1 // SPDX-License-Identifier: GPL-2.0+
3 * segbuf.c - NILFS segment buffer
5 * Copyright (C) 2005-2008 Nippon Telegraph and Telephone Corporation.
7 * Written by Ryusuke Konishi.
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>
20 struct nilfs_write_info {
21 struct the_nilfs *nilfs;
23 int start, end; /* The region to be submitted */
30 static int nilfs_segbuf_write(struct nilfs_segment_buffer *segbuf,
31 struct the_nilfs *nilfs);
32 static int nilfs_segbuf_wait(struct nilfs_segment_buffer *segbuf);
34 struct nilfs_segment_buffer *nilfs_segbuf_new(struct super_block *sb)
36 struct nilfs_segment_buffer *segbuf;
38 segbuf = kmem_cache_alloc(nilfs_segbuf_cachep, GFP_NOFS);
39 if (unlikely(!segbuf))
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;
48 init_completion(&segbuf->sb_bio_event);
49 atomic_set(&segbuf->sb_err, 0);
55 void nilfs_segbuf_free(struct nilfs_segment_buffer *segbuf)
57 kmem_cache_free(nilfs_segbuf_cachep, segbuf);
60 void nilfs_segbuf_map(struct nilfs_segment_buffer *segbuf, __u64 segnum,
61 unsigned long offset, struct the_nilfs *nilfs)
63 segbuf->sb_segnum = segnum;
64 nilfs_get_segment_range(nilfs, segnum, &segbuf->sb_fseg_start,
65 &segbuf->sb_fseg_end);
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;
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
77 void nilfs_segbuf_map_cont(struct nilfs_segment_buffer *segbuf,
78 struct nilfs_segment_buffer *prev)
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;
88 void nilfs_segbuf_set_next_segnum(struct nilfs_segment_buffer *segbuf,
89 __u64 nextnum, struct the_nilfs *nilfs)
91 segbuf->sb_nextnum = nextnum;
92 segbuf->sb_sum.next = nilfs_get_segment_start_blocknr(nilfs, nextnum);
95 int nilfs_segbuf_extend_segsum(struct nilfs_segment_buffer *segbuf)
97 struct buffer_head *bh;
99 bh = sb_getblk(segbuf->sb_super,
100 segbuf->sb_pseg_start + segbuf->sb_sum.nsumblk);
105 if (!buffer_uptodate(bh)) {
106 memset(bh->b_data, 0, bh->b_size);
107 set_buffer_uptodate(bh);
110 nilfs_segbuf_add_segsum_buffer(segbuf, bh);
114 int nilfs_segbuf_extend_payload(struct nilfs_segment_buffer *segbuf,
115 struct buffer_head **bhp)
117 struct buffer_head *bh;
119 bh = sb_getblk(segbuf->sb_super,
120 segbuf->sb_pseg_start + segbuf->sb_sum.nblocks);
124 nilfs_segbuf_add_payload_buffer(segbuf, bh);
129 int nilfs_segbuf_reset(struct nilfs_segment_buffer *segbuf, unsigned int flags,
130 time64_t ctime, __u64 cno)
134 segbuf->sb_sum.nblocks = segbuf->sb_sum.nsumblk = 0;
135 err = nilfs_segbuf_extend_segsum(segbuf);
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;
148 * Setup segment summary
150 void nilfs_segbuf_fill_in_segsum(struct nilfs_segment_buffer *segbuf)
152 struct nilfs_segment_summary *raw_sum;
153 struct buffer_head *bh_sum;
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;
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);
169 raw_sum->ss_cno = cpu_to_le64(segbuf->sb_sum.cno);
173 * CRC calculation routines
176 nilfs_segbuf_fill_in_segsum_crc(struct nilfs_segment_buffer *segbuf, u32 seed)
178 struct buffer_head *bh;
179 struct nilfs_segment_summary *raw_sum;
180 unsigned long size, bytes = segbuf->sb_sum.sumbytes;
183 bh = list_entry(segbuf->sb_segsum_buffers.next, struct buffer_head,
186 raw_sum = (struct nilfs_segment_summary *)bh->b_data;
187 size = min_t(unsigned long, bytes, bh->b_size);
189 (unsigned char *)raw_sum +
190 sizeof(raw_sum->ss_datasum) + sizeof(raw_sum->ss_sumsum),
191 size - (sizeof(raw_sum->ss_datasum) +
192 sizeof(raw_sum->ss_sumsum)));
194 list_for_each_entry_continue(bh, &segbuf->sb_segsum_buffers,
197 size = min_t(unsigned long, bytes, bh->b_size);
198 crc = crc32_le(crc, bh->b_data, size);
200 raw_sum->ss_sumsum = cpu_to_le32(crc);
203 static void nilfs_segbuf_fill_in_data_crc(struct nilfs_segment_buffer *segbuf,
206 struct buffer_head *bh;
207 struct nilfs_segment_summary *raw_sum;
211 bh = list_entry(segbuf->sb_segsum_buffers.next, struct buffer_head,
213 raw_sum = (struct nilfs_segment_summary *)bh->b_data;
215 (unsigned char *)raw_sum + sizeof(raw_sum->ss_datasum),
216 bh->b_size - sizeof(raw_sum->ss_datasum));
218 list_for_each_entry_continue(bh, &segbuf->sb_segsum_buffers,
220 crc = crc32_le(crc, bh->b_data, bh->b_size);
222 list_for_each_entry(bh, &segbuf->sb_payload_buffers, b_assoc_buffers) {
223 kaddr = kmap_atomic(bh->b_page);
224 crc = crc32_le(crc, kaddr + bh_offset(bh), bh->b_size);
225 kunmap_atomic(kaddr);
227 raw_sum->ss_datasum = cpu_to_le32(crc);
231 nilfs_segbuf_fill_in_super_root_crc(struct nilfs_segment_buffer *segbuf,
234 struct nilfs_super_root *raw_sr;
235 struct the_nilfs *nilfs = segbuf->sb_super->s_fs_info;
239 raw_sr = (struct nilfs_super_root *)segbuf->sb_super_root->b_data;
240 srsize = NILFS_SR_BYTES(nilfs->ns_inode_size);
242 (unsigned char *)raw_sr + sizeof(raw_sr->sr_sum),
243 srsize - sizeof(raw_sr->sr_sum));
244 raw_sr->sr_sum = cpu_to_le32(crc);
247 static void nilfs_release_buffers(struct list_head *list)
249 struct buffer_head *bh, *n;
251 list_for_each_entry_safe(bh, n, list, b_assoc_buffers) {
252 list_del_init(&bh->b_assoc_buffers);
257 static void nilfs_segbuf_clear(struct nilfs_segment_buffer *segbuf)
259 nilfs_release_buffers(&segbuf->sb_segsum_buffers);
260 nilfs_release_buffers(&segbuf->sb_payload_buffers);
261 segbuf->sb_super_root = NULL;
265 * Iterators for segment buffers
267 void nilfs_clear_logs(struct list_head *logs)
269 struct nilfs_segment_buffer *segbuf;
271 list_for_each_entry(segbuf, logs, sb_list)
272 nilfs_segbuf_clear(segbuf);
275 void nilfs_truncate_logs(struct list_head *logs,
276 struct nilfs_segment_buffer *last)
278 struct nilfs_segment_buffer *n, *segbuf;
280 segbuf = list_prepare_entry(last, logs, sb_list);
281 list_for_each_entry_safe_continue(segbuf, n, logs, sb_list) {
282 list_del_init(&segbuf->sb_list);
283 nilfs_segbuf_clear(segbuf);
284 nilfs_segbuf_free(segbuf);
288 int nilfs_write_logs(struct list_head *logs, struct the_nilfs *nilfs)
290 struct nilfs_segment_buffer *segbuf;
293 list_for_each_entry(segbuf, logs, sb_list) {
294 ret = nilfs_segbuf_write(segbuf, nilfs);
301 int nilfs_wait_on_logs(struct list_head *logs)
303 struct nilfs_segment_buffer *segbuf;
306 list_for_each_entry(segbuf, logs, sb_list) {
307 err = nilfs_segbuf_wait(segbuf);
315 * nilfs_add_checksums_on_logs - add checksums on the logs
316 * @logs: list of segment buffers storing target logs
317 * @seed: checksum seed value
319 void nilfs_add_checksums_on_logs(struct list_head *logs, u32 seed)
321 struct nilfs_segment_buffer *segbuf;
323 list_for_each_entry(segbuf, logs, sb_list) {
324 if (segbuf->sb_super_root)
325 nilfs_segbuf_fill_in_super_root_crc(segbuf, seed);
326 nilfs_segbuf_fill_in_segsum_crc(segbuf, seed);
327 nilfs_segbuf_fill_in_data_crc(segbuf, seed);
334 static void nilfs_end_bio_write(struct bio *bio)
336 struct nilfs_segment_buffer *segbuf = bio->bi_private;
339 atomic_inc(&segbuf->sb_err);
342 complete(&segbuf->sb_bio_event);
345 static int nilfs_segbuf_submit_bio(struct nilfs_segment_buffer *segbuf,
346 struct nilfs_write_info *wi, int mode,
349 struct bio *bio = wi->bio;
352 if (segbuf->sb_nbio > 0 &&
353 bdi_write_congested(segbuf->sb_super->s_bdi)) {
354 wait_for_completion(&segbuf->sb_bio_event);
356 if (unlikely(atomic_read(&segbuf->sb_err))) {
363 bio->bi_end_io = nilfs_end_bio_write;
364 bio->bi_private = segbuf;
365 bio_set_op_attrs(bio, mode, mode_flags);
370 wi->rest_blocks -= wi->end - wi->start;
371 wi->nr_vecs = min(wi->max_pages, wi->rest_blocks);
381 * nilfs_alloc_seg_bio - allocate a new bio for writing log
382 * @nilfs: nilfs object
383 * @start: start block number of the bio
384 * @nr_vecs: request size of page vector.
386 * Return Value: On success, pointer to the struct bio is returned.
387 * On error, NULL is returned.
389 static struct bio *nilfs_alloc_seg_bio(struct the_nilfs *nilfs, sector_t start,
394 bio = bio_alloc(GFP_NOIO, nr_vecs);
396 while (!bio && (nr_vecs >>= 1))
397 bio = bio_alloc(GFP_NOIO, nr_vecs);
400 bio_set_dev(bio, nilfs->ns_bdev);
401 bio->bi_iter.bi_sector =
402 start << (nilfs->ns_blocksize_bits - 9);
407 static void nilfs_segbuf_prepare_write(struct nilfs_segment_buffer *segbuf,
408 struct nilfs_write_info *wi)
411 wi->rest_blocks = segbuf->sb_sum.nblocks;
412 wi->max_pages = BIO_MAX_PAGES;
413 wi->nr_vecs = min(wi->max_pages, wi->rest_blocks);
414 wi->start = wi->end = 0;
415 wi->blocknr = segbuf->sb_pseg_start;
418 static int nilfs_segbuf_submit_bh(struct nilfs_segment_buffer *segbuf,
419 struct nilfs_write_info *wi,
420 struct buffer_head *bh, int mode)
424 BUG_ON(wi->nr_vecs <= 0);
427 wi->bio = nilfs_alloc_seg_bio(wi->nilfs, wi->blocknr + wi->end,
429 if (unlikely(!wi->bio))
433 len = bio_add_page(wi->bio, bh->b_page, bh->b_size, bh_offset(bh));
434 if (len == bh->b_size) {
439 err = nilfs_segbuf_submit_bio(segbuf, wi, mode, 0);
440 /* never submit current bh */
447 * nilfs_segbuf_write - submit write requests of a log
448 * @segbuf: buffer storing a log to be written
449 * @nilfs: nilfs object
451 * Return Value: On Success, 0 is returned. On Error, one of the following
452 * negative error code is returned.
456 * %-ENOMEM - Insufficient memory available.
458 static int nilfs_segbuf_write(struct nilfs_segment_buffer *segbuf,
459 struct the_nilfs *nilfs)
461 struct nilfs_write_info wi;
462 struct buffer_head *bh;
466 nilfs_segbuf_prepare_write(segbuf, &wi);
468 list_for_each_entry(bh, &segbuf->sb_segsum_buffers, b_assoc_buffers) {
469 res = nilfs_segbuf_submit_bh(segbuf, &wi, bh, REQ_OP_WRITE);
474 list_for_each_entry(bh, &segbuf->sb_payload_buffers, b_assoc_buffers) {
475 res = nilfs_segbuf_submit_bh(segbuf, &wi, bh, REQ_OP_WRITE);
482 * Last BIO is always sent through the following
485 res = nilfs_segbuf_submit_bio(segbuf, &wi, REQ_OP_WRITE,
494 * nilfs_segbuf_wait - wait for completion of requested BIOs
495 * @segbuf: segment buffer
497 * Return Value: On Success, 0 is returned. On Error, one of the following
498 * negative error code is returned.
502 static int nilfs_segbuf_wait(struct nilfs_segment_buffer *segbuf)
506 if (!segbuf->sb_nbio)
510 wait_for_completion(&segbuf->sb_bio_event);
511 } while (--segbuf->sb_nbio > 0);
513 if (unlikely(atomic_read(&segbuf->sb_err) > 0)) {
514 nilfs_err(segbuf->sb_super,
515 "I/O error writing log (start-blocknr=%llu, block-count=%lu) in segment %llu",
516 (unsigned long long)segbuf->sb_pseg_start,
517 segbuf->sb_sum.nblocks,
518 (unsigned long long)segbuf->sb_segnum);