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
  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
  67 typedef 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
  76 struct 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         /* Next two are only valid when R1BIO_BehindIO is set */
  98         struct page             **behind_pages;
  99         int                     behind_page_count;
 100         /*
 101          * if the IO is in WRITE direction, then multiple bios are used.
 102          * We choose the number when they are allocated.
 103          */
 104         struct bio              *bios[0];
 105         /* DO NOT PUT ANY NEW FIELDS HERE - bios array is contiguously alloced*/
 106 };
 107
 108 /* when we get a read error on a read-only array, we redirect to another
 109  * device without failing the first device, or trying to over-write to
 110  * correct the read error.  To keep track of bad blocks on a per-bio
 111  * level, we store IO_BLOCKED in the appropriate 'bios' pointer
 112  */
 113 #define IO_BLOCKED ((struct bio*)1)
 114
 115 /* bits for r1bio.state */
 116 #define R1BIO_Uptodate  0
 117 #define R1BIO_IsSync    1
 118 #define R1BIO_Degraded  2
 119 #define R1BIO_BehindIO  3
 120 /* For write-behind requests, we call bi_end_io when
 121  * the last non-write-behind device completes, providing
 122  * any write was successful.  Otherwise we call when
 123  * any write-behind write succeeds, otherwise we call
 124  * with failure when last write completes (and all failed).
 125  * Record that bi_end_io was called with this flag...
 126  */
 127 #define R1BIO_Returned 6
 128
 129 extern int md_raid1_congested(mddev_t *mddev, int bits);
 130
 131 #endif