diff options
Diffstat (limited to 'drivers/md/md-bitmap.h')
| -rw-r--r-- | drivers/md/md-bitmap.h | 198 |
1 files changed, 198 insertions, 0 deletions
diff --git a/drivers/md/md-bitmap.h b/drivers/md/md-bitmap.h new file mode 100644 index 000000000000..b42a28fa83a0 --- /dev/null +++ b/drivers/md/md-bitmap.h @@ -0,0 +1,198 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * bitmap.h: Copyright (C) Peter T. Breuer (ptb@ot.uc3m.es) 2003 + * + * additions: Copyright (C) 2003-2004, Paul Clements, SteelEye Technology, Inc. + */ +#ifndef BITMAP_H +#define BITMAP_H 1 + +#define BITMAP_MAGIC 0x6d746962 + +/* + * version 3 is host-endian order, this is deprecated and not used for new + * array + */ +#define BITMAP_MAJOR_LO 3 +#define BITMAP_MAJOR_HOSTENDIAN 3 +/* version 4 is little-endian order, the default value */ +#define BITMAP_MAJOR_HI 4 +/* version 5 is only used for cluster */ +#define BITMAP_MAJOR_CLUSTERED 5 +/* version 6 is only used for lockless bitmap */ +#define BITMAP_MAJOR_LOCKLESS 6 + +/* use these for bitmap->flags and bitmap->sb->state bit-fields */ +enum bitmap_state { + BITMAP_STALE = 1, /* the bitmap file is out of date or had -EIO */ + BITMAP_WRITE_ERROR = 2, /* A write error has occurred */ + BITMAP_FIRST_USE = 3, /* llbitmap is just created */ + BITMAP_CLEAN = 4, /* llbitmap is created with assume_clean */ + BITMAP_DAEMON_BUSY = 5, /* llbitmap daemon is not finished after daemon_sleep */ + BITMAP_HOSTENDIAN =15, +}; + +/* the superblock at the front of the bitmap file -- little endian */ +typedef struct bitmap_super_s { + __le32 magic; /* 0 BITMAP_MAGIC */ + __le32 version; /* 4 the bitmap major for now, could change... */ + __u8 uuid[16]; /* 8 128 bit uuid - must match md device uuid */ + __le64 events; /* 24 event counter for the bitmap (1)*/ + __le64 events_cleared;/*32 event counter when last bit cleared (2) */ + __le64 sync_size; /* 40 the size of the md device's sync range(3) */ + __le32 state; /* 48 bitmap state information */ + __le32 chunksize; /* 52 the bitmap chunk size in bytes */ + __le32 daemon_sleep; /* 56 seconds between disk flushes */ + __le32 write_behind; /* 60 number of outstanding write-behind writes */ + __le32 sectors_reserved; /* 64 number of 512-byte sectors that are + * reserved for the bitmap. */ + __le32 nodes; /* 68 the maximum number of nodes in cluster. */ + __u8 cluster_name[64]; /* 72 cluster name to which this md belongs */ + __u8 pad[256 - 136]; /* set to zero */ +} bitmap_super_t; + +/* notes: + * (1) This event counter is updated before the eventcounter in the md superblock + * When a bitmap is loaded, it is only accepted if this event counter is equal + * to, or one greater than, the event counter in the superblock. + * (2) This event counter is updated when the other one is *if*and*only*if* the + * array is not degraded. As bits are not cleared when the array is degraded, + * this represents the last time that any bits were cleared. + * If a device is being added that has an event count with this value or + * higher, it is accepted as conforming to the bitmap. + * (3)This is the number of sectors represented by the bitmap, and is the range that + * resync happens across. For raid1 and raid5/6 it is the size of individual + * devices. For raid10 it is the size of the array. + */ + +struct md_bitmap_stats { + u64 events_cleared; + int behind_writes; + bool behind_wait; + + unsigned long missing_pages; + unsigned long file_pages; + unsigned long sync_size; + unsigned long pages; + struct file *file; +}; + +typedef void (md_bitmap_fn)(struct mddev *mddev, sector_t offset, + unsigned long sectors); + +struct bitmap_operations { + struct md_submodule_head head; + + bool (*enabled)(void *data, bool flush); + int (*create)(struct mddev *mddev); + int (*resize)(struct mddev *mddev, sector_t blocks, int chunksize); + + int (*load)(struct mddev *mddev); + void (*destroy)(struct mddev *mddev); + void (*flush)(struct mddev *mddev); + void (*write_all)(struct mddev *mddev); + void (*dirty_bits)(struct mddev *mddev, unsigned long s, + unsigned long e); + void (*unplug)(struct mddev *mddev, bool sync); + void (*daemon_work)(struct mddev *mddev); + + void (*start_behind_write)(struct mddev *mddev); + void (*end_behind_write)(struct mddev *mddev); + void (*wait_behind_writes)(struct mddev *mddev); + + md_bitmap_fn *start_write; + md_bitmap_fn *end_write; + md_bitmap_fn *start_discard; + md_bitmap_fn *end_discard; + + sector_t (*skip_sync_blocks)(struct mddev *mddev, sector_t offset); + bool (*blocks_synced)(struct mddev *mddev, sector_t offset); + bool (*start_sync)(struct mddev *mddev, sector_t offset, + sector_t *blocks, bool degraded); + void (*end_sync)(struct mddev *mddev, sector_t offset, sector_t *blocks); + void (*cond_end_sync)(struct mddev *mddev, sector_t sector, bool force); + void (*close_sync)(struct mddev *mddev); + + void (*update_sb)(void *data); + int (*get_stats)(void *data, struct md_bitmap_stats *stats); + + void (*sync_with_cluster)(struct mddev *mddev, + sector_t old_lo, sector_t old_hi, + sector_t new_lo, sector_t new_hi); + void *(*get_from_slot)(struct mddev *mddev, int slot); + int (*copy_from_slot)(struct mddev *mddev, int slot, sector_t *lo, + sector_t *hi, bool clear_bits); + void (*set_pages)(void *data, unsigned long pages); + void (*free)(void *data); + + struct attribute_group *group; +}; + +/* the bitmap API */ +static inline bool md_bitmap_registered(struct mddev *mddev) +{ + return mddev->bitmap_ops != NULL; +} + +static inline bool md_bitmap_enabled(struct mddev *mddev, bool flush) +{ + /* bitmap_ops must be registered before creating bitmap. */ + if (!md_bitmap_registered(mddev)) + return false; + + if (!mddev->bitmap) + return false; + + return mddev->bitmap_ops->enabled(mddev->bitmap, flush); +} + +static inline bool md_bitmap_start_sync(struct mddev *mddev, sector_t offset, + sector_t *blocks, bool degraded) +{ + /* always resync if no bitmap */ + if (!md_bitmap_enabled(mddev, false)) { + *blocks = 1024; + return true; + } + + return mddev->bitmap_ops->start_sync(mddev, offset, blocks, degraded); +} + +static inline void md_bitmap_end_sync(struct mddev *mddev, sector_t offset, + sector_t *blocks) +{ + if (!md_bitmap_enabled(mddev, false)) { + *blocks = 1024; + return; + } + + mddev->bitmap_ops->end_sync(mddev, offset, blocks); +} + +#ifdef CONFIG_MD_BITMAP +int md_bitmap_init(void); +void md_bitmap_exit(void); +#else +static inline int md_bitmap_init(void) +{ + return 0; +} +static inline void md_bitmap_exit(void) +{ +} +#endif + +#ifdef CONFIG_MD_LLBITMAP +int md_llbitmap_init(void); +void md_llbitmap_exit(void); +#else +static inline int md_llbitmap_init(void) +{ + return 0; +} +static inline void md_llbitmap_exit(void) +{ +} +#endif + +#endif |