From 4c69672a8b7b2dc8331a8d67c9cc61dbda0800af Mon Sep 17 00:00:00 2001 From: Ryusuke Konishi Date: Sun, 14 Sep 2008 20:42:29 +0900 Subject: [PATCH 21/27] nilfs2: segment buffer This adds the segment buffer which is used to constuct logs. Signed-off-by: Ryusuke Konishi --- fs/nilfs2/segbuf.c | 461 ++++++++++++++++++++++++++++++++++++++++++++++++++++ fs/nilfs2/segbuf.h | 203 +++++++++++++++++++++++ 2 files changed, 664 insertions(+), 0 deletions(-) create mode 100644 fs/nilfs2/segbuf.c create mode 100644 fs/nilfs2/segbuf.h diff --git a/fs/nilfs2/segbuf.c b/fs/nilfs2/segbuf.c new file mode 100644 index 0000000..6505a6a --- /dev/null +++ b/fs/nilfs2/segbuf.c @@ -0,0 +1,461 @@ +/* + * 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 + * + */ + +#include +#include +#include +#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); + segbuf->sb_segent = NULL; + return segbuf; +} + +void nilfs_segbuf_free(struct nilfs_segment_buffer *segbuf) +{ + struct nilfs_segment_entry *ent = segbuf->sb_segent; + + if (ent != NULL && list_empty(&ent->list)) { + /* free isolated segment list head */ + nilfs_free_segment_entry(segbuf->sb_segent); + segbuf->sb_segent = NULL; + } + kmem_cache_free(nilfs_segbuf_cachep, segbuf); +} + +int nilfs_segbuf_map(struct nilfs_segment_buffer *segbuf, __u64 segnum, + unsigned long offset, struct the_nilfs *nilfs) +{ + struct nilfs_segment_entry *ent; + + 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; + + /* Attach a segment list head */ + ent = segbuf->sb_segent; + if (ent == NULL) { + segbuf->sb_segent = nilfs_alloc_segment_entry(segnum); + if (unlikely(!segbuf->sb_segent)) + return -ENOMEM; + } else { + BUG_ON(ent->bh_su || !list_empty(&ent->list)); + ent->segnum = segnum; + } + return 0; +} + +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_SYNC); + 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; +} diff --git a/fs/nilfs2/segbuf.h b/fs/nilfs2/segbuf.h new file mode 100644 index 0000000..25f2a5f --- /dev/null +++ b/fs/nilfs2/segbuf.h @@ -0,0 +1,203 @@ +/* + * segbuf.h - NILFS Segment buffer prototypes and definitions + * + * 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 + * + */ +#ifndef _NILFS_SEGBUF_H +#define _NILFS_SEGBUF_H + +#include +#include +#include +#include +#include + +/** + * struct nilfs_segsum_info - On-memory segment summary + * @flags: Flags + * @nfinfo: Number of file information structures + * @nblocks: Number of blocks included in the partial segment + * @nsumblk: Number of summary blocks + * @sumbytes: Byte count of segment summary + * @nfileblk: Total number of file blocks + * @seg_seq: Segment sequence number + * @ctime: Creation time + * @next: Block number of the next full segment + */ +struct nilfs_segsum_info { + unsigned int flags; + unsigned long nfinfo; + unsigned long nblocks; + unsigned long nsumblk; + unsigned long sumbytes; + unsigned long nfileblk; + u64 seg_seq; + time_t ctime; + sector_t next; +}; + +/* macro for the flags */ +#define NILFS_SEG_HAS_SR(sum) ((sum)->flags & NILFS_SS_SR) +#define NILFS_SEG_LOGBGN(sum) ((sum)->flags & NILFS_SS_LOGBGN) +#define NILFS_SEG_LOGEND(sum) ((sum)->flags & NILFS_SS_LOGEND) +#define NILFS_SEG_DSYNC(sum) ((sum)->flags & NILFS_SS_SYNDT) +#define NILFS_SEG_SIMPLEX(sum) \ + (((sum)->flags & (NILFS_SS_LOGBGN | NILFS_SS_LOGEND)) == \ + (NILFS_SS_LOGBGN | NILFS_SS_LOGEND)) + +#define NILFS_SEG_EMPTY(sum) ((sum)->nblocks == (sum)->nsumblk) + +/** + * struct nilfs_segment_buffer - Segment buffer + * @sb_super: back pointer to a superblock struct + * @sb_list: List head to chain this structure + * @sb_segent: Pointer for attaching a segment entry + * @sb_sum: On-memory segment summary + * @sb_segnum: Index number of the full segment + * @sb_nextnum: Index number of the next full segment + * @sb_fseg_start: Start block number of the full segment + * @sb_fseg_end: End block number of the full segment + * @sb_pseg_start: Disk block number of partial segment + * @sb_rest_blocks: Number of residual blocks in the current segment + * @sb_segsum_buffers: List of buffers for segment summaries + * @sb_payload_buffers: List of buffers for segment payload + * @sb_io_error: I/O error status + */ +struct nilfs_segment_buffer { + struct super_block *sb_super; + struct list_head sb_list; + struct nilfs_segment_entry *sb_segent; + + /* Segment information */ + struct nilfs_segsum_info sb_sum; + __u64 sb_segnum; + __u64 sb_nextnum; + sector_t sb_fseg_start, sb_fseg_end; + sector_t sb_pseg_start; + unsigned sb_rest_blocks; + + /* Buffers */ + struct list_head sb_segsum_buffers; + struct list_head sb_payload_buffers; /* including super root */ + + /* io status */ + int sb_io_error; +}; + +#define NILFS_LIST_SEGBUF(head) \ + list_entry((head), struct nilfs_segment_buffer, sb_list) +#define NILFS_NEXT_SEGBUF(segbuf) NILFS_LIST_SEGBUF((segbuf)->sb_list.next) +#define NILFS_PREV_SEGBUF(segbuf) NILFS_LIST_SEGBUF((segbuf)->sb_list.prev) +#define NILFS_LAST_SEGBUF(head) NILFS_LIST_SEGBUF((head)->prev) +#define NILFS_FIRST_SEGBUF(head) NILFS_LIST_SEGBUF((head)->next) +#define NILFS_SEGBUF_IS_LAST(segbuf, head) ((segbuf)->sb_list.next == (head)) + +#define nilfs_for_each_segbuf_before(s, t, h) \ + for ((s) = NILFS_FIRST_SEGBUF(h); (s) != (t); \ + (s) = NILFS_NEXT_SEGBUF(s)) + +#define NILFS_SEGBUF_FIRST_BH(head) \ + (list_entry((head)->next, struct buffer_head, b_assoc_buffers)) +#define NILFS_SEGBUF_NEXT_BH(bh) \ + (list_entry((bh)->b_assoc_buffers.next, struct buffer_head, \ + b_assoc_buffers)) +#define NILFS_SEGBUF_BH_IS_LAST(bh, head) ((bh)->b_assoc_buffers.next == head) + + +int __init nilfs_init_segbuf_cache(void); +void nilfs_destroy_segbuf_cache(void); +struct nilfs_segment_buffer *nilfs_segbuf_new(struct super_block *); +void nilfs_segbuf_free(struct nilfs_segment_buffer *); +int nilfs_segbuf_map(struct nilfs_segment_buffer *, __u64, unsigned long, + struct the_nilfs *); +void nilfs_segbuf_set_next_segnum(struct nilfs_segment_buffer *, __u64, + struct the_nilfs *); +int nilfs_segbuf_reset(struct nilfs_segment_buffer *, unsigned, time_t); +int nilfs_segbuf_extend_segsum(struct nilfs_segment_buffer *); +int nilfs_segbuf_extend_payload(struct nilfs_segment_buffer *, + struct buffer_head **); +void nilfs_segbuf_fill_in_segsum(struct nilfs_segment_buffer *); +void nilfs_segbuf_fill_in_segsum_crc(struct nilfs_segment_buffer *, u32); +void nilfs_segbuf_fill_in_data_crc(struct nilfs_segment_buffer *, u32); + +static inline void +nilfs_segbuf_add_segsum_buffer(struct nilfs_segment_buffer *segbuf, + struct buffer_head *bh) +{ + list_add_tail(&bh->b_assoc_buffers, &segbuf->sb_segsum_buffers); + segbuf->sb_sum.nblocks++; + segbuf->sb_sum.nsumblk++; +} + +static inline void +nilfs_segbuf_add_payload_buffer(struct nilfs_segment_buffer *segbuf, + struct buffer_head *bh) +{ + list_add_tail(&bh->b_assoc_buffers, &segbuf->sb_payload_buffers); + segbuf->sb_sum.nblocks++; +} + +static inline void +nilfs_segbuf_add_file_buffer(struct nilfs_segment_buffer *segbuf, + struct buffer_head *bh) +{ + get_bh(bh); + nilfs_segbuf_add_payload_buffer(segbuf, bh); + segbuf->sb_sum.nfileblk++; +} + +void nilfs_release_buffers(struct list_head *); + +static inline void nilfs_segbuf_clear(struct nilfs_segment_buffer *segbuf) +{ + nilfs_release_buffers(&segbuf->sb_segsum_buffers); + nilfs_release_buffers(&segbuf->sb_payload_buffers); +} + +struct nilfs_write_info { + struct bio *bio; + int start, end; /* The region to be submitted */ + int rest_blocks; + int max_pages; + int nr_vecs; + sector_t blocknr; + + int nbio; + atomic_t err; + struct completion bio_event; + /* completion event of segment write */ + + /* + * The following fields must be set explicitly + */ + struct super_block *sb; + struct backing_dev_info *bdi; /* backing dev info */ + struct buffer_head *bh_sr; +}; + + +void nilfs_segbuf_prepare_write(struct nilfs_segment_buffer *, + struct nilfs_write_info *); +int nilfs_segbuf_write(struct nilfs_segment_buffer *, + struct nilfs_write_info *); +int nilfs_segbuf_wait(struct nilfs_segment_buffer *, + struct nilfs_write_info *); + +#endif /* _NILFS_SEGBUF_H */ -- 1.5.6.3