drivers/md/raid1.h

   1 #ifndef _RAID1_H
   2 #define _RAID1_H
   3
   4 typedef struct mirror_info mirror_info_t;
   5
   6 struct 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
  19 struct pool_info {
  20         mddev_t *mddev;
  21         int     raid_disks;
  22 };
  23
  24
  25 typedef struct r1bio_s r1bio_t;
  26
  27 struct 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         /* queue of writes that have been unplugged */
  39         struct bio_list         flushing_bio_list;
  40
  41         /* for use when syncing mirrors: */
  42
  43         spinlock_t              resync_lock;
  44         int                     nr_pending;
  45         int                     nr_waiting;
  46         int                     nr_queued;
  47         int                     barrier;
  48         sector_t                next_resync;
  49         int                     fullsync;  /* set to 1 if a full sync is needed,
  50                                             * (fresh device added).
  51                                             * Cleared when a sync completes.
  52                                             */
  53
  54         wait_queue_head_t       wait_barrier;
  55
  56         struct pool_info        *poolinfo;
  57
  58         struct page             *tmppage;
  59
  60         mempool_t *r1bio_pool;
  61         mempool_t *r1buf_pool;
  62 };
  63
  64 typedef struct r1_private_data_s conf_t;
  65
  66 /*
  67  * this is the only point in the RAID code where we violate
  68  * C type safety. mddev->private is an 'opaque' pointer.
  69  */
  70 #define mddev_to_conf(mddev) ((conf_t *) mddev->private)
  71
  72 /*
  73  * this is our 'private' RAID1 bio.
  74  *
  75  * it contains information about what kind of IO operations were started
  76  * for this RAID1 operation, and about their status:
  77  */
  78
  79 struct r1bio_s {
  80         atomic_t                remaining; /* 'have we finished' count,
  81                                             * used from IRQ handlers
  82                                             */
  83         atomic_t                behind_remaining; /* number of write-behind ios remaining
  84                                                  * in this BehindIO request
  85                                                  */
  86         sector_t                sector;
  87         int                     sectors;
  88         unsigned long           state;
  89         mddev_t                 *mddev;
  90         /*
  91          * original bio going to /dev/mdx
  92          */
  93         struct bio              *master_bio;
  94         /*
  95          * if the IO is in READ direction, then this is where we read
  96          */
  97         int                     read_disk;
  98
  99         struct list_head        retry_list;
 100         struct bitmap_update    *bitmap_update;
 101         /*
 102          * if the IO is in WRITE direction, then multiple bios are used.
 103          * We choose the number when they are allocated.
 104          */
 105         struct bio              *bios[0];
 106         /* DO NOT PUT ANY NEW FIELDS HERE - bios array is contiguously alloced*/
 107 };
 108
 109 /* when we get a read error on a read-only array, we redirect to another
 110  * device without failing the first device, or trying to over-write to
 111  * correct the read error.  To keep track of bad blocks on a per-bio
 112  * level, we store IO_BLOCKED in the appropriate 'bios' pointer
 113  */
 114 #define IO_BLOCKED ((struct bio*)1)
 115
 116 /* bits for r1bio.state */
 117 #define R1BIO_Uptodate  0
 118 #define R1BIO_IsSync    1
 119 #define R1BIO_Degraded  2
 120 #define R1BIO_BehindIO  3
 121 #define R1BIO_Barrier   4
 122 #define R1BIO_BarrierRetry 5
 123 /* For write-behind requests, we call bi_end_io when
 124  * the last non-write-behind device completes, providing
 125  * any write was successful.  Otherwise we call when
 126  * any write-behind write succeeds, otherwise we call
 127  * with failure when last write completes (and all failed).
 128  * Record that bi_end_io was called with this flag...
 129  */
 130 #define R1BIO_Returned 6
 131
 132 #endif