| /* |
| * segbuf.c - NILFS segment buffer |
| * |
| * Copyright (C) 2005-2008 Nippon Telegraph and Telephone Corporation. |
| * |
| * This program is free software; you can redistribute it and/or modify |
| * it under the terms of the GNU General Public License as published by |
| * the Free Software Foundation; either version 2 of the License, or |
| * (at your option) any later version. |
| * |
| * This program is distributed in the hope that it will be useful, |
| * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| * GNU General Public License for more details. |
| * |
| * You should have received a copy of the GNU General Public License |
| * along with this program; if not, write to the Free Software |
| * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA |
| * |
| * Written by Ryusuke Konishi <ryusuke@osrg.net> |
| * |
| */ |
| |
| #include <linux/buffer_head.h> |
| #include <linux/writeback.h> |
| #include <linux/crc32.h> |
| #include <linux/backing-dev.h> |
| #include "page.h" |
| #include "segbuf.h" |
| |
| |
| struct nilfs_write_info { |
| struct the_nilfs *nilfs; |
| struct bio *bio; |
| int start, end; /* The region to be submitted */ |
| int rest_blocks; |
| int max_pages; |
| int nr_vecs; |
| sector_t blocknr; |
| }; |
| |
| |
| static struct kmem_cache *nilfs_segbuf_cachep; |
| |
| static void nilfs_segbuf_init_once(void *obj) |
| { |
| memset(obj, 0, sizeof(struct nilfs_segment_buffer)); |
| } |
| |
| int __init nilfs_init_segbuf_cache(void) |
| { |
| nilfs_segbuf_cachep = |
| kmem_cache_create("nilfs2_segbuf_cache", |
| sizeof(struct nilfs_segment_buffer), |
| 0, SLAB_RECLAIM_ACCOUNT, |
| nilfs_segbuf_init_once); |
| |
| return (nilfs_segbuf_cachep == NULL) ? -ENOMEM : 0; |
| } |
| |
| void nilfs_destroy_segbuf_cache(void) |
| { |
| kmem_cache_destroy(nilfs_segbuf_cachep); |
| } |
| |
| struct nilfs_segment_buffer *nilfs_segbuf_new(struct super_block *sb) |
| { |
| struct nilfs_segment_buffer *segbuf; |
| |
| segbuf = kmem_cache_alloc(nilfs_segbuf_cachep, GFP_NOFS); |
| if (unlikely(!segbuf)) |
| return NULL; |
| |
| segbuf->sb_super = sb; |
| INIT_LIST_HEAD(&segbuf->sb_list); |
| INIT_LIST_HEAD(&segbuf->sb_segsum_buffers); |
| INIT_LIST_HEAD(&segbuf->sb_payload_buffers); |
| |
| init_completion(&segbuf->sb_bio_event); |
| atomic_set(&segbuf->sb_err, 0); |
| segbuf->sb_nbio = 0; |
| |
| return segbuf; |
| } |
| |
| void nilfs_segbuf_free(struct nilfs_segment_buffer *segbuf) |
| { |
| kmem_cache_free(nilfs_segbuf_cachep, segbuf); |
| } |
| |
| void nilfs_segbuf_map(struct nilfs_segment_buffer *segbuf, __u64 segnum, |
| unsigned long offset, struct the_nilfs *nilfs) |
| { |
| segbuf->sb_segnum = segnum; |
| nilfs_get_segment_range(nilfs, segnum, &segbuf->sb_fseg_start, |
| &segbuf->sb_fseg_end); |
| |
| segbuf->sb_pseg_start = segbuf->sb_fseg_start + offset; |
| segbuf->sb_rest_blocks = |
| segbuf->sb_fseg_end - segbuf->sb_pseg_start + 1; |
| } |
| |
| void nilfs_segbuf_set_next_segnum(struct nilfs_segment_buffer *segbuf, |
| __u64 nextnum, struct the_nilfs *nilfs) |
| { |
| segbuf->sb_nextnum = nextnum; |
| segbuf->sb_sum.next = nilfs_get_segment_start_blocknr(nilfs, nextnum); |
| } |
| |
| int nilfs_segbuf_extend_segsum(struct nilfs_segment_buffer *segbuf) |
| { |
| struct buffer_head *bh; |
| |
| bh = sb_getblk(segbuf->sb_super, |
| segbuf->sb_pseg_start + segbuf->sb_sum.nsumblk); |
| if (unlikely(!bh)) |
| return -ENOMEM; |
| |
| nilfs_segbuf_add_segsum_buffer(segbuf, bh); |
| return 0; |
| } |
| |
| int nilfs_segbuf_extend_payload(struct nilfs_segment_buffer *segbuf, |
| struct buffer_head **bhp) |
| { |
| struct buffer_head *bh; |
| |
| bh = sb_getblk(segbuf->sb_super, |
| segbuf->sb_pseg_start + segbuf->sb_sum.nblocks); |
| if (unlikely(!bh)) |
| return -ENOMEM; |
| |
| nilfs_segbuf_add_payload_buffer(segbuf, bh); |
| *bhp = bh; |
| return 0; |
| } |
| |
| int nilfs_segbuf_reset(struct nilfs_segment_buffer *segbuf, unsigned flags, |
| time_t ctime) |
| { |
| int err; |
| |
| segbuf->sb_sum.nblocks = segbuf->sb_sum.nsumblk = 0; |
| err = nilfs_segbuf_extend_segsum(segbuf); |
| if (unlikely(err)) |
| return err; |
| |
| segbuf->sb_sum.flags = flags; |
| segbuf->sb_sum.sumbytes = sizeof(struct nilfs_segment_summary); |
| segbuf->sb_sum.nfinfo = segbuf->sb_sum.nfileblk = 0; |
| segbuf->sb_sum.ctime = ctime; |
| return 0; |
| } |
| |
| /* |
| * Setup segument summary |
| */ |
| void nilfs_segbuf_fill_in_segsum(struct nilfs_segment_buffer *segbuf) |
| { |
| struct nilfs_segment_summary *raw_sum; |
| struct buffer_head *bh_sum; |
| |
| bh_sum = list_entry(segbuf->sb_segsum_buffers.next, |
| struct buffer_head, b_assoc_buffers); |
| raw_sum = (struct nilfs_segment_summary *)bh_sum->b_data; |
| |
| raw_sum->ss_magic = cpu_to_le32(NILFS_SEGSUM_MAGIC); |
| raw_sum->ss_bytes = cpu_to_le16(sizeof(*raw_sum)); |
| raw_sum->ss_flags = cpu_to_le16(segbuf->sb_sum.flags); |
| raw_sum->ss_seq = cpu_to_le64(segbuf->sb_sum.seg_seq); |
| raw_sum->ss_create = cpu_to_le64(segbuf->sb_sum.ctime); |
| raw_sum->ss_next = cpu_to_le64(segbuf->sb_sum.next); |
| raw_sum->ss_nblocks = cpu_to_le32(segbuf->sb_sum.nblocks); |
| raw_sum->ss_nfinfo = cpu_to_le32(segbuf->sb_sum.nfinfo); |
| raw_sum->ss_sumbytes = cpu_to_le32(segbuf->sb_sum.sumbytes); |
| raw_sum->ss_pad = 0; |
| } |
| |
| /* |
| * CRC calculation routines |
| */ |
| void nilfs_segbuf_fill_in_segsum_crc(struct nilfs_segment_buffer *segbuf, |
| u32 seed) |
| { |
| struct buffer_head *bh; |
| struct nilfs_segment_summary *raw_sum; |
| unsigned long size, bytes = segbuf->sb_sum.sumbytes; |
| u32 crc; |
| |
| bh = list_entry(segbuf->sb_segsum_buffers.next, struct buffer_head, |
| b_assoc_buffers); |
| |
| raw_sum = (struct nilfs_segment_summary *)bh->b_data; |
| size = min_t(unsigned long, bytes, bh->b_size); |
| crc = crc32_le(seed, |
| (unsigned char *)raw_sum + |
| sizeof(raw_sum->ss_datasum) + sizeof(raw_sum->ss_sumsum), |
| size - (sizeof(raw_sum->ss_datasum) + |
| sizeof(raw_sum->ss_sumsum))); |
| |
| list_for_each_entry_continue(bh, &segbuf->sb_segsum_buffers, |
| b_assoc_buffers) { |
| bytes -= size; |
| size = min_t(unsigned long, bytes, bh->b_size); |
| crc = crc32_le(crc, bh->b_data, size); |
| } |
| raw_sum->ss_sumsum = cpu_to_le32(crc); |
| } |
| |
| void nilfs_segbuf_fill_in_data_crc(struct nilfs_segment_buffer *segbuf, |
| u32 seed) |
| { |
| struct buffer_head *bh; |
| struct nilfs_segment_summary *raw_sum; |
| void *kaddr; |
| u32 crc; |
| |
| bh = list_entry(segbuf->sb_segsum_buffers.next, struct buffer_head, |
| b_assoc_buffers); |
| raw_sum = (struct nilfs_segment_summary *)bh->b_data; |
| crc = crc32_le(seed, |
| (unsigned char *)raw_sum + sizeof(raw_sum->ss_datasum), |
| bh->b_size - sizeof(raw_sum->ss_datasum)); |
| |
| list_for_each_entry_continue(bh, &segbuf->sb_segsum_buffers, |
| b_assoc_buffers) { |
| crc = crc32_le(crc, bh->b_data, bh->b_size); |
| } |
| list_for_each_entry(bh, &segbuf->sb_payload_buffers, b_assoc_buffers) { |
| kaddr = kmap_atomic(bh->b_page, KM_USER0); |
| crc = crc32_le(crc, kaddr + bh_offset(bh), bh->b_size); |
| kunmap_atomic(kaddr, KM_USER0); |
| } |
| raw_sum->ss_datasum = cpu_to_le32(crc); |
| } |
| |
| static void nilfs_release_buffers(struct list_head *list) |
| { |
| struct buffer_head *bh, *n; |
| |
| list_for_each_entry_safe(bh, n, list, b_assoc_buffers) { |
| list_del_init(&bh->b_assoc_buffers); |
| if (buffer_nilfs_allocated(bh)) { |
| struct page *clone_page = bh->b_page; |
| |
| /* remove clone page */ |
| brelse(bh); |
| page_cache_release(clone_page); /* for each bh */ |
| if (page_count(clone_page) <= 2) { |
| lock_page(clone_page); |
| nilfs_free_private_page(clone_page); |
| } |
| continue; |
| } |
| brelse(bh); |
| } |
| } |
| |
| static void nilfs_segbuf_clear(struct nilfs_segment_buffer *segbuf) |
| { |
| nilfs_release_buffers(&segbuf->sb_segsum_buffers); |
| nilfs_release_buffers(&segbuf->sb_payload_buffers); |
| } |
| |
| /* |
| * Iterators for segment buffers |
| */ |
| void nilfs_clear_logs(struct list_head *logs) |
| { |
| struct nilfs_segment_buffer *segbuf; |
| |
| list_for_each_entry(segbuf, logs, sb_list) |
| nilfs_segbuf_clear(segbuf); |
| } |
| |
| void nilfs_truncate_logs(struct list_head *logs, |
| struct nilfs_segment_buffer *last) |
| { |
| struct nilfs_segment_buffer *n, *segbuf; |
| |
| segbuf = list_prepare_entry(last, logs, sb_list); |
| list_for_each_entry_safe_continue(segbuf, n, logs, sb_list) { |
| list_del_init(&segbuf->sb_list); |
| nilfs_segbuf_clear(segbuf); |
| nilfs_segbuf_free(segbuf); |
| } |
| } |
| |
| int nilfs_wait_on_logs(struct list_head *logs) |
| { |
| struct nilfs_segment_buffer *segbuf; |
| int err; |
| |
| list_for_each_entry(segbuf, logs, sb_list) { |
| err = nilfs_segbuf_wait(segbuf); |
| if (err) |
| return err; |
| } |
| return 0; |
| } |
| |
| /* |
| * BIO operations |
| */ |
| static void nilfs_end_bio_write(struct bio *bio, int err) |
| { |
| const int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags); |
| struct nilfs_segment_buffer *segbuf = bio->bi_private; |
| |
| if (err == -EOPNOTSUPP) { |
| set_bit(BIO_EOPNOTSUPP, &bio->bi_flags); |
| bio_put(bio); |
| /* to be detected by submit_seg_bio() */ |
| } |
| |
| if (!uptodate) |
| atomic_inc(&segbuf->sb_err); |
| |
| bio_put(bio); |
| complete(&segbuf->sb_bio_event); |
| } |
| |
| static int nilfs_segbuf_submit_bio(struct nilfs_segment_buffer *segbuf, |
| struct nilfs_write_info *wi, int mode) |
| { |
| struct bio *bio = wi->bio; |
| int err; |
| |
| if (segbuf->sb_nbio > 0 && bdi_write_congested(wi->nilfs->ns_bdi)) { |
| wait_for_completion(&segbuf->sb_bio_event); |
| segbuf->sb_nbio--; |
| if (unlikely(atomic_read(&segbuf->sb_err))) { |
| bio_put(bio); |
| err = -EIO; |
| goto failed; |
| } |
| } |
| |
| bio->bi_end_io = nilfs_end_bio_write; |
| bio->bi_private = segbuf; |
| bio_get(bio); |
| submit_bio(mode, bio); |
| if (bio_flagged(bio, BIO_EOPNOTSUPP)) { |
| bio_put(bio); |
| err = -EOPNOTSUPP; |
| goto failed; |
| } |
| segbuf->sb_nbio++; |
| bio_put(bio); |
| |
| wi->bio = NULL; |
| wi->rest_blocks -= wi->end - wi->start; |
| wi->nr_vecs = min(wi->max_pages, wi->rest_blocks); |
| wi->start = wi->end; |
| return 0; |
| |
| failed: |
| wi->bio = NULL; |
| return err; |
| } |
| |
| /** |
| * nilfs_alloc_seg_bio - allocate a new bio for writing log |
| * @nilfs: nilfs object |
| * @start: start block number of the bio |
| * @nr_vecs: request size of page vector. |
| * |
| * Return Value: On success, pointer to the struct bio is returned. |
| * On error, NULL is returned. |
| */ |
| static struct bio *nilfs_alloc_seg_bio(struct the_nilfs *nilfs, sector_t start, |
| int nr_vecs) |
| { |
| struct bio *bio; |
| |
| bio = bio_alloc(GFP_NOIO, nr_vecs); |
| if (bio == NULL) { |
| while (!bio && (nr_vecs >>= 1)) |
| bio = bio_alloc(GFP_NOIO, nr_vecs); |
| } |
| if (likely(bio)) { |
| bio->bi_bdev = nilfs->ns_bdev; |
| bio->bi_sector = start << (nilfs->ns_blocksize_bits - 9); |
| } |
| return bio; |
| } |
| |
| static void nilfs_segbuf_prepare_write(struct nilfs_segment_buffer *segbuf, |
| struct nilfs_write_info *wi) |
| { |
| wi->bio = NULL; |
| wi->rest_blocks = segbuf->sb_sum.nblocks; |
| wi->max_pages = bio_get_nr_vecs(wi->nilfs->ns_bdev); |
| wi->nr_vecs = min(wi->max_pages, wi->rest_blocks); |
| wi->start = wi->end = 0; |
| wi->blocknr = segbuf->sb_pseg_start; |
| } |
| |
| static int nilfs_segbuf_submit_bh(struct nilfs_segment_buffer *segbuf, |
| struct nilfs_write_info *wi, |
| struct buffer_head *bh, int mode) |
| { |
| int len, err; |
| |
| BUG_ON(wi->nr_vecs <= 0); |
| repeat: |
| if (!wi->bio) { |
| wi->bio = nilfs_alloc_seg_bio(wi->nilfs, wi->blocknr + wi->end, |
| wi->nr_vecs); |
| if (unlikely(!wi->bio)) |
| return -ENOMEM; |
| } |
| |
| len = bio_add_page(wi->bio, bh->b_page, bh->b_size, bh_offset(bh)); |
| if (len == bh->b_size) { |
| wi->end++; |
| return 0; |
| } |
| /* bio is FULL */ |
| err = nilfs_segbuf_submit_bio(segbuf, wi, mode); |
| /* never submit current bh */ |
| if (likely(!err)) |
| goto repeat; |
| return err; |
| } |
| |
| /** |
| * nilfs_segbuf_write - submit write requests of a log |
| * @segbuf: buffer storing a log to be written |
| * @nilfs: nilfs object |
| * |
| * Return Value: On Success, 0 is returned. On Error, one of the following |
| * negative error code is returned. |
| * |
| * %-EIO - I/O error |
| * |
| * %-ENOMEM - Insufficient memory available. |
| */ |
| int nilfs_segbuf_write(struct nilfs_segment_buffer *segbuf, |
| struct the_nilfs *nilfs) |
| { |
| struct nilfs_write_info wi; |
| struct buffer_head *bh; |
| int res = 0, rw = WRITE; |
| |
| wi.nilfs = nilfs; |
| nilfs_segbuf_prepare_write(segbuf, &wi); |
| |
| list_for_each_entry(bh, &segbuf->sb_segsum_buffers, b_assoc_buffers) { |
| res = nilfs_segbuf_submit_bh(segbuf, &wi, bh, rw); |
| if (unlikely(res)) |
| goto failed_bio; |
| } |
| |
| list_for_each_entry(bh, &segbuf->sb_payload_buffers, b_assoc_buffers) { |
| res = nilfs_segbuf_submit_bh(segbuf, &wi, bh, rw); |
| if (unlikely(res)) |
| goto failed_bio; |
| } |
| |
| if (wi.bio) { |
| /* |
| * Last BIO is always sent through the following |
| * submission. |
| */ |
| rw |= (1 << BIO_RW_SYNCIO) | (1 << BIO_RW_UNPLUG); |
| res = nilfs_segbuf_submit_bio(segbuf, &wi, rw); |
| } |
| |
| failed_bio: |
| return res; |
| } |
| |
| /** |
| * nilfs_segbuf_wait - wait for completion of requested BIOs |
| * @segbuf: segment buffer |
| * |
| * Return Value: On Success, 0 is returned. On Error, one of the following |
| * negative error code is returned. |
| * |
| * %-EIO - I/O error |
| */ |
| int nilfs_segbuf_wait(struct nilfs_segment_buffer *segbuf) |
| { |
| int err = 0; |
| |
| if (!segbuf->sb_nbio) |
| return 0; |
| |
| do { |
| wait_for_completion(&segbuf->sb_bio_event); |
| } while (--segbuf->sb_nbio > 0); |
| |
| if (unlikely(atomic_read(&segbuf->sb_err) > 0)) { |
| printk(KERN_ERR "NILFS: IO error writing segment\n"); |
| err = -EIO; |
| } |
| return err; |
| } |