blob: 0f83e93935b2fb02347c7c0a7c0f3e131d94af14 [file] [log] [blame]
Ryusuke Konishi64b5a322009-04-06 19:01:36 -07001/*
2 * segbuf.c - NILFS segment buffer
3 *
4 * Copyright (C) 2005-2008 Nippon Telegraph and Telephone Corporation.
5 *
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.
10 *
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.
15 *
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
19 *
20 * Written by Ryusuke Konishi <ryusuke@osrg.net>
21 *
22 */
23
24#include <linux/buffer_head.h>
25#include <linux/writeback.h>
26#include <linux/crc32.h>
Ryusuke Konishi9c965ba2009-11-29 01:17:31 +090027#include <linux/backing-dev.h>
Tejun Heo5a0e3ad2010-03-24 17:04:11 +090028#include <linux/slab.h>
Ryusuke Konishi64b5a322009-04-06 19:01:36 -070029#include "page.h"
30#include "segbuf.h"
Ryusuke Konishi64b5a322009-04-06 19:01:36 -070031
32
Ryusuke Konishi9c965ba2009-11-29 01:17:31 +090033struct nilfs_write_info {
34 struct the_nilfs *nilfs;
35 struct bio *bio;
Ryusuke Konishi55480a02010-03-14 03:55:56 +090036 int start, end; /* The region to be submitted */
Ryusuke Konishi9c965ba2009-11-29 01:17:31 +090037 int rest_blocks;
38 int max_pages;
39 int nr_vecs;
40 sector_t blocknr;
41};
42
Ryusuke Konishid1c6b722009-12-17 00:55:40 +090043static int nilfs_segbuf_write(struct nilfs_segment_buffer *segbuf,
44 struct the_nilfs *nilfs);
45static int nilfs_segbuf_wait(struct nilfs_segment_buffer *segbuf);
46
Ryusuke Konishi64b5a322009-04-06 19:01:36 -070047struct nilfs_segment_buffer *nilfs_segbuf_new(struct super_block *sb)
48{
49 struct nilfs_segment_buffer *segbuf;
50
51 segbuf = kmem_cache_alloc(nilfs_segbuf_cachep, GFP_NOFS);
52 if (unlikely(!segbuf))
53 return NULL;
54
55 segbuf->sb_super = sb;
56 INIT_LIST_HEAD(&segbuf->sb_list);
57 INIT_LIST_HEAD(&segbuf->sb_segsum_buffers);
58 INIT_LIST_HEAD(&segbuf->sb_payload_buffers);
Ryusuke Konishi1e2b68b2010-03-23 01:15:31 +090059 segbuf->sb_super_root = NULL;
Ryusuke Konishi9284ad22009-11-25 01:04:21 +090060
61 init_completion(&segbuf->sb_bio_event);
62 atomic_set(&segbuf->sb_err, 0);
63 segbuf->sb_nbio = 0;
64
Ryusuke Konishi64b5a322009-04-06 19:01:36 -070065 return segbuf;
66}
67
68void nilfs_segbuf_free(struct nilfs_segment_buffer *segbuf)
69{
Ryusuke Konishi64b5a322009-04-06 19:01:36 -070070 kmem_cache_free(nilfs_segbuf_cachep, segbuf);
71}
72
Ryusuke Konishicece5522009-04-06 19:01:58 -070073void nilfs_segbuf_map(struct nilfs_segment_buffer *segbuf, __u64 segnum,
Ryusuke Konishi64b5a322009-04-06 19:01:36 -070074 unsigned long offset, struct the_nilfs *nilfs)
75{
Ryusuke Konishi64b5a322009-04-06 19:01:36 -070076 segbuf->sb_segnum = segnum;
77 nilfs_get_segment_range(nilfs, segnum, &segbuf->sb_fseg_start,
78 &segbuf->sb_fseg_end);
79
80 segbuf->sb_pseg_start = segbuf->sb_fseg_start + offset;
81 segbuf->sb_rest_blocks =
82 segbuf->sb_fseg_end - segbuf->sb_pseg_start + 1;
Ryusuke Konishi64b5a322009-04-06 19:01:36 -070083}
84
Ryusuke Konishia694291a2009-11-29 23:03:04 +090085/**
86 * nilfs_segbuf_map_cont - map a new log behind a given log
87 * @segbuf: new segment buffer
88 * @prev: segment buffer containing a log to be continued
89 */
90void nilfs_segbuf_map_cont(struct nilfs_segment_buffer *segbuf,
91 struct nilfs_segment_buffer *prev)
92{
93 segbuf->sb_segnum = prev->sb_segnum;
94 segbuf->sb_fseg_start = prev->sb_fseg_start;
95 segbuf->sb_fseg_end = prev->sb_fseg_end;
96 segbuf->sb_pseg_start = prev->sb_pseg_start + prev->sb_sum.nblocks;
97 segbuf->sb_rest_blocks =
98 segbuf->sb_fseg_end - segbuf->sb_pseg_start + 1;
99}
100
Ryusuke Konishi64b5a322009-04-06 19:01:36 -0700101void nilfs_segbuf_set_next_segnum(struct nilfs_segment_buffer *segbuf,
102 __u64 nextnum, struct the_nilfs *nilfs)
103{
104 segbuf->sb_nextnum = nextnum;
105 segbuf->sb_sum.next = nilfs_get_segment_start_blocknr(nilfs, nextnum);
106}
107
108int nilfs_segbuf_extend_segsum(struct nilfs_segment_buffer *segbuf)
109{
110 struct buffer_head *bh;
111
112 bh = sb_getblk(segbuf->sb_super,
113 segbuf->sb_pseg_start + segbuf->sb_sum.nsumblk);
114 if (unlikely(!bh))
115 return -ENOMEM;
116
117 nilfs_segbuf_add_segsum_buffer(segbuf, bh);
118 return 0;
119}
120
121int nilfs_segbuf_extend_payload(struct nilfs_segment_buffer *segbuf,
122 struct buffer_head **bhp)
123{
124 struct buffer_head *bh;
125
126 bh = sb_getblk(segbuf->sb_super,
127 segbuf->sb_pseg_start + segbuf->sb_sum.nblocks);
128 if (unlikely(!bh))
129 return -ENOMEM;
130
131 nilfs_segbuf_add_payload_buffer(segbuf, bh);
132 *bhp = bh;
133 return 0;
134}
135
136int nilfs_segbuf_reset(struct nilfs_segment_buffer *segbuf, unsigned flags,
Ryusuke Konishi50614bc2010-04-10 17:59:15 +0900137 time_t ctime, __u64 cno)
Ryusuke Konishi64b5a322009-04-06 19:01:36 -0700138{
139 int err;
140
141 segbuf->sb_sum.nblocks = segbuf->sb_sum.nsumblk = 0;
142 err = nilfs_segbuf_extend_segsum(segbuf);
143 if (unlikely(err))
144 return err;
145
146 segbuf->sb_sum.flags = flags;
147 segbuf->sb_sum.sumbytes = sizeof(struct nilfs_segment_summary);
148 segbuf->sb_sum.nfinfo = segbuf->sb_sum.nfileblk = 0;
149 segbuf->sb_sum.ctime = ctime;
Ryusuke Konishi50614bc2010-04-10 17:59:15 +0900150 segbuf->sb_sum.cno = cno;
Ryusuke Konishi64b5a322009-04-06 19:01:36 -0700151 return 0;
152}
153
154/*
Ryusuke Konishi7a650042010-03-14 03:32:40 +0900155 * Setup segment summary
Ryusuke Konishi64b5a322009-04-06 19:01:36 -0700156 */
157void nilfs_segbuf_fill_in_segsum(struct nilfs_segment_buffer *segbuf)
158{
159 struct nilfs_segment_summary *raw_sum;
160 struct buffer_head *bh_sum;
161
162 bh_sum = list_entry(segbuf->sb_segsum_buffers.next,
163 struct buffer_head, b_assoc_buffers);
164 raw_sum = (struct nilfs_segment_summary *)bh_sum->b_data;
165
166 raw_sum->ss_magic = cpu_to_le32(NILFS_SEGSUM_MAGIC);
167 raw_sum->ss_bytes = cpu_to_le16(sizeof(*raw_sum));
168 raw_sum->ss_flags = cpu_to_le16(segbuf->sb_sum.flags);
169 raw_sum->ss_seq = cpu_to_le64(segbuf->sb_sum.seg_seq);
170 raw_sum->ss_create = cpu_to_le64(segbuf->sb_sum.ctime);
171 raw_sum->ss_next = cpu_to_le64(segbuf->sb_sum.next);
172 raw_sum->ss_nblocks = cpu_to_le32(segbuf->sb_sum.nblocks);
173 raw_sum->ss_nfinfo = cpu_to_le32(segbuf->sb_sum.nfinfo);
174 raw_sum->ss_sumbytes = cpu_to_le32(segbuf->sb_sum.sumbytes);
175 raw_sum->ss_pad = 0;
Ryusuke Konishi50614bc2010-04-10 17:59:15 +0900176 raw_sum->ss_cno = cpu_to_le64(segbuf->sb_sum.cno);
Ryusuke Konishi64b5a322009-04-06 19:01:36 -0700177}
178
179/*
180 * CRC calculation routines
181 */
Ryusuke Konishiaaed1d52010-03-23 01:50:38 +0900182static void
183nilfs_segbuf_fill_in_segsum_crc(struct nilfs_segment_buffer *segbuf, u32 seed)
Ryusuke Konishi64b5a322009-04-06 19:01:36 -0700184{
185 struct buffer_head *bh;
186 struct nilfs_segment_summary *raw_sum;
187 unsigned long size, bytes = segbuf->sb_sum.sumbytes;
188 u32 crc;
189
190 bh = list_entry(segbuf->sb_segsum_buffers.next, struct buffer_head,
191 b_assoc_buffers);
192
193 raw_sum = (struct nilfs_segment_summary *)bh->b_data;
194 size = min_t(unsigned long, bytes, bh->b_size);
195 crc = crc32_le(seed,
196 (unsigned char *)raw_sum +
197 sizeof(raw_sum->ss_datasum) + sizeof(raw_sum->ss_sumsum),
198 size - (sizeof(raw_sum->ss_datasum) +
199 sizeof(raw_sum->ss_sumsum)));
200
201 list_for_each_entry_continue(bh, &segbuf->sb_segsum_buffers,
202 b_assoc_buffers) {
203 bytes -= size;
204 size = min_t(unsigned long, bytes, bh->b_size);
205 crc = crc32_le(crc, bh->b_data, size);
206 }
207 raw_sum->ss_sumsum = cpu_to_le32(crc);
208}
209
Ryusuke Konishiaaed1d52010-03-23 01:50:38 +0900210static void nilfs_segbuf_fill_in_data_crc(struct nilfs_segment_buffer *segbuf,
211 u32 seed)
Ryusuke Konishi64b5a322009-04-06 19:01:36 -0700212{
213 struct buffer_head *bh;
214 struct nilfs_segment_summary *raw_sum;
215 void *kaddr;
216 u32 crc;
217
218 bh = list_entry(segbuf->sb_segsum_buffers.next, struct buffer_head,
219 b_assoc_buffers);
220 raw_sum = (struct nilfs_segment_summary *)bh->b_data;
221 crc = crc32_le(seed,
222 (unsigned char *)raw_sum + sizeof(raw_sum->ss_datasum),
223 bh->b_size - sizeof(raw_sum->ss_datasum));
224
225 list_for_each_entry_continue(bh, &segbuf->sb_segsum_buffers,
226 b_assoc_buffers) {
227 crc = crc32_le(crc, bh->b_data, bh->b_size);
228 }
229 list_for_each_entry(bh, &segbuf->sb_payload_buffers, b_assoc_buffers) {
230 kaddr = kmap_atomic(bh->b_page, KM_USER0);
231 crc = crc32_le(crc, kaddr + bh_offset(bh), bh->b_size);
232 kunmap_atomic(kaddr, KM_USER0);
233 }
234 raw_sum->ss_datasum = cpu_to_le32(crc);
235}
236
Ryusuke Konishiaaed1d52010-03-23 01:50:38 +0900237static void
238nilfs_segbuf_fill_in_super_root_crc(struct nilfs_segment_buffer *segbuf,
239 u32 seed)
240{
241 struct nilfs_super_root *raw_sr;
242 u32 crc;
243
244 raw_sr = (struct nilfs_super_root *)segbuf->sb_super_root->b_data;
245 crc = crc32_le(seed,
246 (unsigned char *)raw_sr + sizeof(raw_sr->sr_sum),
247 NILFS_SR_BYTES - sizeof(raw_sr->sr_sum));
248 raw_sr->sr_sum = cpu_to_le32(crc);
249}
250
Ryusuke Konishie29df392009-11-29 16:51:16 +0900251static void nilfs_release_buffers(struct list_head *list)
Ryusuke Konishi64b5a322009-04-06 19:01:36 -0700252{
253 struct buffer_head *bh, *n;
254
255 list_for_each_entry_safe(bh, n, list, b_assoc_buffers) {
256 list_del_init(&bh->b_assoc_buffers);
257 if (buffer_nilfs_allocated(bh)) {
258 struct page *clone_page = bh->b_page;
259
260 /* remove clone page */
261 brelse(bh);
262 page_cache_release(clone_page); /* for each bh */
263 if (page_count(clone_page) <= 2) {
264 lock_page(clone_page);
265 nilfs_free_private_page(clone_page);
266 }
267 continue;
268 }
269 brelse(bh);
270 }
271}
272
Ryusuke Konishie29df392009-11-29 16:51:16 +0900273static void nilfs_segbuf_clear(struct nilfs_segment_buffer *segbuf)
274{
275 nilfs_release_buffers(&segbuf->sb_segsum_buffers);
276 nilfs_release_buffers(&segbuf->sb_payload_buffers);
Ryusuke Konishi1e2b68b2010-03-23 01:15:31 +0900277 segbuf->sb_super_root = NULL;
Ryusuke Konishie29df392009-11-29 16:51:16 +0900278}
279
280/*
281 * Iterators for segment buffers
282 */
283void nilfs_clear_logs(struct list_head *logs)
284{
285 struct nilfs_segment_buffer *segbuf;
286
287 list_for_each_entry(segbuf, logs, sb_list)
288 nilfs_segbuf_clear(segbuf);
289}
290
291void nilfs_truncate_logs(struct list_head *logs,
292 struct nilfs_segment_buffer *last)
293{
294 struct nilfs_segment_buffer *n, *segbuf;
295
296 segbuf = list_prepare_entry(last, logs, sb_list);
297 list_for_each_entry_safe_continue(segbuf, n, logs, sb_list) {
298 list_del_init(&segbuf->sb_list);
299 nilfs_segbuf_clear(segbuf);
300 nilfs_segbuf_free(segbuf);
301 }
302}
303
Ryusuke Konishid1c6b722009-12-17 00:55:40 +0900304int nilfs_write_logs(struct list_head *logs, struct the_nilfs *nilfs)
305{
306 struct nilfs_segment_buffer *segbuf;
307 int ret = 0;
308
309 list_for_each_entry(segbuf, logs, sb_list) {
310 ret = nilfs_segbuf_write(segbuf, nilfs);
311 if (ret)
312 break;
313 }
314 return ret;
315}
316
Ryusuke Konishie29df392009-11-29 16:51:16 +0900317int nilfs_wait_on_logs(struct list_head *logs)
318{
319 struct nilfs_segment_buffer *segbuf;
Ryusuke Konishid0676332010-03-22 19:33:43 +0900320 int err, ret = 0;
Ryusuke Konishie29df392009-11-29 16:51:16 +0900321
322 list_for_each_entry(segbuf, logs, sb_list) {
323 err = nilfs_segbuf_wait(segbuf);
Ryusuke Konishid0676332010-03-22 19:33:43 +0900324 if (err && !ret)
325 ret = err;
Ryusuke Konishie29df392009-11-29 16:51:16 +0900326 }
Ryusuke Konishid0676332010-03-22 19:33:43 +0900327 return ret;
Ryusuke Konishie29df392009-11-29 16:51:16 +0900328}
329
Ryusuke Konishiaaed1d52010-03-23 01:50:38 +0900330/**
331 * nilfs_add_checksums_on_logs - add checksums on the logs
332 * @logs: list of segment buffers storing target logs
333 * @seed: checksum seed value
334 */
335void nilfs_add_checksums_on_logs(struct list_head *logs, u32 seed)
336{
337 struct nilfs_segment_buffer *segbuf;
338
339 list_for_each_entry(segbuf, logs, sb_list) {
340 if (segbuf->sb_super_root)
341 nilfs_segbuf_fill_in_super_root_crc(segbuf, seed);
342 nilfs_segbuf_fill_in_segsum_crc(segbuf, seed);
343 nilfs_segbuf_fill_in_data_crc(segbuf, seed);
344 }
345}
346
Ryusuke Konishi64b5a322009-04-06 19:01:36 -0700347/*
348 * BIO operations
349 */
350static void nilfs_end_bio_write(struct bio *bio, int err)
351{
352 const int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags);
Ryusuke Konishi9284ad22009-11-25 01:04:21 +0900353 struct nilfs_segment_buffer *segbuf = bio->bi_private;
Ryusuke Konishi64b5a322009-04-06 19:01:36 -0700354
355 if (err == -EOPNOTSUPP) {
356 set_bit(BIO_EOPNOTSUPP, &bio->bi_flags);
357 bio_put(bio);
358 /* to be detected by submit_seg_bio() */
359 }
360
361 if (!uptodate)
Ryusuke Konishi9284ad22009-11-25 01:04:21 +0900362 atomic_inc(&segbuf->sb_err);
Ryusuke Konishi64b5a322009-04-06 19:01:36 -0700363
364 bio_put(bio);
Ryusuke Konishi9284ad22009-11-25 01:04:21 +0900365 complete(&segbuf->sb_bio_event);
Ryusuke Konishi64b5a322009-04-06 19:01:36 -0700366}
367
Ryusuke Konishi9284ad22009-11-25 01:04:21 +0900368static int nilfs_segbuf_submit_bio(struct nilfs_segment_buffer *segbuf,
369 struct nilfs_write_info *wi, int mode)
Ryusuke Konishi64b5a322009-04-06 19:01:36 -0700370{
371 struct bio *bio = wi->bio;
372 int err;
373
Ryusuke Konishi026a7d62010-10-07 14:19:48 +0900374 if (segbuf->sb_nbio > 0 &&
375 bdi_write_congested(segbuf->sb_super->s_bdi)) {
Ryusuke Konishi9284ad22009-11-25 01:04:21 +0900376 wait_for_completion(&segbuf->sb_bio_event);
377 segbuf->sb_nbio--;
378 if (unlikely(atomic_read(&segbuf->sb_err))) {
Ryusuke Konishi64b5a322009-04-06 19:01:36 -0700379 bio_put(bio);
380 err = -EIO;
381 goto failed;
382 }
383 }
384
385 bio->bi_end_io = nilfs_end_bio_write;
Ryusuke Konishi9284ad22009-11-25 01:04:21 +0900386 bio->bi_private = segbuf;
Ryusuke Konishi64b5a322009-04-06 19:01:36 -0700387 bio_get(bio);
388 submit_bio(mode, bio);
389 if (bio_flagged(bio, BIO_EOPNOTSUPP)) {
390 bio_put(bio);
391 err = -EOPNOTSUPP;
392 goto failed;
393 }
Ryusuke Konishi9284ad22009-11-25 01:04:21 +0900394 segbuf->sb_nbio++;
Ryusuke Konishi64b5a322009-04-06 19:01:36 -0700395 bio_put(bio);
396
397 wi->bio = NULL;
398 wi->rest_blocks -= wi->end - wi->start;
399 wi->nr_vecs = min(wi->max_pages, wi->rest_blocks);
400 wi->start = wi->end;
401 return 0;
402
403 failed:
404 wi->bio = NULL;
405 return err;
406}
407
408/**
Ryusuke Konishi9c965ba2009-11-29 01:17:31 +0900409 * nilfs_alloc_seg_bio - allocate a new bio for writing log
410 * @nilfs: nilfs object
411 * @start: start block number of the bio
Ryusuke Konishi64b5a322009-04-06 19:01:36 -0700412 * @nr_vecs: request size of page vector.
413 *
Ryusuke Konishi64b5a322009-04-06 19:01:36 -0700414 * Return Value: On success, pointer to the struct bio is returned.
415 * On error, NULL is returned.
416 */
Ryusuke Konishi9c965ba2009-11-29 01:17:31 +0900417static struct bio *nilfs_alloc_seg_bio(struct the_nilfs *nilfs, sector_t start,
Ryusuke Konishi64b5a322009-04-06 19:01:36 -0700418 int nr_vecs)
419{
420 struct bio *bio;
421
Ryusuke Konishic1b353f2009-06-19 15:25:42 +0900422 bio = bio_alloc(GFP_NOIO, nr_vecs);
Ryusuke Konishi64b5a322009-04-06 19:01:36 -0700423 if (bio == NULL) {
424 while (!bio && (nr_vecs >>= 1))
Ryusuke Konishic1b353f2009-06-19 15:25:42 +0900425 bio = bio_alloc(GFP_NOIO, nr_vecs);
Ryusuke Konishi64b5a322009-04-06 19:01:36 -0700426 }
427 if (likely(bio)) {
Ryusuke Konishi9c965ba2009-11-29 01:17:31 +0900428 bio->bi_bdev = nilfs->ns_bdev;
429 bio->bi_sector = start << (nilfs->ns_blocksize_bits - 9);
Ryusuke Konishi64b5a322009-04-06 19:01:36 -0700430 }
431 return bio;
432}
433
Ryusuke Konishi9c965ba2009-11-29 01:17:31 +0900434static void nilfs_segbuf_prepare_write(struct nilfs_segment_buffer *segbuf,
435 struct nilfs_write_info *wi)
Ryusuke Konishi64b5a322009-04-06 19:01:36 -0700436{
437 wi->bio = NULL;
438 wi->rest_blocks = segbuf->sb_sum.nblocks;
Ryusuke Konishi9c965ba2009-11-29 01:17:31 +0900439 wi->max_pages = bio_get_nr_vecs(wi->nilfs->ns_bdev);
Ryusuke Konishi64b5a322009-04-06 19:01:36 -0700440 wi->nr_vecs = min(wi->max_pages, wi->rest_blocks);
441 wi->start = wi->end = 0;
Ryusuke Konishi64b5a322009-04-06 19:01:36 -0700442 wi->blocknr = segbuf->sb_pseg_start;
Ryusuke Konishi64b5a322009-04-06 19:01:36 -0700443}
444
Ryusuke Konishi9284ad22009-11-25 01:04:21 +0900445static int nilfs_segbuf_submit_bh(struct nilfs_segment_buffer *segbuf,
446 struct nilfs_write_info *wi,
447 struct buffer_head *bh, int mode)
Ryusuke Konishi64b5a322009-04-06 19:01:36 -0700448{
449 int len, err;
450
451 BUG_ON(wi->nr_vecs <= 0);
452 repeat:
453 if (!wi->bio) {
Ryusuke Konishi9c965ba2009-11-29 01:17:31 +0900454 wi->bio = nilfs_alloc_seg_bio(wi->nilfs, wi->blocknr + wi->end,
Ryusuke Konishi64b5a322009-04-06 19:01:36 -0700455 wi->nr_vecs);
456 if (unlikely(!wi->bio))
457 return -ENOMEM;
458 }
459
460 len = bio_add_page(wi->bio, bh->b_page, bh->b_size, bh_offset(bh));
461 if (len == bh->b_size) {
462 wi->end++;
463 return 0;
464 }
465 /* bio is FULL */
Ryusuke Konishi9284ad22009-11-25 01:04:21 +0900466 err = nilfs_segbuf_submit_bio(segbuf, wi, mode);
Ryusuke Konishi64b5a322009-04-06 19:01:36 -0700467 /* never submit current bh */
468 if (likely(!err))
469 goto repeat;
470 return err;
471}
472
Ryusuke Konishi9c965ba2009-11-29 01:17:31 +0900473/**
474 * nilfs_segbuf_write - submit write requests of a log
475 * @segbuf: buffer storing a log to be written
476 * @nilfs: nilfs object
477 *
478 * Return Value: On Success, 0 is returned. On Error, one of the following
479 * negative error code is returned.
480 *
481 * %-EIO - I/O error
482 *
483 * %-ENOMEM - Insufficient memory available.
484 */
Ryusuke Konishi6c477d42010-03-14 02:01:51 +0900485static int nilfs_segbuf_write(struct nilfs_segment_buffer *segbuf,
486 struct the_nilfs *nilfs)
Ryusuke Konishi64b5a322009-04-06 19:01:36 -0700487{
Ryusuke Konishi9c965ba2009-11-29 01:17:31 +0900488 struct nilfs_write_info wi;
Ryusuke Konishi64b5a322009-04-06 19:01:36 -0700489 struct buffer_head *bh;
Ryusuke Konishi5f1586d2009-11-29 19:14:17 +0900490 int res = 0, rw = WRITE;
Ryusuke Konishi64b5a322009-04-06 19:01:36 -0700491
Ryusuke Konishi9c965ba2009-11-29 01:17:31 +0900492 wi.nilfs = nilfs;
493 nilfs_segbuf_prepare_write(segbuf, &wi);
494
Ryusuke Konishi64b5a322009-04-06 19:01:36 -0700495 list_for_each_entry(bh, &segbuf->sb_segsum_buffers, b_assoc_buffers) {
Ryusuke Konishi9c965ba2009-11-29 01:17:31 +0900496 res = nilfs_segbuf_submit_bh(segbuf, &wi, bh, rw);
Ryusuke Konishi64b5a322009-04-06 19:01:36 -0700497 if (unlikely(res))
498 goto failed_bio;
499 }
500
501 list_for_each_entry(bh, &segbuf->sb_payload_buffers, b_assoc_buffers) {
Ryusuke Konishi9c965ba2009-11-29 01:17:31 +0900502 res = nilfs_segbuf_submit_bh(segbuf, &wi, bh, rw);
Ryusuke Konishi64b5a322009-04-06 19:01:36 -0700503 if (unlikely(res))
504 goto failed_bio;
505 }
506
Ryusuke Konishi9c965ba2009-11-29 01:17:31 +0900507 if (wi.bio) {
Ryusuke Konishi64b5a322009-04-06 19:01:36 -0700508 /*
509 * Last BIO is always sent through the following
510 * submission.
511 */
Christoph Hellwig7b6d91d2010-08-07 18:20:39 +0200512 rw |= REQ_SYNC | REQ_UNPLUG;
Ryusuke Konishi9c965ba2009-11-29 01:17:31 +0900513 res = nilfs_segbuf_submit_bio(segbuf, &wi, rw);
Ryusuke Konishi64b5a322009-04-06 19:01:36 -0700514 }
515
Ryusuke Konishi64b5a322009-04-06 19:01:36 -0700516 failed_bio:
Ryusuke Konishi5f1586d2009-11-29 19:14:17 +0900517 return res;
Ryusuke Konishi64b5a322009-04-06 19:01:36 -0700518}
519
520/**
521 * nilfs_segbuf_wait - wait for completion of requested BIOs
Ryusuke Konishi9284ad22009-11-25 01:04:21 +0900522 * @segbuf: segment buffer
Ryusuke Konishi64b5a322009-04-06 19:01:36 -0700523 *
524 * Return Value: On Success, 0 is returned. On Error, one of the following
525 * negative error code is returned.
526 *
527 * %-EIO - I/O error
528 */
Ryusuke Konishi6c477d42010-03-14 02:01:51 +0900529static int nilfs_segbuf_wait(struct nilfs_segment_buffer *segbuf)
Ryusuke Konishi64b5a322009-04-06 19:01:36 -0700530{
531 int err = 0;
532
Ryusuke Konishi9284ad22009-11-25 01:04:21 +0900533 if (!segbuf->sb_nbio)
Ryusuke Konishi64b5a322009-04-06 19:01:36 -0700534 return 0;
535
536 do {
Ryusuke Konishi9284ad22009-11-25 01:04:21 +0900537 wait_for_completion(&segbuf->sb_bio_event);
538 } while (--segbuf->sb_nbio > 0);
Ryusuke Konishi64b5a322009-04-06 19:01:36 -0700539
Ryusuke Konishi9284ad22009-11-25 01:04:21 +0900540 if (unlikely(atomic_read(&segbuf->sb_err) > 0)) {
Ryusuke Konishi64b5a322009-04-06 19:01:36 -0700541 printk(KERN_ERR "NILFS: IO error writing segment\n");
542 err = -EIO;
Ryusuke Konishi64b5a322009-04-06 19:01:36 -0700543 }
544 return err;
545}