LXR linux/drivers/md/raid10.h

   1#ifndef _RAID10_H
   2#define _RAID10_H
   3
   4typedef struct mirror_info mirror_info_t;
   5
   6struct mirror_info {
   7        mdk_rdev_t      *rdev;
   8        sector_t        head_position;
   9};
  10
  11typedef struct r10bio_s r10bio_t;
  12
  13struct 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        int chunk_shift; /* shift from chunks to sectors */
  37        sector_t chunk_mask;
  38
  39        struct list_head        retry_list;
  40        /* queue pending writes and submit them on unplug */
  41        struct bio_list         pending_bio_list;
  42
  43
  44        spinlock_t              resync_lock;
  45        int nr_pending;
  46        int nr_waiting;
  47        int nr_queued;
  48        int barrier;
  49        sector_t                next_resync;
  50        int                     fullsync;  /* set to 1 if a full sync is needed,
  51                                            * (fresh device added).
  52                                            * Cleared when a sync completes.
  53                                            */
  54
  55        wait_queue_head_t       wait_barrier;
  56
  57        mempool_t *r10bio_pool;
  58        mempool_t *r10buf_pool;
  59        struct page             *tmppage;
  60};
  61
  62typedef struct r10_private_data_s conf_t;
  63
  64/*
  65 * this is our 'private' RAID10 bio.
  66 *
  67 * it contains information about what kind of IO operations were started
  68 * for this RAID10 operation, and about their status:
  69 */
  70
  71struct r10bio_s {
  72        atomic_t                remaining; /* 'have we finished' count,
  73                                            * used from IRQ handlers
  74                                            */
  75        sector_t                sector; /* virtual sector number */
  76        int                     sectors;
  77        unsigned long           state;
  78        mddev_t                 *mddev;
  79        /*
  80         * original bio going to /dev/mdx
  81         */
  82        struct bio              *master_bio;
  83        /*
  84         * if the IO is in READ direction, then this is where we read
  85         */
  86        int                     read_slot;
  87
  88        struct list_head        retry_list;
  89        /*
  90         * if the IO is in WRITE direction, then multiple bios are used,
  91         * one for each copy.
  92         * When resyncing we also use one for each copy.
  93         * When reconstructing, we use 2 bios, one for read, one for write.
  94         * We choose the number when they are allocated.
  95         */
  96        struct {
  97                struct bio              *bio;
  98                sector_t addr;
  99                int devnum;
 100        } devs[0];
 101};
 102
 103/* when we get a read error on a read-only array, we redirect to another
 104 * device without failing the first device, or trying to over-write to
 105 * correct the read error.  To keep track of bad blocks on a per-bio
 106 * level, we store IO_BLOCKED in the appropriate 'bios' pointer
 107 */
 108#define IO_BLOCKED ((struct bio*)1)
 109
 110/* bits for r10bio.state */
 111#define R10BIO_Uptodate 0
 112#define R10BIO_IsSync   1
 113#define R10BIO_IsRecover 2
 114#define R10BIO_Degraded 3
 115#endif
 116