include/linux/raid/raid10.h

   1 #ifndef _RAID10_H
   2 #define _RAID10_H
   3
   4 #include <linux/raid/md.h>
   5
   6 typedef struct mirror_info mirror_info_t;
   7
   8 struct mirror_info {
   9         mdk_rdev_t      *rdev;
  10         sector_t        head_position;
  11 };
  12
  13 typedef struct r10bio_s r10bio_t;
  14
  15 struct r10_private_data_s {
  16         mddev_t                 *mddev;
  17         mirror_info_t           *mirrors;
  18         int                     raid_disks;
  19         int                     working_disks;
  20         spinlock_t              device_lock;
  21
  22         /* geometry */
  23         int                     near_copies;  /* number of copies layed out raid0 style */
  24         int                     far_copies;   /* number of copies layed out
  25                                                * at large strides across drives
  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
  32                                                */
  33
  34         int chunk_shift; /* shift from chunks to sectors */
  35         sector_t chunk_mask;
  36
  37         struct list_head        retry_list;
  38         /* for use when syncing mirrors: */
  39
  40         spinlock_t              resync_lock;
  41         int nr_pending;
  42         int barrier;
  43         sector_t                next_resync;
  44
  45         wait_queue_head_t       wait_idle;
  46         wait_queue_head_t       wait_resume;
  47
  48         mempool_t *r10bio_pool;
  49         mempool_t *r10buf_pool;
  50 };
  51
  52 typedef struct r10_private_data_s conf_t;
  53
  54 /*
  55  * this is the only point in the RAID code where we violate
  56  * C type safety. mddev->private is an 'opaque' pointer.
  57  */
  58 #define mddev_to_conf(mddev) ((conf_t *) mddev->private)
  59
  60 /*
  61  * this is our 'private' RAID10 bio.
  62  *
  63  * it contains information about what kind of IO operations were started
  64  * for this RAID10 operation, and about their status:
  65  */
  66
  67 struct r10bio_s {
  68         atomic_t                remaining; /* 'have we finished' count,
  69                                             * used from IRQ handlers
  70                                             */
  71         sector_t                sector; /* virtual sector number */
  72         int                     sectors;
  73         unsigned long           state;
  74         mddev_t                 *mddev;
  75         /*
  76          * original bio going to /dev/mdx
  77          */
  78         struct bio              *master_bio;
  79         /*
  80          * if the IO is in READ direction, then this is where we read
  81          */
  82         int                     read_slot;
  83
  84         struct list_head        retry_list;
  85         /*
  86          * if the IO is in WRITE direction, then multiple bios are used,
  87          * one for each copy.
  88          * When resyncing we also use one for each copy.
  89          * When reconstructing, we use 2 bios, one for read, one for write.
  90          * We choose the number when they are allocated.
  91          */
  92         struct {
  93                 struct bio              *bio;
  94                 sector_t addr;
  95                 int devnum;
  96         } devs[0];
  97 };
  98
  99 /* bits for r10bio.state */
 100 #define R10BIO_Uptodate 0
 101 #define R10BIO_IsSync   1
 102 #define R10BIO_IsRecover 2
 103 #endif