drivers/md/raid10.h

   1 #ifndef _RAID10_H
   2 #define _RAID10_H
   3
   4 struct raid10_info {
   5         struct md_rdev  *rdev, *replacement;
   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 raid10_info      *mirrors;
  17         struct raid10_info      *mirrors_new, *mirrors_old;
  18         spinlock_t              device_lock;
  19
  20         /* geometry */
  21         struct geom {
  22                 int             raid_disks;
  23                 int             near_copies;  /* number of copies laid out
  24                                                * raid0 style */
  25                 int             far_copies;   /* number of copies laid out
  26                                                * at large strides across drives
  27                                                */
  28                 int             far_offset;   /* far_copies are offset by 1
  29                                                * stripe instead of many
  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                 int             far_set_size; /* The number of devices in a set,
  37                                                * where a 'set' are devices that
  38                                                * contain far/offset copies of
  39                                                * each other.
  40                                                */
  41                 int             chunk_shift; /* shift from chunks to sectors */
  42                 sector_t        chunk_mask;
  43         } prev, geo;
  44         int                     copies;       /* near_copies * far_copies.
  45                                                * must be <= raid_disks
  46                                                */
  47
  48         sector_t                dev_sectors;  /* temp copy of
  49                                                * mddev->dev_sectors */
  50         sector_t                reshape_progress;
  51         sector_t                reshape_safe;
  52         unsigned long           reshape_checkpoint;
  53         sector_t                offset_diff;
  54
  55         struct list_head        retry_list;
  56         /* queue pending writes and submit them on unplug */
  57         struct bio_list         pending_bio_list;
  58         int                     pending_count;
  59
  60         spinlock_t              resync_lock;
  61         int                     nr_pending;
  62         int                     nr_waiting;
  63         int                     nr_queued;
  64         int                     barrier;
  65         sector_t                next_resync;
  66         int                     fullsync;  /* set to 1 if a full sync is needed,
  67                                             * (fresh device added).
  68                                             * Cleared when a sync completes.
  69                                             */
  70         int                     have_replacement; /* There is at least one
  71                                                    * replacement device.
  72                                                    */
  73         wait_queue_head_t       wait_barrier;
  74
  75         mempool_t               *r10bio_pool;
  76         mempool_t               *r10buf_pool;
  77         struct page             *tmppage;
  78
  79         /* When taking over an array from a different personality, we store
  80          * the new thread here until we fully activate the array.
  81          */
  82         struct md_thread        *thread;
  83 };
  84
  85 /*
  86  * this is our 'private' RAID10 bio.
  87  *
  88  * it contains information about what kind of IO operations were started
  89  * for this RAID10 operation, and about their status:
  90  */
  91
  92 struct r10bio {
  93         atomic_t                remaining; /* 'have we finished' count,
  94                                             * used from IRQ handlers
  95                                             */
  96         sector_t                sector; /* virtual sector number */
  97         int                     sectors;
  98         unsigned long           state;
  99         struct mddev            *mddev;
 100         /*
 101          * original bio going to /dev/mdx
 102          */
 103         struct bio              *master_bio;
 104         /*
 105          * if the IO is in READ direction, then this is where we read
 106          */
 107         int                     read_slot;
 108
 109         struct list_head        retry_list;
 110         /*
 111          * if the IO is in WRITE direction, then multiple bios are used,
 112          * one for each copy.
 113          * When resyncing we also use one for each copy.
 114          * When reconstructing, we use 2 bios, one for read, one for write.
 115          * We choose the number when they are allocated.
 116          * We sometimes need an extra bio to write to the replacement.
 117          */
 118         struct r10dev {
 119                 struct bio      *bio;
 120                 union {
 121                         struct bio      *repl_bio; /* used for resync and
 122                                                     * writes */
 123                         struct md_rdev  *rdev;     /* used for reads
 124                                                     * (read_slot >= 0) */
 125                 };
 126                 sector_t        addr;
 127                 int             devnum;
 128         } devs[0];
 129 };
 130
 131 /* bits for r10bio.state */
 132 enum r10bio_state {
 133         R10BIO_Uptodate,
 134         R10BIO_IsSync,
 135         R10BIO_IsRecover,
 136         R10BIO_IsReshape,
 137         R10BIO_Degraded,
 138 /* Set ReadError on bios that experience a read error
 139  * so that raid10d knows what to do with them.
 140  */
 141         R10BIO_ReadError,
 142 /* If a write for this request means we can clear some
 143  * known-bad-block records, we set this flag.
 144  */
 145         R10BIO_MadeGood,
 146         R10BIO_WriteError,
 147 /* During a reshape we might be performing IO on the
 148  * 'previous' part of the array, in which case this
 149  * flag is set
 150  */
 151         R10BIO_Previous,
 152 };
 153 #endif