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),
96 static void nilfs_sufile_mod_counter(struct buffer_head *header_bh,
97 u64 ncleanadd, u64 ndirtyadd)
99 struct nilfs_sufile_header *header;
102 kaddr = kmap_atomic(header_bh->b_page, KM_USER0);
103 header = kaddr + bh_offset(header_bh);
104 le64_add_cpu(&header->sh_ncleansegs, ncleanadd);
105 le64_add_cpu(&header->sh_ndirtysegs, ndirtyadd);
106 kunmap_atomic(kaddr, KM_USER0);
108 nilfs_mdt_mark_buffer_dirty(header_bh);
111 int nilfs_sufile_update(struct inode *sufile, __u64 segnum, int create,
112 void (*dofunc)(struct inode *, __u64,
113 struct buffer_head *,
114 struct buffer_head *))
116 struct buffer_head *header_bh, *bh;
119 if (unlikely(segnum >= nilfs_sufile_get_nsegments(sufile))) {
120 printk(KERN_WARNING "%s: invalid segment number: %llu\n",
121 __func__, (unsigned long long)segnum);
124 down_write(&NILFS_MDT(sufile)->mi_sem);
126 ret = nilfs_sufile_get_header_block(sufile, &header_bh);
130 ret = nilfs_sufile_get_segment_usage_block(sufile, segnum, create, &bh);
132 dofunc(sufile, segnum, header_bh, bh);
138 up_write(&NILFS_MDT(sufile)->mi_sem);
143 * nilfs_sufile_alloc - allocate a segment
144 * @sufile: inode of segment usage file
145 * @segnump: pointer to segment number
147 * Description: nilfs_sufile_alloc() allocates a clean segment.
149 * Return Value: On success, 0 is returned and the segment number of the
150 * allocated segment is stored in the place pointed by @segnump. On error, one
151 * of the following negative error codes is returned.
155 * %-ENOMEM - Insufficient amount of memory available.
157 * %-ENOSPC - No clean segment left.
159 int nilfs_sufile_alloc(struct inode *sufile, __u64 *segnump)
161 struct buffer_head *header_bh, *su_bh;
162 struct nilfs_sufile_header *header;
163 struct nilfs_segment_usage *su;
164 size_t susz = NILFS_MDT(sufile)->mi_entry_size;
165 __u64 segnum, maxsegnum, last_alloc;
167 unsigned long nsegments, ncleansegs, nsus;
170 down_write(&NILFS_MDT(sufile)->mi_sem);
172 ret = nilfs_sufile_get_header_block(sufile, &header_bh);
175 kaddr = kmap_atomic(header_bh->b_page, KM_USER0);
176 header = nilfs_sufile_block_get_header(sufile, header_bh, kaddr);
177 ncleansegs = le64_to_cpu(header->sh_ncleansegs);
178 last_alloc = le64_to_cpu(header->sh_last_alloc);
179 kunmap_atomic(kaddr, KM_USER0);
181 nsegments = nilfs_sufile_get_nsegments(sufile);
182 segnum = last_alloc + 1;
183 maxsegnum = nsegments - 1;
184 for (i = 0; i < nsegments; i += nsus) {
185 if (segnum >= nsegments) {
188 maxsegnum = last_alloc;
190 ret = nilfs_sufile_get_segment_usage_block(sufile, segnum, 1,
194 kaddr = kmap_atomic(su_bh->b_page, KM_USER0);
195 su = nilfs_sufile_block_get_segment_usage(
196 sufile, segnum, su_bh, kaddr);
198 nsus = nilfs_sufile_segment_usages_in_block(
199 sufile, segnum, maxsegnum);
200 for (j = 0; j < nsus; j++, su = (void *)su + susz, segnum++) {
201 if (!nilfs_segment_usage_clean(su))
203 /* found a clean segment */
204 nilfs_segment_usage_set_dirty(su);
205 kunmap_atomic(kaddr, KM_USER0);
207 kaddr = kmap_atomic(header_bh->b_page, KM_USER0);
208 header = nilfs_sufile_block_get_header(
209 sufile, header_bh, kaddr);
210 le64_add_cpu(&header->sh_ncleansegs, -1);
211 le64_add_cpu(&header->sh_ndirtysegs, 1);
212 header->sh_last_alloc = cpu_to_le64(segnum);
213 kunmap_atomic(kaddr, KM_USER0);
215 nilfs_mdt_mark_buffer_dirty(header_bh);
216 nilfs_mdt_mark_buffer_dirty(su_bh);
217 nilfs_mdt_mark_dirty(sufile);
223 kunmap_atomic(kaddr, KM_USER0);
227 /* no segments left */
234 up_write(&NILFS_MDT(sufile)->mi_sem);
238 void nilfs_sufile_do_cancel_free(struct inode *sufile, __u64 segnum,
239 struct buffer_head *header_bh,
240 struct buffer_head *su_bh)
242 struct nilfs_segment_usage *su;
245 kaddr = kmap_atomic(su_bh->b_page, KM_USER0);
246 su = nilfs_sufile_block_get_segment_usage(sufile, segnum, su_bh, kaddr);
247 if (unlikely(!nilfs_segment_usage_clean(su))) {
248 printk(KERN_WARNING "%s: segment %llu must be clean\n",
249 __func__, (unsigned long long)segnum);
250 kunmap_atomic(kaddr, KM_USER0);
253 nilfs_segment_usage_set_dirty(su);
254 kunmap_atomic(kaddr, KM_USER0);
256 nilfs_sufile_mod_counter(header_bh, -1, 1);
257 nilfs_mdt_mark_buffer_dirty(su_bh);
258 nilfs_mdt_mark_dirty(sufile);
261 void nilfs_sufile_do_free(struct inode *sufile, __u64 segnum,
262 struct buffer_head *header_bh,
263 struct buffer_head *su_bh)
265 struct nilfs_segment_usage *su;
269 kaddr = kmap_atomic(su_bh->b_page, KM_USER0);
270 su = nilfs_sufile_block_get_segment_usage(sufile, segnum, su_bh, kaddr);
271 if (nilfs_segment_usage_clean(su)) {
272 printk(KERN_WARNING "%s: segment %llu is already clean\n",
273 __func__, (unsigned long long)segnum);
274 kunmap_atomic(kaddr, KM_USER0);
277 WARN_ON(nilfs_segment_usage_error(su));
278 WARN_ON(!nilfs_segment_usage_dirty(su));
280 sudirty = nilfs_segment_usage_dirty(su);
281 nilfs_segment_usage_set_clean(su);
282 kunmap_atomic(kaddr, KM_USER0);
283 nilfs_mdt_mark_buffer_dirty(su_bh);
285 nilfs_sufile_mod_counter(header_bh, 1, sudirty ? (u64)-1 : 0);
286 nilfs_mdt_mark_dirty(sufile);
290 * nilfs_sufile_get_segment_usage - get a segment usage
291 * @sufile: inode of segment usage file
292 * @segnum: segment number
293 * @sup: pointer to segment usage
294 * @bhp: pointer to buffer head
296 * Description: nilfs_sufile_get_segment_usage() acquires the segment usage
297 * specified by @segnum.
299 * Return Value: On success, 0 is returned, and the segment usage and the
300 * buffer head of the buffer on which the segment usage is located are stored
301 * in the place pointed by @sup and @bhp, respectively. On error, one of the
302 * following negative error codes is returned.
306 * %-ENOMEM - Insufficient amount of memory available.
308 * %-EINVAL - Invalid segment usage number.
310 int nilfs_sufile_get_segment_usage(struct inode *sufile, __u64 segnum,
311 struct nilfs_segment_usage **sup,
312 struct buffer_head **bhp)
314 struct buffer_head *bh;
315 struct nilfs_segment_usage *su;
319 /* segnum is 0 origin */
320 if (segnum >= nilfs_sufile_get_nsegments(sufile))
322 down_write(&NILFS_MDT(sufile)->mi_sem);
323 ret = nilfs_sufile_get_segment_usage_block(sufile, segnum, 1, &bh);
326 kaddr = kmap(bh->b_page);
327 su = nilfs_sufile_block_get_segment_usage(sufile, segnum, bh, kaddr);
328 if (nilfs_segment_usage_error(su)) {
340 up_write(&NILFS_MDT(sufile)->mi_sem);
345 * nilfs_sufile_put_segment_usage - put a segment usage
346 * @sufile: inode of segment usage file
347 * @segnum: segment number
350 * Description: nilfs_sufile_put_segment_usage() releases the segment usage
351 * specified by @segnum. @bh must be the buffer head which have been returned
352 * by a previous call to nilfs_sufile_get_segment_usage() with @segnum.
354 void nilfs_sufile_put_segment_usage(struct inode *sufile, __u64 segnum,
355 struct buffer_head *bh)
362 * nilfs_sufile_get_stat - get segment usage statistics
363 * @sufile: inode of segment usage file
364 * @stat: pointer to a structure of segment usage statistics
366 * Description: nilfs_sufile_get_stat() returns information about segment
369 * Return Value: On success, 0 is returned, and segment usage information is
370 * stored in the place pointed by @stat. On error, one of the following
371 * negative error codes is returned.
375 * %-ENOMEM - Insufficient amount of memory available.
377 int nilfs_sufile_get_stat(struct inode *sufile, struct nilfs_sustat *sustat)
379 struct buffer_head *header_bh;
380 struct nilfs_sufile_header *header;
381 struct the_nilfs *nilfs = NILFS_MDT(sufile)->mi_nilfs;
385 down_read(&NILFS_MDT(sufile)->mi_sem);
387 ret = nilfs_sufile_get_header_block(sufile, &header_bh);
391 kaddr = kmap_atomic(header_bh->b_page, KM_USER0);
392 header = nilfs_sufile_block_get_header(sufile, header_bh, kaddr);
393 sustat->ss_nsegs = nilfs_sufile_get_nsegments(sufile);
394 sustat->ss_ncleansegs = le64_to_cpu(header->sh_ncleansegs);
395 sustat->ss_ndirtysegs = le64_to_cpu(header->sh_ndirtysegs);
396 sustat->ss_ctime = nilfs->ns_ctime;
397 sustat->ss_nongc_ctime = nilfs->ns_nongc_ctime;
398 spin_lock(&nilfs->ns_last_segment_lock);
399 sustat->ss_prot_seq = nilfs->ns_prot_seq;
400 spin_unlock(&nilfs->ns_last_segment_lock);
401 kunmap_atomic(kaddr, KM_USER0);
405 up_read(&NILFS_MDT(sufile)->mi_sem);
410 * nilfs_sufile_get_ncleansegs - get the number of clean segments
411 * @sufile: inode of segment usage file
412 * @nsegsp: pointer to the number of clean segments
414 * Description: nilfs_sufile_get_ncleansegs() acquires the number of clean
417 * Return Value: On success, 0 is returned and the number of clean segments is
418 * stored in the place pointed by @nsegsp. On error, one of the following
419 * negative error codes is returned.
423 * %-ENOMEM - Insufficient amount of memory available.
425 int nilfs_sufile_get_ncleansegs(struct inode *sufile, unsigned long *nsegsp)
427 struct nilfs_sustat sustat;
430 ret = nilfs_sufile_get_stat(sufile, &sustat);
432 *nsegsp = sustat.ss_ncleansegs;
436 void nilfs_sufile_do_set_error(struct inode *sufile, __u64 segnum,
437 struct buffer_head *header_bh,
438 struct buffer_head *su_bh)
440 struct nilfs_segment_usage *su;
444 kaddr = kmap_atomic(su_bh->b_page, KM_USER0);
445 su = nilfs_sufile_block_get_segment_usage(sufile, segnum, su_bh, kaddr);
446 if (nilfs_segment_usage_error(su)) {
447 kunmap_atomic(kaddr, KM_USER0);
450 suclean = nilfs_segment_usage_clean(su);
451 nilfs_segment_usage_set_error(su);
452 kunmap_atomic(kaddr, KM_USER0);
455 nilfs_sufile_mod_counter(header_bh, -1, 0);
456 nilfs_mdt_mark_buffer_dirty(su_bh);
457 nilfs_mdt_mark_dirty(sufile);
461 * nilfs_sufile_get_suinfo -
462 * @sufile: inode of segment usage file
463 * @segnum: segment number to start looking
464 * @si: array of suinfo
465 * @nsi: size of suinfo array
469 * Return Value: On success, 0 is returned and .... On error, one of the
470 * following negative error codes is returned.
474 * %-ENOMEM - Insufficient amount of memory available.
476 ssize_t nilfs_sufile_get_suinfo(struct inode *sufile, __u64 segnum,
477 struct nilfs_suinfo *si, size_t nsi)
479 struct buffer_head *su_bh;
480 struct nilfs_segment_usage *su;
481 size_t susz = NILFS_MDT(sufile)->mi_entry_size;
482 struct the_nilfs *nilfs = NILFS_MDT(sufile)->mi_nilfs;
484 unsigned long nsegs, segusages_per_block;
488 down_read(&NILFS_MDT(sufile)->mi_sem);
490 segusages_per_block = nilfs_sufile_segment_usages_per_block(sufile);
491 nsegs = min_t(unsigned long,
492 nilfs_sufile_get_nsegments(sufile) - segnum,
494 for (i = 0; i < nsegs; i += n, segnum += n) {
495 n = min_t(unsigned long,
496 segusages_per_block -
497 nilfs_sufile_get_offset(sufile, segnum),
499 ret = nilfs_sufile_get_segment_usage_block(sufile, segnum, 0,
505 memset(&si[i], 0, sizeof(struct nilfs_suinfo) * n);
509 kaddr = kmap_atomic(su_bh->b_page, KM_USER0);
510 su = nilfs_sufile_block_get_segment_usage(
511 sufile, segnum, su_bh, kaddr);
512 for (j = 0; j < n; j++, su = (void *)su + susz) {
513 si[i + j].sui_lastmod = le64_to_cpu(su->su_lastmod);
514 si[i + j].sui_nblocks = le32_to_cpu(su->su_nblocks);
515 si[i + j].sui_flags = le32_to_cpu(su->su_flags) &
516 ~(1UL << NILFS_SEGMENT_USAGE_ACTIVE);
517 if (nilfs_segment_is_active(nilfs, segnum + j))
518 si[i + j].sui_flags |=
519 (1UL << NILFS_SEGMENT_USAGE_ACTIVE);
521 kunmap_atomic(kaddr, KM_USER0);
527 up_read(&NILFS_MDT(sufile)->mi_sem);