2 * segbuf.h - NILFS Segment buffer prototypes and definitions
4 * Copyright (C) 2005-2008 Nippon Telegraph and Telephone Corporation.
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by
8 * the Free Software Foundation; either version 2 of the License, or
9 * (at your option) any later version.
11 * This program is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU General Public License for more details.
16 * You should have received a copy of the GNU General Public License
17 * along with this program; if not, write to the Free Software
18 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
20 * Written by Ryusuke Konishi <ryusuke@osrg.net>
23 #ifndef _NILFS_SEGBUF_H
24 #define _NILFS_SEGBUF_H
27 #include <linux/buffer_head.h>
28 #include <linux/bio.h>
29 #include <linux/completion.h>
30 #include <linux/backing-dev.h>
33 * struct nilfs_segsum_info - On-memory segment summary
35 * @nfinfo: Number of file information structures
36 * @nblocks: Number of blocks included in the partial segment
37 * @nsumblk: Number of summary blocks
38 * @sumbytes: Byte count of segment summary
39 * @nfileblk: Total number of file blocks
40 * @seg_seq: Segment sequence number
41 * @ctime: Creation time
42 * @next: Block number of the next full segment
44 struct nilfs_segsum_info {
47 unsigned long nblocks;
48 unsigned long nsumblk;
49 unsigned long sumbytes;
50 unsigned long nfileblk;
56 /* macro for the flags */
57 #define NILFS_SEG_HAS_SR(sum) ((sum)->flags & NILFS_SS_SR)
58 #define NILFS_SEG_LOGBGN(sum) ((sum)->flags & NILFS_SS_LOGBGN)
59 #define NILFS_SEG_LOGEND(sum) ((sum)->flags & NILFS_SS_LOGEND)
60 #define NILFS_SEG_DSYNC(sum) ((sum)->flags & NILFS_SS_SYNDT)
61 #define NILFS_SEG_SIMPLEX(sum) \
62 (((sum)->flags & (NILFS_SS_LOGBGN | NILFS_SS_LOGEND)) == \
63 (NILFS_SS_LOGBGN | NILFS_SS_LOGEND))
65 #define NILFS_SEG_EMPTY(sum) ((sum)->nblocks == (sum)->nsumblk)
68 * struct nilfs_segment_buffer - Segment buffer
69 * @sb_super: back pointer to a superblock struct
70 * @sb_list: List head to chain this structure
71 * @sb_sum: On-memory segment summary
72 * @sb_segnum: Index number of the full segment
73 * @sb_nextnum: Index number of the next full segment
74 * @sb_fseg_start: Start block number of the full segment
75 * @sb_fseg_end: End block number of the full segment
76 * @sb_pseg_start: Disk block number of partial segment
77 * @sb_rest_blocks: Number of residual blocks in the current segment
78 * @sb_segsum_buffers: List of buffers for segment summaries
79 * @sb_payload_buffers: List of buffers for segment payload
80 * @sb_nbio: Number of flying bio requests
81 * @sb_err: I/O error status
82 * @sb_bio_event: Completion event of log writing
84 struct nilfs_segment_buffer {
85 struct super_block *sb_super;
86 struct list_head sb_list;
88 /* Segment information */
89 struct nilfs_segsum_info sb_sum;
92 sector_t sb_fseg_start, sb_fseg_end;
93 sector_t sb_pseg_start;
94 unsigned sb_rest_blocks;
97 struct list_head sb_segsum_buffers;
98 struct list_head sb_payload_buffers; /* including super root */
103 struct completion sb_bio_event;
106 #define NILFS_LIST_SEGBUF(head) \
107 list_entry((head), struct nilfs_segment_buffer, sb_list)
108 #define NILFS_NEXT_SEGBUF(segbuf) NILFS_LIST_SEGBUF((segbuf)->sb_list.next)
109 #define NILFS_PREV_SEGBUF(segbuf) NILFS_LIST_SEGBUF((segbuf)->sb_list.prev)
110 #define NILFS_LAST_SEGBUF(head) NILFS_LIST_SEGBUF((head)->prev)
111 #define NILFS_FIRST_SEGBUF(head) NILFS_LIST_SEGBUF((head)->next)
112 #define NILFS_SEGBUF_IS_LAST(segbuf, head) ((segbuf)->sb_list.next == (head))
114 #define nilfs_for_each_segbuf_before(s, t, h) \
115 for ((s) = NILFS_FIRST_SEGBUF(h); (s) != (t); \
116 (s) = NILFS_NEXT_SEGBUF(s))
118 #define NILFS_SEGBUF_FIRST_BH(head) \
119 (list_entry((head)->next, struct buffer_head, b_assoc_buffers))
120 #define NILFS_SEGBUF_NEXT_BH(bh) \
121 (list_entry((bh)->b_assoc_buffers.next, struct buffer_head, \
123 #define NILFS_SEGBUF_BH_IS_LAST(bh, head) ((bh)->b_assoc_buffers.next == head)
126 int __init nilfs_init_segbuf_cache(void);
127 void nilfs_destroy_segbuf_cache(void);
128 struct nilfs_segment_buffer *nilfs_segbuf_new(struct super_block *);
129 void nilfs_segbuf_free(struct nilfs_segment_buffer *);
130 void nilfs_segbuf_map(struct nilfs_segment_buffer *, __u64, unsigned long,
132 void nilfs_segbuf_set_next_segnum(struct nilfs_segment_buffer *, __u64,
134 int nilfs_segbuf_reset(struct nilfs_segment_buffer *, unsigned, time_t);
135 int nilfs_segbuf_extend_segsum(struct nilfs_segment_buffer *);
136 int nilfs_segbuf_extend_payload(struct nilfs_segment_buffer *,
137 struct buffer_head **);
138 void nilfs_segbuf_fill_in_segsum(struct nilfs_segment_buffer *);
139 void nilfs_segbuf_fill_in_segsum_crc(struct nilfs_segment_buffer *, u32);
140 void nilfs_segbuf_fill_in_data_crc(struct nilfs_segment_buffer *, u32);
143 nilfs_segbuf_add_segsum_buffer(struct nilfs_segment_buffer *segbuf,
144 struct buffer_head *bh)
146 list_add_tail(&bh->b_assoc_buffers, &segbuf->sb_segsum_buffers);
147 segbuf->sb_sum.nblocks++;
148 segbuf->sb_sum.nsumblk++;
152 nilfs_segbuf_add_payload_buffer(struct nilfs_segment_buffer *segbuf,
153 struct buffer_head *bh)
155 list_add_tail(&bh->b_assoc_buffers, &segbuf->sb_payload_buffers);
156 segbuf->sb_sum.nblocks++;
160 nilfs_segbuf_add_file_buffer(struct nilfs_segment_buffer *segbuf,
161 struct buffer_head *bh)
164 nilfs_segbuf_add_payload_buffer(segbuf, bh);
165 segbuf->sb_sum.nfileblk++;
168 void nilfs_release_buffers(struct list_head *);
170 static inline void nilfs_segbuf_clear(struct nilfs_segment_buffer *segbuf)
172 nilfs_release_buffers(&segbuf->sb_segsum_buffers);
173 nilfs_release_buffers(&segbuf->sb_payload_buffers);
176 struct nilfs_write_info {
178 int start, end; /* The region to be submitted */
185 * The following fields must be set explicitly
187 struct super_block *sb;
188 struct backing_dev_info *bdi; /* backing dev info */
189 struct buffer_head *bh_sr;
193 void nilfs_segbuf_prepare_write(struct nilfs_segment_buffer *,
194 struct nilfs_write_info *);
195 int nilfs_segbuf_write(struct nilfs_segment_buffer *,
196 struct nilfs_write_info *);
197 int nilfs_segbuf_wait(struct nilfs_segment_buffer *segbuf);
199 #endif /* _NILFS_SEGBUF_H */