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