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Diffstat (limited to 'kernel/fs/nilfs2/segbuf.h')
| -rw-r--r-- | kernel/fs/nilfs2/segbuf.h | 184 |
1 files changed, 184 insertions, 0 deletions
diff --git a/kernel/fs/nilfs2/segbuf.h b/kernel/fs/nilfs2/segbuf.h new file mode 100644 index 000000000..b04f08cc2 --- /dev/null +++ b/kernel/fs/nilfs2/segbuf.h @@ -0,0 +1,184 @@ +/* + * 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 <ryusuke@osrg.net> + * + */ +#ifndef _NILFS_SEGBUF_H +#define _NILFS_SEGBUF_H + +#include <linux/fs.h> +#include <linux/buffer_head.h> +#include <linux/bio.h> +#include <linux/completion.h> + +/** + * 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 + * @cno: Checkpoint 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; + __u64 cno; + time_t ctime; + sector_t next; +}; + +/** + * struct nilfs_segment_buffer - Segment buffer + * @sb_super: back pointer to a superblock struct + * @sb_list: List head to chain this structure + * @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_super_root: Pointer to buffer storing a super root block (if exists) + * @sb_nbio: Number of flying bio requests + * @sb_err: I/O error status + * @sb_bio_event: Completion event of log writing + */ +struct nilfs_segment_buffer { + struct super_block *sb_super; + struct list_head sb_list; + + /* 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 */ + struct buffer_head *sb_super_root; + + /* io status */ + int sb_nbio; + atomic_t sb_err; + struct completion sb_bio_event; +}; + +#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) + +extern struct kmem_cache *nilfs_segbuf_cachep; + +struct nilfs_segment_buffer *nilfs_segbuf_new(struct super_block *); +void nilfs_segbuf_free(struct nilfs_segment_buffer *); +void nilfs_segbuf_map(struct nilfs_segment_buffer *, __u64, unsigned long, + struct the_nilfs *); +void nilfs_segbuf_map_cont(struct nilfs_segment_buffer *segbuf, + struct nilfs_segment_buffer *prev); +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, __u64); +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 *); + +static inline int nilfs_segbuf_simplex(struct nilfs_segment_buffer *segbuf) +{ + unsigned int flags = segbuf->sb_sum.flags; + + return (flags & (NILFS_SS_LOGBGN | NILFS_SS_LOGEND)) == + (NILFS_SS_LOGBGN | NILFS_SS_LOGEND); +} + +static inline int nilfs_segbuf_empty(struct nilfs_segment_buffer *segbuf) +{ + return segbuf->sb_sum.nblocks == segbuf->sb_sum.nsumblk; +} + +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_clear_logs(struct list_head *logs); +void nilfs_truncate_logs(struct list_head *logs, + struct nilfs_segment_buffer *last); +int nilfs_write_logs(struct list_head *logs, struct the_nilfs *nilfs); +int nilfs_wait_on_logs(struct list_head *logs); +void nilfs_add_checksums_on_logs(struct list_head *logs, u32 seed); + +static inline void nilfs_destroy_logs(struct list_head *logs) +{ + nilfs_truncate_logs(logs, NULL); +} + +#endif /* _NILFS_SEGBUF_H */ |