diff options
Diffstat (limited to 'drivers/md')
| -rw-r--r-- | drivers/md/bitmap.c | 2 | ||||
| -rw-r--r-- | drivers/md/bitmap.h | 288 | ||||
| -rw-r--r-- | drivers/md/linear.c | 2 | ||||
| -rw-r--r-- | drivers/md/linear.h | 31 | ||||
| -rw-r--r-- | drivers/md/md.c | 2 | ||||
| -rw-r--r-- | drivers/md/multipath.c | 2 | ||||
| -rw-r--r-- | drivers/md/multipath.h | 42 | ||||
| -rw-r--r-- | drivers/md/raid0.c | 2 | ||||
| -rw-r--r-- | drivers/md/raid0.h | 30 | ||||
| -rw-r--r-- | drivers/md/raid1.c | 4 | ||||
| -rw-r--r-- | drivers/md/raid1.h | 134 | ||||
| -rw-r--r-- | drivers/md/raid10.c | 4 | ||||
| -rw-r--r-- | drivers/md/raid10.h | 123 | ||||
| -rw-r--r-- | drivers/md/raid5.c | 5 | ||||
| -rw-r--r-- | drivers/md/raid5.h | 402 | ||||
| -rw-r--r-- | drivers/md/raid6.h | 2 |
16 files changed, 1062 insertions, 13 deletions
diff --git a/drivers/md/bitmap.c b/drivers/md/bitmap.c index 27f978dfe6a..7666117738c 100644 --- a/drivers/md/bitmap.c +++ b/drivers/md/bitmap.c @@ -27,7 +27,7 @@ #include <linux/mount.h> #include <linux/buffer_head.h> #include <linux/raid/md.h> -#include <linux/raid/bitmap.h> +#include "bitmap.h" /* debug macros */ diff --git a/drivers/md/bitmap.h b/drivers/md/bitmap.h new file mode 100644 index 00000000000..e98900671ca --- /dev/null +++ b/drivers/md/bitmap.h @@ -0,0 +1,288 @@ +/* + * 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/drivers/md/linear.c b/drivers/md/linear.c index 09658b21847..3603ffa9edc 100644 --- a/drivers/md/linear.c +++ b/drivers/md/linear.c @@ -16,7 +16,7 @@ Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */ -#include <linux/raid/linear.h> +#include "linear.h" /* * find which device holds a particular offset diff --git a/drivers/md/linear.h b/drivers/md/linear.h new file mode 100644 index 00000000000..f38b9c586af --- /dev/null +++ b/drivers/md/linear.h @@ -0,0 +1,31 @@ +#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/drivers/md/md.c b/drivers/md/md.c index 3efc0bceada..9a3214c8585 100644 --- a/drivers/md/md.c +++ b/drivers/md/md.c @@ -34,7 +34,6 @@ #include <linux/kthread.h> #include <linux/raid/md.h> -#include <linux/raid/bitmap.h> #include <linux/sysctl.h> #include <linux/buffer_head.h> /* for invalidate_bdev */ #include <linux/poll.h> @@ -45,6 +44,7 @@ #include <linux/reboot.h> #include <linux/file.h> #include <linux/delay.h> +#include "bitmap.h" /* 63 partitions with the alternate major number (mdp) */ #define MdpMinorShift 6 diff --git a/drivers/md/multipath.c b/drivers/md/multipath.c index f6d08f24167..547df09a7af 100644 --- a/drivers/md/multipath.c +++ b/drivers/md/multipath.c @@ -19,7 +19,7 @@ * Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */ -#include <linux/raid/multipath.h> +#include "multipath.h" #define MAX_WORK_PER_DISK 128 diff --git a/drivers/md/multipath.h b/drivers/md/multipath.h new file mode 100644 index 00000000000..6f53fc177a4 --- /dev/null +++ b/drivers/md/multipath.h @@ -0,0 +1,42 @@ +#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/drivers/md/raid0.c b/drivers/md/raid0.c index c605ba80558..ef09ed04864 100644 --- a/drivers/md/raid0.c +++ b/drivers/md/raid0.c @@ -18,7 +18,7 @@ Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */ -#include <linux/raid/raid0.h> +#include "raid0.h" static void raid0_unplug(struct request_queue *q) { diff --git a/drivers/md/raid0.h b/drivers/md/raid0.h new file mode 100644 index 00000000000..fd42aa87c39 --- /dev/null +++ b/drivers/md/raid0.h @@ -0,0 +1,30 @@ +#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/drivers/md/raid1.c b/drivers/md/raid1.c index e2466425d9c..bff32285f8b 100644 --- a/drivers/md/raid1.c +++ b/drivers/md/raid1.c @@ -33,8 +33,8 @@ #include "dm-bio-list.h" #include <linux/delay.h> -#include <linux/raid/raid1.h> -#include <linux/raid/bitmap.h> +#include "raid1.h" +#include "bitmap.h" #define DEBUG 0 #if DEBUG diff --git a/drivers/md/raid1.h b/drivers/md/raid1.h new file mode 100644 index 00000000000..0a9ba7c3302 --- /dev/null +++ b/drivers/md/raid1.h @@ -0,0 +1,134 @@ +#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/drivers/md/raid10.c b/drivers/md/raid10.c index 7301631abe0..f03dd70d12a 100644 --- a/drivers/md/raid10.c +++ b/drivers/md/raid10.c @@ -20,8 +20,8 @@ #include "dm-bio-list.h" #include <linux/delay.h> -#include <linux/raid/raid10.h> -#include <linux/raid/bitmap.h> +#include "raid10.h" +#include "bitmap.h" /* * RAID10 provides a combination of RAID0 and RAID1 functionality. diff --git a/drivers/md/raid10.h b/drivers/md/raid10.h new file mode 100644 index 00000000000..e9091cfeb28 --- /dev/null +++ b/drivers/md/raid10.h @@ -0,0 +1,123 @@ +#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/drivers/md/raid5.c b/drivers/md/raid5.c index a5ba080d303..f75698b1f63 100644 --- a/drivers/md/raid5.c +++ b/drivers/md/raid5.c @@ -44,10 +44,9 @@ */ #include <linux/kthread.h> -#include "raid6.h" - -#include <linux/raid/bitmap.h> #include <linux/async_tx.h> +#include "raid6.h" +#include "bitmap.h" /* * Stripe cache diff --git a/drivers/md/raid5.h b/drivers/md/raid5.h new file mode 100644 index 00000000000..40f1d0335c7 --- /dev/null +++ b/drivers/md/raid5.h @@ -0,0 +1,402 @@ +#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 diff --git a/drivers/md/raid6.h b/drivers/md/raid6.h index 98dcde88470..f6c13af6500 100644 --- a/drivers/md/raid6.h +++ b/drivers/md/raid6.h @@ -19,7 +19,7 @@ #define RAID6_USE_EMPTY_ZERO_PAGE 0 #include <linux/raid/md.h> -#include <linux/raid/raid5.h> +#include "raid5.h" typedef raid5_conf_t raid6_conf_t; /* Same configuration */ |