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 31 /** 32 * struct nilfs_segsum_info - On-memory segment summary 33 * @flags: Flags 34 * @nfinfo: Number of file information structures 35 * @nblocks: Number of blocks included in the partial segment 36 * @nsumblk: Number of summary blocks 37 * @sumbytes: Byte count of segment summary 38 * @nfileblk: Total number of file blocks 39 * @seg_seq: Segment sequence number 40 * @ctime: Creation time 41 * @next: Block number of the next full segment 42 */ 43 struct nilfs_segsum_info { 44 unsigned int flags; 45 unsigned long nfinfo; 46 unsigned long nblocks; 47 unsigned long nsumblk; 48 unsigned long sumbytes; 49 unsigned long nfileblk; 50 u64 seg_seq; 51 time_t ctime; 52 sector_t next; 53 }; 54 55 /* macro for the flags */ 56 #define NILFS_SEG_HAS_SR(sum) ((sum)->flags & NILFS_SS_SR) 57 #define NILFS_SEG_LOGBGN(sum) ((sum)->flags & NILFS_SS_LOGBGN) 58 #define NILFS_SEG_LOGEND(sum) ((sum)->flags & NILFS_SS_LOGEND) 59 #define NILFS_SEG_DSYNC(sum) ((sum)->flags & NILFS_SS_SYNDT) 60 #define NILFS_SEG_SIMPLEX(sum) \ 61 (((sum)->flags & (NILFS_SS_LOGBGN | NILFS_SS_LOGEND)) == \ 62 (NILFS_SS_LOGBGN | NILFS_SS_LOGEND)) 63 64 #define NILFS_SEG_EMPTY(sum) ((sum)->nblocks == (sum)->nsumblk) 65 66 /** 67 * struct nilfs_segment_buffer - Segment buffer 68 * @sb_super: back pointer to a superblock struct 69 * @sb_list: List head to chain this structure 70 * @sb_sum: On-memory segment summary 71 * @sb_segnum: Index number of the full segment 72 * @sb_nextnum: Index number of the next full segment 73 * @sb_fseg_start: Start block number of the full segment 74 * @sb_fseg_end: End block number of the full segment 75 * @sb_pseg_start: Disk block number of partial segment 76 * @sb_rest_blocks: Number of residual blocks in the current segment 77 * @sb_segsum_buffers: List of buffers for segment summaries 78 * @sb_payload_buffers: List of buffers for segment payload 79 * @sb_nbio: Number of flying bio requests 80 * @sb_err: I/O error status 81 * @sb_bio_event: Completion event of log writing 82 */ 83 struct nilfs_segment_buffer { 84 struct super_block *sb_super; 85 struct list_head sb_list; 86 87 /* Segment information */ 88 struct nilfs_segsum_info sb_sum; 89 __u64 sb_segnum; 90 __u64 sb_nextnum; 91 sector_t sb_fseg_start, sb_fseg_end; 92 sector_t sb_pseg_start; 93 unsigned sb_rest_blocks; 94 95 /* Buffers */ 96 struct list_head sb_segsum_buffers; 97 struct list_head sb_payload_buffers; /* including super root */ 98 99 /* io status */ 100 int sb_nbio; 101 atomic_t sb_err; 102 struct completion sb_bio_event; 103 }; 104 105 #define NILFS_LIST_SEGBUF(head) \ 106 list_entry((head), struct nilfs_segment_buffer, sb_list) 107 #define NILFS_NEXT_SEGBUF(segbuf) NILFS_LIST_SEGBUF((segbuf)->sb_list.next) 108 #define NILFS_PREV_SEGBUF(segbuf) NILFS_LIST_SEGBUF((segbuf)->sb_list.prev) 109 #define NILFS_LAST_SEGBUF(head) NILFS_LIST_SEGBUF((head)->prev) 110 #define NILFS_FIRST_SEGBUF(head) NILFS_LIST_SEGBUF((head)->next) 111 #define NILFS_SEGBUF_IS_LAST(segbuf, head) ((segbuf)->sb_list.next == (head)) 112 113 #define nilfs_for_each_segbuf_before(s, t, h) \ 114 for ((s) = NILFS_FIRST_SEGBUF(h); (s) != (t); \ 115 (s) = NILFS_NEXT_SEGBUF(s)) 116 117 #define NILFS_SEGBUF_FIRST_BH(head) \ 118 (list_entry((head)->next, struct buffer_head, b_assoc_buffers)) 119 #define NILFS_SEGBUF_NEXT_BH(bh) \ 120 (list_entry((bh)->b_assoc_buffers.next, struct buffer_head, \ 121 b_assoc_buffers)) 122 #define NILFS_SEGBUF_BH_IS_LAST(bh, head) ((bh)->b_assoc_buffers.next == head) 123 124 125 int __init nilfs_init_segbuf_cache(void); 126 void nilfs_destroy_segbuf_cache(void); 127 struct nilfs_segment_buffer *nilfs_segbuf_new(struct super_block *); 128 void nilfs_segbuf_free(struct nilfs_segment_buffer *); 129 void nilfs_segbuf_map(struct nilfs_segment_buffer *, __u64, unsigned long, 130 struct the_nilfs *); 131 void nilfs_segbuf_map_cont(struct nilfs_segment_buffer *segbuf, 132 struct nilfs_segment_buffer *prev); 133 void nilfs_segbuf_set_next_segnum(struct nilfs_segment_buffer *, __u64, 134 struct the_nilfs *); 135 int nilfs_segbuf_reset(struct nilfs_segment_buffer *, unsigned, time_t); 136 int nilfs_segbuf_extend_segsum(struct nilfs_segment_buffer *); 137 int nilfs_segbuf_extend_payload(struct nilfs_segment_buffer *, 138 struct buffer_head **); 139 void nilfs_segbuf_fill_in_segsum(struct nilfs_segment_buffer *); 140 void nilfs_segbuf_fill_in_segsum_crc(struct nilfs_segment_buffer *, u32); 141 void nilfs_segbuf_fill_in_data_crc(struct nilfs_segment_buffer *, u32); 142 143 static inline void 144 nilfs_segbuf_add_segsum_buffer(struct nilfs_segment_buffer *segbuf, 145 struct buffer_head *bh) 146 { 147 list_add_tail(&bh->b_assoc_buffers, &segbuf->sb_segsum_buffers); 148 segbuf->sb_sum.nblocks++; 149 segbuf->sb_sum.nsumblk++; 150 } 151 152 static inline void 153 nilfs_segbuf_add_payload_buffer(struct nilfs_segment_buffer *segbuf, 154 struct buffer_head *bh) 155 { 156 list_add_tail(&bh->b_assoc_buffers, &segbuf->sb_payload_buffers); 157 segbuf->sb_sum.nblocks++; 158 } 159 160 static inline void 161 nilfs_segbuf_add_file_buffer(struct nilfs_segment_buffer *segbuf, 162 struct buffer_head *bh) 163 { 164 get_bh(bh); 165 nilfs_segbuf_add_payload_buffer(segbuf, bh); 166 segbuf->sb_sum.nfileblk++; 167 } 168 169 int nilfs_segbuf_write(struct nilfs_segment_buffer *segbuf, 170 struct the_nilfs *nilfs); 171 int nilfs_segbuf_wait(struct nilfs_segment_buffer *segbuf); 172 173 void nilfs_clear_logs(struct list_head *logs); 174 void nilfs_truncate_logs(struct list_head *logs, 175 struct nilfs_segment_buffer *last); 176 int nilfs_wait_on_logs(struct list_head *logs); 177 178 static inline void nilfs_destroy_logs(struct list_head *logs) 179 { 180 nilfs_truncate_logs(logs, NULL); 181 } 182 183 #endif /* _NILFS_SEGBUF_H */ 184