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 typedef __u16 bitmap_counter_t; 13 #define COUNTER_BITS 16 14 #define COUNTER_BIT_SHIFT 4 15 #define COUNTER_BYTE_SHIFT (COUNTER_BIT_SHIFT - 3) 16 17 #define NEEDED_MASK ((bitmap_counter_t) (1 << (COUNTER_BITS - 1))) 18 #define RESYNC_MASK ((bitmap_counter_t) (1 << (COUNTER_BITS - 2))) 19 #define COUNTER_MAX ((bitmap_counter_t) RESYNC_MASK - 1) 20 21 /* use these for bitmap->flags and bitmap->sb->state bit-fields */ 22 enum bitmap_state { 23 BITMAP_STALE = 1, /* the bitmap file is out of date or had -EIO */ 24 BITMAP_WRITE_ERROR = 2, /* A write error has occurred */ 25 BITMAP_HOSTENDIAN =15, 26 }; 27 28 /* the superblock at the front of the bitmap file -- little endian */ 29 typedef struct bitmap_super_s { 30 __le32 magic; /* 0 BITMAP_MAGIC */ 31 __le32 version; /* 4 the bitmap major for now, could change... */ 32 __u8 uuid[16]; /* 8 128 bit uuid - must match md device uuid */ 33 __le64 events; /* 24 event counter for the bitmap (1)*/ 34 __le64 events_cleared;/*32 event counter when last bit cleared (2) */ 35 __le64 sync_size; /* 40 the size of the md device's sync range(3) */ 36 __le32 state; /* 48 bitmap state information */ 37 __le32 chunksize; /* 52 the bitmap chunk size in bytes */ 38 __le32 daemon_sleep; /* 56 seconds between disk flushes */ 39 __le32 write_behind; /* 60 number of outstanding write-behind writes */ 40 __le32 sectors_reserved; /* 64 number of 512-byte sectors that are 41 * reserved for the bitmap. */ 42 __le32 nodes; /* 68 the maximum number of nodes in cluster. */ 43 __u8 cluster_name[64]; /* 72 cluster name to which this md belongs */ 44 __u8 pad[256 - 136]; /* set to zero */ 45 } bitmap_super_t; 46 47 /* notes: 48 * (1) This event counter is updated before the eventcounter in the md superblock 49 * When a bitmap is loaded, it is only accepted if this event counter is equal 50 * to, or one greater than, the event counter in the superblock. 51 * (2) This event counter is updated when the other one is *if*and*only*if* the 52 * array is not degraded. As bits are not cleared when the array is degraded, 53 * this represents the last time that any bits were cleared. 54 * If a device is being added that has an event count with this value or 55 * higher, it is accepted as conforming to the bitmap. 56 * (3)This is the number of sectors represented by the bitmap, and is the range that 57 * resync happens across. For raid1 and raid5/6 it is the size of individual 58 * devices. For raid10 it is the size of the array. 59 */ 60 61 struct md_bitmap_stats { 62 u64 events_cleared; 63 int behind_writes; 64 bool behind_wait; 65 66 unsigned long missing_pages; 67 unsigned long file_pages; 68 unsigned long sync_size; 69 unsigned long pages; 70 struct file *file; 71 }; 72 73 struct bitmap_operations { 74 bool (*enabled)(struct mddev *mddev); 75 int (*create)(struct mddev *mddev, int slot); 76 int (*resize)(struct mddev *mddev, sector_t blocks, int chunksize, 77 bool init); 78 79 int (*load)(struct mddev *mddev); 80 void (*destroy)(struct mddev *mddev); 81 void (*flush)(struct mddev *mddev); 82 void (*write_all)(struct mddev *mddev); 83 void (*dirty_bits)(struct mddev *mddev, unsigned long s, 84 unsigned long e); 85 void (*unplug)(struct mddev *mddev, bool sync); 86 void (*daemon_work)(struct mddev *mddev); 87 void (*wait_behind_writes)(struct mddev *mddev); 88 89 int (*startwrite)(struct mddev *mddev, sector_t offset, 90 unsigned long sectors, bool behind); 91 void (*endwrite)(struct mddev *mddev, sector_t offset, 92 unsigned long sectors, bool success, bool behind); 93 bool (*start_sync)(struct mddev *mddev, sector_t offset, 94 sector_t *blocks, bool degraded); 95 void (*end_sync)(struct mddev *mddev, sector_t offset, sector_t *blocks); 96 void (*cond_end_sync)(struct mddev *mddev, sector_t sector, bool force); 97 void (*close_sync)(struct mddev *mddev); 98 99 void (*update_sb)(void *data); 100 int (*get_stats)(void *data, struct md_bitmap_stats *stats); 101 102 void (*sync_with_cluster)(struct mddev *mddev, 103 sector_t old_lo, sector_t old_hi, 104 sector_t new_lo, sector_t new_hi); 105 void *(*get_from_slot)(struct mddev *mddev, int slot); 106 int (*copy_from_slot)(struct mddev *mddev, int slot, sector_t *lo, 107 sector_t *hi, bool clear_bits); 108 void (*set_pages)(void *data, unsigned long pages); 109 void (*free)(void *data); 110 }; 111 112 /* the bitmap API */ 113 void mddev_set_bitmap_ops(struct mddev *mddev); 114 115 #endif 116