include/linux/raid/raid1.h

   1 #ifndef _RAID1_H
   2 #define _RAID1_H
   3
   4 #include <linux/raid/md.h>
   5
   6 typedef struct mirror_info mirror_info_t;
   7
   8 struct mirror_info {
   9         mdk_rdev_t      *rdev;
  10         sector_t        head_position;
  11 };
  12
  13 /*
  14  * memory pools need a pointer to the mddev, so they can force an unplug
  15  * when memory is tight, and a count of the number of drives that the
  16  * pool was allocated for, so they know how much to allocate and free.
  17  * mddev->raid_disks cannot be used, as it can change while a pool is active
  18  * These two datums are stored in a kmalloced struct.
  19  */
  20
  21 struct pool_info {
  22         mddev_t *mddev;
  23         int     raid_disks;
  24 };
  25
  26
  27 typedef struct r1bio_s r1bio_t;
  28
  29 struct r1_private_data_s {
  30         mddev_t                 *mddev;
  31         mirror_info_t           *mirrors;
  32         int                     raid_disks;
  33         int                     working_disks;
  34         int                     last_used;
  35         sector_t                next_seq_sect;
  36         spinlock_t              device_lock;
  37
  38         struct list_head        retry_list;
  39         /* queue pending writes and submit them on unplug */
  40         struct bio_list         pending_bio_list;
  41         /* queue of writes that have been unplugged */
  42         struct bio_list         flushing_bio_list;
  43
  44         /* for use when syncing mirrors: */
  45
  46         spinlock_t              resync_lock;
  47         int                     nr_pending;
  48         int                     nr_waiting;
  49         int                     nr_queued;
  50         int                     barrier;
  51         sector_t                next_resync;
  52         int                     fullsync;  /* set to 1 if a full sync is needed,
  53                                             * (fresh device added).
  54                                             * Cleared when a sync completes.
  55                                             */
  56
  57         wait_queue_head_t       wait_barrier;
  58
  59         struct pool_info        *poolinfo;
  60
  61         struct page             *tmppage;
  62
  63         mempool_t *r1bio_pool;
  64         mempool_t *r1buf_pool;
  65 };
  66
  67 typedef struct r1_private_data_s conf_t;
  68
  69 /*
  70  * this is the only point in the RAID code where we violate
  71  * C type safety. mddev->private is an 'opaque' pointer.
  72  */
  73 #define mddev_to_conf(mddev) ((conf_t *) mddev->private)
  74
  75 /*
  76  * this is our 'private' RAID1 bio.
  77  *
  78  * it contains information about what kind of IO operations were started
  79  * for this RAID1 operation, and about their status:
  80  */
  81
  82 struct r1bio_s {
  83         atomic_t                remaining; /* 'have we finished' count,
  84                                             * used from IRQ handlers
  85                                             */
  86         atomic_t                behind_remaining; /* number of write-behind ios remaining
  87                                                  * in this BehindIO request
  88                                                  */
  89         sector_t                sector;
  90         int                     sectors;
  91         unsigned long           state;
  92         mddev_t                 *mddev;
  93         /*
  94          * original bio going to /dev/mdx
  95          */
  96         struct bio              *master_bio;
  97         /*
  98          * if the IO is in READ direction, then this is where we read
  99          */
 100         int                     read_disk;
 101
 102         struct list_head        retry_list;
 103         struct bitmap_update    *bitmap_update;
 104         /*
 105          * if the IO is in WRITE direction, then multiple bios are used.
 106          * We choose the number when they are allocated.
 107          */
 108         struct bio              *bios[0];
 109         /* DO NOT PUT ANY NEW FIELDS HERE - bios array is contiguously alloced*/
 110 };
 111
 112 /* when we get a read error on a read-only array, we redirect to another
 113  * device without failing the first device, or trying to over-write to
 114  * correct the read error.  To keep track of bad blocks on a per-bio
 115  * level, we store IO_BLOCKED in the appropriate 'bios' pointer
 116  */
 117 #define IO_BLOCKED ((struct bio*)1)
 118
 119 /* bits for r1bio.state */
 120 #define R1BIO_Uptodate  0
 121 #define R1BIO_IsSync    1
 122 #define R1BIO_Degraded  2
 123 #define R1BIO_BehindIO  3
 124 #define R1BIO_Barrier   4
 125 #define R1BIO_BarrierRetry 5
 126 /* For write-behind requests, we call bi_end_io when
 127  * the last non-write-behind device completes, providing
 128  * any write was successful.  Otherwise we call when
 129  * any write-behind write succeeds, otherwise we call
 130  * with failure when last write completes (and all failed).
 131  * Record that bi_end_io was called with this flag...
 132  */
 133 #define R1BIO_Returned 6
 134
 135 #endif