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         sector_t                dev_sectors;  /* temp copy of mddev->dev_sectors */
  37
  38         int chunk_shift; /* shift from chunks to sectors */
  39         sector_t chunk_mask;
  40
  41         int                     scale_disks;  /* When starting array, multiply
  42                                                * each ->raid_disk by this.
  43                                                * Need for raid0->raid10 migration
  44                                                */
  45
  46         struct list_head        retry_list;
  47         /* queue pending writes and submit them on unplug */
  48         struct bio_list         pending_bio_list;
  49
  50
  51         spinlock_t              resync_lock;
  52         int nr_pending;
  53         int nr_waiting;
  54         int nr_queued;
  55         int barrier;
  56         sector_t                next_resync;
  57         int                     fullsync;  /* set to 1 if a full sync is needed,
  58                                             * (fresh device added).
  59                                             * Cleared when a sync completes.
  60                                             */
  61
  62         wait_queue_head_t       wait_barrier;
  63
  64         mempool_t *r10bio_pool;
  65         mempool_t *r10buf_pool;
  66         struct page             *tmppage;
  67
  68         /* When taking over an array from a different personality, we store
  69          * the new thread here until we fully activate the array.
  70          */
  71         struct mdk_thread_s     *thread;
  72 };
  73
  74 typedef struct r10_private_data_s conf_t;
  75
  76 /*
  77  * this is our 'private' RAID10 bio.
  78  *
  79  * it contains information about what kind of IO operations were started
  80  * for this RAID10 operation, and about their status:
  81  */
  82
  83 struct r10bio_s {
  84         atomic_t                remaining; /* 'have we finished' count,
  85                                             * used from IRQ handlers
  86                                             */
  87         sector_t                sector; /* virtual sector number */
  88         int                     sectors;
  89         unsigned long           state;
  90         mddev_t                 *mddev;
  91         /*
  92          * original bio going to /dev/mdx
  93          */
  94         struct bio              *master_bio;
  95         /*
  96          * if the IO is in READ direction, then this is where we read
  97          */
  98         int                     read_slot;
  99
 100         struct list_head        retry_list;
 101         /*
 102          * if the IO is in WRITE direction, then multiple bios are used,
 103          * one for each copy.
 104          * When resyncing we also use one for each copy.
 105          * When reconstructing, we use 2 bios, one for read, one for write.
 106          * We choose the number when they are allocated.
 107          */
 108         struct {
 109                 struct bio              *bio;
 110                 sector_t addr;
 111                 int devnum;
 112         } devs[0];
 113 };
 114
 115 /* when we get a read error on a read-only array, we redirect to another
 116  * device without failing the first device, or trying to over-write to
 117  * correct the read error.  To keep track of bad blocks on a per-bio
 118  * level, we store IO_BLOCKED in the appropriate 'bios' pointer
 119  */
 120 #define IO_BLOCKED ((struct bio*)1)
 121
 122 /* bits for r10bio.state */
 123 #define R10BIO_Uptodate 0
 124 #define R10BIO_IsSync   1
 125 #define R10BIO_IsRecover 2
 126 #define R10BIO_Degraded 3
 127 #endif