LXR linux/drivers/md/raid1.h

   1#ifndef _RAID1_H
   2#define _RAID1_H
   3
   4typedef struct mirror_info mirror_info_t;
   5
   6struct mirror_info {
   7        mdk_rdev_t      *rdev;
   8        sector_t        head_position;
   9};
  10
  11/*
  12 * memory pools need a pointer to the mddev, so they can force an unplug
  13 * when memory is tight, and a count of the number of drives that the
  14 * pool was allocated for, so they know how much to allocate and free.
  15 * mddev->raid_disks cannot be used, as it can change while a pool is active
  16 * These two datums are stored in a kmalloced struct.
  17 */
  18
  19struct pool_info {
  20        mddev_t *mddev;
  21        int     raid_disks;
  22};
  23
  24
  25typedef struct r1bio_s r1bio_t;
  26
  27struct r1_private_data_s {
  28        mddev_t                 *mddev;
  29        mirror_info_t           *mirrors;
  30        int                     raid_disks;
  31        int                     last_used;
  32        sector_t                next_seq_sect;
  33        spinlock_t              device_lock;
  34
  35        struct list_head        retry_list;
  36        /* queue pending writes and submit them on unplug */
  37        struct bio_list         pending_bio_list;
  38
  39        /* for use when syncing mirrors: */
  40
  41        spinlock_t              resync_lock;
  42        int                     nr_pending;
  43        int                     nr_waiting;
  44        int                     nr_queued;
  45        int                     barrier;
  46        sector_t                next_resync;
  47        int                     fullsync;  /* set to 1 if a full sync is needed,
  48                                            * (fresh device added).
  49                                            * Cleared when a sync completes.
  50                                            */
  51
  52        wait_queue_head_t       wait_barrier;
  53
  54        struct pool_info        *poolinfo;
  55
  56        struct page             *tmppage;
  57
  58        mempool_t *r1bio_pool;
  59        mempool_t *r1buf_pool;
  60
  61        /* When taking over an array from a different personality, we store
  62         * the new thread here until we fully activate the array.
  63         */
  64        struct mdk_thread_s     *thread;
  65};
  66
  67typedef struct r1_private_data_s conf_t;
  68
  69/*
  70 * this is our 'private' RAID1 bio.
  71 *
  72 * it contains information about what kind of IO operations were started
  73 * for this RAID1 operation, and about their status:
  74 */
  75
  76struct r1bio_s {
  77        atomic_t                remaining; /* 'have we finished' count,
  78                                            * used from IRQ handlers
  79                                            */
  80        atomic_t                behind_remaining; /* number of write-behind ios remaining
  81                                                 * in this BehindIO request
  82                                                 */
  83        sector_t                sector;
  84        int                     sectors;
  85        unsigned long           state;
  86        mddev_t                 *mddev;
  87        /*
  88         * original bio going to /dev/mdx
  89         */
  90        struct bio              *master_bio;
  91        /*
  92         * if the IO is in READ direction, then this is where we read
  93         */
  94        int                     read_disk;
  95
  96        struct list_head        retry_list;
  97        struct bitmap_update    *bitmap_update;
  98        /*
  99         * if the IO is in WRITE direction, then multiple bios are used.
 100         * We choose the number when they are allocated.
 101         */
 102        struct bio              *bios[0];
 103        /* DO NOT PUT ANY NEW FIELDS HERE - bios array is contiguously alloced*/
 104};
 105
 106/* when we get a read error on a read-only array, we redirect to another
 107 * device without failing the first device, or trying to over-write to
 108 * correct the read error.  To keep track of bad blocks on a per-bio
 109 * level, we store IO_BLOCKED in the appropriate 'bios' pointer
 110 */
 111#define IO_BLOCKED ((struct bio*)1)
 112
 113/* bits for r1bio.state */
 114#define R1BIO_Uptodate  0
 115#define R1BIO_IsSync    1
 116#define R1BIO_Degraded  2
 117#define R1BIO_BehindIO  3
 118/* For write-behind requests, we call bi_end_io when
 119 * the last non-write-behind device completes, providing
 120 * any write was successful.  Otherwise we call when
 121 * any write-behind write succeeds, otherwise we call
 122 * with failure when last write completes (and all failed).
 123 * Record that bi_end_io was called with this flag...
 124 */
 125#define R1BIO_Returned 6
 126
 127#endif
 128