drivers/md/raid1.h

   1 #ifndef _RAID1_H
   2 #define _RAID1_H
   3
   4 typedef struct mirror_info mirror_info_t;
   5
   6 struct mirror_info {
   7         mdk_rdev_t      *rdev;
   8         sector_t        head_position;
   9 };
  10
  11 /*
  12  * memory pools need a pointer to the mddev, so they can force an unplug
  13  * when memory is tight, and a count of the number of drives that the
  14  * pool was allocated for, so they know how much to allocate and free.
  15  * mddev->raid_disks cannot be used, as it can change while a pool is active
  16  * These two datums are stored in a kmalloced struct.
  17  */
  18
  19 struct pool_info {
  20         mddev_t *mddev;
  21         int     raid_disks;
  22 };
  23
  24
  25 typedef struct r1bio_s r1bio_t;
  26
  27 struct r1_private_data_s {
  28         mddev_t                 *mddev;
  29         mirror_info_t           *mirrors;
  30         int                     raid_disks;
  31         int                     last_used;
  32         sector_t                next_seq_sect;
  33         spinlock_t              device_lock;
  34
  35         struct list_head        retry_list;
  36         /* queue pending writes and submit them on unplug */
  37         struct bio_list         pending_bio_list;
  38
  39         /* for use when syncing mirrors: */
  40
  41         spinlock_t              resync_lock;
  42         int                     nr_pending;
  43         int                     nr_waiting;
  44         int                     nr_queued;
  45         int                     barrier;
  46         sector_t                next_resync;
  47         int                     fullsync;  /* set to 1 if a full sync is needed,
  48                                             * (fresh device added).
  49                                             * Cleared when a sync completes.
  50                                             */
  51         int                     recovery_disabled; /* when the same as
  52                                                     * mddev->recovery_disabled
  53                                                     * we don't allow recovery
  54                                                     * to be attempted as we
  55                                                     * expect a read error
  56                                                     */
  57
  58         wait_queue_head_t       wait_barrier;
  59
  60         struct pool_info        *poolinfo;
  61
  62         struct page             *tmppage;
  63
  64         mempool_t *r1bio_pool;
  65         mempool_t *r1buf_pool;
  66
  67         /* When taking over an array from a different personality, we store
  68          * the new thread here until we fully activate the array.
  69          */
  70         struct mdk_thread_s     *thread;
  71 };
  72
  73 typedef struct r1_private_data_s conf_t;
  74
  75 /*
  76  * this is our 'private' RAID1 bio.
  77  *
  78  * it contains information about what kind of IO operations were started
  79  * for this RAID1 operation, and about their status:
  80  */
  81
  82 struct r1bio_s {
  83         atomic_t                remaining; /* 'have we finished' count,
  84                                             * used from IRQ handlers
  85                                             */
  86         atomic_t                behind_remaining; /* number of write-behind ios remaining
  87                                                  * in this BehindIO request
  88                                                  */
  89         sector_t                sector;
  90         int                     sectors;
  91         unsigned long           state;
  92         mddev_t                 *mddev;
  93         /*
  94          * original bio going to /dev/mdx
  95          */
  96         struct bio              *master_bio;
  97         /*
  98          * if the IO is in READ direction, then this is where we read
  99          */
 100         int                     read_disk;
 101
 102         struct list_head        retry_list;
 103         /* Next two are only valid when R1BIO_BehindIO is set */
 104         struct bio_vec          *behind_bvecs;
 105         int                     behind_page_count;
 106         /*
 107          * if the IO is in WRITE direction, then multiple bios are used.
 108          * We choose the number when they are allocated.
 109          */
 110         struct bio              *bios[0];
 111         /* DO NOT PUT ANY NEW FIELDS HERE - bios array is contiguously alloced*/
 112 };
 113
 114 /* when we get a read error on a read-only array, we redirect to another
 115  * device without failing the first device, or trying to over-write to
 116  * correct the read error.  To keep track of bad blocks on a per-bio
 117  * level, we store IO_BLOCKED in the appropriate 'bios' pointer
 118  */
 119 #define IO_BLOCKED ((struct bio *)1)
 120 /* When we successfully write to a known bad-block, we need to remove the
 121  * bad-block marking which must be done from process context.  So we record
 122  * the success by setting bios[n] to IO_MADE_GOOD
 123  */
 124 #define IO_MADE_GOOD ((struct bio *)2)
 125
 126 #define BIO_SPECIAL(bio) ((unsigned long)bio <= 2)
 127
 128 /* bits for r1bio.state */
 129 #define R1BIO_Uptodate  0
 130 #define R1BIO_IsSync    1
 131 #define R1BIO_Degraded  2
 132 #define R1BIO_BehindIO  3
 133 /* Set ReadError on bios that experience a readerror so that
 134  * raid1d knows what to do with them.
 135  */
 136 #define R1BIO_ReadError 4
 137 /* For write-behind requests, we call bi_end_io when
 138  * the last non-write-behind device completes, providing
 139  * any write was successful.  Otherwise we call when
 140  * any write-behind write succeeds, otherwise we call
 141  * with failure when last write completes (and all failed).
 142  * Record that bi_end_io was called with this flag...
 143  */
 144 #define R1BIO_Returned 6
 145 /* If a write for this request means we can clear some
 146  * known-bad-block records, we set this flag
 147  */
 148 #define R1BIO_MadeGood 7
 149 #define R1BIO_WriteError 8
 150
 151 extern int md_raid1_congested(mddev_t *mddev, int bits);
 152
 153 #endif