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         atomic_t                nr_pending;
  68         int                     nr_waiting;
  69         int                     nr_queued;
  70         int                     barrier;
  71         int                     array_freeze_pending;
  72         sector_t                next_resync;
  73         int                     fullsync;  /* set to 1 if a full sync is needed,
  74                                             * (fresh device added).
  75                                             * Cleared when a sync completes.
  76                                             */
  77         int                     have_replacement; /* There is at least one
  78                                                    * replacement device.
  79                                                    */
  80         wait_queue_head_t       wait_barrier;
  81
  82         mempool_t               *r10bio_pool;
  83         mempool_t               *r10buf_pool;
  84         struct page             *tmppage;
  85         struct bio_set          *bio_split;
  86
  87         /* When taking over an array from a different personality, we store
  88          * the new thread here until we fully activate the array.
  89          */
  90         struct md_thread        *thread;
  91 };
  92
  93 /*
  94  * this is our 'private' RAID10 bio.
  95  *
  96  * it contains information about what kind of IO operations were started
  97  * for this RAID10 operation, and about their status:
  98  */
  99
 100 struct r10bio {
 101         atomic_t                remaining; /* 'have we finished' count,
 102                                             * used from IRQ handlers
 103                                             */
 104         sector_t                sector; /* virtual sector number */
 105         int                     sectors;
 106         unsigned long           state;
 107         struct mddev            *mddev;
 108         /*
 109          * original bio going to /dev/mdx
 110          */
 111         struct bio              *master_bio;
 112         /*
 113          * if the IO is in READ direction, then this is where we read
 114          */
 115         int                     read_slot;
 116
 117         struct list_head        retry_list;
 118         /*
 119          * if the IO is in WRITE direction, then multiple bios are used,
 120          * one for each copy.
 121          * When resyncing we also use one for each copy.
 122          * When reconstructing, we use 2 bios, one for read, one for write.
 123          * We choose the number when they are allocated.
 124          * We sometimes need an extra bio to write to the replacement.
 125          */
 126         struct r10dev {
 127                 struct bio      *bio;
 128                 union {
 129                         struct bio      *repl_bio; /* used for resync and
 130                                                     * writes */
 131                         struct md_rdev  *rdev;     /* used for reads
 132                                                     * (read_slot >= 0) */
 133                 };
 134                 sector_t        addr;
 135                 int             devnum;
 136         } devs[0];
 137 };
 138
 139 /* bits for r10bio.state */
 140 enum r10bio_state {
 141         R10BIO_Uptodate,
 142         R10BIO_IsSync,
 143         R10BIO_IsRecover,
 144         R10BIO_IsReshape,
 145         R10BIO_Degraded,
 146 /* Set ReadError on bios that experience a read error
 147  * so that raid10d knows what to do with them.
 148  */
 149         R10BIO_ReadError,
 150 /* If a write for this request means we can clear some
 151  * known-bad-block records, we set this flag.
 152  */
 153         R10BIO_MadeGood,
 154         R10BIO_WriteError,
 155 /* During a reshape we might be performing IO on the
 156  * 'previous' part of the array, in which case this
 157  * flag is set
 158  */
 159         R10BIO_Previous,
 160 /* failfast devices did receive failfast requests. */
 161         R10BIO_FailFast,
 162 };
 163 #endif