drivers/md/raid10.h

   1 #ifndef _RAID10_H
   2 #define _RAID10_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 typedef struct r10bio_s r10bio_t;
  12
  13 struct r10_private_data_s {
  14         mddev_t                 *mddev;
  15         mirror_info_t           *mirrors;
  16         int                     raid_disks;
  17         spinlock_t              device_lock;
  18
  19         /* geometry */
  20         int                     near_copies;  /* number of copies layed out raid0 style */
  21         int                     far_copies;   /* number of copies layed out
  22                                                * at large strides across drives
  23                                                */
  24         int                     far_offset;   /* far_copies are offset by 1 stripe
  25                                                * instead of many
  26                                                */
  27         int                     copies;       /* near_copies * far_copies.
  28                                                * must be <= raid_disks
  29                                                */
  30         sector_t                stride;       /* distance between far copies.
  31                                                * This is size / far_copies unless
  32                                                * far_offset, in which case it is
  33                                                * 1 stripe.
  34                                                */
  35
  36         int chunk_shift; /* shift from chunks to sectors */
  37         sector_t chunk_mask;
  38
  39         struct list_head        retry_list;
  40         /* queue pending writes and submit them on unplug */
  41         struct bio_list         pending_bio_list;
  42
  43
  44         spinlock_t              resync_lock;
  45         int nr_pending;
  46         int nr_waiting;
  47         int nr_queued;
  48         int barrier;
  49         sector_t                next_resync;
  50         int                     fullsync;  /* set to 1 if a full sync is needed,
  51                                             * (fresh device added).
  52                                             * Cleared when a sync completes.
  53                                             */
  54
  55         wait_queue_head_t       wait_barrier;
  56
  57         mempool_t *r10bio_pool;
  58         mempool_t *r10buf_pool;
  59         struct page             *tmppage;
  60 };
  61
  62 typedef struct r10_private_data_s conf_t;
  63
  64 /*
  65  * this is the only point in the RAID code where we violate
  66  * C type safety. mddev->private is an 'opaque' pointer.
  67  */
  68 #define mddev_to_conf(mddev) ((conf_t *) mddev->private)
  69
  70 /*
  71  * this is our 'private' RAID10 bio.
  72  *
  73  * it contains information about what kind of IO operations were started
  74  * for this RAID10 operation, and about their status:
  75  */
  76
  77 struct r10bio_s {
  78         atomic_t                remaining; /* 'have we finished' count,
  79                                             * used from IRQ handlers
  80                                             */
  81         sector_t                sector; /* virtual sector number */
  82         int                     sectors;
  83         unsigned long           state;
  84         mddev_t                 *mddev;
  85         /*
  86          * original bio going to /dev/mdx
  87          */
  88         struct bio              *master_bio;
  89         /*
  90          * if the IO is in READ direction, then this is where we read
  91          */
  92         int                     read_slot;
  93
  94         struct list_head        retry_list;
  95         /*
  96          * if the IO is in WRITE direction, then multiple bios are used,
  97          * one for each copy.
  98          * When resyncing we also use one for each copy.
  99          * When reconstructing, we use 2 bios, one for read, one for write.
 100          * We choose the number when they are allocated.
 101          */
 102         struct {
 103                 struct bio              *bio;
 104                 sector_t addr;
 105                 int devnum;
 106         } devs[0];
 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 r10bio.state */
 117 #define R10BIO_Uptodate 0
 118 #define R10BIO_IsSync   1
 119 #define R10BIO_IsRecover 2
 120 #define R10BIO_Degraded 3
 121 #endif