/* * 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 /** * 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 */