mtd: pxa32xx_nand: add support for partition table parsing
[linux/fpc-iii.git] / fs / nilfs2 / segbuf.c
blob636eaafd6ea257c7bfaf53dc7b7ce8399f81a103
1 /*
2 * segbuf.c - NILFS segment buffer
4 * Copyright (C) 2005-2008 Nippon Telegraph and Telephone Corporation.
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.
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.
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
20 * Written by Ryusuke Konishi <ryusuke@osrg.net>
24 #include <linux/buffer_head.h>
25 #include <linux/writeback.h>
26 #include <linux/crc32.h>
27 #include <linux/backing-dev.h>
28 #include "page.h"
29 #include "segbuf.h"
32 struct nilfs_write_info {
33 struct the_nilfs *nilfs;
34 struct bio *bio;
35 int start, end; /* The region to be submitted */
36 int rest_blocks;
37 int max_pages;
38 int nr_vecs;
39 sector_t blocknr;
43 static int nilfs_segbuf_write(struct nilfs_segment_buffer *segbuf,
44 struct the_nilfs *nilfs);
45 static int nilfs_segbuf_wait(struct nilfs_segment_buffer *segbuf);
48 static struct kmem_cache *nilfs_segbuf_cachep;
50 static void nilfs_segbuf_init_once(void *obj)
52 memset(obj, 0, sizeof(struct nilfs_segment_buffer));
55 int __init nilfs_init_segbuf_cache(void)
57 nilfs_segbuf_cachep =
58 kmem_cache_create("nilfs2_segbuf_cache",
59 sizeof(struct nilfs_segment_buffer),
60 0, SLAB_RECLAIM_ACCOUNT,
61 nilfs_segbuf_init_once);
63 return (nilfs_segbuf_cachep == NULL) ? -ENOMEM : 0;
66 void nilfs_destroy_segbuf_cache(void)
68 kmem_cache_destroy(nilfs_segbuf_cachep);
71 struct nilfs_segment_buffer *nilfs_segbuf_new(struct super_block *sb)
73 struct nilfs_segment_buffer *segbuf;
75 segbuf = kmem_cache_alloc(nilfs_segbuf_cachep, GFP_NOFS);
76 if (unlikely(!segbuf))
77 return NULL;
79 segbuf->sb_super = sb;
80 INIT_LIST_HEAD(&segbuf->sb_list);
81 INIT_LIST_HEAD(&segbuf->sb_segsum_buffers);
82 INIT_LIST_HEAD(&segbuf->sb_payload_buffers);
84 init_completion(&segbuf->sb_bio_event);
85 atomic_set(&segbuf->sb_err, 0);
86 segbuf->sb_nbio = 0;
88 return segbuf;
91 void nilfs_segbuf_free(struct nilfs_segment_buffer *segbuf)
93 kmem_cache_free(nilfs_segbuf_cachep, segbuf);
96 void nilfs_segbuf_map(struct nilfs_segment_buffer *segbuf, __u64 segnum,
97 unsigned long offset, struct the_nilfs *nilfs)
99 segbuf->sb_segnum = segnum;
100 nilfs_get_segment_range(nilfs, segnum, &segbuf->sb_fseg_start,
101 &segbuf->sb_fseg_end);
103 segbuf->sb_pseg_start = segbuf->sb_fseg_start + offset;
104 segbuf->sb_rest_blocks =
105 segbuf->sb_fseg_end - segbuf->sb_pseg_start + 1;
109 * nilfs_segbuf_map_cont - map a new log behind a given log
110 * @segbuf: new segment buffer
111 * @prev: segment buffer containing a log to be continued
113 void nilfs_segbuf_map_cont(struct nilfs_segment_buffer *segbuf,
114 struct nilfs_segment_buffer *prev)
116 segbuf->sb_segnum = prev->sb_segnum;
117 segbuf->sb_fseg_start = prev->sb_fseg_start;
118 segbuf->sb_fseg_end = prev->sb_fseg_end;
119 segbuf->sb_pseg_start = prev->sb_pseg_start + prev->sb_sum.nblocks;
120 segbuf->sb_rest_blocks =
121 segbuf->sb_fseg_end - segbuf->sb_pseg_start + 1;
124 void nilfs_segbuf_set_next_segnum(struct nilfs_segment_buffer *segbuf,
125 __u64 nextnum, struct the_nilfs *nilfs)
127 segbuf->sb_nextnum = nextnum;
128 segbuf->sb_sum.next = nilfs_get_segment_start_blocknr(nilfs, nextnum);
131 int nilfs_segbuf_extend_segsum(struct nilfs_segment_buffer *segbuf)
133 struct buffer_head *bh;
135 bh = sb_getblk(segbuf->sb_super,
136 segbuf->sb_pseg_start + segbuf->sb_sum.nsumblk);
137 if (unlikely(!bh))
138 return -ENOMEM;
140 nilfs_segbuf_add_segsum_buffer(segbuf, bh);
141 return 0;
144 int nilfs_segbuf_extend_payload(struct nilfs_segment_buffer *segbuf,
145 struct buffer_head **bhp)
147 struct buffer_head *bh;
149 bh = sb_getblk(segbuf->sb_super,
150 segbuf->sb_pseg_start + segbuf->sb_sum.nblocks);
151 if (unlikely(!bh))
152 return -ENOMEM;
154 nilfs_segbuf_add_payload_buffer(segbuf, bh);
155 *bhp = bh;
156 return 0;
159 int nilfs_segbuf_reset(struct nilfs_segment_buffer *segbuf, unsigned flags,
160 time_t ctime)
162 int err;
164 segbuf->sb_sum.nblocks = segbuf->sb_sum.nsumblk = 0;
165 err = nilfs_segbuf_extend_segsum(segbuf);
166 if (unlikely(err))
167 return err;
169 segbuf->sb_sum.flags = flags;
170 segbuf->sb_sum.sumbytes = sizeof(struct nilfs_segment_summary);
171 segbuf->sb_sum.nfinfo = segbuf->sb_sum.nfileblk = 0;
172 segbuf->sb_sum.ctime = ctime;
173 return 0;
177 * Setup segment summary
179 void nilfs_segbuf_fill_in_segsum(struct nilfs_segment_buffer *segbuf)
181 struct nilfs_segment_summary *raw_sum;
182 struct buffer_head *bh_sum;
184 bh_sum = list_entry(segbuf->sb_segsum_buffers.next,
185 struct buffer_head, b_assoc_buffers);
186 raw_sum = (struct nilfs_segment_summary *)bh_sum->b_data;
188 raw_sum->ss_magic = cpu_to_le32(NILFS_SEGSUM_MAGIC);
189 raw_sum->ss_bytes = cpu_to_le16(sizeof(*raw_sum));
190 raw_sum->ss_flags = cpu_to_le16(segbuf->sb_sum.flags);
191 raw_sum->ss_seq = cpu_to_le64(segbuf->sb_sum.seg_seq);
192 raw_sum->ss_create = cpu_to_le64(segbuf->sb_sum.ctime);
193 raw_sum->ss_next = cpu_to_le64(segbuf->sb_sum.next);
194 raw_sum->ss_nblocks = cpu_to_le32(segbuf->sb_sum.nblocks);
195 raw_sum->ss_nfinfo = cpu_to_le32(segbuf->sb_sum.nfinfo);
196 raw_sum->ss_sumbytes = cpu_to_le32(segbuf->sb_sum.sumbytes);
197 raw_sum->ss_pad = 0;
201 * CRC calculation routines
203 void nilfs_segbuf_fill_in_segsum_crc(struct nilfs_segment_buffer *segbuf,
204 u32 seed)
206 struct buffer_head *bh;
207 struct nilfs_segment_summary *raw_sum;
208 unsigned long size, bytes = segbuf->sb_sum.sumbytes;
209 u32 crc;
211 bh = list_entry(segbuf->sb_segsum_buffers.next, struct buffer_head,
212 b_assoc_buffers);
214 raw_sum = (struct nilfs_segment_summary *)bh->b_data;
215 size = min_t(unsigned long, bytes, bh->b_size);
216 crc = crc32_le(seed,
217 (unsigned char *)raw_sum +
218 sizeof(raw_sum->ss_datasum) + sizeof(raw_sum->ss_sumsum),
219 size - (sizeof(raw_sum->ss_datasum) +
220 sizeof(raw_sum->ss_sumsum)));
222 list_for_each_entry_continue(bh, &segbuf->sb_segsum_buffers,
223 b_assoc_buffers) {
224 bytes -= size;
225 size = min_t(unsigned long, bytes, bh->b_size);
226 crc = crc32_le(crc, bh->b_data, size);
228 raw_sum->ss_sumsum = cpu_to_le32(crc);
231 void nilfs_segbuf_fill_in_data_crc(struct nilfs_segment_buffer *segbuf,
232 u32 seed)
234 struct buffer_head *bh;
235 struct nilfs_segment_summary *raw_sum;
236 void *kaddr;
237 u32 crc;
239 bh = list_entry(segbuf->sb_segsum_buffers.next, struct buffer_head,
240 b_assoc_buffers);
241 raw_sum = (struct nilfs_segment_summary *)bh->b_data;
242 crc = crc32_le(seed,
243 (unsigned char *)raw_sum + sizeof(raw_sum->ss_datasum),
244 bh->b_size - sizeof(raw_sum->ss_datasum));
246 list_for_each_entry_continue(bh, &segbuf->sb_segsum_buffers,
247 b_assoc_buffers) {
248 crc = crc32_le(crc, bh->b_data, bh->b_size);
250 list_for_each_entry(bh, &segbuf->sb_payload_buffers, b_assoc_buffers) {
251 kaddr = kmap_atomic(bh->b_page, KM_USER0);
252 crc = crc32_le(crc, kaddr + bh_offset(bh), bh->b_size);
253 kunmap_atomic(kaddr, KM_USER0);
255 raw_sum->ss_datasum = cpu_to_le32(crc);
258 static void nilfs_release_buffers(struct list_head *list)
260 struct buffer_head *bh, *n;
262 list_for_each_entry_safe(bh, n, list, b_assoc_buffers) {
263 list_del_init(&bh->b_assoc_buffers);
264 if (buffer_nilfs_allocated(bh)) {
265 struct page *clone_page = bh->b_page;
267 /* remove clone page */
268 brelse(bh);
269 page_cache_release(clone_page); /* for each bh */
270 if (page_count(clone_page) <= 2) {
271 lock_page(clone_page);
272 nilfs_free_private_page(clone_page);
274 continue;
276 brelse(bh);
280 static void nilfs_segbuf_clear(struct nilfs_segment_buffer *segbuf)
282 nilfs_release_buffers(&segbuf->sb_segsum_buffers);
283 nilfs_release_buffers(&segbuf->sb_payload_buffers);
287 * Iterators for segment buffers
289 void nilfs_clear_logs(struct list_head *logs)
291 struct nilfs_segment_buffer *segbuf;
293 list_for_each_entry(segbuf, logs, sb_list)
294 nilfs_segbuf_clear(segbuf);
297 void nilfs_truncate_logs(struct list_head *logs,
298 struct nilfs_segment_buffer *last)
300 struct nilfs_segment_buffer *n, *segbuf;
302 segbuf = list_prepare_entry(last, logs, sb_list);
303 list_for_each_entry_safe_continue(segbuf, n, logs, sb_list) {
304 list_del_init(&segbuf->sb_list);
305 nilfs_segbuf_clear(segbuf);
306 nilfs_segbuf_free(segbuf);
310 int nilfs_write_logs(struct list_head *logs, struct the_nilfs *nilfs)
312 struct nilfs_segment_buffer *segbuf;
313 int ret = 0;
315 list_for_each_entry(segbuf, logs, sb_list) {
316 ret = nilfs_segbuf_write(segbuf, nilfs);
317 if (ret)
318 break;
320 return ret;
323 int nilfs_wait_on_logs(struct list_head *logs)
325 struct nilfs_segment_buffer *segbuf;
326 int err;
328 list_for_each_entry(segbuf, logs, sb_list) {
329 err = nilfs_segbuf_wait(segbuf);
330 if (err)
331 return err;
333 return 0;
337 * BIO operations
339 static void nilfs_end_bio_write(struct bio *bio, int err)
341 const int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags);
342 struct nilfs_segment_buffer *segbuf = bio->bi_private;
344 if (err == -EOPNOTSUPP) {
345 set_bit(BIO_EOPNOTSUPP, &bio->bi_flags);
346 bio_put(bio);
347 /* to be detected by submit_seg_bio() */
350 if (!uptodate)
351 atomic_inc(&segbuf->sb_err);
353 bio_put(bio);
354 complete(&segbuf->sb_bio_event);
357 static int nilfs_segbuf_submit_bio(struct nilfs_segment_buffer *segbuf,
358 struct nilfs_write_info *wi, int mode)
360 struct bio *bio = wi->bio;
361 int err;
363 if (segbuf->sb_nbio > 0 && bdi_write_congested(wi->nilfs->ns_bdi)) {
364 wait_for_completion(&segbuf->sb_bio_event);
365 segbuf->sb_nbio--;
366 if (unlikely(atomic_read(&segbuf->sb_err))) {
367 bio_put(bio);
368 err = -EIO;
369 goto failed;
373 bio->bi_end_io = nilfs_end_bio_write;
374 bio->bi_private = segbuf;
375 bio_get(bio);
376 submit_bio(mode, bio);
377 if (bio_flagged(bio, BIO_EOPNOTSUPP)) {
378 bio_put(bio);
379 err = -EOPNOTSUPP;
380 goto failed;
382 segbuf->sb_nbio++;
383 bio_put(bio);
385 wi->bio = NULL;
386 wi->rest_blocks -= wi->end - wi->start;
387 wi->nr_vecs = min(wi->max_pages, wi->rest_blocks);
388 wi->start = wi->end;
389 return 0;
391 failed:
392 wi->bio = NULL;
393 return err;
397 * nilfs_alloc_seg_bio - allocate a new bio for writing log
398 * @nilfs: nilfs object
399 * @start: start block number of the bio
400 * @nr_vecs: request size of page vector.
402 * Return Value: On success, pointer to the struct bio is returned.
403 * On error, NULL is returned.
405 static struct bio *nilfs_alloc_seg_bio(struct the_nilfs *nilfs, sector_t start,
406 int nr_vecs)
408 struct bio *bio;
410 bio = bio_alloc(GFP_NOIO, nr_vecs);
411 if (bio == NULL) {
412 while (!bio && (nr_vecs >>= 1))
413 bio = bio_alloc(GFP_NOIO, nr_vecs);
415 if (likely(bio)) {
416 bio->bi_bdev = nilfs->ns_bdev;
417 bio->bi_sector = start << (nilfs->ns_blocksize_bits - 9);
419 return bio;
422 static void nilfs_segbuf_prepare_write(struct nilfs_segment_buffer *segbuf,
423 struct nilfs_write_info *wi)
425 wi->bio = NULL;
426 wi->rest_blocks = segbuf->sb_sum.nblocks;
427 wi->max_pages = bio_get_nr_vecs(wi->nilfs->ns_bdev);
428 wi->nr_vecs = min(wi->max_pages, wi->rest_blocks);
429 wi->start = wi->end = 0;
430 wi->blocknr = segbuf->sb_pseg_start;
433 static int nilfs_segbuf_submit_bh(struct nilfs_segment_buffer *segbuf,
434 struct nilfs_write_info *wi,
435 struct buffer_head *bh, int mode)
437 int len, err;
439 BUG_ON(wi->nr_vecs <= 0);
440 repeat:
441 if (!wi->bio) {
442 wi->bio = nilfs_alloc_seg_bio(wi->nilfs, wi->blocknr + wi->end,
443 wi->nr_vecs);
444 if (unlikely(!wi->bio))
445 return -ENOMEM;
448 len = bio_add_page(wi->bio, bh->b_page, bh->b_size, bh_offset(bh));
449 if (len == bh->b_size) {
450 wi->end++;
451 return 0;
453 /* bio is FULL */
454 err = nilfs_segbuf_submit_bio(segbuf, wi, mode);
455 /* never submit current bh */
456 if (likely(!err))
457 goto repeat;
458 return err;
462 * nilfs_segbuf_write - submit write requests of a log
463 * @segbuf: buffer storing a log to be written
464 * @nilfs: nilfs object
466 * Return Value: On Success, 0 is returned. On Error, one of the following
467 * negative error code is returned.
469 * %-EIO - I/O error
471 * %-ENOMEM - Insufficient memory available.
473 static int nilfs_segbuf_write(struct nilfs_segment_buffer *segbuf,
474 struct the_nilfs *nilfs)
476 struct nilfs_write_info wi;
477 struct buffer_head *bh;
478 int res = 0, rw = WRITE;
480 wi.nilfs = nilfs;
481 nilfs_segbuf_prepare_write(segbuf, &wi);
483 list_for_each_entry(bh, &segbuf->sb_segsum_buffers, b_assoc_buffers) {
484 res = nilfs_segbuf_submit_bh(segbuf, &wi, bh, rw);
485 if (unlikely(res))
486 goto failed_bio;
489 list_for_each_entry(bh, &segbuf->sb_payload_buffers, b_assoc_buffers) {
490 res = nilfs_segbuf_submit_bh(segbuf, &wi, bh, rw);
491 if (unlikely(res))
492 goto failed_bio;
495 if (wi.bio) {
497 * Last BIO is always sent through the following
498 * submission.
500 rw |= (1 << BIO_RW_SYNCIO) | (1 << BIO_RW_UNPLUG);
501 res = nilfs_segbuf_submit_bio(segbuf, &wi, rw);
504 failed_bio:
505 return res;
509 * nilfs_segbuf_wait - wait for completion of requested BIOs
510 * @segbuf: segment buffer
512 * Return Value: On Success, 0 is returned. On Error, one of the following
513 * negative error code is returned.
515 * %-EIO - I/O error
517 static int nilfs_segbuf_wait(struct nilfs_segment_buffer *segbuf)
519 int err = 0;
521 if (!segbuf->sb_nbio)
522 return 0;
524 do {
525 wait_for_completion(&segbuf->sb_bio_event);
526 } while (--segbuf->sb_nbio > 0);
528 if (unlikely(atomic_read(&segbuf->sb_err) > 0)) {
529 printk(KERN_ERR "NILFS: IO error writing segment\n");
530 err = -EIO;
532 return err;