include/linux/raid/raid1.h

   1 #ifndef _RAID1_H
   2 #define _RAID1_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 /*
  14  * memory pools need a pointer to the mddev, so they can force an unplug
  15  * when memory is tight, and a count of the number of drives that the
  16  * pool was allocated for, so they know how much to allocate and free.
  17  * mddev->raid_disks cannot be used, as it can change while a pool is active
  18  * These two datums are stored in a kmalloced struct.
  19  */
  20
  21 struct pool_info {
  22         mddev_t *mddev;
  23         int     raid_disks;
  24 };
  25
  26
  27 typedef struct r1bio_s r1bio_t;
  28
  29 struct r1_private_data_s {
  30         mddev_t                 *mddev;
  31         mirror_info_t           *mirrors;
  32         int                     raid_disks;
  33         int                     working_disks;
  34         int                     last_used;
  35         sector_t                next_seq_sect;
  36         spinlock_t              device_lock;
  37
  38         struct list_head        retry_list;
  39         /* queue pending writes and submit them on unplug */
  40         struct bio_list         pending_bio_list;
  41         /* queue of writes that have been unplugged */
  42         struct bio_list         flushing_bio_list;
  43
  44         /* for use when syncing mirrors: */
  45
  46         spinlock_t              resync_lock;
  47         int                     nr_pending;
  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_idle;
  56         wait_queue_head_t       wait_resume;
  57
  58         struct pool_info        *poolinfo;
  59
  60         mempool_t *r1bio_pool;
  61         mempool_t *r1buf_pool;
  62 };
  63
  64 typedef struct r1_private_data_s conf_t;
  65
  66 /*
  67  * this is the only point in the RAID code where we violate
  68  * C type safety. mddev->private is an 'opaque' pointer.
  69  */
  70 #define mddev_to_conf(mddev) ((conf_t *) mddev->private)
  71
  72 /*
  73  * this is our 'private' RAID1 bio.
  74  *
  75  * it contains information about what kind of IO operations were started
  76  * for this RAID1 operation, and about their status:
  77  */
  78
  79 struct r1bio_s {
  80         atomic_t                remaining; /* 'have we finished' count,
  81                                             * used from IRQ handlers
  82                                             */
  83         atomic_t                behind_remaining; /* number of write-behind ios remaining
  84                                                  * in this BehindIO request
  85                                                  */
  86         sector_t                sector;
  87         int                     sectors;
  88         unsigned long           state;
  89         mddev_t                 *mddev;
  90         /*
  91          * original bio going to /dev/mdx
  92          */
  93         struct bio              *master_bio;
  94         /*
  95          * if the IO is in READ direction, then this is where we read
  96          */
  97         int                     read_disk;
  98
  99         struct list_head        retry_list;
 100         struct bitmap_update    *bitmap_update;
 101         /*
 102          * if the IO is in WRITE direction, then multiple bios are used.
 103          * We choose the number when they are allocated.
 104          */
 105         struct bio              *bios[0];
 106         /* DO NOT PUT ANY NEW FIELDS HERE - bios array is contiguously alloced*/
 107 };
 108
 109 /* bits for r1bio.state */
 110 #define R1BIO_Uptodate  0
 111 #define R1BIO_IsSync    1
 112 #define R1BIO_Degraded  2
 113 #define R1BIO_BehindIO   3
 114 /* For write-behind requests, we call bi_end_io when
 115  * the last non-write-behind device completes, providing
 116  * any write was successful.  Otherwise we call when
 117  * any write-behind write succeeds, otherwise we call
 118  * with failure when last write completes (and all failed).
 119  * Record that bi_end_io was called with this flag...
 120  */
 121 #define R1BIO_Returned 4
 122
 123 #endif