fs/nilfs2/segbuf.h

   1 /* SPDX-License-Identifier: GPL-2.0+ */
   2 /*
   3  * 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 */