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 * Written by Ryusuke Konishi. 17 * 18 */ 19 #ifndef _NILFS_SEGBUF_H 20 #define _NILFS_SEGBUF_H 21 22 #include <linux/fs.h> 23 #include <linux/buffer_head.h> 24 #include <linux/bio.h> 25 #include <linux/completion.h> 26 27 /** 28 * struct nilfs_segsum_info - On-memory segment summary 29 * @flags: Flags 30 * @nfinfo: Number of file information structures 31 * @nblocks: Number of blocks included in the partial segment 32 * @nsumblk: Number of summary blocks 33 * @sumbytes: Byte count of segment summary 34 * @nfileblk: Total number of file blocks 35 * @seg_seq: Segment sequence number 36 * @cno: Checkpoint number 37 * @ctime: Creation time 38 * @next: Block number of the next full segment 39 */ 40 struct nilfs_segsum_info { 41 unsigned int flags; 42 unsigned long nfinfo; 43 unsigned long nblocks; 44 unsigned long nsumblk; 45 unsigned long sumbytes; 46 unsigned long nfileblk; 47 u64 seg_seq; 48 __u64 cno; 49 time_t ctime; 50 sector_t next; 51 }; 52 53 /** 54 * struct nilfs_segment_buffer - Segment buffer 55 * @sb_super: back pointer to a superblock struct 56 * @sb_list: List head to chain this structure 57 * @sb_sum: On-memory segment summary 58 * @sb_segnum: Index number of the full segment 59 * @sb_nextnum: Index number of the next full segment 60 * @sb_fseg_start: Start block number of the full segment 61 * @sb_fseg_end: End block number of the full segment 62 * @sb_pseg_start: Disk block number of partial segment 63 * @sb_rest_blocks: Number of residual blocks in the current segment 64 * @sb_segsum_buffers: List of buffers for segment summaries 65 * @sb_payload_buffers: List of buffers for segment payload 66 * @sb_super_root: Pointer to buffer storing a super root block (if exists) 67 * @sb_nbio: Number of flying bio requests 68 * @sb_err: I/O error status 69 * @sb_bio_event: Completion event of log writing 70 */ 71 struct nilfs_segment_buffer { 72 struct super_block *sb_super; 73 struct list_head sb_list; 74 75 /* Segment information */ 76 struct nilfs_segsum_info sb_sum; 77 __u64 sb_segnum; 78 __u64 sb_nextnum; 79 sector_t sb_fseg_start, sb_fseg_end; 80 sector_t sb_pseg_start; 81 unsigned int sb_rest_blocks; 82 83 /* Buffers */ 84 struct list_head sb_segsum_buffers; 85 struct list_head sb_payload_buffers; /* including super root */ 86 struct buffer_head *sb_super_root; 87 88 /* io status */ 89 int sb_nbio; 90 atomic_t sb_err; 91 struct completion sb_bio_event; 92 }; 93 94 #define NILFS_LIST_SEGBUF(head) \ 95 list_entry((head), struct nilfs_segment_buffer, sb_list) 96 #define NILFS_NEXT_SEGBUF(segbuf) NILFS_LIST_SEGBUF((segbuf)->sb_list.next) 97 #define NILFS_PREV_SEGBUF(segbuf) NILFS_LIST_SEGBUF((segbuf)->sb_list.prev) 98 #define NILFS_LAST_SEGBUF(head) NILFS_LIST_SEGBUF((head)->prev) 99 #define NILFS_FIRST_SEGBUF(head) NILFS_LIST_SEGBUF((head)->next) 100 #define NILFS_SEGBUF_IS_LAST(segbuf, head) ((segbuf)->sb_list.next == (head)) 101 102 #define nilfs_for_each_segbuf_before(s, t, h) \ 103 for ((s) = NILFS_FIRST_SEGBUF(h); (s) != (t); \ 104 (s) = NILFS_NEXT_SEGBUF(s)) 105 106 #define NILFS_SEGBUF_FIRST_BH(head) \ 107 (list_entry((head)->next, struct buffer_head, b_assoc_buffers)) 108 #define NILFS_SEGBUF_NEXT_BH(bh) \ 109 (list_entry((bh)->b_assoc_buffers.next, struct buffer_head, \ 110 b_assoc_buffers)) 111 #define NILFS_SEGBUF_BH_IS_LAST(bh, head) ((bh)->b_assoc_buffers.next == head) 112 113 extern struct kmem_cache *nilfs_segbuf_cachep; 114 115 struct nilfs_segment_buffer *nilfs_segbuf_new(struct super_block *); 116 void nilfs_segbuf_free(struct nilfs_segment_buffer *); 117 void nilfs_segbuf_map(struct nilfs_segment_buffer *, __u64, unsigned long, 118 struct the_nilfs *); 119 void nilfs_segbuf_map_cont(struct nilfs_segment_buffer *segbuf, 120 struct nilfs_segment_buffer *prev); 121 void nilfs_segbuf_set_next_segnum(struct nilfs_segment_buffer *, __u64, 122 struct the_nilfs *); 123 int nilfs_segbuf_reset(struct nilfs_segment_buffer *, unsigned int, time_t, 124 __u64); 125 int nilfs_segbuf_extend_segsum(struct nilfs_segment_buffer *); 126 int nilfs_segbuf_extend_payload(struct nilfs_segment_buffer *, 127 struct buffer_head **); 128 void nilfs_segbuf_fill_in_segsum(struct nilfs_segment_buffer *); 129 130 static inline int nilfs_segbuf_simplex(struct nilfs_segment_buffer *segbuf) 131 { 132 unsigned int flags = segbuf->sb_sum.flags; 133 134 return (flags & (NILFS_SS_LOGBGN | NILFS_SS_LOGEND)) == 135 (NILFS_SS_LOGBGN | NILFS_SS_LOGEND); 136 } 137 138 static inline int nilfs_segbuf_empty(struct nilfs_segment_buffer *segbuf) 139 { 140 return segbuf->sb_sum.nblocks == segbuf->sb_sum.nsumblk; 141 } 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 void nilfs_clear_logs(struct list_head *logs); 170 void nilfs_truncate_logs(struct list_head *logs, 171 struct nilfs_segment_buffer *last); 172 int nilfs_write_logs(struct list_head *logs, struct the_nilfs *nilfs); 173 int nilfs_wait_on_logs(struct list_head *logs); 174 void nilfs_add_checksums_on_logs(struct list_head *logs, u32 seed); 175 176 static inline void nilfs_destroy_logs(struct list_head *logs) 177 { 178 nilfs_truncate_logs(logs, NULL); 179 } 180 181 #endif /* _NILFS_SEGBUF_H */ 182