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state bit-fields */ 13 enum bitmap_state { 14 BITMAP_STALE = 1, /* the bitmap file is out of date or had -EIO */ 15 BITMAP_WRITE_ERROR = 2, /* A write error has occurred */ 16 BITMAP_HOSTENDIAN =15, 17 }; 18 19 /* the superblock at the front of the bitmap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 */ 20 typedef 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 52 struct 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 64 struct 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 */ 107 void mddev_set_bitmap_ops(struct mddev *mddev); 108 109 #endif 110