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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 /* to be detected by nilfs_segbuf_submit_bio() */
349 }
350
351 if (!uptodate)
352 atomic_inc(&segbuf->sb_err);
353
354 bio_put(bio);
355 complete(&segbuf->sb_bio_event);
356}
357
358static int nilfs_segbuf_submit_bio(struct nilfs_segment_buffer *segbuf,
359 struct nilfs_write_info *wi, int mode)
360{
361 struct bio *bio = wi->bio;
362 int err;
363
364 if (segbuf->sb_nbio > 0 &&
365 bdi_write_congested(segbuf->sb_super->s_bdi)) {
366 wait_for_completion(&segbuf->sb_bio_event);
367 segbuf->sb_nbio--;
368 if (unlikely(atomic_read(&segbuf->sb_err))) {
369 bio_put(bio);
370 err = -EIO;
371 goto failed;
372 }
373 }
374
375 bio->bi_end_io = nilfs_end_bio_write;
376 bio->bi_private = segbuf;
377 bio_get(bio);
378 submit_bio(mode, bio);
379 segbuf->sb_nbio++;
380 if (bio_flagged(bio, BIO_EOPNOTSUPP)) {
381 bio_put(bio);
382 err = -EOPNOTSUPP;
383 goto failed;
384 }
385 bio_put(bio);
386
387 wi->bio = NULL;
388 wi->rest_blocks -= wi->end - wi->start;
389 wi->nr_vecs = min(wi->max_pages, wi->rest_blocks);
390 wi->start = wi->end;
391 return 0;
392
393 failed:
394 wi->bio = NULL;
395 return err;
396}
397
398/**
399 * nilfs_alloc_seg_bio - allocate a new bio for writing log
400 * @nilfs: nilfs object
401 * @start: start block number of the bio
402 * @nr_vecs: request size of page vector.
403 *
404 * Return Value: On success, pointer to the struct bio is returned.
405 * On error, NULL is returned.
406 */
407static struct bio *nilfs_alloc_seg_bio(struct the_nilfs *nilfs, sector_t start,
408 int nr_vecs)
409{
410 struct bio *bio;
411
412 bio = bio_alloc(GFP_NOIO, nr_vecs);
413 if (bio == NULL) {
414 while (!bio && (nr_vecs >>= 1))
415 bio = bio_alloc(GFP_NOIO, nr_vecs);
416 }
417 if (likely(bio)) {
418 bio->bi_bdev = nilfs->ns_bdev;
419 bio->bi_iter.bi_sector =
420 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}
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}