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