diff options
author | Ingo Molnar <mingo@elte.hu> | 2009-04-08 10:35:30 +0200 |
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committer | Ingo Molnar <mingo@elte.hu> | 2009-04-08 10:35:30 +0200 |
commit | 5ea472a77f8e4811ceee3f44a9deda6ad6e8b789 (patch) | |
tree | a9ec5019e2b666a19874fc344ffb0dd5da6bce94 /fs/nilfs2/segbuf.c | |
parent | 6c009ecef8cca28c7c09eb16d0802e37915a76e1 (diff) | |
parent | 577c9c456f0e1371cbade38eaf91ae8e8a308555 (diff) |
Merge commit 'v2.6.30-rc1' into perfcounters/core
Conflicts:
arch/powerpc/include/asm/systbl.h
arch/powerpc/include/asm/unistd.h
include/linux/init_task.h
Merge reason: the conflicts are non-trivial: PowerPC placement
of sys_perf_counter_open has to be mixed with the
new preadv/pwrite syscalls.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'fs/nilfs2/segbuf.c')
-rw-r--r-- | fs/nilfs2/segbuf.c | 439 |
1 files changed, 439 insertions, 0 deletions
diff --git a/fs/nilfs2/segbuf.c b/fs/nilfs2/segbuf.c new file mode 100644 index 00000000000..1e68821b4a9 --- /dev/null +++ b/fs/nilfs2/segbuf.c @@ -0,0 +1,439 @@ +/* + * 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 "page.h" +#include "segbuf.h" +#include "seglist.h" + + +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); + 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; + + segbuf->sb_io_error = 0; + 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); +} + +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); + } +} + +/* + * 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_write_info *wi = 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(&wi->err); + + bio_put(bio); + complete(&wi->bio_event); +} + +static int nilfs_submit_seg_bio(struct nilfs_write_info *wi, int mode) +{ + struct bio *bio = wi->bio; + int err; + + if (wi->nbio > 0 && bdi_write_congested(wi->bdi)) { + wait_for_completion(&wi->bio_event); + wi->nbio--; + if (unlikely(atomic_read(&wi->err))) { + bio_put(bio); + err = -EIO; + goto failed; + } + } + + bio->bi_end_io = nilfs_end_bio_write; + bio->bi_private = wi; + bio_get(bio); + submit_bio(mode, bio); + if (bio_flagged(bio, BIO_EOPNOTSUPP)) { + bio_put(bio); + err = -EOPNOTSUPP; + goto failed; + } + wi->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 bio for writing segment. + * @sb: super block + * @start: beginning disk block number of this BIO. + * @nr_vecs: request size of page vector. + * + * alloc_seg_bio() allocates a new BIO structure and initialize it. + * + * Return Value: On success, pointer to the struct bio is returned. + * On error, NULL is returned. + */ +static struct bio *nilfs_alloc_seg_bio(struct super_block *sb, sector_t start, + int nr_vecs) +{ + struct bio *bio; + + bio = bio_alloc(GFP_NOWAIT, nr_vecs); + if (bio == NULL) { + while (!bio && (nr_vecs >>= 1)) + bio = bio_alloc(GFP_NOWAIT, nr_vecs); + } + if (likely(bio)) { + bio->bi_bdev = sb->s_bdev; + bio->bi_sector = (sector_t)start << (sb->s_blocksize_bits - 9); + } + return bio; +} + +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->sb->s_bdev); + wi->nr_vecs = min(wi->max_pages, wi->rest_blocks); + wi->start = wi->end = 0; + wi->nbio = 0; + wi->blocknr = segbuf->sb_pseg_start; + + atomic_set(&wi->err, 0); + init_completion(&wi->bio_event); +} + +static int nilfs_submit_bh(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->sb, 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_submit_seg_bio(wi, mode); + /* never submit current bh */ + if (likely(!err)) + goto repeat; + return err; +} + +int nilfs_segbuf_write(struct nilfs_segment_buffer *segbuf, + struct nilfs_write_info *wi) +{ + struct buffer_head *bh; + int res, rw = WRITE; + + list_for_each_entry(bh, &segbuf->sb_segsum_buffers, b_assoc_buffers) { + res = nilfs_submit_bh(wi, bh, rw); + if (unlikely(res)) + goto failed_bio; + } + + list_for_each_entry(bh, &segbuf->sb_payload_buffers, b_assoc_buffers) { + res = nilfs_submit_bh(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); + res = nilfs_submit_seg_bio(wi, rw); + if (unlikely(res)) + goto failed_bio; + } + + res = 0; + out: + return res; + + failed_bio: + atomic_inc(&wi->err); + goto out; +} + +/** + * nilfs_segbuf_wait - wait for completion of requested BIOs + * @wi: nilfs_write_info + * + * 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, + struct nilfs_write_info *wi) +{ + int err = 0; + + if (!wi->nbio) + return 0; + + do { + wait_for_completion(&wi->bio_event); + } while (--wi->nbio > 0); + + if (unlikely(atomic_read(&wi->err) > 0)) { + printk(KERN_ERR "NILFS: IO error writing segment\n"); + err = -EIO; + segbuf->sb_io_error = 1; + } + return err; +} |