1// SPDX-License-Identifier: GPL-2.0+
2/*
3 * 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(list: &segbuf->sb_list);
44 INIT_LIST_HEAD(list: &segbuf->sb_segsum_buffers);
45 INIT_LIST_HEAD(list: &segbuf->sb_payload_buffers);
46 segbuf->sb_super_root = NULL;
47
48 init_completion(x: &segbuf->sb_bio_event);
49 atomic_set(v: &segbuf->sb_err, i: 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(s: nilfs_segbuf_cachep, objp: 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, seg_start: &segbuf->sb_fseg_start,
65 seg_end: &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, segnum: nextnum);
93}
94
95int nilfs_segbuf_extend_segsum(struct nilfs_segment_buffer *segbuf)
96{
97 struct buffer_head *bh;
98
99 bh = sb_getblk(sb: segbuf->sb_super,
100 block: segbuf->sb_pseg_start + segbuf->sb_sum.nsumblk);
101 if (unlikely(!bh))
102 return -ENOMEM;
103
104 lock_buffer(bh);
105 if (!buffer_uptodate(bh)) {
106 memset(bh->b_data, 0, bh->b_size);
107 set_buffer_uptodate(bh);
108 }
109 unlock_buffer(bh);
110 nilfs_segbuf_add_segsum_buffer(segbuf, bh);
111 return 0;
112}
113
114int nilfs_segbuf_extend_payload(struct nilfs_segment_buffer *segbuf,
115 struct buffer_head **bhp)
116{
117 struct buffer_head *bh;
118
119 bh = sb_getblk(sb: segbuf->sb_super,
120 block: segbuf->sb_pseg_start + segbuf->sb_sum.nblocks);
121 if (unlikely(!bh))
122 return -ENOMEM;
123
124 nilfs_segbuf_add_payload_buffer(segbuf, bh);
125 *bhp = bh;
126 return 0;
127}
128
129int nilfs_segbuf_reset(struct nilfs_segment_buffer *segbuf, unsigned int flags,
130 time64_t ctime, __u64 cno)
131{
132 int err;
133
134 segbuf->sb_sum.nblocks = segbuf->sb_sum.nsumblk = 0;
135 err = nilfs_segbuf_extend_segsum(segbuf);
136 if (unlikely(err))
137 return err;
138
139 segbuf->sb_sum.flags = flags;
140 segbuf->sb_sum.sumbytes = sizeof(struct nilfs_segment_summary);
141 segbuf->sb_sum.nfinfo = segbuf->sb_sum.nfileblk = 0;
142 segbuf->sb_sum.ctime = ctime;
143 segbuf->sb_sum.cno = cno;
144 return 0;
145}
146
147/*
148 * Setup segment summary
149 */
150void nilfs_segbuf_fill_in_segsum(struct nilfs_segment_buffer *segbuf)
151{
152 struct nilfs_segment_summary *raw_sum;
153 struct buffer_head *bh_sum;
154
155 bh_sum = list_entry(segbuf->sb_segsum_buffers.next,
156 struct buffer_head, b_assoc_buffers);
157 raw_sum = (struct nilfs_segment_summary *)bh_sum->b_data;
158
159 raw_sum->ss_magic = cpu_to_le32(NILFS_SEGSUM_MAGIC);
160 raw_sum->ss_bytes = cpu_to_le16(sizeof(*raw_sum));
161 raw_sum->ss_flags = cpu_to_le16(segbuf->sb_sum.flags);
162 raw_sum->ss_seq = cpu_to_le64(segbuf->sb_sum.seg_seq);
163 raw_sum->ss_create = cpu_to_le64(segbuf->sb_sum.ctime);
164 raw_sum->ss_next = cpu_to_le64(segbuf->sb_sum.next);
165 raw_sum->ss_nblocks = cpu_to_le32(segbuf->sb_sum.nblocks);
166 raw_sum->ss_nfinfo = cpu_to_le32(segbuf->sb_sum.nfinfo);
167 raw_sum->ss_sumbytes = cpu_to_le32(segbuf->sb_sum.sumbytes);
168 raw_sum->ss_pad = 0;
169 raw_sum->ss_cno = cpu_to_le64(segbuf->sb_sum.cno);
170}
171
172/*
173 * CRC calculation routines
174 */
175static void
176nilfs_segbuf_fill_in_segsum_crc(struct nilfs_segment_buffer *segbuf, u32 seed)
177{
178 struct buffer_head *bh;
179 struct nilfs_segment_summary *raw_sum;
180 unsigned long size, bytes = segbuf->sb_sum.sumbytes;
181 u32 crc;
182
183 bh = list_entry(segbuf->sb_segsum_buffers.next, struct buffer_head,
184 b_assoc_buffers);
185
186 raw_sum = (struct nilfs_segment_summary *)bh->b_data;
187 size = min_t(unsigned long, bytes, bh->b_size);
188 crc = crc32_le(crc: seed,
189 p: (unsigned char *)raw_sum +
190 sizeof(raw_sum->ss_datasum) + sizeof(raw_sum->ss_sumsum),
191 len: size - (sizeof(raw_sum->ss_datasum) +
192 sizeof(raw_sum->ss_sumsum)));
193
194 list_for_each_entry_continue(bh, &segbuf->sb_segsum_buffers,
195 b_assoc_buffers) {
196 bytes -= size;
197 size = min_t(unsigned long, bytes, bh->b_size);
198 crc = crc32_le(crc, p: bh->b_data, len: size);
199 }
200 raw_sum->ss_sumsum = cpu_to_le32(crc);
201}
202
203static void nilfs_segbuf_fill_in_data_crc(struct nilfs_segment_buffer *segbuf,
204 u32 seed)
205{
206 struct buffer_head *bh;
207 struct nilfs_segment_summary *raw_sum;
208 u32 crc;
209
210 bh = list_entry(segbuf->sb_segsum_buffers.next, struct buffer_head,
211 b_assoc_buffers);
212 raw_sum = (struct nilfs_segment_summary *)bh->b_data;
213 crc = crc32_le(crc: seed,
214 p: (unsigned char *)raw_sum + sizeof(raw_sum->ss_datasum),
215 len: bh->b_size - sizeof(raw_sum->ss_datasum));
216
217 list_for_each_entry_continue(bh, &segbuf->sb_segsum_buffers,
218 b_assoc_buffers) {
219 crc = crc32_le(crc, p: bh->b_data, len: bh->b_size);
220 }
221 list_for_each_entry(bh, &segbuf->sb_payload_buffers, b_assoc_buffers) {
222 size_t offset = offset_in_folio(bh->b_folio, bh->b_data);
223 unsigned char *from;
224
225 /* Do not support block sizes larger than PAGE_SIZE */
226 from = kmap_local_folio(folio: bh->b_folio, offset);
227 crc = crc32_le(crc, p: from, len: bh->b_size);
228 kunmap_local(from);
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(crc: seed,
245 p: (unsigned char *)raw_sr + sizeof(raw_sr->sr_sum),
246 len: 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(entry: &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(list: &segbuf->sb_segsum_buffers);
263 nilfs_release_buffers(list: &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(entry: &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(v: &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)
350{
351 struct bio *bio = wi->bio;
352
353 bio->bi_end_io = nilfs_end_bio_write;
354 bio->bi_private = segbuf;
355 submit_bio(bio);
356 segbuf->sb_nbio++;
357
358 wi->bio = NULL;
359 wi->rest_blocks -= wi->end - wi->start;
360 wi->nr_vecs = min(wi->max_pages, wi->rest_blocks);
361 wi->start = wi->end;
362 return 0;
363}
364
365static void nilfs_segbuf_prepare_write(struct nilfs_segment_buffer *segbuf,
366 struct nilfs_write_info *wi)
367{
368 wi->bio = NULL;
369 wi->rest_blocks = segbuf->sb_sum.nblocks;
370 wi->max_pages = BIO_MAX_VECS;
371 wi->nr_vecs = min(wi->max_pages, wi->rest_blocks);
372 wi->start = wi->end = 0;
373 wi->blocknr = segbuf->sb_pseg_start;
374}
375
376static int nilfs_segbuf_submit_bh(struct nilfs_segment_buffer *segbuf,
377 struct nilfs_write_info *wi,
378 struct buffer_head *bh)
379{
380 int err;
381
382 BUG_ON(wi->nr_vecs <= 0);
383 repeat:
384 if (!wi->bio) {
385 wi->bio = bio_alloc(bdev: wi->nilfs->ns_bdev, nr_vecs: wi->nr_vecs,
386 opf: REQ_OP_WRITE, GFP_NOIO);
387 wi->bio->bi_iter.bi_sector = (wi->blocknr + wi->end) <<
388 (wi->nilfs->ns_blocksize_bits - 9);
389 }
390
391 if (bio_add_folio(bio: wi->bio, folio: bh->b_folio, len: bh->b_size,
392 offset_in_folio(bh->b_folio, bh->b_data))) {
393 wi->end++;
394 return 0;
395 }
396 /* bio is FULL */
397 err = nilfs_segbuf_submit_bio(segbuf, wi);
398 /* never submit current bh */
399 if (likely(!err))
400 goto repeat;
401 return err;
402}
403
404/**
405 * nilfs_segbuf_write - submit write requests of a log
406 * @segbuf: buffer storing a log to be written
407 * @nilfs: nilfs object
408 *
409 * Return: Always 0.
410 */
411static int nilfs_segbuf_write(struct nilfs_segment_buffer *segbuf,
412 struct the_nilfs *nilfs)
413{
414 struct nilfs_write_info wi;
415 struct buffer_head *bh;
416 int res = 0;
417
418 wi.nilfs = nilfs;
419 nilfs_segbuf_prepare_write(segbuf, wi: &wi);
420
421 list_for_each_entry(bh, &segbuf->sb_segsum_buffers, b_assoc_buffers) {
422 res = nilfs_segbuf_submit_bh(segbuf, wi: &wi, bh);
423 if (unlikely(res))
424 goto failed_bio;
425 }
426
427 list_for_each_entry(bh, &segbuf->sb_payload_buffers, b_assoc_buffers) {
428 res = nilfs_segbuf_submit_bh(segbuf, wi: &wi, bh);
429 if (unlikely(res))
430 goto failed_bio;
431 }
432
433 if (wi.bio) {
434 /*
435 * Last BIO is always sent through the following
436 * submission.
437 */
438 wi.bio->bi_opf |= REQ_SYNC;
439 res = nilfs_segbuf_submit_bio(segbuf, wi: &wi);
440 }
441
442 failed_bio:
443 return res;
444}
445
446/**
447 * nilfs_segbuf_wait - wait for completion of requested BIOs
448 * @segbuf: segment buffer
449 *
450 * Return: 0 on success, or %-EIO if I/O error is detected.
451 */
452static int nilfs_segbuf_wait(struct nilfs_segment_buffer *segbuf)
453{
454 int err = 0;
455
456 if (!segbuf->sb_nbio)
457 return 0;
458
459 do {
460 wait_for_completion(&segbuf->sb_bio_event);
461 } while (--segbuf->sb_nbio > 0);
462
463 if (unlikely(atomic_read(&segbuf->sb_err) > 0)) {
464 nilfs_err(segbuf->sb_super,
465 "I/O error writing log (start-blocknr=%llu, block-count=%lu) in segment %llu",
466 (unsigned long long)segbuf->sb_pseg_start,
467 segbuf->sb_sum.nblocks,
468 (unsigned long long)segbuf->sb_segnum);
469 err = -EIO;
470 }
471 return err;
472}
473

source code of linux/fs/nilfs2/segbuf.c