drivers/md/raid10.h

   1 #ifndef _RAID10_H
   2 #define _RAID10_H
   3
   4 struct mirror_info {
   5         struct md_rdev  *rdev;
   6         sector_t        head_position;
   7         int             recovery_disabled;      /* matches
   8                                                  * mddev->recovery_disabled
   9                                                  * when we shouldn't try
  10                                                  * recovering this device.
  11                                                  */
  12 };
  13
  14 struct r10conf {
  15         struct mddev            *mddev;
  16         struct mirror_info      *mirrors;
  17         int                     raid_disks;
  18         spinlock_t              device_lock;
  19
  20         /* geometry */
  21         int                     near_copies;  /* number of copies laid out raid0 style */
  22         int                     far_copies;   /* number of copies laid out
  23                                                * at large strides across drives
  24                                                */
  25         int                     far_offset;   /* far_copies are offset by 1 stripe
  26                                                * instead of many
  27                                                */
  28         int                     copies;       /* near_copies * far_copies.
  29                                                * must be <= raid_disks
  30                                                */
  31         sector_t                stride;       /* distance between far copies.
  32                                                * This is size / far_copies unless
  33                                                * far_offset, in which case it is
  34                                                * 1 stripe.
  35                                                */
  36
  37         sector_t                dev_sectors;  /* temp copy of mddev->dev_sectors */
  38
  39         int chunk_shift; /* shift from chunks to sectors */
  40         sector_t chunk_mask;
  41
  42         struct list_head        retry_list;
  43         /* queue pending writes and submit them on unplug */
  44         struct bio_list         pending_bio_list;
  45         int                     pending_count;
  46
  47         spinlock_t              resync_lock;
  48         int nr_pending;
  49         int nr_waiting;
  50         int nr_queued;
  51         int barrier;
  52         sector_t                next_resync;
  53         int                     fullsync;  /* set to 1 if a full sync is needed,
  54                                             * (fresh device added).
  55                                             * Cleared when a sync completes.
  56                                             */
  57
  58         wait_queue_head_t       wait_barrier;
  59
  60         mempool_t *r10bio_pool;
  61         mempool_t *r10buf_pool;
  62         struct page             *tmppage;
  63
  64         /* When taking over an array from a different personality, we store
  65          * the new thread here until we fully activate the array.
  66          */
  67         struct md_thread        *thread;
  68 };
  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 {
  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         struct mddev            *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 /* When we successfully write to a known bad-block, we need to remove the
 116  * bad-block marking which must be done from process context.  So we record
 117  * the success by setting devs[n].bio to IO_MADE_GOOD
 118  */
 119 #define IO_MADE_GOOD ((struct bio *)2)
 120
 121 #define BIO_SPECIAL(bio) ((unsigned long)bio <= 2)
 122
 123 /* bits for r10bio.state */
 124 #define R10BIO_Uptodate 0
 125 #define R10BIO_IsSync   1
 126 #define R10BIO_IsRecover 2
 127 #define R10BIO_Degraded 3
 128 /* Set ReadError on bios that experience a read error
 129  * so that raid10d knows what to do with them.
 130  */
 131 #define R10BIO_ReadError 4
 132 /* If a write for this request means we can clear some
 133  * known-bad-block records, we set this flag.
 134  */
 135 #define R10BIO_MadeGood 5
 136 #define R10BIO_WriteError 6
 137 #endif