1 /* SPDX-License-Identifier: GPL-2.0+ */ 2 /* 3 * segbuf.h - NILFS Segment buffer prototypes and definitions 4 * 5 * Copyright (C) 2005-2008 Nippon Telegraph and Telephone Corporation. 6 * 7 * Written by Ryusuke Konishi. 8 * 9 */ 10 #ifndef _NILFS_SEGBUF_H 11 #define _NILFS_SEGBUF_H 12 13 #include <linux/fs.h> 14 #include <linux/buffer_head.h> 15 #include <linux/bio.h> 16 #include <linux/completion.h> 17 18 /** 19 * struct nilfs_segsum_info - On-memory segment summary 20 * @flags: Flags 21 * @nfinfo: Number of file information structures 22 * @nblocks: Number of blocks included in the partial segment 23 * @nsumblk: Number of summary blocks 24 * @sumbytes: Byte count of segment summary 25 * @nfileblk: Total number of file blocks 26 * @seg_seq: Segment sequence number 27 * @cno: Checkpoint number 28 * @ctime: Creation time 29 * @next: Block number of the next full segment 30 */ 31 struct nilfs_segsum_info { 32 unsigned int flags; 33 unsigned long nfinfo; 34 unsigned long nblocks; 35 unsigned long nsumblk; 36 unsigned long sumbytes; 37 unsigned long nfileblk; 38 u64 seg_seq; 39 __u64 cno; 40 time64_t ctime; 41 sector_t next; 42 }; 43 44 /** 45 * struct nilfs_segment_buffer - Segment buffer 46 * @sb_super: back pointer to a superblock struct 47 * @sb_list: List head to chain this structure 48 * @sb_sum: On-memory segment summary 49 * @sb_segnum: Index number of the full segment 50 * @sb_nextnum: Index number of the next full segment 51 * @sb_fseg_start: Start block number of the full segment 52 * @sb_fseg_end: End block number of the full segment 53 * @sb_pseg_start: Disk block number of partial segment 54 * @sb_rest_blocks: Number of residual blocks in the current segment 55 * @sb_segsum_buffers: List of buffers for segment summaries 56 * @sb_payload_buffers: List of buffers for segment payload 57 * @sb_super_root: Pointer to buffer storing a super root block (if exists) 58 * @sb_nbio: Number of flying bio requests 59 * @sb_err: I/O error status 60 * @sb_bio_event: Completion event of log writing 61 */ 62 struct nilfs_segment_buffer { 63 struct super_block *sb_super; 64 struct list_head sb_list; 65 66 /* Segment information */ 67 struct nilfs_segsum_info sb_sum; 68 __u64 sb_segnum; 69 __u64 sb_nextnum; 70 sector_t sb_fseg_start, sb_fseg_end; 71 sector_t sb_pseg_start; 72 unsigned int sb_rest_blocks; 73 74 /* Buffers */ 75 struct list_head sb_segsum_buffers; 76 struct list_head sb_payload_buffers; /* including super root */ 77 struct buffer_head *sb_super_root; 78 79 /* io status */ 80 int sb_nbio; 81 atomic_t sb_err; 82 struct completion sb_bio_event; 83 }; 84 85 #define NILFS_LIST_SEGBUF(head) \ 86 list_entry((head), struct nilfs_segment_buffer, sb_list) 87 #define NILFS_NEXT_SEGBUF(segbuf) NILFS_LIST_SEGBUF((segbuf)->sb_list.next) 88 #define NILFS_PREV_SEGBUF(segbuf) NILFS_LIST_SEGBUF((segbuf)->sb_list.prev) 89 #define NILFS_LAST_SEGBUF(head) NILFS_LIST_SEGBUF((head)->prev) 90 #define NILFS_FIRST_SEGBUF(head) NILFS_LIST_SEGBUF((head)->next) 91 #define NILFS_SEGBUF_IS_LAST(segbuf, head) ((segbuf)->sb_list.next == (head)) 92 93 #define nilfs_for_each_segbuf_before(s, t, h) \ 94 for ((s) = NILFS_FIRST_SEGBUF(h); (s) != (t); \ 95 (s) = NILFS_NEXT_SEGBUF(s)) 96 97 #define NILFS_SEGBUF_FIRST_BH(head) \ 98 (list_entry((head)->next, struct buffer_head, b_assoc_buffers)) 99 #define NILFS_SEGBUF_NEXT_BH(bh) \ 100 (list_entry((bh)->b_assoc_buffers.next, struct buffer_head, \ 101 b_assoc_buffers)) 102 #define NILFS_SEGBUF_BH_IS_LAST(bh, head) ((bh)->b_assoc_buffers.next == head) 103 104 extern struct kmem_cache *nilfs_segbuf_cachep; 105 106 struct nilfs_segment_buffer *nilfs_segbuf_new(struct super_block *); 107 void nilfs_segbuf_free(struct nilfs_segment_buffer *); 108 void nilfs_segbuf_map(struct nilfs_segment_buffer *, __u64, unsigned long, 109 struct the_nilfs *); 110 void nilfs_segbuf_map_cont(struct nilfs_segment_buffer *segbuf, 111 struct nilfs_segment_buffer *prev); 112 void nilfs_segbuf_set_next_segnum(struct nilfs_segment_buffer *, __u64, 113 struct the_nilfs *); 114 int nilfs_segbuf_reset(struct nilfs_segment_buffer *, unsigned int, time64_t, 115 __u64); 116 int nilfs_segbuf_extend_segsum(struct nilfs_segment_buffer *); 117 int nilfs_segbuf_extend_payload(struct nilfs_segment_buffer *, 118 struct buffer_head **); 119 void nilfs_segbuf_fill_in_segsum(struct nilfs_segment_buffer *); 120 121 static inline int nilfs_segbuf_simplex(struct nilfs_segment_buffer *segbuf) 122 { 123 unsigned int flags = segbuf->sb_sum.flags; 124 125 return (flags & (NILFS_SS_LOGBGN | NILFS_SS_LOGEND)) == 126 (NILFS_SS_LOGBGN | NILFS_SS_LOGEND); 127 } 128 129 static inline int nilfs_segbuf_empty(struct nilfs_segment_buffer *segbuf) 130 { 131 return segbuf->sb_sum.nblocks == segbuf->sb_sum.nsumblk; 132 } 133 134 static inline void 135 nilfs_segbuf_add_segsum_buffer(struct nilfs_segment_buffer *segbuf, 136 struct buffer_head *bh) 137 { 138 list_add_tail(&bh->b_assoc_buffers, &segbuf->sb_segsum_buffers); 139 segbuf->sb_sum.nblocks++; 140 segbuf->sb_sum.nsumblk++; 141 } 142 143 static inline void 144 nilfs_segbuf_add_payload_buffer(struct nilfs_segment_buffer *segbuf, 145 struct buffer_head *bh) 146 { 147 list_add_tail(&bh->b_assoc_buffers, &segbuf->sb_payload_buffers); 148 segbuf->sb_sum.nblocks++; 149 } 150 151 static inline void 152 nilfs_segbuf_add_file_buffer(struct nilfs_segment_buffer *segbuf, 153 struct buffer_head *bh) 154 { 155 get_bh(bh); 156 nilfs_segbuf_add_payload_buffer(segbuf, bh); 157 segbuf->sb_sum.nfileblk++; 158 } 159 160 void nilfs_clear_logs(struct list_head *logs); 161 void nilfs_truncate_logs(struct list_head *logs, 162 struct nilfs_segment_buffer *last); 163 int nilfs_write_logs(struct list_head *logs, struct the_nilfs *nilfs); 164 int nilfs_wait_on_logs(struct list_head *logs); 165 void nilfs_add_checksums_on_logs(struct list_head *logs, u32 seed); 166 167 static inline void nilfs_destroy_logs(struct list_head *logs) 168 { 169 nilfs_truncate_logs(logs, NULL); 170 } 171 172 #endif /* _NILFS_SEGBUF_H */ 173