2 * sufile.c - NILFS segment usage file.
4 * Copyright (C) 2006-2008 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 Koji Sato <koji@osrg.net>.
23 #include <linux/kernel.h>
25 #include <linux/string.h>
26 #include <linux/buffer_head.h>
27 #include <linux/errno.h>
28 #include <linux/nilfs2_fs.h>
33 static inline unsigned long
34 nilfs_sufile_segment_usages_per_block(const struct inode *sufile)
36 return NILFS_MDT(sufile)->mi_entries_per_block;
40 nilfs_sufile_get_blkoff(const struct inode *sufile, __u64 segnum)
42 __u64 t = segnum + NILFS_MDT(sufile)->mi_first_entry_offset;
43 do_div(t, nilfs_sufile_segment_usages_per_block(sufile));
44 return (unsigned long)t;
48 nilfs_sufile_get_offset(const struct inode *sufile, __u64 segnum)
50 __u64 t = segnum + NILFS_MDT(sufile)->mi_first_entry_offset;
51 return do_div(t, nilfs_sufile_segment_usages_per_block(sufile));
55 nilfs_sufile_segment_usages_in_block(const struct inode *sufile, __u64 curr,
58 return min_t(unsigned long,
59 nilfs_sufile_segment_usages_per_block(sufile) -
60 nilfs_sufile_get_offset(sufile, curr),
64 static inline struct nilfs_sufile_header *
65 nilfs_sufile_block_get_header(const struct inode *sufile,
66 struct buffer_head *bh,
69 return kaddr + bh_offset(bh);
72 static struct nilfs_segment_usage *
73 nilfs_sufile_block_get_segment_usage(const struct inode *sufile, __u64 segnum,
74 struct buffer_head *bh, void *kaddr)
76 return kaddr + bh_offset(bh) +
77 nilfs_sufile_get_offset(sufile, segnum) *
78 NILFS_MDT(sufile)->mi_entry_size;
81 static inline int nilfs_sufile_get_header_block(struct inode *sufile,
82 struct buffer_head **bhp)
84 return nilfs_mdt_get_block(sufile, 0, 0, NULL, bhp);
88 nilfs_sufile_get_segment_usage_block(struct inode *sufile, __u64 segnum,
89 int create, struct buffer_head **bhp)
91 return nilfs_mdt_get_block(sufile,
92 nilfs_sufile_get_blkoff(sufile, segnum),
97 * nilfs_sufile_alloc - allocate a segment
98 * @sufile: inode of segment usage file
99 * @segnump: pointer to segment number
101 * Description: nilfs_sufile_alloc() allocates a clean segment.
103 * Return Value: On success, 0 is returned and the segment number of the
104 * allocated segment is stored in the place pointed by @segnump. On error, one
105 * of the following negative error codes is returned.
109 * %-ENOMEM - Insufficient amount of memory available.
111 * %-ENOSPC - No clean segment left.
113 int nilfs_sufile_alloc(struct inode *sufile, __u64 *segnump)
115 struct buffer_head *header_bh, *su_bh;
116 struct the_nilfs *nilfs;
117 struct nilfs_sufile_header *header;
118 struct nilfs_segment_usage *su;
119 size_t susz = NILFS_MDT(sufile)->mi_entry_size;
120 __u64 segnum, maxsegnum, last_alloc;
122 unsigned long nsegments, ncleansegs, nsus;
125 down_write(&NILFS_MDT(sufile)->mi_sem);
127 nilfs = NILFS_MDT(sufile)->mi_nilfs;
129 ret = nilfs_sufile_get_header_block(sufile, &header_bh);
132 kaddr = kmap_atomic(header_bh->b_page, KM_USER0);
133 header = nilfs_sufile_block_get_header(sufile, header_bh, kaddr);
134 ncleansegs = le64_to_cpu(header->sh_ncleansegs);
135 last_alloc = le64_to_cpu(header->sh_last_alloc);
136 kunmap_atomic(kaddr, KM_USER0);
138 nsegments = nilfs_sufile_get_nsegments(sufile);
139 segnum = last_alloc + 1;
140 maxsegnum = nsegments - 1;
141 for (i = 0; i < nsegments; i += nsus) {
142 if (segnum >= nsegments) {
145 maxsegnum = last_alloc;
147 ret = nilfs_sufile_get_segment_usage_block(sufile, segnum, 1,
151 kaddr = kmap_atomic(su_bh->b_page, KM_USER0);
152 su = nilfs_sufile_block_get_segment_usage(
153 sufile, segnum, su_bh, kaddr);
155 nsus = nilfs_sufile_segment_usages_in_block(
156 sufile, segnum, maxsegnum);
157 for (j = 0; j < nsus; j++, su = (void *)su + susz, segnum++) {
158 if (!nilfs_segment_usage_clean(su))
160 /* found a clean segment */
161 nilfs_segment_usage_set_active(su);
162 nilfs_segment_usage_set_dirty(su);
163 kunmap_atomic(kaddr, KM_USER0);
165 kaddr = kmap_atomic(header_bh->b_page, KM_USER0);
166 header = nilfs_sufile_block_get_header(
167 sufile, header_bh, kaddr);
168 le64_add_cpu(&header->sh_ncleansegs, -1);
169 le64_add_cpu(&header->sh_ndirtysegs, 1);
170 header->sh_last_alloc = cpu_to_le64(segnum);
171 kunmap_atomic(kaddr, KM_USER0);
173 nilfs_mdt_mark_buffer_dirty(header_bh);
174 nilfs_mdt_mark_buffer_dirty(su_bh);
175 nilfs_mdt_mark_dirty(sufile);
181 kunmap_atomic(kaddr, KM_USER0);
185 /* no segments left */
192 up_write(&NILFS_MDT(sufile)->mi_sem);
197 * nilfs_sufile_cancel_free -
198 * @sufile: inode of segment usage file
199 * @segnum: segment number
203 * Return Value: On success, 0 is returned. On error, one of the following
204 * negative error codes is returned.
208 * %-ENOMEM - Insufficient amount of memory available.
210 int nilfs_sufile_cancel_free(struct inode *sufile, __u64 segnum)
212 struct buffer_head *header_bh, *su_bh;
213 struct the_nilfs *nilfs;
214 struct nilfs_sufile_header *header;
215 struct nilfs_segment_usage *su;
219 down_write(&NILFS_MDT(sufile)->mi_sem);
221 nilfs = NILFS_MDT(sufile)->mi_nilfs;
223 ret = nilfs_sufile_get_header_block(sufile, &header_bh);
227 ret = nilfs_sufile_get_segment_usage_block(sufile, segnum, 0, &su_bh);
231 kaddr = kmap_atomic(su_bh->b_page, KM_USER0);
232 su = nilfs_sufile_block_get_segment_usage(
233 sufile, segnum, su_bh, kaddr);
234 if (!nilfs_segment_usage_clean(su)) {
235 printk(KERN_CRIT "%s: segment %llu must be clean\n",
236 __func__, (unsigned long long)segnum);
239 nilfs_segment_usage_set_dirty(su);
240 kunmap_atomic(kaddr, KM_USER0);
242 kaddr = kmap_atomic(header_bh->b_page, KM_USER0);
243 header = nilfs_sufile_block_get_header(sufile, header_bh, kaddr);
244 le64_add_cpu(&header->sh_ncleansegs, -1);
245 le64_add_cpu(&header->sh_ndirtysegs, 1);
246 kunmap_atomic(kaddr, KM_USER0);
248 nilfs_mdt_mark_buffer_dirty(header_bh);
249 nilfs_mdt_mark_buffer_dirty(su_bh);
250 nilfs_mdt_mark_dirty(sufile);
258 up_write(&NILFS_MDT(sufile)->mi_sem);
263 * nilfs_sufile_freev - free segments
264 * @sufile: inode of segment usage file
265 * @segnum: array of segment numbers
266 * @nsegs: number of segments
268 * Description: nilfs_sufile_freev() frees segments specified by @segnum and
269 * @nsegs, which must have been returned by a previous call to
270 * nilfs_sufile_alloc().
272 * Return Value: On success, 0 is returned. On error, one of the following
273 * negative error codes is returned.
277 * %-ENOMEM - Insufficient amount of memory available.
279 #define NILFS_SUFILE_FREEV_PREALLOC 16
280 int nilfs_sufile_freev(struct inode *sufile, __u64 *segnum, size_t nsegs)
282 struct buffer_head *header_bh, **su_bh,
283 *su_bh_prealloc[NILFS_SUFILE_FREEV_PREALLOC];
284 struct the_nilfs *nilfs;
285 struct nilfs_sufile_header *header;
286 struct nilfs_segment_usage *su;
290 down_write(&NILFS_MDT(sufile)->mi_sem);
292 nilfs = NILFS_MDT(sufile)->mi_nilfs;
294 /* prepare resources */
295 if (nsegs <= NILFS_SUFILE_FREEV_PREALLOC)
296 su_bh = su_bh_prealloc;
298 su_bh = kmalloc(sizeof(*su_bh) * nsegs, GFP_NOFS);
305 ret = nilfs_sufile_get_header_block(sufile, &header_bh);
308 for (i = 0; i < nsegs; i++) {
309 ret = nilfs_sufile_get_segment_usage_block(sufile, segnum[i],
316 for (i = 0; i < nsegs; i++) {
317 kaddr = kmap_atomic(su_bh[i]->b_page, KM_USER0);
318 su = nilfs_sufile_block_get_segment_usage(
319 sufile, segnum[i], su_bh[i], kaddr);
320 BUG_ON(nilfs_segment_usage_error(su));
321 nilfs_segment_usage_set_clean(su);
322 kunmap_atomic(kaddr, KM_USER0);
323 nilfs_mdt_mark_buffer_dirty(su_bh[i]);
325 kaddr = kmap_atomic(header_bh->b_page, KM_USER0);
326 header = nilfs_sufile_block_get_header(sufile, header_bh, kaddr);
327 le64_add_cpu(&header->sh_ncleansegs, nsegs);
328 le64_add_cpu(&header->sh_ndirtysegs, -(u64)nsegs);
329 kunmap_atomic(kaddr, KM_USER0);
330 nilfs_mdt_mark_buffer_dirty(header_bh);
331 nilfs_mdt_mark_dirty(sufile);
334 for (i--; i >= 0; i--)
339 if (su_bh != su_bh_prealloc)
343 up_write(&NILFS_MDT(sufile)->mi_sem);
348 * nilfs_sufile_free -
352 int nilfs_sufile_free(struct inode *sufile, __u64 segnum)
354 return nilfs_sufile_freev(sufile, &segnum, 1);
358 * nilfs_sufile_get_segment_usage - get a segment usage
359 * @sufile: inode of segment usage file
360 * @segnum: segment number
361 * @sup: pointer to segment usage
362 * @bhp: pointer to buffer head
364 * Description: nilfs_sufile_get_segment_usage() acquires the segment usage
365 * specified by @segnum.
367 * Return Value: On success, 0 is returned, and the segment usage and the
368 * buffer head of the buffer on which the segment usage is located are stored
369 * in the place pointed by @sup and @bhp, respectively. On error, one of the
370 * following negative error codes is returned.
374 * %-ENOMEM - Insufficient amount of memory available.
376 * %-EINVAL - Invalid segment usage number.
378 int nilfs_sufile_get_segment_usage(struct inode *sufile, __u64 segnum,
379 struct nilfs_segment_usage **sup,
380 struct buffer_head **bhp)
382 struct buffer_head *bh;
383 struct nilfs_segment_usage *su;
387 /* segnum is 0 origin */
388 BUG_ON(segnum >= nilfs_sufile_get_nsegments(sufile));
390 down_write(&NILFS_MDT(sufile)->mi_sem);
391 ret = nilfs_sufile_get_segment_usage_block(sufile, segnum, 1, &bh);
394 kaddr = kmap(bh->b_page);
395 su = nilfs_sufile_block_get_segment_usage(sufile, segnum, bh, kaddr);
396 if (nilfs_segment_usage_error(su)) {
408 up_write(&NILFS_MDT(sufile)->mi_sem);
413 * nilfs_sufile_put_segment_usage - put a segment usage
414 * @sufile: inode of segment usage file
415 * @segnum: segment number
418 * Description: nilfs_sufile_put_segment_usage() releases the segment usage
419 * specified by @segnum. @bh must be the buffer head which have been returned
420 * by a previous call to nilfs_sufile_get_segment_usage() with @segnum.
422 void nilfs_sufile_put_segment_usage(struct inode *sufile, __u64 segnum,
423 struct buffer_head *bh)
430 * nilfs_sufile_get_stat - get segment usage statistics
431 * @sufile: inode of segment usage file
432 * @stat: pointer to a structure of segment usage statistics
434 * Description: nilfs_sufile_get_stat() returns information about segment
437 * Return Value: On success, 0 is returned, and segment usage information is
438 * stored in the place pointed by @stat. On error, one of the following
439 * negative error codes is returned.
443 * %-ENOMEM - Insufficient amount of memory available.
445 int nilfs_sufile_get_stat(struct inode *sufile, struct nilfs_sustat *sustat)
447 struct buffer_head *header_bh;
448 struct nilfs_sufile_header *header;
452 down_read(&NILFS_MDT(sufile)->mi_sem);
454 ret = nilfs_sufile_get_header_block(sufile, &header_bh);
458 kaddr = kmap_atomic(header_bh->b_page, KM_USER0);
459 header = nilfs_sufile_block_get_header(sufile, header_bh, kaddr);
460 sustat->ss_nsegs = nilfs_sufile_get_nsegments(sufile);
461 sustat->ss_ncleansegs = le64_to_cpu(header->sh_ncleansegs);
462 sustat->ss_ndirtysegs = le64_to_cpu(header->sh_ndirtysegs);
463 sustat->ss_ctime = NILFS_MDT(sufile)->mi_nilfs->ns_ctime;
464 sustat->ss_nongc_ctime = NILFS_MDT(sufile)->mi_nilfs->ns_nongc_ctime;
465 kunmap_atomic(kaddr, KM_USER0);
469 up_read(&NILFS_MDT(sufile)->mi_sem);
474 * nilfs_sufile_get_ncleansegs - get the number of clean segments
475 * @sufile: inode of segment usage file
476 * @nsegsp: pointer to the number of clean segments
478 * Description: nilfs_sufile_get_ncleansegs() acquires the number of clean
481 * Return Value: On success, 0 is returned and the number of clean segments is
482 * stored in the place pointed by @nsegsp. On error, one of the following
483 * negative error codes is returned.
487 * %-ENOMEM - Insufficient amount of memory available.
489 int nilfs_sufile_get_ncleansegs(struct inode *sufile, unsigned long *nsegsp)
491 struct nilfs_sustat sustat;
494 ret = nilfs_sufile_get_stat(sufile, &sustat);
496 *nsegsp = sustat.ss_ncleansegs;
501 * nilfs_sufile_set_error - mark a segment as erroneous
502 * @sufile: inode of segment usage file
503 * @segnum: segment number
505 * Description: nilfs_sufile_set_error() marks the segment specified by
506 * @segnum as erroneous. The error segment will never be used again.
508 * Return Value: On success, 0 is returned. On error, one of the following
509 * negative error codes is returned.
513 * %-ENOMEM - Insufficient amount of memory available.
515 int nilfs_sufile_set_error(struct inode *sufile, __u64 segnum)
517 struct buffer_head *header_bh, *su_bh;
518 struct nilfs_segment_usage *su;
519 struct nilfs_sufile_header *header;
523 BUG_ON(segnum >= nilfs_sufile_get_nsegments(sufile));
525 down_write(&NILFS_MDT(sufile)->mi_sem);
527 ret = nilfs_sufile_get_header_block(sufile, &header_bh);
530 ret = nilfs_sufile_get_segment_usage_block(sufile, segnum, 0, &su_bh);
534 kaddr = kmap_atomic(su_bh->b_page, KM_USER0);
535 su = nilfs_sufile_block_get_segment_usage(sufile, segnum, su_bh, kaddr);
536 if (nilfs_segment_usage_error(su)) {
537 kunmap_atomic(kaddr, KM_USER0);
542 nilfs_segment_usage_set_error(su);
543 kunmap_atomic(kaddr, KM_USER0);
546 kaddr = kmap_atomic(header_bh->b_page, KM_USER0);
547 header = nilfs_sufile_block_get_header(sufile, header_bh, kaddr);
548 le64_add_cpu(&header->sh_ndirtysegs, -1);
549 kunmap_atomic(kaddr, KM_USER0);
550 nilfs_mdt_mark_buffer_dirty(header_bh);
551 nilfs_mdt_mark_buffer_dirty(su_bh);
552 nilfs_mdt_mark_dirty(sufile);
559 up_write(&NILFS_MDT(sufile)->mi_sem);
564 * nilfs_sufile_get_suinfo -
565 * @sufile: inode of segment usage file
566 * @segnum: segment number to start looking
567 * @si: array of suinfo
568 * @nsi: size of suinfo array
572 * Return Value: On success, 0 is returned and .... On error, one of the
573 * following negative error codes is returned.
577 * %-ENOMEM - Insufficient amount of memory available.
579 ssize_t nilfs_sufile_get_suinfo(struct inode *sufile, __u64 segnum,
580 struct nilfs_suinfo *si, size_t nsi)
582 struct buffer_head *su_bh;
583 struct nilfs_segment_usage *su;
584 size_t susz = NILFS_MDT(sufile)->mi_entry_size;
586 unsigned long nsegs, segusages_per_block;
590 down_read(&NILFS_MDT(sufile)->mi_sem);
592 segusages_per_block = nilfs_sufile_segment_usages_per_block(sufile);
593 nsegs = min_t(unsigned long,
594 nilfs_sufile_get_nsegments(sufile) - segnum,
596 for (i = 0; i < nsegs; i += n, segnum += n) {
597 n = min_t(unsigned long,
598 segusages_per_block -
599 nilfs_sufile_get_offset(sufile, segnum),
601 ret = nilfs_sufile_get_segment_usage_block(sufile, segnum, 0,
607 memset(&si[i], 0, sizeof(struct nilfs_suinfo) * n);
611 kaddr = kmap_atomic(su_bh->b_page, KM_USER0);
612 su = nilfs_sufile_block_get_segment_usage(
613 sufile, segnum, su_bh, kaddr);
614 for (j = 0; j < n; j++, su = (void *)su + susz) {
615 si[i + j].sui_lastmod = le64_to_cpu(su->su_lastmod);
616 si[i + j].sui_nblocks = le32_to_cpu(su->su_nblocks);
617 si[i + j].sui_flags = le32_to_cpu(su->su_flags);
619 kunmap_atomic(kaddr, KM_USER0);
625 up_read(&NILFS_MDT(sufile)->mi_sem);