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1// SPDX-License-Identifier: GPL-2.0+
2/*
3 * segbuf.c - NILFS segment buffer
4 *
5 * Copyright (C) 2005-2008 Nippon Telegraph and Telephone Corporation.
6 *
7 * Written by Ryusuke Konishi.
8 *
9 */
10
11#include <linux/buffer_head.h>
12#include <linux/writeback.h>
13#include <linux/crc32.h>
14#include <linux/backing-dev.h>
15#include <linux/slab.h>
16#include "page.h"
17#include "segbuf.h"
18
19
20struct nilfs_write_info {
21 struct the_nilfs *nilfs;
22 struct bio *bio;
23 int start, end; /* The region to be submitted */
24 int rest_blocks;
25 int max_pages;
26 int nr_vecs;
27 sector_t blocknr;
28};
29
30static int nilfs_segbuf_write(struct nilfs_segment_buffer *segbuf,
31 struct the_nilfs *nilfs);
32static int nilfs_segbuf_wait(struct nilfs_segment_buffer *segbuf);
33
34struct nilfs_segment_buffer *nilfs_segbuf_new(struct super_block *sb)
35{
36 struct nilfs_segment_buffer *segbuf;
37
38 segbuf = kmem_cache_alloc(nilfs_segbuf_cachep, GFP_NOFS);
39 if (unlikely(!segbuf))
40 return NULL;
41
42 segbuf->sb_super = sb;
43 INIT_LIST_HEAD(&segbuf->sb_list);
44 INIT_LIST_HEAD(&segbuf->sb_segsum_buffers);
45 INIT_LIST_HEAD(&segbuf->sb_payload_buffers);
46 segbuf->sb_super_root = NULL;
47
48 init_completion(&segbuf->sb_bio_event);
49 atomic_set(&segbuf->sb_err, 0);
50 segbuf->sb_nbio = 0;
51
52 return segbuf;
53}
54
55void nilfs_segbuf_free(struct nilfs_segment_buffer *segbuf)
56{
57 kmem_cache_free(nilfs_segbuf_cachep, segbuf);
58}
59
60void nilfs_segbuf_map(struct nilfs_segment_buffer *segbuf, __u64 segnum,
61 unsigned long offset, struct the_nilfs *nilfs)
62{
63 segbuf->sb_segnum = segnum;
64 nilfs_get_segment_range(nilfs, segnum, &segbuf->sb_fseg_start,
65 &segbuf->sb_fseg_end);
66
67 segbuf->sb_pseg_start = segbuf->sb_fseg_start + offset;
68 segbuf->sb_rest_blocks =
69 segbuf->sb_fseg_end - segbuf->sb_pseg_start + 1;
70}
71
72/**
73 * nilfs_segbuf_map_cont - map a new log behind a given log
74 * @segbuf: new segment buffer
75 * @prev: segment buffer containing a log to be continued
76 */
77void nilfs_segbuf_map_cont(struct nilfs_segment_buffer *segbuf,
78 struct nilfs_segment_buffer *prev)
79{
80 segbuf->sb_segnum = prev->sb_segnum;
81 segbuf->sb_fseg_start = prev->sb_fseg_start;
82 segbuf->sb_fseg_end = prev->sb_fseg_end;
83 segbuf->sb_pseg_start = prev->sb_pseg_start + prev->sb_sum.nblocks;
84 segbuf->sb_rest_blocks =
85 segbuf->sb_fseg_end - segbuf->sb_pseg_start + 1;
86}
87
88void nilfs_segbuf_set_next_segnum(struct nilfs_segment_buffer *segbuf,
89 __u64 nextnum, struct the_nilfs *nilfs)
90{
91 segbuf->sb_nextnum = nextnum;
92 segbuf->sb_sum.next = nilfs_get_segment_start_blocknr(nilfs, nextnum);
93}
94
95int nilfs_segbuf_extend_segsum(struct nilfs_segment_buffer *segbuf)
96{
97 struct buffer_head *bh;
98
99 bh = sb_getblk(segbuf->sb_super,
100 segbuf->sb_pseg_start + segbuf->sb_sum.nsumblk);
101 if (unlikely(!bh))
102 return -ENOMEM;
103
104 nilfs_segbuf_add_segsum_buffer(segbuf, bh);
105 return 0;
106}
107
108int nilfs_segbuf_extend_payload(struct nilfs_segment_buffer *segbuf,
109 struct buffer_head **bhp)
110{
111 struct buffer_head *bh;
112
113 bh = sb_getblk(segbuf->sb_super,
114 segbuf->sb_pseg_start + segbuf->sb_sum.nblocks);
115 if (unlikely(!bh))
116 return -ENOMEM;
117
118 nilfs_segbuf_add_payload_buffer(segbuf, bh);
119 *bhp = bh;
120 return 0;
121}
122
123int nilfs_segbuf_reset(struct nilfs_segment_buffer *segbuf, unsigned int flags,
124 time64_t ctime, __u64 cno)
125{
126 int err;
127
128 segbuf->sb_sum.nblocks = segbuf->sb_sum.nsumblk = 0;
129 err = nilfs_segbuf_extend_segsum(segbuf);
130 if (unlikely(err))
131 return err;
132
133 segbuf->sb_sum.flags = flags;
134 segbuf->sb_sum.sumbytes = sizeof(struct nilfs_segment_summary);
135 segbuf->sb_sum.nfinfo = segbuf->sb_sum.nfileblk = 0;
136 segbuf->sb_sum.ctime = ctime;
137 segbuf->sb_sum.cno = cno;
138 return 0;
139}
140
141/*
142 * Setup segment summary
143 */
144void nilfs_segbuf_fill_in_segsum(struct nilfs_segment_buffer *segbuf)
145{
146 struct nilfs_segment_summary *raw_sum;
147 struct buffer_head *bh_sum;
148
149 bh_sum = list_entry(segbuf->sb_segsum_buffers.next,
150 struct buffer_head, b_assoc_buffers);
151 raw_sum = (struct nilfs_segment_summary *)bh_sum->b_data;
152
153 raw_sum->ss_magic = cpu_to_le32(NILFS_SEGSUM_MAGIC);
154 raw_sum->ss_bytes = cpu_to_le16(sizeof(*raw_sum));
155 raw_sum->ss_flags = cpu_to_le16(segbuf->sb_sum.flags);
156 raw_sum->ss_seq = cpu_to_le64(segbuf->sb_sum.seg_seq);
157 raw_sum->ss_create = cpu_to_le64(segbuf->sb_sum.ctime);
158 raw_sum->ss_next = cpu_to_le64(segbuf->sb_sum.next);
159 raw_sum->ss_nblocks = cpu_to_le32(segbuf->sb_sum.nblocks);
160 raw_sum->ss_nfinfo = cpu_to_le32(segbuf->sb_sum.nfinfo);
161 raw_sum->ss_sumbytes = cpu_to_le32(segbuf->sb_sum.sumbytes);
162 raw_sum->ss_pad = 0;
163 raw_sum->ss_cno = cpu_to_le64(segbuf->sb_sum.cno);
164}
165
166/*
167 * CRC calculation routines
168 */
169static void
170nilfs_segbuf_fill_in_segsum_crc(struct nilfs_segment_buffer *segbuf, u32 seed)
171{
172 struct buffer_head *bh;
173 struct nilfs_segment_summary *raw_sum;
174 unsigned long size, bytes = segbuf->sb_sum.sumbytes;
175 u32 crc;
176
177 bh = list_entry(segbuf->sb_segsum_buffers.next, struct buffer_head,
178 b_assoc_buffers);
179
180 raw_sum = (struct nilfs_segment_summary *)bh->b_data;
181 size = min_t(unsigned long, bytes, bh->b_size);
182 crc = crc32_le(seed,
183 (unsigned char *)raw_sum +
184 sizeof(raw_sum->ss_datasum) + sizeof(raw_sum->ss_sumsum),
185 size - (sizeof(raw_sum->ss_datasum) +
186 sizeof(raw_sum->ss_sumsum)));
187
188 list_for_each_entry_continue(bh, &segbuf->sb_segsum_buffers,
189 b_assoc_buffers) {
190 bytes -= size;
191 size = min_t(unsigned long, bytes, bh->b_size);
192 crc = crc32_le(crc, bh->b_data, size);
193 }
194 raw_sum->ss_sumsum = cpu_to_le32(crc);
195}
196
197static void nilfs_segbuf_fill_in_data_crc(struct nilfs_segment_buffer *segbuf,
198 u32 seed)
199{
200 struct buffer_head *bh;
201 struct nilfs_segment_summary *raw_sum;
202 void *kaddr;
203 u32 crc;
204
205 bh = list_entry(segbuf->sb_segsum_buffers.next, struct buffer_head,
206 b_assoc_buffers);
207 raw_sum = (struct nilfs_segment_summary *)bh->b_data;
208 crc = crc32_le(seed,
209 (unsigned char *)raw_sum + sizeof(raw_sum->ss_datasum),
210 bh->b_size - sizeof(raw_sum->ss_datasum));
211
212 list_for_each_entry_continue(bh, &segbuf->sb_segsum_buffers,
213 b_assoc_buffers) {
214 crc = crc32_le(crc, bh->b_data, bh->b_size);
215 }
216 list_for_each_entry(bh, &segbuf->sb_payload_buffers, b_assoc_buffers) {
217 kaddr = kmap_atomic(bh->b_page);
218 crc = crc32_le(crc, kaddr + bh_offset(bh), bh->b_size);
219 kunmap_atomic(kaddr);
220 }
221 raw_sum->ss_datasum = cpu_to_le32(crc);
222}
223
224static void
225nilfs_segbuf_fill_in_super_root_crc(struct nilfs_segment_buffer *segbuf,
226 u32 seed)
227{
228 struct nilfs_super_root *raw_sr;
229 struct the_nilfs *nilfs = segbuf->sb_super->s_fs_info;
230 unsigned int srsize;
231 u32 crc;
232
233 raw_sr = (struct nilfs_super_root *)segbuf->sb_super_root->b_data;
234 srsize = NILFS_SR_BYTES(nilfs->ns_inode_size);
235 crc = crc32_le(seed,
236 (unsigned char *)raw_sr + sizeof(raw_sr->sr_sum),
237 srsize - sizeof(raw_sr->sr_sum));
238 raw_sr->sr_sum = cpu_to_le32(crc);
239}
240
241static void nilfs_release_buffers(struct list_head *list)
242{
243 struct buffer_head *bh, *n;
244
245 list_for_each_entry_safe(bh, n, list, b_assoc_buffers) {
246 list_del_init(&bh->b_assoc_buffers);
247 brelse(bh);
248 }
249}
250
251static void nilfs_segbuf_clear(struct nilfs_segment_buffer *segbuf)
252{
253 nilfs_release_buffers(&segbuf->sb_segsum_buffers);
254 nilfs_release_buffers(&segbuf->sb_payload_buffers);
255 segbuf->sb_super_root = NULL;
256}
257
258/*
259 * Iterators for segment buffers
260 */
261void nilfs_clear_logs(struct list_head *logs)
262{
263 struct nilfs_segment_buffer *segbuf;
264
265 list_for_each_entry(segbuf, logs, sb_list)
266 nilfs_segbuf_clear(segbuf);
267}
268
269void nilfs_truncate_logs(struct list_head *logs,
270 struct nilfs_segment_buffer *last)
271{
272 struct nilfs_segment_buffer *n, *segbuf;
273
274 segbuf = list_prepare_entry(last, logs, sb_list);
275 list_for_each_entry_safe_continue(segbuf, n, logs, sb_list) {
276 list_del_init(&segbuf->sb_list);
277 nilfs_segbuf_clear(segbuf);
278 nilfs_segbuf_free(segbuf);
279 }
280}
281
282int nilfs_write_logs(struct list_head *logs, struct the_nilfs *nilfs)
283{
284 struct nilfs_segment_buffer *segbuf;
285 int ret = 0;
286
287 list_for_each_entry(segbuf, logs, sb_list) {
288 ret = nilfs_segbuf_write(segbuf, nilfs);
289 if (ret)
290 break;
291 }
292 return ret;
293}
294
295int nilfs_wait_on_logs(struct list_head *logs)
296{
297 struct nilfs_segment_buffer *segbuf;
298 int err, ret = 0;
299
300 list_for_each_entry(segbuf, logs, sb_list) {
301 err = nilfs_segbuf_wait(segbuf);
302 if (err && !ret)
303 ret = err;
304 }
305 return ret;
306}
307
308/**
309 * nilfs_add_checksums_on_logs - add checksums on the logs
310 * @logs: list of segment buffers storing target logs
311 * @seed: checksum seed value
312 */
313void nilfs_add_checksums_on_logs(struct list_head *logs, u32 seed)
314{
315 struct nilfs_segment_buffer *segbuf;
316
317 list_for_each_entry(segbuf, logs, sb_list) {
318 if (segbuf->sb_super_root)
319 nilfs_segbuf_fill_in_super_root_crc(segbuf, seed);
320 nilfs_segbuf_fill_in_segsum_crc(segbuf, seed);
321 nilfs_segbuf_fill_in_data_crc(segbuf, seed);
322 }
323}
324
325/*
326 * BIO operations
327 */
328static void nilfs_end_bio_write(struct bio *bio)
329{
330 struct nilfs_segment_buffer *segbuf = bio->bi_private;
331
332 if (bio->bi_status)
333 atomic_inc(&segbuf->sb_err);
334
335 bio_put(bio);
336 complete(&segbuf->sb_bio_event);
337}
338
339static int nilfs_segbuf_submit_bio(struct nilfs_segment_buffer *segbuf,
340 struct nilfs_write_info *wi, int mode,
341 int mode_flags)
342{
343 struct bio *bio = wi->bio;
344 int err;
345
346 if (segbuf->sb_nbio > 0 &&
347 bdi_write_congested(segbuf->sb_super->s_bdi)) {
348 wait_for_completion(&segbuf->sb_bio_event);
349 segbuf->sb_nbio--;
350 if (unlikely(atomic_read(&segbuf->sb_err))) {
351 bio_put(bio);
352 err = -EIO;
353 goto failed;
354 }
355 }
356
357 bio->bi_end_io = nilfs_end_bio_write;
358 bio->bi_private = segbuf;
359 bio_set_op_attrs(bio, mode, mode_flags);
360 submit_bio(bio);
361 segbuf->sb_nbio++;
362
363 wi->bio = NULL;
364 wi->rest_blocks -= wi->end - wi->start;
365 wi->nr_vecs = min(wi->max_pages, wi->rest_blocks);
366 wi->start = wi->end;
367 return 0;
368
369 failed:
370 wi->bio = NULL;
371 return err;
372}
373
374/**
375 * nilfs_alloc_seg_bio - allocate a new bio for writing log
376 * @nilfs: nilfs object
377 * @start: start block number of the bio
378 * @nr_vecs: request size of page vector.
379 *
380 * Return Value: On success, pointer to the struct bio is returned.
381 * On error, NULL is returned.
382 */
383static struct bio *nilfs_alloc_seg_bio(struct the_nilfs *nilfs, sector_t start,
384 int nr_vecs)
385{
386 struct bio *bio;
387
388 bio = bio_alloc(GFP_NOIO, nr_vecs);
389 if (bio == NULL) {
390 while (!bio && (nr_vecs >>= 1))
391 bio = bio_alloc(GFP_NOIO, nr_vecs);
392 }
393 if (likely(bio)) {
394 bio_set_dev(bio, nilfs->ns_bdev);
395 bio->bi_iter.bi_sector =
396 start << (nilfs->ns_blocksize_bits - 9);
397 }
398 return bio;
399}
400
401static void nilfs_segbuf_prepare_write(struct nilfs_segment_buffer *segbuf,
402 struct nilfs_write_info *wi)
403{
404 wi->bio = NULL;
405 wi->rest_blocks = segbuf->sb_sum.nblocks;
406 wi->max_pages = BIO_MAX_PAGES;
407 wi->nr_vecs = min(wi->max_pages, wi->rest_blocks);
408 wi->start = wi->end = 0;
409 wi->blocknr = segbuf->sb_pseg_start;
410}
411
412static int nilfs_segbuf_submit_bh(struct nilfs_segment_buffer *segbuf,
413 struct nilfs_write_info *wi,
414 struct buffer_head *bh, int mode)
415{
416 int len, err;
417
418 BUG_ON(wi->nr_vecs <= 0);
419 repeat:
420 if (!wi->bio) {
421 wi->bio = nilfs_alloc_seg_bio(wi->nilfs, wi->blocknr + wi->end,
422 wi->nr_vecs);
423 if (unlikely(!wi->bio))
424 return -ENOMEM;
425 }
426
427 len = bio_add_page(wi->bio, bh->b_page, bh->b_size, bh_offset(bh));
428 if (len == bh->b_size) {
429 wi->end++;
430 return 0;
431 }
432 /* bio is FULL */
433 err = nilfs_segbuf_submit_bio(segbuf, wi, mode, 0);
434 /* never submit current bh */
435 if (likely(!err))
436 goto repeat;
437 return err;
438}
439
440/**
441 * nilfs_segbuf_write - submit write requests of a log
442 * @segbuf: buffer storing a log to be written
443 * @nilfs: nilfs object
444 *
445 * Return Value: On Success, 0 is returned. On Error, one of the following
446 * negative error code is returned.
447 *
448 * %-EIO - I/O error
449 *
450 * %-ENOMEM - Insufficient memory available.
451 */
452static int nilfs_segbuf_write(struct nilfs_segment_buffer *segbuf,
453 struct the_nilfs *nilfs)
454{
455 struct nilfs_write_info wi;
456 struct buffer_head *bh;
457 int res = 0;
458
459 wi.nilfs = nilfs;
460 nilfs_segbuf_prepare_write(segbuf, &wi);
461
462 list_for_each_entry(bh, &segbuf->sb_segsum_buffers, b_assoc_buffers) {
463 res = nilfs_segbuf_submit_bh(segbuf, &wi, bh, REQ_OP_WRITE);
464 if (unlikely(res))
465 goto failed_bio;
466 }
467
468 list_for_each_entry(bh, &segbuf->sb_payload_buffers, b_assoc_buffers) {
469 res = nilfs_segbuf_submit_bh(segbuf, &wi, bh, REQ_OP_WRITE);
470 if (unlikely(res))
471 goto failed_bio;
472 }
473
474 if (wi.bio) {
475 /*
476 * Last BIO is always sent through the following
477 * submission.
478 */
479 res = nilfs_segbuf_submit_bio(segbuf, &wi, REQ_OP_WRITE,
480 REQ_SYNC);
481 }
482
483 failed_bio:
484 return res;
485}
486
487/**
488 * nilfs_segbuf_wait - wait for completion of requested BIOs
489 * @segbuf: segment buffer
490 *
491 * Return Value: On Success, 0 is returned. On Error, one of the following
492 * negative error code is returned.
493 *
494 * %-EIO - I/O error
495 */
496static int nilfs_segbuf_wait(struct nilfs_segment_buffer *segbuf)
497{
498 int err = 0;
499
500 if (!segbuf->sb_nbio)
501 return 0;
502
503 do {
504 wait_for_completion(&segbuf->sb_bio_event);
505 } while (--segbuf->sb_nbio > 0);
506
507 if (unlikely(atomic_read(&segbuf->sb_err) > 0)) {
508 nilfs_msg(segbuf->sb_super, KERN_ERR,
509 "I/O error writing log (start-blocknr=%llu, block-count=%lu) in segment %llu",
510 (unsigned long long)segbuf->sb_pseg_start,
511 segbuf->sb_sum.nblocks,
512 (unsigned long long)segbuf->sb_segnum);
513 err = -EIO;
514 }
515 return err;
516}
1/*
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>
27#include <linux/backing-dev.h>
28#include <linux/slab.h>
29#include "page.h"
30#include "segbuf.h"
31
32
33struct nilfs_write_info {
34 struct the_nilfs *nilfs;
35 struct bio *bio;
36 int start, end; /* The region to be submitted */
37 int rest_blocks;
38 int max_pages;
39 int nr_vecs;
40 sector_t blocknr;
41};
42
43static 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
47struct 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);
59 segbuf->sb_super_root = NULL;
60
61 init_completion(&segbuf->sb_bio_event);
62 atomic_set(&segbuf->sb_err, 0);
63 segbuf->sb_nbio = 0;
64
65 return segbuf;
66}
67
68void nilfs_segbuf_free(struct nilfs_segment_buffer *segbuf)
69{
70 kmem_cache_free(nilfs_segbuf_cachep, segbuf);
71}
72
73void nilfs_segbuf_map(struct nilfs_segment_buffer *segbuf, __u64 segnum,
74 unsigned long offset, struct the_nilfs *nilfs)
75{
76 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;
83}
84
85/**
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
101void 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,
137 time_t ctime, __u64 cno)
138{
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;
150 segbuf->sb_sum.cno = cno;
151 return 0;
152}
153
154/*
155 * Setup segment summary
156 */
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;
176 raw_sum->ss_cno = cpu_to_le64(segbuf->sb_sum.cno);
177}
178
179/*
180 * CRC calculation routines
181 */
182static void
183nilfs_segbuf_fill_in_segsum_crc(struct nilfs_segment_buffer *segbuf, u32 seed)
184{
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
210static void nilfs_segbuf_fill_in_data_crc(struct nilfs_segment_buffer *segbuf,
211 u32 seed)
212{
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);
231 crc = crc32_le(crc, kaddr + bh_offset(bh), bh->b_size);
232 kunmap_atomic(kaddr);
233 }
234 raw_sum->ss_datasum = cpu_to_le32(crc);
235}
236
237static 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 struct the_nilfs *nilfs = segbuf->sb_super->s_fs_info;
243 unsigned srsize;
244 u32 crc;
245
246 raw_sr = (struct nilfs_super_root *)segbuf->sb_super_root->b_data;
247 srsize = NILFS_SR_BYTES(nilfs->ns_inode_size);
248 crc = crc32_le(seed,
249 (unsigned char *)raw_sr + sizeof(raw_sr->sr_sum),
250 srsize - sizeof(raw_sr->sr_sum));
251 raw_sr->sr_sum = cpu_to_le32(crc);
252}
253
254static void nilfs_release_buffers(struct list_head *list)
255{
256 struct buffer_head *bh, *n;
257
258 list_for_each_entry_safe(bh, n, list, b_assoc_buffers) {
259 list_del_init(&bh->b_assoc_buffers);
260 brelse(bh);
261 }
262}
263
264static void nilfs_segbuf_clear(struct nilfs_segment_buffer *segbuf)
265{
266 nilfs_release_buffers(&segbuf->sb_segsum_buffers);
267 nilfs_release_buffers(&segbuf->sb_payload_buffers);
268 segbuf->sb_super_root = NULL;
269}
270
271/*
272 * Iterators for segment buffers
273 */
274void nilfs_clear_logs(struct list_head *logs)
275{
276 struct nilfs_segment_buffer *segbuf;
277
278 list_for_each_entry(segbuf, logs, sb_list)
279 nilfs_segbuf_clear(segbuf);
280}
281
282void nilfs_truncate_logs(struct list_head *logs,
283 struct nilfs_segment_buffer *last)
284{
285 struct nilfs_segment_buffer *n, *segbuf;
286
287 segbuf = list_prepare_entry(last, logs, sb_list);
288 list_for_each_entry_safe_continue(segbuf, n, logs, sb_list) {
289 list_del_init(&segbuf->sb_list);
290 nilfs_segbuf_clear(segbuf);
291 nilfs_segbuf_free(segbuf);
292 }
293}
294
295int nilfs_write_logs(struct list_head *logs, struct the_nilfs *nilfs)
296{
297 struct nilfs_segment_buffer *segbuf;
298 int ret = 0;
299
300 list_for_each_entry(segbuf, logs, sb_list) {
301 ret = nilfs_segbuf_write(segbuf, nilfs);
302 if (ret)
303 break;
304 }
305 return ret;
306}
307
308int nilfs_wait_on_logs(struct list_head *logs)
309{
310 struct nilfs_segment_buffer *segbuf;
311 int err, ret = 0;
312
313 list_for_each_entry(segbuf, logs, sb_list) {
314 err = nilfs_segbuf_wait(segbuf);
315 if (err && !ret)
316 ret = err;
317 }
318 return ret;
319}
320
321/**
322 * nilfs_add_checksums_on_logs - add checksums on the logs
323 * @logs: list of segment buffers storing target logs
324 * @seed: checksum seed value
325 */
326void nilfs_add_checksums_on_logs(struct list_head *logs, u32 seed)
327{
328 struct nilfs_segment_buffer *segbuf;
329
330 list_for_each_entry(segbuf, logs, sb_list) {
331 if (segbuf->sb_super_root)
332 nilfs_segbuf_fill_in_super_root_crc(segbuf, seed);
333 nilfs_segbuf_fill_in_segsum_crc(segbuf, seed);
334 nilfs_segbuf_fill_in_data_crc(segbuf, seed);
335 }
336}
337
338/*
339 * BIO operations
340 */
341static void nilfs_end_bio_write(struct bio *bio, int err)
342{
343 const int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags);
344 struct nilfs_segment_buffer *segbuf = bio->bi_private;
345
346 if (err == -EOPNOTSUPP) {
347 set_bit(BIO_EOPNOTSUPP, &bio->bi_flags);
348 bio_put(bio);
349 /* to be detected by submit_seg_bio() */
350 }
351
352 if (!uptodate)
353 atomic_inc(&segbuf->sb_err);
354
355 bio_put(bio);
356 complete(&segbuf->sb_bio_event);
357}
358
359static int nilfs_segbuf_submit_bio(struct nilfs_segment_buffer *segbuf,
360 struct nilfs_write_info *wi, int mode)
361{
362 struct bio *bio = wi->bio;
363 int err;
364
365 if (segbuf->sb_nbio > 0 &&
366 bdi_write_congested(segbuf->sb_super->s_bdi)) {
367 wait_for_completion(&segbuf->sb_bio_event);
368 segbuf->sb_nbio--;
369 if (unlikely(atomic_read(&segbuf->sb_err))) {
370 bio_put(bio);
371 err = -EIO;
372 goto failed;
373 }
374 }
375
376 bio->bi_end_io = nilfs_end_bio_write;
377 bio->bi_private = segbuf;
378 bio_get(bio);
379 submit_bio(mode, bio);
380 if (bio_flagged(bio, BIO_EOPNOTSUPP)) {
381 bio_put(bio);
382 err = -EOPNOTSUPP;
383 goto failed;
384 }
385 segbuf->sb_nbio++;
386 bio_put(bio);
387
388 wi->bio = NULL;
389 wi->rest_blocks -= wi->end - wi->start;
390 wi->nr_vecs = min(wi->max_pages, wi->rest_blocks);
391 wi->start = wi->end;
392 return 0;
393
394 failed:
395 wi->bio = NULL;
396 return err;
397}
398
399/**
400 * nilfs_alloc_seg_bio - allocate a new bio for writing log
401 * @nilfs: nilfs object
402 * @start: start block number of the bio
403 * @nr_vecs: request size of page vector.
404 *
405 * Return Value: On success, pointer to the struct bio is returned.
406 * On error, NULL is returned.
407 */
408static struct bio *nilfs_alloc_seg_bio(struct the_nilfs *nilfs, sector_t start,
409 int nr_vecs)
410{
411 struct bio *bio;
412
413 bio = bio_alloc(GFP_NOIO, nr_vecs);
414 if (bio == NULL) {
415 while (!bio && (nr_vecs >>= 1))
416 bio = bio_alloc(GFP_NOIO, nr_vecs);
417 }
418 if (likely(bio)) {
419 bio->bi_bdev = nilfs->ns_bdev;
420 bio->bi_sector = start << (nilfs->ns_blocksize_bits - 9);
421 }
422 return bio;
423}
424
425static void nilfs_segbuf_prepare_write(struct nilfs_segment_buffer *segbuf,
426 struct nilfs_write_info *wi)
427{
428 wi->bio = NULL;
429 wi->rest_blocks = segbuf->sb_sum.nblocks;
430 wi->max_pages = bio_get_nr_vecs(wi->nilfs->ns_bdev);
431 wi->nr_vecs = min(wi->max_pages, wi->rest_blocks);
432 wi->start = wi->end = 0;
433 wi->blocknr = segbuf->sb_pseg_start;
434}
435
436static int nilfs_segbuf_submit_bh(struct nilfs_segment_buffer *segbuf,
437 struct nilfs_write_info *wi,
438 struct buffer_head *bh, int mode)
439{
440 int len, err;
441
442 BUG_ON(wi->nr_vecs <= 0);
443 repeat:
444 if (!wi->bio) {
445 wi->bio = nilfs_alloc_seg_bio(wi->nilfs, wi->blocknr + wi->end,
446 wi->nr_vecs);
447 if (unlikely(!wi->bio))
448 return -ENOMEM;
449 }
450
451 len = bio_add_page(wi->bio, bh->b_page, bh->b_size, bh_offset(bh));
452 if (len == bh->b_size) {
453 wi->end++;
454 return 0;
455 }
456 /* bio is FULL */
457 err = nilfs_segbuf_submit_bio(segbuf, wi, mode);
458 /* never submit current bh */
459 if (likely(!err))
460 goto repeat;
461 return err;
462}
463
464/**
465 * nilfs_segbuf_write - submit write requests of a log
466 * @segbuf: buffer storing a log to be written
467 * @nilfs: nilfs object
468 *
469 * Return Value: On Success, 0 is returned. On Error, one of the following
470 * negative error code is returned.
471 *
472 * %-EIO - I/O error
473 *
474 * %-ENOMEM - Insufficient memory available.
475 */
476static int nilfs_segbuf_write(struct nilfs_segment_buffer *segbuf,
477 struct the_nilfs *nilfs)
478{
479 struct nilfs_write_info wi;
480 struct buffer_head *bh;
481 int res = 0, rw = WRITE;
482
483 wi.nilfs = nilfs;
484 nilfs_segbuf_prepare_write(segbuf, &wi);
485
486 list_for_each_entry(bh, &segbuf->sb_segsum_buffers, b_assoc_buffers) {
487 res = nilfs_segbuf_submit_bh(segbuf, &wi, bh, rw);
488 if (unlikely(res))
489 goto failed_bio;
490 }
491
492 list_for_each_entry(bh, &segbuf->sb_payload_buffers, b_assoc_buffers) {
493 res = nilfs_segbuf_submit_bh(segbuf, &wi, bh, rw);
494 if (unlikely(res))
495 goto failed_bio;
496 }
497
498 if (wi.bio) {
499 /*
500 * Last BIO is always sent through the following
501 * submission.
502 */
503 rw |= REQ_SYNC;
504 res = nilfs_segbuf_submit_bio(segbuf, &wi, rw);
505 }
506
507 failed_bio:
508 return res;
509}
510
511/**
512 * nilfs_segbuf_wait - wait for completion of requested BIOs
513 * @segbuf: segment buffer
514 *
515 * Return Value: On Success, 0 is returned. On Error, one of the following
516 * negative error code is returned.
517 *
518 * %-EIO - I/O error
519 */
520static int nilfs_segbuf_wait(struct nilfs_segment_buffer *segbuf)
521{
522 int err = 0;
523
524 if (!segbuf->sb_nbio)
525 return 0;
526
527 do {
528 wait_for_completion(&segbuf->sb_bio_event);
529 } while (--segbuf->sb_nbio > 0);
530
531 if (unlikely(atomic_read(&segbuf->sb_err) > 0)) {
532 printk(KERN_ERR "NILFS: IO error writing segment\n");
533 err = -EIO;
534 }
535 return err;
536}