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>
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
);
113 static int nilfs_load_super_root(struct the_nilfs
*nilfs
,
114 struct nilfs_sb_info
*sbi
, sector_t sr_block
)
116 struct buffer_head
*bh_sr
;
117 struct nilfs_super_root
*raw_sr
;
118 unsigned dat_entry_size
, segment_usage_size
, checkpoint_size
;
122 err
= nilfs_read_super_root_block(sbi
->s_super
, sr_block
, &bh_sr
, 1);
126 down_read(&nilfs
->ns_sem
);
127 dat_entry_size
= le16_to_cpu(nilfs
->ns_sbp
->s_dat_entry_size
);
128 checkpoint_size
= le16_to_cpu(nilfs
->ns_sbp
->s_checkpoint_size
);
129 segment_usage_size
= le16_to_cpu(nilfs
->ns_sbp
->s_segment_usage_size
);
130 up_read(&nilfs
->ns_sem
);
132 inode_size
= nilfs
->ns_inode_size
;
135 nilfs
->ns_dat
= nilfs_mdt_new(
136 nilfs
, NULL
, NILFS_DAT_INO
, NILFS_DAT_GFP
);
137 if (unlikely(!nilfs
->ns_dat
))
140 nilfs
->ns_gc_dat
= nilfs_mdt_new(
141 nilfs
, NULL
, NILFS_DAT_INO
, NILFS_DAT_GFP
);
142 if (unlikely(!nilfs
->ns_gc_dat
))
145 nilfs
->ns_cpfile
= nilfs_mdt_new(
146 nilfs
, NULL
, NILFS_CPFILE_INO
, NILFS_CPFILE_GFP
);
147 if (unlikely(!nilfs
->ns_cpfile
))
150 nilfs
->ns_sufile
= nilfs_mdt_new(
151 nilfs
, NULL
, NILFS_SUFILE_INO
, NILFS_SUFILE_GFP
);
152 if (unlikely(!nilfs
->ns_sufile
))
155 err
= nilfs_palloc_init_blockgroup(nilfs
->ns_dat
, dat_entry_size
);
159 err
= nilfs_palloc_init_blockgroup(nilfs
->ns_gc_dat
, dat_entry_size
);
163 nilfs_mdt_set_shadow(nilfs
->ns_dat
, nilfs
->ns_gc_dat
);
164 nilfs_mdt_set_entry_size(nilfs
->ns_cpfile
, checkpoint_size
,
165 sizeof(struct nilfs_cpfile_header
));
166 nilfs_mdt_set_entry_size(nilfs
->ns_sufile
, segment_usage_size
,
167 sizeof(struct nilfs_sufile_header
));
169 err
= nilfs_mdt_read_inode_direct(
170 nilfs
->ns_dat
, bh_sr
, NILFS_SR_DAT_OFFSET(inode_size
));
174 err
= nilfs_mdt_read_inode_direct(
175 nilfs
->ns_cpfile
, bh_sr
, NILFS_SR_CPFILE_OFFSET(inode_size
));
179 err
= nilfs_mdt_read_inode_direct(
180 nilfs
->ns_sufile
, bh_sr
, NILFS_SR_SUFILE_OFFSET(inode_size
));
184 raw_sr
= (struct nilfs_super_root
*)bh_sr
->b_data
;
185 nilfs
->ns_nongc_ctime
= le64_to_cpu(raw_sr
->sr_nongc_ctime
);
192 nilfs_mdt_destroy(nilfs
->ns_sufile
);
195 nilfs_mdt_destroy(nilfs
->ns_cpfile
);
198 nilfs_mdt_destroy(nilfs
->ns_gc_dat
);
201 nilfs_mdt_destroy(nilfs
->ns_dat
);
205 static void nilfs_init_recovery_info(struct nilfs_recovery_info
*ri
)
207 memset(ri
, 0, sizeof(*ri
));
208 INIT_LIST_HEAD(&ri
->ri_used_segments
);
211 static void nilfs_clear_recovery_info(struct nilfs_recovery_info
*ri
)
213 nilfs_dispose_segment_list(&ri
->ri_used_segments
);
217 * load_nilfs - load and recover the nilfs
218 * @nilfs: the_nilfs structure to be released
219 * @sbi: nilfs_sb_info used to recover past segment
221 * load_nilfs() searches and load the latest super root,
222 * attaches the last segment, and does recovery if needed.
223 * The caller must call this exclusively for simultaneous mounts.
225 int load_nilfs(struct the_nilfs
*nilfs
, struct nilfs_sb_info
*sbi
)
227 struct nilfs_recovery_info ri
;
228 unsigned int s_flags
= sbi
->s_super
->s_flags
;
229 int really_read_only
= bdev_read_only(nilfs
->ns_bdev
);
233 nilfs_init_recovery_info(&ri
);
235 down_write(&nilfs
->ns_sem
);
236 valid_fs
= (nilfs
->ns_mount_state
& NILFS_VALID_FS
);
237 up_write(&nilfs
->ns_sem
);
239 if (!valid_fs
&& (s_flags
& MS_RDONLY
)) {
240 printk(KERN_INFO
"NILFS: INFO: recovery "
241 "required for readonly filesystem.\n");
242 if (really_read_only
) {
243 printk(KERN_ERR
"NILFS: write access "
244 "unavailable, cannot proceed.\n");
248 printk(KERN_INFO
"NILFS: write access will "
249 "be enabled during recovery.\n");
250 sbi
->s_super
->s_flags
&= ~MS_RDONLY
;
253 err
= nilfs_search_super_root(nilfs
, sbi
, &ri
);
255 printk(KERN_ERR
"NILFS: error searching super root.\n");
259 err
= nilfs_load_super_root(nilfs
, sbi
, ri
.ri_super_root
);
261 printk(KERN_ERR
"NILFS: error loading super root.\n");
266 err
= nilfs_recover_logical_segments(nilfs
, sbi
, &ri
);
268 nilfs_mdt_destroy(nilfs
->ns_cpfile
);
269 nilfs_mdt_destroy(nilfs
->ns_sufile
);
270 nilfs_mdt_destroy(nilfs
->ns_dat
);
273 if (ri
.ri_need_recovery
== NILFS_RECOVERY_SR_UPDATED
) {
274 down_write(&nilfs
->ns_sem
);
275 nilfs_update_last_segment(sbi
, 0);
276 up_write(&nilfs
->ns_sem
);
280 set_nilfs_loaded(nilfs
);
283 nilfs_clear_recovery_info(&ri
);
284 sbi
->s_super
->s_flags
= s_flags
;
288 static unsigned long long nilfs_max_size(unsigned int blkbits
)
290 unsigned int max_bits
;
291 unsigned long long res
= MAX_LFS_FILESIZE
; /* page cache limit */
293 max_bits
= blkbits
+ NILFS_BMAP_KEY_BIT
; /* bmap size limit */
295 res
= min_t(unsigned long long, res
, (1ULL << max_bits
) - 1);
300 nilfs_store_disk_layout(struct the_nilfs
*nilfs
, struct super_block
*sb
,
301 struct nilfs_super_block
*sbp
)
303 if (le32_to_cpu(sbp
->s_rev_level
) != NILFS_CURRENT_REV
) {
304 printk(KERN_ERR
"NILFS: revision mismatch "
305 "(superblock rev.=%d.%d, current rev.=%d.%d). "
306 "Please check the version of mkfs.nilfs.\n",
307 le32_to_cpu(sbp
->s_rev_level
),
308 le16_to_cpu(sbp
->s_minor_rev_level
),
309 NILFS_CURRENT_REV
, NILFS_MINOR_REV
);
312 nilfs
->ns_inode_size
= le16_to_cpu(sbp
->s_inode_size
);
313 nilfs
->ns_first_ino
= le32_to_cpu(sbp
->s_first_ino
);
315 nilfs
->ns_blocks_per_segment
= le32_to_cpu(sbp
->s_blocks_per_segment
);
316 if (nilfs
->ns_blocks_per_segment
< NILFS_SEG_MIN_BLOCKS
) {
317 printk(KERN_ERR
"NILFS: too short segment. \n");
321 nilfs
->ns_first_data_block
= le64_to_cpu(sbp
->s_first_data_block
);
322 nilfs
->ns_nsegments
= le64_to_cpu(sbp
->s_nsegments
);
323 nilfs
->ns_r_segments_percentage
=
324 le32_to_cpu(sbp
->s_r_segments_percentage
);
326 max_t(unsigned long, NILFS_MIN_NRSVSEGS
,
327 DIV_ROUND_UP(nilfs
->ns_nsegments
*
328 nilfs
->ns_r_segments_percentage
, 100));
329 nilfs
->ns_crc_seed
= le32_to_cpu(sbp
->s_crc_seed
);
334 * init_nilfs - initialize a NILFS instance.
335 * @nilfs: the_nilfs structure
336 * @sbi: nilfs_sb_info
338 * @data: mount options
340 * init_nilfs() performs common initialization per block device (e.g.
341 * reading the super block, getting disk layout information, initializing
342 * shared fields in the_nilfs). It takes on some portion of the jobs
343 * typically done by a fill_super() routine. This division arises from
344 * the nature that multiple NILFS instances may be simultaneously
345 * mounted on a device.
346 * For multiple mounts on the same device, only the first mount
347 * invokes these tasks.
349 * Return Value: On success, 0 is returned. On error, a negative error
352 int init_nilfs(struct the_nilfs
*nilfs
, struct nilfs_sb_info
*sbi
, char *data
)
354 struct super_block
*sb
= sbi
->s_super
;
355 struct buffer_head
*sbh
;
356 struct nilfs_super_block
*sbp
;
357 struct backing_dev_info
*bdi
;
361 down_write(&nilfs
->ns_sem
);
362 if (nilfs_init(nilfs
)) {
363 /* Load values from existing the_nilfs */
365 err
= nilfs_store_magic_and_option(sb
, sbp
, data
);
369 blocksize
= BLOCK_SIZE
<< le32_to_cpu(sbp
->s_log_block_size
);
370 if (sb
->s_blocksize
!= blocksize
&&
371 !sb_set_blocksize(sb
, blocksize
)) {
372 printk(KERN_ERR
"NILFS: blocksize %d unfit to device\n",
376 sb
->s_maxbytes
= nilfs_max_size(sb
->s_blocksize_bits
);
380 sbp
= nilfs_load_super_block(sb
, &sbh
);
385 err
= nilfs_store_magic_and_option(sb
, sbp
, data
);
389 blocksize
= BLOCK_SIZE
<< le32_to_cpu(sbp
->s_log_block_size
);
390 if (sb
->s_blocksize
!= blocksize
) {
391 sbp
= nilfs_reload_super_block(sb
, &sbh
, blocksize
);
395 /* not failed_sbh; sbh is released automatically
396 when reloading fails. */
399 nilfs
->ns_blocksize_bits
= sb
->s_blocksize_bits
;
401 err
= nilfs_store_disk_layout(nilfs
, sb
, sbp
);
405 sb
->s_maxbytes
= nilfs_max_size(sb
->s_blocksize_bits
);
407 nilfs
->ns_mount_state
= le16_to_cpu(sbp
->s_state
);
411 bdi
= nilfs
->ns_bdev
->bd_inode_backing_dev_info
;
413 bdi
= nilfs
->ns_bdev
->bd_inode
->i_mapping
->backing_dev_info
;
414 nilfs
->ns_bdi
= bdi
? : &default_backing_dev_info
;
416 /* Finding last segment */
417 nilfs
->ns_last_pseg
= le64_to_cpu(sbp
->s_last_pseg
);
418 nilfs
->ns_last_cno
= le64_to_cpu(sbp
->s_last_cno
);
419 nilfs
->ns_last_seq
= le64_to_cpu(sbp
->s_last_seq
);
421 nilfs
->ns_seg_seq
= nilfs
->ns_last_seq
;
423 nilfs_get_segnum_of_block(nilfs
, nilfs
->ns_last_pseg
);
424 nilfs
->ns_cno
= nilfs
->ns_last_cno
+ 1;
425 if (nilfs
->ns_segnum
>= nilfs
->ns_nsegments
) {
426 printk(KERN_ERR
"NILFS invalid last segment number.\n");
431 nilfs
->ns_free_segments_count
=
432 nilfs
->ns_nsegments
- (nilfs
->ns_segnum
+ 1);
434 /* Initialize gcinode cache */
435 err
= nilfs_init_gccache(nilfs
);
439 set_nilfs_init(nilfs
);
442 up_write(&nilfs
->ns_sem
);
450 int nilfs_count_free_blocks(struct the_nilfs
*nilfs
, sector_t
*nblocks
)
452 struct inode
*dat
= nilfs_dat_inode(nilfs
);
453 unsigned long ncleansegs
;
456 down_read(&NILFS_MDT(dat
)->mi_sem
); /* XXX */
457 err
= nilfs_sufile_get_ncleansegs(nilfs
->ns_sufile
, &ncleansegs
);
458 up_read(&NILFS_MDT(dat
)->mi_sem
); /* XXX */
460 *nblocks
= (sector_t
)ncleansegs
* nilfs
->ns_blocks_per_segment
;
464 int nilfs_near_disk_full(struct the_nilfs
*nilfs
)
466 struct inode
*sufile
= nilfs
->ns_sufile
;
467 unsigned long ncleansegs
, nincsegs
;
470 ret
= nilfs_sufile_get_ncleansegs(sufile
, &ncleansegs
);
472 nincsegs
= atomic_read(&nilfs
->ns_ndirtyblks
) /
473 nilfs
->ns_blocks_per_segment
+ 1;
474 if (ncleansegs
<= nilfs
->ns_nrsvsegs
+ nincsegs
)
480 int nilfs_checkpoint_is_mounted(struct the_nilfs
*nilfs
, __u64 cno
,
483 struct nilfs_sb_info
*sbi
;
486 down_read(&nilfs
->ns_sem
);
487 if (cno
== 0 || cno
> nilfs
->ns_cno
)
490 list_for_each_entry(sbi
, &nilfs
->ns_supers
, s_list
) {
491 if (sbi
->s_snapshot_cno
== cno
&&
492 (!snapshot_mount
|| nilfs_test_opt(sbi
, SNAPSHOT
))) {
493 /* exclude read-only mounts */
498 /* for protecting recent checkpoints */
499 if (cno
>= nilfs_last_cno(nilfs
))
503 up_read(&nilfs
->ns_sem
);