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1/* SPDX-License-Identifier: GPL-2.0 */
2/*
3 * bitmap.h: Copyright (C) Peter T. Breuer (ptb@ot.uc3m.es) 2003
4 *
5 * additions: Copyright (C) 2003-2004, Paul Clements, SteelEye Technology, Inc.
6 */
7#ifndef BITMAP_H
8#define BITMAP_H 1
9
10#define BITMAP_MAGIC 0x6d746962
11
12/* use these for bitmap->flags and bitmap->sb->state bit-fields */
13enum bitmap_state {
14 BITMAP_STALE = 1, /* the bitmap file is out of date or had -EIO */
15 BITMAP_WRITE_ERROR = 2, /* A write error has occurred */
16 BITMAP_HOSTENDIAN =15,
17};
18
19/* the superblock at the front of the bitmap file -- little endian */
20typedef struct bitmap_super_s {
21 __le32 magic; /* 0 BITMAP_MAGIC */
22 __le32 version; /* 4 the bitmap major for now, could change... */
23 __u8 uuid[16]; /* 8 128 bit uuid - must match md device uuid */
24 __le64 events; /* 24 event counter for the bitmap (1)*/
25 __le64 events_cleared;/*32 event counter when last bit cleared (2) */
26 __le64 sync_size; /* 40 the size of the md device's sync range(3) */
27 __le32 state; /* 48 bitmap state information */
28 __le32 chunksize; /* 52 the bitmap chunk size in bytes */
29 __le32 daemon_sleep; /* 56 seconds between disk flushes */
30 __le32 write_behind; /* 60 number of outstanding write-behind writes */
31 __le32 sectors_reserved; /* 64 number of 512-byte sectors that are
32 * reserved for the bitmap. */
33 __le32 nodes; /* 68 the maximum number of nodes in cluster. */
34 __u8 cluster_name[64]; /* 72 cluster name to which this md belongs */
35 __u8 pad[256 - 136]; /* set to zero */
36} bitmap_super_t;
37
38/* notes:
39 * (1) This event counter is updated before the eventcounter in the md superblock
40 * When a bitmap is loaded, it is only accepted if this event counter is equal
41 * to, or one greater than, the event counter in the superblock.
42 * (2) This event counter is updated when the other one is *if*and*only*if* the
43 * array is not degraded. As bits are not cleared when the array is degraded,
44 * this represents the last time that any bits were cleared.
45 * If a device is being added that has an event count with this value or
46 * higher, it is accepted as conforming to the bitmap.
47 * (3)This is the number of sectors represented by the bitmap, and is the range that
48 * resync happens across. For raid1 and raid5/6 it is the size of individual
49 * devices. For raid10 it is the size of the array.
50 */
51
52struct md_bitmap_stats {
53 u64 events_cleared;
54 int behind_writes;
55 bool behind_wait;
56
57 unsigned long missing_pages;
58 unsigned long file_pages;
59 unsigned long sync_size;
60 unsigned long pages;
61 struct file *file;
62};
63
64struct bitmap_operations {
65 bool (*enabled)(struct mddev *mddev);
66 int (*create)(struct mddev *mddev);
67 int (*resize)(struct mddev *mddev, sector_t blocks, int chunksize,
68 bool init);
69
70 int (*load)(struct mddev *mddev);
71 void (*destroy)(struct mddev *mddev);
72 void (*flush)(struct mddev *mddev);
73 void (*write_all)(struct mddev *mddev);
74 void (*dirty_bits)(struct mddev *mddev, unsigned long s,
75 unsigned long e);
76 void (*unplug)(struct mddev *mddev, bool sync);
77 void (*daemon_work)(struct mddev *mddev);
78
79 void (*start_behind_write)(struct mddev *mddev);
80 void (*end_behind_write)(struct mddev *mddev);
81 void (*wait_behind_writes)(struct mddev *mddev);
82
83 void (*start_write)(struct mddev *mddev, sector_t offset,
84 unsigned long sectors);
85 void (*end_write)(struct mddev *mddev, sector_t offset,
86 unsigned long sectors);
87 bool (*start_sync)(struct mddev *mddev, sector_t offset,
88 sector_t *blocks, bool degraded);
89 void (*end_sync)(struct mddev *mddev, sector_t offset, sector_t *blocks);
90 void (*cond_end_sync)(struct mddev *mddev, sector_t sector, bool force);
91 void (*close_sync)(struct mddev *mddev);
92
93 void (*update_sb)(void *data);
94 int (*get_stats)(void *data, struct md_bitmap_stats *stats);
95
96 void (*sync_with_cluster)(struct mddev *mddev,
97 sector_t old_lo, sector_t old_hi,
98 sector_t new_lo, sector_t new_hi);
99 void *(*get_from_slot)(struct mddev *mddev, int slot);
100 int (*copy_from_slot)(struct mddev *mddev, int slot, sector_t *lo,
101 sector_t *hi, bool clear_bits);
102 void (*set_pages)(void *data, unsigned long pages);
103 void (*free)(void *data);
104};
105
106/* the bitmap API */
107void mddev_set_bitmap_ops(struct mddev *mddev);
108
109#endif