diff options
Diffstat (limited to 'include/linux/raid')
| -rw-r--r-- | include/linux/raid/bitmap.h | 288 | ||||
| -rw-r--r-- | include/linux/raid/linear.h | 31 | ||||
| -rw-r--r-- | include/linux/raid/multipath.h | 42 | ||||
| -rw-r--r-- | include/linux/raid/raid0.h | 30 | ||||
| -rw-r--r-- | include/linux/raid/raid1.h | 134 | ||||
| -rw-r--r-- | include/linux/raid/raid10.h | 123 | ||||
| -rw-r--r-- | include/linux/raid/raid5.h | 402 |
7 files changed, 0 insertions, 1050 deletions
diff --git a/include/linux/raid/bitmap.h b/include/linux/raid/bitmap.h deleted file mode 100644 index e98900671ca9..000000000000 --- a/include/linux/raid/bitmap.h +++ /dev/null @@ -1,288 +0,0 @@ -/* - * 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_MAJOR_LO 3 -/* version 4 insists the bitmap is in little-endian order - * with version 3, it is host-endian which is non-portable - */ -#define BITMAP_MAJOR_HI 4 -#define BITMAP_MAJOR_HOSTENDIAN 3 - -#define BITMAP_MINOR 39 - -/* - * 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 aswell, 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 stipe is clean - * Anything that dirties the stipe 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) - -typedef __u16 bitmap_counter_t; -#define COUNTER_BITS 16 -#define COUNTER_BIT_SHIFT 4 -#define COUNTER_BYTE_RATIO (COUNTER_BITS / 8) -#define COUNTER_BYTE_SHIFT (COUNTER_BIT_SHIFT - 3) - -#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_SIZE 512 -#define BITMAP_BLOCK_SHIFT 9 - -/* how many blocks per chunk? (this is variable) */ -#define CHUNK_BLOCK_RATIO(bitmap) ((bitmap)->chunksize >> BITMAP_BLOCK_SHIFT) -#define CHUNK_BLOCK_SHIFT(bitmap) ((bitmap)->chunkshift - BITMAP_BLOCK_SHIFT) -#define CHUNK_BLOCK_MASK(bitmap) (CHUNK_BLOCK_RATIO(bitmap) - 1) - -/* when hijacked, the counters and bits represent even larger "chunks" */ -/* there will be 1024 chunks represented by each counter in the page pointers */ -#define PAGEPTR_BLOCK_RATIO(bitmap) \ - (CHUNK_BLOCK_RATIO(bitmap) << PAGE_COUNTER_SHIFT >> 1) -#define PAGEPTR_BLOCK_SHIFT(bitmap) \ - (CHUNK_BLOCK_SHIFT(bitmap) + PAGE_COUNTER_SHIFT - 1) -#define PAGEPTR_BLOCK_MASK(bitmap) (PAGEPTR_BLOCK_RATIO(bitmap) - 1) - -/* - * on-disk bitmap: - * - * Use one bit per "chunk" (block set). We do the disk I/O on the bitmap - * file a page at a time. There's a superblock at the start of the file. - */ - -/* map chunks (bits) to file pages - offset by the size of the superblock */ -#define CHUNK_BIT_OFFSET(chunk) ((chunk) + (sizeof(bitmap_super_t) << 3)) - -#endif - -/* - * bitmap structures: - */ - -#define BITMAP_MAGIC 0x6d746962 - -/* use these for bitmap->flags and bitmap->sb->state bit-fields */ -enum bitmap_state { - BITMAP_STALE = 0x002, /* the bitmap file is out of date or had -EIO */ - BITMAP_WRITE_ERROR = 0x004, /* A write error has occurred */ - BITMAP_HOSTENDIAN = 0x8000, -}; - -/* 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 */ - - __u8 pad[256 - 64]; /* 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. - */ - -#ifdef __KERNEL__ - -/* 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; - /* - * count of dirty bits on the page - */ - unsigned int count:31; -}; - -/* keep track of bitmap file pages that have pending writes on them */ -struct page_list { - struct list_head list; - struct page *page; -}; - -/* the main bitmap structure - one per mddev */ -struct bitmap { - struct bitmap_page *bp; - unsigned long pages; /* total number of pages in the bitmap */ - unsigned long missing_pages; /* number of pages not yet allocated */ - - mddev_t *mddev; /* the md device that the bitmap is for */ - - int counter_bits; /* how many bits per block counter */ - - /* bitmap chunksize -- how much data does each bit represent? */ - unsigned long chunksize; - unsigned long chunkshift; /* chunksize = 2^chunkshift (for bitops) */ - unsigned long chunks; /* total number of data chunks for the array */ - - /* We hold a count on the chunk currently being synced, and drop - * it when the last block is started. If the resync is aborted - * midway, we need to be able to drop that count, so we remember - * the counted chunk.. - */ - unsigned long syncchunk; - - __u64 events_cleared; - int need_sync; - - /* bitmap spinlock */ - spinlock_t lock; - - long offset; /* offset from superblock if file is NULL */ - struct file *file; /* backing disk file */ - struct page *sb_page; /* cached copy of the bitmap file superblock */ - 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 */ - int last_page_size; /* bytes in the last page */ - - unsigned long flags; - - int allclean; - - unsigned long max_write_behind; /* write-behind mode */ - atomic_t behind_writes; - - /* - * 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 daemon_sleep; /* how many seconds between updates? */ - 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; - -}; - -/* the bitmap API */ - -/* these are used only by md/bitmap */ -int bitmap_create(mddev_t *mddev); -void bitmap_flush(mddev_t *mddev); -void bitmap_destroy(mddev_t *mddev); - -void bitmap_print_sb(struct bitmap *bitmap); -void bitmap_update_sb(struct bitmap *bitmap); - -int bitmap_setallbits(struct bitmap *bitmap); -void bitmap_write_all(struct bitmap *bitmap); - -void bitmap_dirty_bits(struct bitmap *bitmap, unsigned long s, unsigned long e); - -/* these are exported */ -int bitmap_startwrite(struct bitmap *bitmap, sector_t offset, - unsigned long sectors, int behind); -void bitmap_endwrite(struct bitmap *bitmap, sector_t offset, - unsigned long sectors, int success, int behind); -int bitmap_start_sync(struct bitmap *bitmap, sector_t offset, int *blocks, int degraded); -void bitmap_end_sync(struct bitmap *bitmap, sector_t offset, int *blocks, int aborted); -void bitmap_close_sync(struct bitmap *bitmap); -void bitmap_cond_end_sync(struct bitmap *bitmap, sector_t sector); - -void bitmap_unplug(struct bitmap *bitmap); -void bitmap_daemon_work(struct bitmap *bitmap); -#endif - -#endif diff --git a/include/linux/raid/linear.h b/include/linux/raid/linear.h deleted file mode 100644 index f38b9c586afb..000000000000 --- a/include/linux/raid/linear.h +++ /dev/null @@ -1,31 +0,0 @@ -#ifndef _LINEAR_H -#define _LINEAR_H - -#include <linux/raid/md.h> - -struct dev_info { - mdk_rdev_t *rdev; - sector_t num_sectors; - sector_t start_sector; -}; - -typedef struct dev_info dev_info_t; - -struct linear_private_data -{ - struct linear_private_data *prev; /* earlier version */ - dev_info_t **hash_table; - sector_t spacing; - sector_t array_sectors; - int sector_shift; /* shift before dividing - * by spacing - */ - dev_info_t disks[0]; -}; - - -typedef struct linear_private_data linear_conf_t; - -#define mddev_to_conf(mddev) ((linear_conf_t *) mddev->private) - -#endif diff --git a/include/linux/raid/multipath.h b/include/linux/raid/multipath.h deleted file mode 100644 index 6f53fc177a47..000000000000 --- a/include/linux/raid/multipath.h +++ /dev/null @@ -1,42 +0,0 @@ -#ifndef _MULTIPATH_H -#define _MULTIPATH_H - -#include <linux/raid/md.h> - -struct multipath_info { - mdk_rdev_t *rdev; -}; - -struct multipath_private_data { - mddev_t *mddev; - struct multipath_info *multipaths; - int raid_disks; - int working_disks; - spinlock_t device_lock; - struct list_head retry_list; - - mempool_t *pool; -}; - -typedef struct multipath_private_data multipath_conf_t; - -/* - * this is the only point in the RAID code where we violate - * C type safety. mddev->private is an 'opaque' pointer. - */ -#define mddev_to_conf(mddev) ((multipath_conf_t *) mddev->private) - -/* - * this is our 'private' 'collective' MULTIPATH buffer head. - * it contains information about what kind of IO operations were started - * for this MULTIPATH operation, and about their status: - */ - -struct multipath_bh { - mddev_t *mddev; - struct bio *master_bio; - struct bio bio; - int path; - struct list_head retry_list; -}; -#endif diff --git a/include/linux/raid/raid0.h b/include/linux/raid/raid0.h deleted file mode 100644 index fd42aa87c391..000000000000 --- a/include/linux/raid/raid0.h +++ /dev/null @@ -1,30 +0,0 @@ -#ifndef _RAID0_H -#define _RAID0_H - -#include <linux/raid/md.h> - -struct strip_zone -{ - sector_t zone_start; /* Zone offset in md_dev (in sectors) */ - sector_t dev_start; /* Zone offset in real dev (in sectors) */ - sector_t sectors; /* Zone size in sectors */ - int nb_dev; /* # of devices attached to the zone */ - mdk_rdev_t **dev; /* Devices attached to the zone */ -}; - -struct raid0_private_data -{ - struct strip_zone **hash_table; /* Table of indexes into strip_zone */ - struct strip_zone *strip_zone; - mdk_rdev_t **devlist; /* lists of rdevs, pointed to by strip_zone->dev */ - int nr_strip_zones; - - sector_t spacing; - int sector_shift; /* shift this before divide by spacing */ -}; - -typedef struct raid0_private_data raid0_conf_t; - -#define mddev_to_conf(mddev) ((raid0_conf_t *) mddev->private) - -#endif diff --git a/include/linux/raid/raid1.h b/include/linux/raid/raid1.h deleted file mode 100644 index 0a9ba7c3302e..000000000000 --- a/include/linux/raid/raid1.h +++ /dev/null @@ -1,134 +0,0 @@ -#ifndef _RAID1_H -#define _RAID1_H - -#include <linux/raid/md.h> - -typedef struct mirror_info mirror_info_t; - -struct mirror_info { - mdk_rdev_t *rdev; - sector_t head_position; -}; - -/* - * memory pools need a pointer to the mddev, so they can force an unplug - * when memory is tight, and a count of the number of drives that the - * pool was allocated for, so they know how much to allocate and free. - * mddev->raid_disks cannot be used, as it can change while a pool is active - * These two datums are stored in a kmalloced struct. - */ - -struct pool_info { - mddev_t *mddev; - int raid_disks; -}; - - -typedef struct r1bio_s r1bio_t; - -struct r1_private_data_s { - mddev_t *mddev; - mirror_info_t *mirrors; - int raid_disks; - int last_used; - sector_t next_seq_sect; - spinlock_t device_lock; - - struct list_head retry_list; - /* queue pending writes and submit them on unplug */ - struct bio_list pending_bio_list; - /* queue of writes that have been unplugged */ - struct bio_list flushing_bio_list; - - /* for use when syncing mirrors: */ - - spinlock_t resync_lock; - int nr_pending; - int nr_waiting; - int nr_queued; - int barrier; - sector_t next_resync; - int fullsync; /* set to 1 if a full sync is needed, - * (fresh device added). - * Cleared when a sync completes. - */ - - wait_queue_head_t wait_barrier; - - struct pool_info *poolinfo; - - struct page *tmppage; - - mempool_t *r1bio_pool; - mempool_t *r1buf_pool; -}; - -typedef struct r1_private_data_s conf_t; - -/* - * this is the only point in the RAID code where we violate - * C type safety. mddev->private is an 'opaque' pointer. - */ -#define mddev_to_conf(mddev) ((conf_t *) mddev->private) - -/* - * this is our 'private' RAID1 bio. - * - * it contains information about what kind of IO operations were started - * for this RAID1 operation, and about their status: - */ - -struct r1bio_s { - atomic_t remaining; /* 'have we finished' count, - * used from IRQ handlers - */ - atomic_t behind_remaining; /* number of write-behind ios remaining - * in this BehindIO request - */ - sector_t sector; - int sectors; - unsigned long state; - mddev_t *mddev; - /* - * original bio going to /dev/mdx - */ - struct bio *master_bio; - /* - * if the IO is in READ direction, then this is where we read - */ - int read_disk; - - struct list_head retry_list; - struct bitmap_update *bitmap_update; - /* - * if the IO is in WRITE direction, then multiple bios are used. - * We choose the number when they are allocated. - */ - struct bio *bios[0]; - /* DO NOT PUT ANY NEW FIELDS HERE - bios array is contiguously alloced*/ -}; - -/* when we get a read error on a read-only array, we redirect to another - * device without failing the first device, or trying to over-write to - * correct the read error. To keep track of bad blocks on a per-bio - * level, we store IO_BLOCKED in the appropriate 'bios' pointer - */ -#define IO_BLOCKED ((struct bio*)1) - -/* bits for r1bio.state */ -#define R1BIO_Uptodate 0 -#define R1BIO_IsSync 1 -#define R1BIO_Degraded 2 -#define R1BIO_BehindIO 3 -#define R1BIO_Barrier 4 -#define R1BIO_BarrierRetry 5 -/* For write-behind requests, we call bi_end_io when - * the last non-write-behind device completes, providing - * any write was successful. Otherwise we call when - * any write-behind write succeeds, otherwise we call - * with failure when last write completes (and all failed). - * Record that bi_end_io was called with this flag... - */ -#define R1BIO_Returned 6 - -#endif diff --git a/include/linux/raid/raid10.h b/include/linux/raid/raid10.h deleted file mode 100644 index e9091cfeb286..000000000000 --- a/include/linux/raid/raid10.h +++ /dev/null @@ -1,123 +0,0 @@ -#ifndef _RAID10_H -#define _RAID10_H - -#include <linux/raid/md.h> - -typedef struct mirror_info mirror_info_t; - -struct mirror_info { - mdk_rdev_t *rdev; - sector_t head_position; -}; - -typedef struct r10bio_s r10bio_t; - -struct r10_private_data_s { - mddev_t *mddev; - mirror_info_t *mirrors; - int raid_disks; - spinlock_t device_lock; - - /* geometry */ - int near_copies; /* number of copies layed out raid0 style */ - int far_copies; /* number of copies layed out - * at large strides across drives - */ - int far_offset; /* far_copies are offset by 1 stripe - * instead of many - */ - int copies; /* near_copies * far_copies. - * must be <= raid_disks - */ - sector_t stride; /* distance between far copies. - * This is size / far_copies unless - * far_offset, in which case it is - * 1 stripe. - */ - - int chunk_shift; /* shift from chunks to sectors */ - sector_t chunk_mask; - - struct list_head retry_list; - /* queue pending writes and submit them on unplug */ - struct bio_list pending_bio_list; - - - spinlock_t resync_lock; - int nr_pending; - int nr_waiting; - int nr_queued; - int barrier; - sector_t next_resync; - int fullsync; /* set to 1 if a full sync is needed, - * (fresh device added). - * Cleared when a sync completes. - */ - - wait_queue_head_t wait_barrier; - - mempool_t *r10bio_pool; - mempool_t *r10buf_pool; - struct page *tmppage; -}; - -typedef struct r10_private_data_s conf_t; - -/* - * this is the only point in the RAID code where we violate - * C type safety. mddev->private is an 'opaque' pointer. - */ -#define mddev_to_conf(mddev) ((conf_t *) mddev->private) - -/* - * this is our 'private' RAID10 bio. - * - * it contains information about what kind of IO operations were started - * for this RAID10 operation, and about their status: - */ - -struct r10bio_s { - atomic_t remaining; /* 'have we finished' count, - * used from IRQ handlers - */ - sector_t sector; /* virtual sector number */ - int sectors; - unsigned long state; - mddev_t *mddev; - /* - * original bio going to /dev/mdx - */ - struct bio *master_bio; - /* - * if the IO is in READ direction, then this is where we read - */ - int read_slot; - - struct list_head retry_list; - /* - * if the IO is in WRITE direction, then multiple bios are used, - * one for each copy. - * When resyncing we also use one for each copy. - * When reconstructing, we use 2 bios, one for read, one for write. - * We choose the number when they are allocated. - */ - struct { - struct bio *bio; - sector_t addr; - int devnum; - } devs[0]; -}; - -/* when we get a read error on a read-only array, we redirect to another - * device without failing the first device, or trying to over-write to - * correct the read error. To keep track of bad blocks on a per-bio - * level, we store IO_BLOCKED in the appropriate 'bios' pointer - */ -#define IO_BLOCKED ((struct bio*)1) - -/* bits for r10bio.state */ -#define R10BIO_Uptodate 0 -#define R10BIO_IsSync 1 -#define R10BIO_IsRecover 2 -#define R10BIO_Degraded 3 -#endif diff --git a/include/linux/raid/raid5.h b/include/linux/raid/raid5.h deleted file mode 100644 index 3b2672792457..000000000000 --- a/include/linux/raid/raid5.h +++ /dev/null @@ -1,402 +0,0 @@ -#ifndef _RAID5_H -#define _RAID5_H - -#include <linux/raid/md.h> -#include <linux/raid/xor.h> - -/* - * - * Each stripe contains one buffer per disc. Each buffer can be in - * one of a number of states stored in "flags". Changes between - * these states happen *almost* exclusively under a per-stripe - * spinlock. Some very specific changes can happen in bi_end_io, and - * these are not protected by the spin lock. - * - * The flag bits that are used to represent these states are: - * R5_UPTODATE and R5_LOCKED - * - * State Empty == !UPTODATE, !LOCK - * We have no data, and there is no active request - * State Want == !UPTODATE, LOCK - * A read request is being submitted for this block - * State Dirty == UPTODATE, LOCK - * Some new data is in this buffer, and it is being written out - * State Clean == UPTODATE, !LOCK - * We have valid data which is the same as on disc - * - * The possible state transitions are: - * - * Empty -> Want - on read or write to get old data for parity calc - * Empty -> Dirty - on compute_parity to satisfy write/sync request.(RECONSTRUCT_WRITE) - * Empty -> Clean - on compute_block when computing a block for failed drive - * Want -> Empty - on failed read - * Want -> Clean - on successful completion of read request - * Dirty -> Clean - on successful completion of write request - * Dirty -> Clean - on failed write - * Clean -> Dirty - on compute_parity to satisfy write/sync (RECONSTRUCT or RMW) - * - * The Want->Empty, Want->Clean, Dirty->Clean, transitions - * all happen in b_end_io at interrupt time. - * Each sets the Uptodate bit before releasing the Lock bit. - * This leaves one multi-stage transition: - * Want->Dirty->Clean - * This is safe because thinking that a Clean buffer is actually dirty - * will at worst delay some action, and the stripe will be scheduled - * for attention after the transition is complete. - * - * There is one possibility that is not covered by these states. That - * is if one drive has failed and there is a spare being rebuilt. We - * can't distinguish between a clean block that has been generated - * from parity calculations, and a clean block that has been - * successfully written to the spare ( or to parity when resyncing). - * To distingush these states we have a stripe bit STRIPE_INSYNC that - * is set whenever a write is scheduled to the spare, or to the parity - * disc if there is no spare. A sync request clears this bit, and - * when we find it set with no buffers locked, we know the sync is - * complete. - * - * Buffers for the md device that arrive via make_request are attached - * to the appropriate stripe in one of two lists linked on b_reqnext. - * One list (bh_read) for read requests, one (bh_write) for write. - * There should never be more than one buffer on the two lists - * together, but we are not guaranteed of that so we allow for more. - * - * If a buffer is on the read list when the associated cache buffer is - * Uptodate, the data is copied into the read buffer and it's b_end_io - * routine is called. This may happen in the end_request routine only - * if the buffer has just successfully been read. end_request should - * remove the buffers from the list and then set the Uptodate bit on - * the buffer. Other threads may do this only if they first check - * that the Uptodate bit is set. Once they have checked that they may - * take buffers off the read queue. - * - * When a buffer on the write list is committed for write it is copied - * into the cache buffer, which is then marked dirty, and moved onto a - * third list, the written list (bh_written). Once both the parity - * block and the cached buffer are successfully written, any buffer on - * a written list can be returned with b_end_io. - * - * The write list and read list both act as fifos. The read list is - * protected by the device_lock. The write and written lists are - * protected by the stripe lock. The device_lock, which can be - * claimed while the stipe lock is held, is only for list - * manipulations and will only be held for a very short time. It can - * be claimed from interrupts. - * - * - * Stripes in the stripe cache can be on one of two lists (or on - * neither). The "inactive_list" contains stripes which are not - * currently being used for any request. They can freely be reused - * for another stripe. The "handle_list" contains stripes that need - * to be handled in some way. Both of these are fifo queues. Each - * stripe is also (potentially) linked to a hash bucket in the hash - * table so that it can be found by sector number. Stripes that are - * not hashed must be on the inactive_list, and will normally be at - * the front. All stripes start life this way. - * - * The inactive_list, handle_list and hash bucket lists are all protected by the - * device_lock. - * - stripes on the inactive_list never have their stripe_lock held. - * - stripes have a reference counter. If count==0, they are on a list. - * - If a stripe might need handling, STRIPE_HANDLE is set. - * - When refcount reaches zero, then if STRIPE_HANDLE it is put on - * handle_list else inactive_list - * - * This, combined with the fact that STRIPE_HANDLE is only ever - * cleared while a stripe has a non-zero count means that if the - * refcount is 0 and STRIPE_HANDLE is set, then it is on the - * handle_list and if recount is 0 and STRIPE_HANDLE is not set, then - * the stripe is on inactive_list. - * - * The possible transitions are: - * activate an unhashed/inactive stripe (get_active_stripe()) - * lockdev check-hash unlink-stripe cnt++ clean-stripe hash-stripe unlockdev - * activate a hashed, possibly active stripe (get_active_stripe()) - * lockdev check-hash if(!cnt++)unlink-stripe unlockdev - * attach a request to an active stripe (add_stripe_bh()) - * lockdev attach-buffer unlockdev - * handle a stripe (handle_stripe()) - * lockstripe clrSTRIPE_HANDLE ... - * (lockdev check-buffers unlockdev) .. - * change-state .. - * record io/ops needed unlockstripe schedule io/ops - * release an active stripe (release_stripe()) - * lockdev if (!--cnt) { if STRIPE_HANDLE, add to handle_list else add to inactive-list } unlockdev - * - * The refcount counts each thread that have activated the stripe, - * plus raid5d if it is handling it, plus one for each active request - * on a cached buffer, and plus one if the stripe is undergoing stripe - * operations. - * - * Stripe operations are performed outside the stripe lock, - * the stripe operations are: - * -copying data between the stripe cache and user application buffers - * -computing blocks to save a disk access, or to recover a missing block - * -updating the parity on a write operation (reconstruct write and - * read-modify-write) - * -checking parity correctness - * -running i/o to disk - * These operations are carried out by raid5_run_ops which uses the async_tx - * api to (optionally) offload operations to dedicated hardware engines. - * When requesting an operation handle_stripe sets the pending bit for the - * operation and increments the count. raid5_run_ops is then run whenever - * the count is non-zero. - * There are some critical dependencies between the operations that prevent some - * from being requested while another is in flight. - * 1/ Parity check operations destroy the in cache version of the parity block, - * so we prevent parity dependent operations like writes and compute_blocks - * from starting while a check is in progress. Some dma engines can perform - * the check without damaging the parity block, in these cases the parity - * block is re-marked up to date (assuming the check was successful) and is - * not re-read from disk. - * 2/ When a write operation is requested we immediately lock the affected - * blocks, and mark them as not up to date. This causes new read requests - * to be held off, as well as parity checks and compute block operations. - * 3/ Once a compute block operation has been requested handle_stripe treats - * that block as if it is up to date. raid5_run_ops guaruntees that any - * operation that is dependent on the compute block result is initiated after - * the compute block completes. - */ - -/* - * Operations state - intermediate states that are visible outside of sh->lock - * In general _idle indicates nothing is running, _run indicates a data - * processing operation is active, and _result means the data processing result - * is stable and can be acted upon. For simple operations like biofill and - * compute that only have an _idle and _run state they are indicated with - * sh->state flags (STRIPE_BIOFILL_RUN and STRIPE_COMPUTE_RUN) - */ -/** - * enum check_states - handles syncing / repairing a stripe - * @check_state_idle - check operations are quiesced - * @check_state_run - check operation is running - * @check_state_result - set outside lock when check result is valid - * @check_state_compute_run - check failed and we are repairing - * @check_state_compute_result - set outside lock when compute result is valid - */ -enum check_states { - check_state_idle = 0, - check_state_run, /* parity check */ - check_state_check_result, - check_state_compute_run, /* parity repair */ - check_state_compute_result, -}; - -/** - * enum reconstruct_states - handles writing or expanding a stripe - */ -enum reconstruct_states { - reconstruct_state_idle = 0, - reconstruct_state_prexor_drain_run, /* prexor-write */ - reconstruct_state_drain_run, /* write */ - reconstruct_state_run, /* expand */ - reconstruct_state_prexor_drain_result, - reconstruct_state_drain_result, - reconstruct_state_result, -}; - -struct stripe_head { - struct hlist_node hash; - struct list_head lru; /* inactive_list or handle_list */ - struct raid5_private_data *raid_conf; - sector_t sector; /* sector of this row */ - int pd_idx; /* parity disk index */ - unsigned long state; /* state flags */ - atomic_t count; /* nr of active thread/requests */ - spinlock_t lock; - int bm_seq; /* sequence number for bitmap flushes */ - int disks; /* disks in stripe */ - enum check_states check_state; - enum reconstruct_states reconstruct_state; - /* stripe_operations - * @target - STRIPE_OP_COMPUTE_BLK target - */ - struct stripe_operations { - int target; - u32 zero_sum_result; - } ops; - struct r5dev { - struct bio req; - struct bio_vec vec; - struct page *page; - struct bio *toread, *read, *towrite, *written; - sector_t sector; /* sector of this page */ - unsigned long flags; - } dev[1]; /* allocated with extra space depending of RAID geometry */ -}; - -/* stripe_head_state - collects and tracks the dynamic state of a stripe_head - * for handle_stripe. It is only valid under spin_lock(sh->lock); - */ -struct stripe_head_state { - int syncing, expanding, expanded; - int locked, uptodate, to_read, to_write, failed, written; - int to_fill, compute, req_compute, non_overwrite; - int failed_num; - unsigned long ops_request; -}; - -/* r6_state - extra state data only relevant to r6 */ -struct r6_state { - int p_failed, q_failed, qd_idx, failed_num[2]; -}; - -/* Flags */ -#define R5_UPTODATE 0 /* page contains current data */ -#define R5_LOCKED 1 /* IO has been submitted on "req" */ -#define R5_OVERWRITE 2 /* towrite covers whole page */ -/* and some that are internal to handle_stripe */ -#define R5_Insync 3 /* rdev && rdev->in_sync at start */ -#define R5_Wantread 4 /* want to schedule a read */ -#define R5_Wantwrite 5 -#define R5_Overlap 7 /* There is a pending overlapping request on this block */ -#define R5_ReadError 8 /* seen a read error here recently */ -#define R5_ReWrite 9 /* have tried to over-write the readerror */ - -#define R5_Expanded 10 /* This block now has post-expand data */ -#define R5_Wantcompute 11 /* compute_block in progress treat as - * uptodate - */ -#define R5_Wantfill 12 /* dev->toread contains a bio that needs - * filling - */ -#define R5_Wantdrain 13 /* dev->towrite needs to be drained */ -/* - * Write method - */ -#define RECONSTRUCT_WRITE 1 -#define READ_MODIFY_WRITE 2 -/* not a write method, but a compute_parity mode */ -#define CHECK_PARITY 3 - -/* - * Stripe state - */ -#define STRIPE_HANDLE 2 -#define STRIPE_SYNCING 3 -#define STRIPE_INSYNC 4 -#define STRIPE_PREREAD_ACTIVE 5 -#define STRIPE_DELAYED 6 -#define STRIPE_DEGRADED 7 -#define STRIPE_BIT_DELAY 8 -#define STRIPE_EXPANDING 9 -#define STRIPE_EXPAND_SOURCE 10 -#define STRIPE_EXPAND_READY 11 -#define STRIPE_IO_STARTED 12 /* do not count towards 'bypass_count' */ -#define STRIPE_FULL_WRITE 13 /* all blocks are set to be overwritten */ -#define STRIPE_BIOFILL_RUN 14 -#define STRIPE_COMPUTE_RUN 15 -/* - * Operation request flags - */ -#define STRIPE_OP_BIOFILL 0 -#define STRIPE_OP_COMPUTE_BLK 1 -#define STRIPE_OP_PREXOR 2 -#define STRIPE_OP_BIODRAIN 3 -#define STRIPE_OP_POSTXOR 4 -#define STRIPE_OP_CHECK 5 - -/* - * Plugging: - * - * To improve write throughput, we need to delay the handling of some - * stripes until there has been a chance that several write requests - * for the one stripe have all been collected. - * In particular, any write request that would require pre-reading - * is put on a "delayed" queue until there are no stripes currently - * in a pre-read phase. Further, if the "delayed" queue is empty when - * a stripe is put on it then we "plug" the queue and do not process it - * until an unplug call is made. (the unplug_io_fn() is called). - * - * When preread is initiated on a stripe, we set PREREAD_ACTIVE and add - * it to the count of prereading stripes. - * When write is initiated, or the stripe refcnt == 0 (just in case) we - * clear the PREREAD_ACTIVE flag and decrement the count - * Whenever the 'handle' queue is empty and the device is not plugged, we - * move any strips from delayed to handle and clear the DELAYED flag and set - * PREREAD_ACTIVE. - * In stripe_handle, if we find pre-reading is necessary, we do it if - * PREREAD_ACTIVE is set, else we set DELAYED which will send it to the delayed queue. - * HANDLE gets cleared if stripe_handle leave nothing locked. - */ - - -struct disk_info { - mdk_rdev_t *rdev; -}; - -struct raid5_private_data { - struct hlist_head *stripe_hashtbl; - mddev_t *mddev; - struct disk_info *spare; - int chunk_size, level, algorithm; - int max_degraded; - int raid_disks; - int max_nr_stripes; - - /* used during an expand */ - sector_t expand_progress; /* MaxSector when no expand happening */ - sector_t expand_lo; /* from here up to expand_progress it out-of-bounds - * as we haven't flushed the metadata yet - */ - int previous_raid_disks; - - struct list_head handle_list; /* stripes needing handling */ - struct list_head hold_list; /* preread ready stripes */ - struct list_head delayed_list; /* stripes that have plugged requests */ - struct list_head bitmap_list; /* stripes delaying awaiting bitmap update */ - struct bio *retry_read_aligned; /* currently retrying aligned bios */ - struct bio *retry_read_aligned_list; /* aligned bios retry list */ - atomic_t preread_active_stripes; /* stripes with scheduled io */ - atomic_t active_aligned_reads; - atomic_t pending_full_writes; /* full write backlog */ - int bypass_count; /* bypassed prereads */ - int bypass_threshold; /* preread nice */ - struct list_head *last_hold; /* detect hold_list promotions */ - - atomic_t reshape_stripes; /* stripes with pending writes for reshape */ - /* unfortunately we need two cache names as we temporarily have - * two caches. - */ - int active_name; - char cache_name[2][20]; - struct kmem_cache *slab_cache; /* for allocating stripes */ - - int seq_flush, seq_write; - int quiesce; - - int fullsync; /* set to 1 if a full sync is needed, - * (fresh device added). - * Cleared when a sync completes. - */ - - struct page *spare_page; /* Used when checking P/Q in raid6 */ - - /* - * Free stripes pool - */ - atomic_t active_stripes; - struct list_head inactive_list; - wait_queue_head_t wait_for_stripe; - wait_queue_head_t wait_for_overlap; - int inactive_blocked; /* release of inactive stripes blocked, - * waiting for 25% to be free - */ - int pool_size; /* number of disks in stripeheads in pool */ - spinlock_t device_lock; - struct disk_info *disks; -}; - -typedef struct raid5_private_data raid5_conf_t; - -#define mddev_to_conf(mddev) ((raid5_conf_t *) mddev->private) - -/* - * Our supported algorithms - */ -#define ALGORITHM_LEFT_ASYMMETRIC 0 -#define ALGORITHM_RIGHT_ASYMMETRIC 1 -#define ALGORITHM_LEFT_SYMMETRIC 2 -#define ALGORITHM_RIGHT_SYMMETRIC 3 - -#endif |