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         /* A separate list of r1bio which just need raid_end_bio_io called.
  57          * This mustn't happen for writes which had any errors if the superblock
  58          * needs to be written.
  59          */
  60         struct list_head        bio_end_io_list;
  61
  62         /* queue pending writes and submit them on unplug */
  63         struct bio_list         pending_bio_list;
  64         int                     pending_count;
  65
  66         spinlock_t              resync_lock;
  67         int                     nr_pending;
  68         int                     nr_waiting;
  69         int                     nr_queued;
  70         int                     barrier;
  71         sector_t                next_resync;
  72         int                     fullsync;  /* set to 1 if a full sync is needed,
  73                                             * (fresh device added).
  74                                             * Cleared when a sync completes.
  75                                             */
  76         int                     have_replacement; /* There is at least one
  77                                                    * replacement device.
  78                                                    */
  79         wait_queue_head_t       wait_barrier;
  80
  81         mempool_t               *r10bio_pool;
  82         mempool_t               *r10buf_pool;
  83         struct page             *tmppage;
  84
  85         /* When taking over an array from a different personality, we store
  86          * the new thread here until we fully activate the array.
  87          */
  88         struct md_thread        *thread;
  89 };
  90
  91 /*
  92  * this is our 'private' RAID10 bio.
  93  *
  94  * it contains information about what kind of IO operations were started
  95  * for this RAID10 operation, and about their status:
  96  */
  97
  98 struct r10bio {
  99         atomic_t                remaining; /* 'have we finished' count,
 100                                             * used from IRQ handlers
 101                                             */
 102         sector_t                sector; /* virtual sector number */
 103         int                     sectors;
 104         unsigned long           state;
 105         struct mddev            *mddev;
 106         /*
 107          * original bio going to /dev/mdx
 108          */
 109         struct bio              *master_bio;
 110         /*
 111          * if the IO is in READ direction, then this is where we read
 112          */
 113         int                     read_slot;
 114
 115         struct list_head        retry_list;
 116         /*
 117          * if the IO is in WRITE direction, then multiple bios are used,
 118          * one for each copy.
 119          * When resyncing we also use one for each copy.
 120          * When reconstructing, we use 2 bios, one for read, one for write.
 121          * We choose the number when they are allocated.
 122          * We sometimes need an extra bio to write to the replacement.
 123          */
 124         struct r10dev {
 125                 struct bio      *bio;
 126                 union {
 127                         struct bio      *repl_bio; /* used for resync and
 128                                                     * writes */
 129                         struct md_rdev  *rdev;     /* used for reads
 130                                                     * (read_slot >= 0) */
 131                 };
 132                 sector_t        addr;
 133                 int             devnum;
 134         } devs[0];
 135 };
 136
 137 /* bits for r10bio.state */
 138 enum r10bio_state {
 139         R10BIO_Uptodate,
 140         R10BIO_IsSync,
 141         R10BIO_IsRecover,
 142         R10BIO_IsReshape,
 143         R10BIO_Degraded,
 144 /* Set ReadError on bios that experience a read error
 145  * so that raid10d knows what to do with them.
 146  */
 147         R10BIO_ReadError,
 148 /* If a write for this request means we can clear some
 149  * known-bad-block records, we set this flag.
 150  */
 151         R10BIO_MadeGood,
 152         R10BIO_WriteError,
 153 /* During a reshape we might be performing IO on the
 154  * 'previous' part of the array, in which case this
 155  * flag is set
 156  */
 157         R10BIO_Previous,
 158 };
 159 #endif