diff options
Diffstat (limited to 'drivers/md/md-bitmap.h')
| -rw-r--r-- | drivers/md/md-bitmap.h | 268 |
1 files changed, 48 insertions, 220 deletions
diff --git a/drivers/md/md-bitmap.h b/drivers/md/md-bitmap.h index bb9eb418780a..662e6fc141a7 100644 --- a/drivers/md/md-bitmap.h +++ b/drivers/md/md-bitmap.h @@ -7,81 +7,7 @@ #ifndef BITMAP_H #define BITMAP_H 1 -#define BITMAP_MAJOR_LO 3 -/* version 4 insists the bitmap is in little-endian order - * with version 3, it is host-endian which is non-portable - * Version 5 is currently set only for clustered devices - */ -#define BITMAP_MAJOR_HI 4 -#define BITMAP_MAJOR_CLUSTERED 5 -#define BITMAP_MAJOR_HOSTENDIAN 3 - -/* - * in-memory bitmap: - * - * Use 16 bit block counters to track pending writes to each "chunk". - * The 2 high order bits are special-purpose, the first is a flag indicating - * whether a resync is needed. The second is a flag indicating whether a - * resync is active. - * This means that the counter is actually 14 bits: - * - * +--------+--------+------------------------------------------------+ - * | resync | resync | counter | - * | needed | active | | - * | (0-1) | (0-1) | (0-16383) | - * +--------+--------+------------------------------------------------+ - * - * The "resync needed" bit is set when: - * a '1' bit is read from storage at startup. - * a write request fails on some drives - * a resync is aborted on a chunk with 'resync active' set - * It is cleared (and resync-active set) when a resync starts across all drives - * of the chunk. - * - * - * The "resync active" bit is set when: - * a resync is started on all drives, and resync_needed is set. - * resync_needed will be cleared (as long as resync_active wasn't already set). - * It is cleared when a resync completes. - * - * The counter counts pending write requests, plus the on-disk bit. - * When the counter is '1' and the resync bits are clear, the on-disk - * bit can be cleared as well, thus setting the counter to 0. - * When we set a bit, or in the counter (to start a write), if the fields is - * 0, we first set the disk bit and set the counter to 1. - * - * If the counter is 0, the on-disk bit is clear and the stripe is clean - * Anything that dirties the stripe pushes the counter to 2 (at least) - * and sets the on-disk bit (lazily). - * If a periodic sweep find the counter at 2, it is decremented to 1. - * If the sweep find the counter at 1, the on-disk bit is cleared and the - * counter goes to zero. - * - * Also, we'll hijack the "map" pointer itself and use it as two 16 bit block - * counters as a fallback when "page" memory cannot be allocated: - * - * Normal case (page memory allocated): - * - * page pointer (32-bit) - * - * [ ] ------+ - * | - * +-------> [ ][ ]..[ ] (4096 byte page == 2048 counters) - * c1 c2 c2048 - * - * Hijacked case (page memory allocation failed): - * - * hijacked page pointer (32-bit) - * - * [ ][ ] (no page memory allocated) - * counter #1 (16-bit) counter #2 (16-bit) - * - */ - -#ifdef __KERNEL__ - -#define PAGE_BITS (PAGE_SIZE << 3) -#define PAGE_BIT_SHIFT (PAGE_SHIFT + 3) +#define BITMAP_MAGIC 0x6d746962 typedef __u16 bitmap_counter_t; #define COUNTER_BITS 16 @@ -91,26 +17,6 @@ typedef __u16 bitmap_counter_t; #define NEEDED_MASK ((bitmap_counter_t) (1 << (COUNTER_BITS - 1))) #define RESYNC_MASK ((bitmap_counter_t) (1 << (COUNTER_BITS - 2))) #define COUNTER_MAX ((bitmap_counter_t) RESYNC_MASK - 1) -#define NEEDED(x) (((bitmap_counter_t) x) & NEEDED_MASK) -#define RESYNC(x) (((bitmap_counter_t) x) & RESYNC_MASK) -#define COUNTER(x) (((bitmap_counter_t) x) & COUNTER_MAX) - -/* how many counters per page? */ -#define PAGE_COUNTER_RATIO (PAGE_BITS / COUNTER_BITS) -/* same, except a shift value for more efficient bitops */ -#define PAGE_COUNTER_SHIFT (PAGE_BIT_SHIFT - COUNTER_BIT_SHIFT) -/* same, except a mask value for more efficient bitops */ -#define PAGE_COUNTER_MASK (PAGE_COUNTER_RATIO - 1) - -#define BITMAP_BLOCK_SHIFT 9 - -#endif - -/* - * bitmap structures: - */ - -#define BITMAP_MAGIC 0x6d746962 /* use these for bitmap->flags and bitmap->sb->state bit-fields */ enum bitmap_state { @@ -152,136 +58,58 @@ typedef struct bitmap_super_s { * devices. For raid10 it is the size of the array. */ -#ifdef __KERNEL__ +struct md_bitmap_stats { + u64 events_cleared; + int behind_writes; + bool behind_wait; -/* the in-memory bitmap is represented by bitmap_pages */ -struct bitmap_page { - /* - * map points to the actual memory page - */ - char *map; - /* - * in emergencies (when map cannot be alloced), hijack the map - * pointer and use it as two counters itself - */ - unsigned int hijacked:1; - /* - * If any counter in this page is '1' or '2' - and so could be - * cleared then that page is marked as 'pending' - */ - unsigned int pending:1; - /* - * count of dirty bits on the page - */ - unsigned int count:30; + unsigned long missing_pages; + unsigned long file_pages; + unsigned long sync_size; + unsigned long pages; + struct file *file; }; -/* the main bitmap structure - one per mddev */ -struct bitmap { - - struct bitmap_counts { - spinlock_t lock; - struct bitmap_page *bp; - unsigned long pages; /* total number of pages - * in the bitmap */ - unsigned long missing_pages; /* number of pages - * not yet allocated */ - unsigned long chunkshift; /* chunksize = 2^chunkshift - * (for bitops) */ - unsigned long chunks; /* Total number of data - * chunks for the array */ - } counts; - - struct mddev *mddev; /* the md device that the bitmap is for */ - - __u64 events_cleared; - int need_sync; - - struct bitmap_storage { - struct file *file; /* backing disk file */ - struct page *sb_page; /* cached copy of the bitmap - * file superblock */ - unsigned long sb_index; - struct page **filemap; /* list of cache pages for - * the file */ - unsigned long *filemap_attr; /* attributes associated - * w/ filemap pages */ - unsigned long file_pages; /* number of pages in the file*/ - unsigned long bytes; /* total bytes in the bitmap */ - } storage; - - unsigned long flags; - - int allclean; - - atomic_t behind_writes; - unsigned long behind_writes_used; /* highest actual value at runtime */ - - /* - * the bitmap daemon - periodically wakes up and sweeps the bitmap - * file, cleaning up bits and flushing out pages to disk as necessary - */ - unsigned long daemon_lastrun; /* jiffies of last run */ - unsigned long last_end_sync; /* when we lasted called end_sync to - * update bitmap with resync progress */ - - atomic_t pending_writes; /* pending writes to the bitmap file */ - wait_queue_head_t write_wait; - wait_queue_head_t overflow_wait; - wait_queue_head_t behind_wait; - - struct kernfs_node *sysfs_can_clear; - int cluster_slot; /* Slot offset for clustered env */ +struct bitmap_operations { + bool (*enabled)(struct mddev *mddev); + int (*create)(struct mddev *mddev, int slot); + int (*resize)(struct mddev *mddev, sector_t blocks, int chunksize, + bool init); + + 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 (*wait_behind_writes)(struct mddev *mddev); + + int (*startwrite)(struct mddev *mddev, sector_t offset, + unsigned long sectors, bool behind); + void (*endwrite)(struct mddev *mddev, sector_t offset, + unsigned long sectors, bool success, bool behind); + 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); }; /* the bitmap API */ - -/* these are used only by md/bitmap */ -struct bitmap *md_bitmap_create(struct mddev *mddev, int slot); -int md_bitmap_load(struct mddev *mddev); -void md_bitmap_flush(struct mddev *mddev); -void md_bitmap_destroy(struct mddev *mddev); - -void md_bitmap_print_sb(struct bitmap *bitmap); -void md_bitmap_update_sb(struct bitmap *bitmap); -void md_bitmap_status(struct seq_file *seq, struct bitmap *bitmap); - -int md_bitmap_setallbits(struct bitmap *bitmap); -void md_bitmap_write_all(struct bitmap *bitmap); - -void md_bitmap_dirty_bits(struct bitmap *bitmap, unsigned long s, unsigned long e); - -/* these are exported */ -int md_bitmap_startwrite(struct bitmap *bitmap, sector_t offset, - unsigned long sectors, int behind); -void md_bitmap_endwrite(struct bitmap *bitmap, sector_t offset, - unsigned long sectors, int success, int behind); -int md_bitmap_start_sync(struct bitmap *bitmap, sector_t offset, sector_t *blocks, int degraded); -void md_bitmap_end_sync(struct bitmap *bitmap, sector_t offset, sector_t *blocks, int aborted); -void md_bitmap_close_sync(struct bitmap *bitmap); -void md_bitmap_cond_end_sync(struct bitmap *bitmap, sector_t sector, bool force); -void md_bitmap_sync_with_cluster(struct mddev *mddev, - sector_t old_lo, sector_t old_hi, - sector_t new_lo, sector_t new_hi); - -void md_bitmap_unplug(struct bitmap *bitmap); -void md_bitmap_unplug_async(struct bitmap *bitmap); -void md_bitmap_daemon_work(struct mddev *mddev); - -int md_bitmap_resize(struct bitmap *bitmap, sector_t blocks, - int chunksize, int init); -struct bitmap *get_bitmap_from_slot(struct mddev *mddev, int slot); -int md_bitmap_copy_from_slot(struct mddev *mddev, int slot, - sector_t *lo, sector_t *hi, bool clear_bits); -void md_bitmap_free(struct bitmap *bitmap); -void md_bitmap_wait_behind_writes(struct mddev *mddev); - -static inline bool md_bitmap_enabled(struct bitmap *bitmap) -{ - return bitmap && bitmap->storage.filemap && - !test_bit(BITMAP_STALE, &bitmap->flags); -} - -#endif +void mddev_set_bitmap_ops(struct mddev *mddev); #endif |