sufile
);
201 nilfs_mdt_destroy(nilfs
->ns_cpfile
);
204 nilfs_mdt_destroy(nilfs
->ns_gc_dat
);
207 nilfs_mdt_destroy(nilfs
->ns_dat
);
211 static void nilfs_init_recovery_info(struct nilfs_recovery_info
*ri
)
213 memset(ri
, 0, sizeof(*ri
));
214 INIT_LIST_HEAD(&ri
->ri_used_segments
);
217 static void nilfs_clear_recovery_info(struct nilfs_recovery_info
*ri
)
219 nilfs_dispose_segment_list(&ri
->ri_used_segments
);
223 * load_nilfs - load and recover the nilfs
224 * @nilfs: the_nilfs structure to be released
225 * @sbi: nilfs_sb_info used to recover past segment
227 * load_nilfs() searches and load the latest super root,
228 * attaches the last segment, and does recovery if needed.
229 * The caller must call this exclusively for simultaneous mounts.
231 int load_nilfs(struct the_nilfs
*nilfs
, struct nilfs_sb_info
*sbi
)
233 struct nilfs_recovery_info ri
;
234 unsigned int s_flags
= sbi
->s_super
->s_flags
;
235 int really_read_only
= bdev_read_only(nilfs
->ns_bdev
);
239 nilfs_init_recovery_info(&ri
);
241 down_write(&nilfs
->ns_sem
);
242 valid_fs
= (nilfs
->ns_mount_state
& NILFS_VALID_FS
);
243 up_write(&nilfs
->ns_sem
);
245 if (!valid_fs
&& (s_flags
& MS_RDONLY
)) {
246 printk(KERN_INFO
"NILFS: INFO: recovery "
247 "required for readonly filesystem.\n");
248 if (really_read_only
) {
249 printk(KERN_ERR
"NILFS: write access "
250 "unavailable, cannot proceed.\n");
254 printk(KERN_INFO
"NILFS: write access will "
255 "be enabled during recovery.\n");
256 sbi
->s_super
->s_flags
&= ~MS_RDONLY
;
259 err
= nilfs_search_super_root(nilfs
, sbi
, &ri
);
261 printk(KERN_ERR
"NILFS: error searching super root.\n");
265 err
= nilfs_load_super_root(nilfs
, sbi
, ri
.ri_super_root
);
267 printk(KERN_ERR
"NILFS: error loading super root.\n");
272 err
= nilfs_recover_logical_segments(nilfs
, sbi
, &ri
);
274 nilfs_mdt_destroy(nilfs
->ns_cpfile
);
275 nilfs_mdt_destroy(nilfs
->ns_sufile
);
276 nilfs_mdt_destroy(nilfs
->ns_dat
);
279 if (ri
.ri_need_recovery
== NILFS_RECOVERY_SR_UPDATED
)
280 sbi
->s_super
->s_dirt
= 1;
283 set_nilfs_loaded(nilfs
);
286 nilfs_clear_recovery_info(&ri
);
287 sbi
->s_super
->s_flags
= s_flags
;
291 static unsigned long long nilfs_max_size(unsigned int blkbits
)
293 unsigned int max_bits
;
294 unsigned long long res
= MAX_LFS_FILESIZE
; /* page cache limit */
296 max_bits
= blkbits
+ NILFS_BMAP_KEY_BIT
; /* bmap size limit */
298 res
= min_t(unsigned long long, res
, (1ULL << max_bits
) - 1);
302 static int nilfs_store_disk_layout(struct the_nilfs
*nilfs
,
303 struct nilfs_super_block
*sbp
)
305 if (le32_to_cpu(sbp
->s_rev_level
) != NILFS_CURRENT_REV
) {
306 printk(KERN_ERR
"NILFS: revision mismatch "
307 "(superblock rev.=%d.%d, current rev.=%d.%d). "
308 "Please check the version of mkfs.nilfs.\n",
309 le32_to_cpu(sbp
->s_rev_level
),
310 le16_to_cpu(sbp
->s_minor_rev_level
),
311 NILFS_CURRENT_REV
, NILFS_MINOR_REV
);
314 nilfs
->ns_sbsize
= le16_to_cpu(sbp
->s_bytes
);
315 if (nilfs
->ns_sbsize
> BLOCK_SIZE
)
318 nilfs
->ns_inode_size
= le16_to_cpu(sbp
->s_inode_size
);
319 nilfs
->ns_first_ino
= le32_to_cpu(sbp
->s_first_ino
);
321 nilfs
->ns_blocks_per_segment
= le32_to_cpu(sbp
->s_blocks_per_segment
);
322 if (nilfs
->ns_blocks_per_segment
< NILFS_SEG_MIN_BLOCKS
) {
323 printk(KERN_ERR
"NILFS: too short segment. \n");
327 nilfs
->ns_first_data_block
= le64_to_cpu(sbp
->s_first_data_block
);
328 nilfs
->ns_nsegments
= le64_to_cpu(sbp
->s_nsegments
);
329 nilfs
->ns_r_segments_percentage
=
330 le32_to_cpu(sbp
->s_r_segments_percentage
);
332 max_t(unsigned long, NILFS_MIN_NRSVSEGS
,
333 DIV_ROUND_UP(nilfs
->ns_nsegments
*
334 nilfs
->ns_r_segments_percentage
, 100));
335 nilfs
->ns_crc_seed
= le32_to_cpu(sbp
->s_crc_seed
);
339 static int nilfs_valid_sb(struct nilfs_super_block
*sbp
)
341 static unsigned char sum
[4];
342 const int sumoff
= offsetof(struct nilfs_super_block
, s_sum
);
346 if (!sbp
|| le16_to_cpu(sbp
->s_magic
) != NILFS_SUPER_MAGIC
)
348 bytes
= le16_to_cpu(sbp
->s_bytes
);
349 if (bytes
> BLOCK_SIZE
)
351 crc
= crc32_le(le32_to_cpu(sbp
->s_crc_seed
), (unsigned char *)sbp
,
353 crc
= crc32_le(crc
, sum
, 4);
354 crc
= crc32_le(crc
, (unsigned char *)sbp
+ sumoff
+ 4,
356 return crc
== le32_to_cpu(sbp
->s_sum
);
359 static int nilfs_sb2_bad_offset(struct nilfs_super_block
*sbp
, u64 offset
)
361 return offset
< ((le64_to_cpu(sbp
->s_nsegments
) *
362 le32_to_cpu(sbp
->s_blocks_per_segment
)) <<
363 (le32_to_cpu(sbp
->s_log_block_size
) + 10));
366 static void nilfs_release_super_block(struct the_nilfs
*nilfs
)
370 for (i
= 0; i
< 2; i
++) {
371 if (nilfs
->ns_sbp
[i
]) {
372 brelse(nilfs
->ns_sbh
[i
]);
373 nilfs
->ns_sbh
[i
] = NULL
;
374 nilfs
->ns_sbp
[i
] = NULL
;
379 void nilfs_fall_back_super_block(struct the_nilfs
*nilfs
)
381 brelse(nilfs
->ns_sbh
[0]);
382 nilfs
->ns_sbh
[0] = nilfs
->ns_sbh
[1];
383 nilfs
->ns_sbp
[0] = nilfs
->ns_sbp
[1];
384 nilfs
->ns_sbh
[1] = NULL
;
385 nilfs
->ns_sbp
[1] = NULL
;
388 void nilfs_swap_super_block(struct the_nilfs
*nilfs
)
390 struct buffer_head
*tsbh
= nilfs
->ns_sbh
[0];
391 struct nilfs_super_block
*tsbp
= nilfs
->ns_sbp
[0];
393 nilfs
->ns_sbh
[0] = nilfs
->ns_sbh
[1];
394 nilfs
->ns_sbp
[0] = nilfs
->ns_sbp
[1];
395 nilfs
->ns_sbh
[1] = tsbh
;
396 nilfs
->ns_sbp
[1] = tsbp
;
399 static int nilfs_load_super_block(struct the_nilfs
*nilfs
,
400 struct super_block
*sb
, int blocksize
,
401 struct nilfs_super_block
**sbpp
)
403 struct nilfs_super_block
**sbp
= nilfs
->ns_sbp
;
404 struct buffer_head
**sbh
= nilfs
->ns_sbh
;
405 u64 sb2off
= NILFS_SB2_OFFSET_BYTES(nilfs
->ns_bdev
->bd_inode
->i_size
);
406 int valid
[2], swp
= 0;
408 sbp
[0] = nilfs_read_super_block(sb
, NILFS_SB_OFFSET_BYTES
, blocksize
,
410 sbp
[1] = nilfs_read_super_block(sb
, sb2off
, blocksize
, &sbh
[1]);
414 printk(KERN_ERR
"NILFS: unable to read superblock\n");
418 "NILFS warning: unable to read primary superblock\n");
421 "NILFS warning: unable to read secondary superblock\n");
423 valid
[0] = nilfs_valid_sb(sbp
[0]);
424 valid
[1] = nilfs_valid_sb(sbp
[1]);
427 le64_to_cpu(sbp
[1]->s_wtime
) > le64_to_cpu(sbp
[0]->s_wtime
));
429 if (valid
[swp
] && nilfs_sb2_bad_offset(sbp
[swp
], sb2off
)) {
436 nilfs_release_super_block(nilfs
);
437 printk(KERN_ERR
"NILFS: Can't find nilfs on dev %s.\n",
443 printk(KERN_WARNING
"NILFS warning: broken superblock. "
444 "using spare superblock.\n");
445 nilfs_swap_super_block(nilfs
);
448 nilfs
->ns_sbwtime
[0] = le64_to_cpu(sbp
[0]->s_wtime
);
449 nilfs
->ns_sbwtime
[1] = valid
[!swp
] ? le64_to_cpu(sbp
[1]->s_wtime
) : 0;
450 nilfs
->ns_prot_seq
= le64_to_cpu(sbp
[valid
[1] & !swp
]->s_last_seq
);
456 * init_nilfs - initialize a NILFS instance.
457 * @nilfs: the_nilfs structure
458 * @sbi: nilfs_sb_info
460 * @data: mount options
462 * init_nilfs() performs common initialization per block device (e.g.
463 * reading the super block, getting disk layout information, initializing
464 * shared fields in the_nilfs). It takes on some portion of the jobs
465 * typically done by a fill_super() routine. This division arises from
466 * the nature that multiple NILFS instances may be simultaneously
467 * mounted on a device.
468 * For multiple mounts on the same device, only the first mount
469 * invokes these tasks.
471 * Return Value: On success, 0 is returned. On error, a negative error
474 int init_nilfs(struct the_nilfs
*nilfs
, struct nilfs_sb_info
*sbi
, char *data
)
476 struct super_block
*sb
= sbi
->s_super
;
477 struct nilfs_super_block
*sbp
;
478 struct backing_dev_info
*bdi
;
482 down_write(&nilfs
->ns_sem
);
483 if (nilfs_init(nilfs
)) {
484 /* Load values from existing the_nilfs */
485 sbp
= nilfs
->ns_sbp
[0];
486 err
= nilfs_store_magic_and_option(sb
, sbp
, data
);
490 blocksize
= BLOCK_SIZE
<< le32_to_cpu(sbp
->s_log_block_size
);
491 if (sb
->s_blocksize
!= blocksize
&&
492 !sb_set_blocksize(sb
, blocksize
)) {
493 printk(KERN_ERR
"NILFS: blocksize %d unfit to device\n",
497 sb
->s_maxbytes
= nilfs_max_size(sb
->s_blocksize_bits
);
501 blocksize
= sb_min_blocksize(sb
, BLOCK_SIZE
);
503 printk(KERN_ERR
"NILFS: unable to set blocksize\n");
507 err
= nilfs_load_super_block(nilfs
, sb
, blocksize
, &sbp
);
511 err
= nilfs_store_magic_and_option(sb
, sbp
, data
);
515 blocksize
= BLOCK_SIZE
<< le32_to_cpu(sbp
->s_log_block_size
);
516 if (sb
->s_blocksize
!= blocksize
) {
517 int hw_blocksize
= bdev_hardsect_size(sb
->s_bdev
);
519 if (blocksize
< hw_blocksize
) {
521 "NILFS: blocksize %d too small for device "
522 "(sector-size = %d).\n",
523 blocksize
, hw_blocksize
);
527 nilfs_release_super_block(nilfs
);
528 sb_set_blocksize(sb
, blocksize
);
530 err
= nilfs_load_super_block(nilfs
, sb
, blocksize
, &sbp
);
533 /* not failed_sbh; sbh is released automatically
534 when reloading fails. */
536 nilfs
->ns_blocksize_bits
= sb
->s_blocksize_bits
;
538 err
= nilfs_store_disk_layout(nilfs
, sbp
);
542 sb
->s_maxbytes
= nilfs_max_size(sb
->s_blocksize_bits
);
544 nilfs
->ns_mount_state
= le16_to_cpu(sbp
->s_state
);
546 bdi
= nilfs
->ns_bdev
->bd_inode_backing_dev_info
;
548 bdi
= nilfs
->ns_bdev
->bd_inode
->i_mapping
->backing_dev_info
;
549 nilfs
->ns_bdi
= bdi
? : &default_backing_dev_info
;
551 /* Finding last segment */
552 nilfs
->ns_last_pseg
= le64_to_cpu(sbp
->s_last_pseg
);
553 nilfs
->ns_last_cno
= le64_to_cpu(sbp
->s_last_cno
);
554 nilfs
->ns_last_seq
= le64_to_cpu(sbp
->s_last_seq
);
556 nilfs
->ns_seg_seq
= nilfs
->ns_last_seq
;
558 nilfs_get_segnum_of_block(nilfs
, nilfs
->ns_last_pseg
);
559 nilfs
->ns_cno
= nilfs
->ns_last_cno
+ 1;
560 if (nilfs
->ns_segnum
>= nilfs
->ns_nsegments
) {
561 printk(KERN_ERR
"NILFS invalid last segment number.\n");
566 nilfs
->ns_free_segments_count
=
567 nilfs
->ns_nsegments
- (nilfs
->ns_segnum
+ 1);
569 /* Initialize gcinode cache */
570 err
= nilfs_init_gccache(nilfs
);
574 set_nilfs_init(nilfs
);
577 up_write(&nilfs
->ns_sem
);
581 nilfs_release_super_block(nilfs
);
585 int nilfs_count_free_blocks(struct the_nilfs
*nilfs
, sector_t
*nblocks
)
587 struct inode
*dat
= nilfs_dat_inode(nilfs
);
588 unsigned long ncleansegs
;
591 down_read(&NILFS_MDT(dat
)->mi_sem
); /* XXX */
592 err
= nilfs_sufile_get_ncleansegs(nilfs
->ns_sufile
, &ncleansegs
);
593 up_read(&NILFS_MDT(dat
)->mi_sem
); /* XXX */
595 *nblocks
= (sector_t
)ncleansegs
* nilfs
->ns_blocks_per_segment
;
599 int nilfs_near_disk_full(struct the_nilfs
*nilfs
)
601 struct inode
*sufile
= nilfs
->ns_sufile
;
602 unsigned long ncleansegs
, nincsegs
;
605 ret
= nilfs_sufile_get_ncleansegs(sufile
, &ncleansegs
);
607 nincsegs
= atomic_read(&nilfs
->ns_ndirtyblks
) /
608 nilfs
->ns_blocks_per_segment
+ 1;
609 if (ncleansegs
<= nilfs
->ns_nrsvsegs
+ nincsegs
)
615 int nilfs_checkpoint_is_mounted(struct the_nilfs
*nilfs
, __u64 cno
,
618 struct nilfs_sb_info
*sbi
;
621 down_read(&nilfs
->ns_sem
);
622 if (cno
== 0 || cno
> nilfs
->ns_cno
)
625 list_for_each_entry(sbi
, &nilfs
->ns_supers
, s_list
) {
626 if (sbi
->s_snapshot_cno
== cno
&&
627 (!snapshot_mount
|| nilfs_test_opt(sbi
, SNAPSHOT
))) {
628 /* exclude read-only mounts */
633 /* for protecting recent checkpoints */
634 if (cno
>= nilfs_last_cno(nilfs
))
638 up_read(&nilfs
->ns_sem
);