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 */ 44 struct 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 */ 82 struct 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) 120 121 122 int __init nilfs_init_segbuf_cache(void); 123 void nilfs_destroy_segbuf_cache(void); 124 struct nilfs_segment_buffer *nilfs_segbuf_new(struct super_block *); 125 void nilfs_segbuf_free(struct nilfs_segment_buffer *); 126 void nilfs_segbuf_map(struct nilfs_segment_buffer *, __u64, unsigned long, 127 struct the_nilfs *); 128 void nilfs_segbuf_set_next_segnum(struct nilfs_segment_buffer *, __u64, 129 struct the_nilfs *); 130 int nilfs_segbuf_reset(struct nilfs_segment_buffer *, unsigned, time_t); 131 int nilfs_segbuf_extend_segsum(struct nilfs_segment_buffer *); 132 int nilfs_segbuf_extend_payload(struct nilfs_segment_buffer *, 133 struct buffer_head **); 134 void nilfs_segbuf_fill_in_segsum(struct nilfs_segment_buffer *); 135 void nilfs_segbuf_fill_in_segsum_crc(struct nilfs_segment_buffer *, u32); 136 void nilfs_segbuf_fill_in_data_crc(struct nilfs_segment_buffer *, u32); 137 138 static inline void 139 nilfs_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 } 146 147 static inline void 148 nilfs_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 } 154 155 static inline void 156 nilfs_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 } 163 164 void nilfs_release_buffers(struct list_head *); 165 166 static 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 } 171 172 struct 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 }; 192 193 194 void nilfs_segbuf_prepare_write(struct nilfs_segment_buffer *, 195 struct nilfs_write_info *); 196 int nilfs_segbuf_write(struct nilfs_segment_buffer *, 197 struct nilfs_write_info *); 198 int nilfs_segbuf_wait(struct nilfs_segment_buffer *, 199 struct nilfs_write_info *); 200 201 #endif /* _NILFS_SEGBUF_H */ 202