tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
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linux
1/*
2 * segbuf.h - NILFS Segment buffer prototypes and definitions
3 *
4 * Copyright (C) 2005-2008 Nippon Telegraph and Telephone Corporation.
5 *
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.
10 *
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.
15 *
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
19 *
20 * Written by Ryusuke Konishi <ryusuke@osrg.net>
21 *
22 */
23#ifndef _NILFS_SEGBUF_H
24#define _NILFS_SEGBUF_H
25
26#include <linux/fs.h>
27#include <linux/buffer_head.h>
28#include <linux/bio.h>
29#include <linux/completion.h>
30#include <linux/backing-dev.h>
31
32/**
33 * struct nilfs_segsum_info - On-memory segment summary
34 * @flags: Flags
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
43 */
44struct nilfs_segsum_info {
45 unsigned int flags;
46 unsigned long nfinfo;
47 unsigned long nblocks;
48 unsigned long nsumblk;
49 unsigned long sumbytes;
50 unsigned long nfileblk;
51 u64 seg_seq;
52 time_t ctime;
53 sector_t next;
54};
55
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))
64
65#define NILFS_SEG_EMPTY(sum) ((sum)->nblocks == (sum)->nsumblk)
66
67/**
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_io_error: I/O error status
81 */
82struct nilfs_segment_buffer {
83 struct super_block *sb_super;
84 struct list_head sb_list;
85
86 /* Segment information */
87 struct nilfs_segsum_info sb_sum;
88 __u64 sb_segnum;
89 __u64 sb_nextnum;
90 sector_t sb_fseg_start, sb_fseg_end;
91 sector_t sb_pseg_start;
92 unsigned sb_rest_blocks;
93
94 /* Buffers */
95 struct list_head sb_segsum_buffers;
96 struct list_head sb_payload_buffers; /* including super root */
97
98 /* io status */
99 int sb_io_error;
100};
101
102#define NILFS_LIST_SEGBUF(head) \
103 list_entry((head), struct nilfs_segment_buffer, sb_list)
104#define NILFS_NEXT_SEGBUF(segbuf) NILFS_LIST_SEGBUF((segbuf)->sb_list.next)
105#define NILFS_PREV_SEGBUF(segbuf) NILFS_LIST_SEGBUF((segbuf)->sb_list.prev)
106#define NILFS_LAST_SEGBUF(head) NILFS_LIST_SEGBUF((head)->prev)
107#define NILFS_FIRST_SEGBUF(head) NILFS_LIST_SEGBUF((head)->next)
108#define NILFS_SEGBUF_IS_LAST(segbuf, head) ((segbuf)->sb_list.next == (head))
109
110#define nilfs_for_each_segbuf_before(s, t, h) \
111 for ((s) = NILFS_FIRST_SEGBUF(h); (s) != (t); \
112 (s) = NILFS_NEXT_SEGBUF(s))
113
114#define NILFS_SEGBUF_FIRST_BH(head) \
115 (list_entry((head)->next, struct buffer_head, b_assoc_buffers))
116#define NILFS_SEGBUF_NEXT_BH(bh) \
117 (list_entry((bh)->b_assoc_buffers.next, struct buffer_head, \
118 b_assoc_buffers))
119#define NILFS_SEGBUF_BH_IS_LAST(bh, head) ((bh)->b_assoc_buffers.next == head)
120
121
122int __init nilfs_init_segbuf_cache(void);
123void nilfs_destroy_segbuf_cache(void);
124struct nilfs_segment_buffer *nilfs_segbuf_new(struct super_block *);
125void nilfs_segbuf_free(struct nilfs_segment_buffer *);
126void nilfs_segbuf_map(struct nilfs_segment_buffer *, __u64, unsigned long,
127 struct the_nilfs *);
128void nilfs_segbuf_set_next_segnum(struct nilfs_segment_buffer *, __u64,
129 struct the_nilfs *);
130int nilfs_segbuf_reset(struct nilfs_segment_buffer *, unsigned, time_t);
131int nilfs_segbuf_extend_segsum(struct nilfs_segment_buffer *);
132int nilfs_segbuf_extend_payload(struct nilfs_segment_buffer *,
133 struct buffer_head **);
134void nilfs_segbuf_fill_in_segsum(struct nilfs_segment_buffer *);
135void nilfs_segbuf_fill_in_segsum_crc(struct nilfs_segment_buffer *, u32);
136void nilfs_segbuf_fill_in_data_crc(struct nilfs_segment_buffer *, u32);
137
138static inline void
139nilfs_segbuf_add_segsum_buffer(struct nilfs_segment_buffer *segbuf,
140 struct buffer_head *bh)
141{
142 list_add_tail(&bh->b_assoc_buffers, &segbuf->sb_segsum_buffers);
143 segbuf->sb_sum.nblocks++;
144 segbuf->sb_sum.nsumblk++;
145}
146
147static inline void
148nilfs_segbuf_add_payload_buffer(struct nilfs_segment_buffer *segbuf,
149 struct buffer_head *bh)
150{
151 list_add_tail(&bh->b_assoc_buffers, &segbuf->sb_payload_buffers);
152 segbuf->sb_sum.nblocks++;
153}
154
155static inline void
156nilfs_segbuf_add_file_buffer(struct nilfs_segment_buffer *segbuf,
157 struct buffer_head *bh)
158{
159 get_bh(bh);
160 nilfs_segbuf_add_payload_buffer(segbuf, bh);
161 segbuf->sb_sum.nfileblk++;
162}
163
164void nilfs_release_buffers(struct list_head *);
165
166static inline void nilfs_segbuf_clear(struct nilfs_segment_buffer *segbuf)
167{
168 nilfs_release_buffers(&segbuf->sb_segsum_buffers);
169 nilfs_release_buffers(&segbuf->sb_payload_buffers);
170}
171
172struct nilfs_write_info {
173 struct bio *bio;
174 int start, end; /* The region to be submitted */
175 int rest_blocks;
176 int max_pages;
177 int nr_vecs;
178 sector_t blocknr;
179
180 int nbio;
181 atomic_t err;
182 struct completion bio_event;
183 /* completion event of segment write */
184
185 /*
186 * The following fields must be set explicitly
187 */
188 struct super_block *sb;
189 struct backing_dev_info *bdi; /* backing dev info */
190 struct buffer_head *bh_sr;
191};
192
193
194void nilfs_segbuf_prepare_write(struct nilfs_segment_buffer *,
195 struct nilfs_write_info *);
196int nilfs_segbuf_write(struct nilfs_segment_buffer *,
197 struct nilfs_write_info *);
198int nilfs_segbuf_wait(struct nilfs_segment_buffer *,
199 struct nilfs_write_info *);
200
201#endif /* _NILFS_SEGBUF_H */