include/linux/raid/raid5.h

   1 #ifndef _RAID5_H
   2 #define _RAID5_H
   3
   4 #include <linux/raid/md.h>
   5 #include <linux/raid/xor.h>
   6
   7 struct disk_info {
   8         kdev_t  dev;
   9         int     operational;
  10         int     number;
  11         int     raid_disk;
  12         int     write_only;
  13         int     spare;
  14         int     used_slot;
  15 };
  16
  17 struct stripe_head {
  18         md_spinlock_t           stripe_lock;
  19         struct stripe_head      *hash_next, **hash_pprev; /* hash pointers */
  20         struct stripe_head      *free_next;             /* pool of free sh's */
  21         struct buffer_head      *buffer_pool;           /* pool of free buffers */
  22         struct buffer_head      *bh_pool;               /* pool of free bh's */
  23         struct raid5_private_data       *raid_conf;
  24         struct buffer_head      *bh_old[MD_SB_DISKS];   /* disk image */
  25         struct buffer_head      *bh_new[MD_SB_DISKS];   /* buffers of the MD device (present in buffer cache) */
  26         struct buffer_head      *bh_copy[MD_SB_DISKS];  /* copy on write of bh_new (bh_new can change from under us) */
  27         struct buffer_head      *bh_req[MD_SB_DISKS];   /* copy of bh_new (only the buffer heads), queued to the lower levels */
  28         int                     cmd_new[MD_SB_DISKS];   /* READ/WRITE for new */
  29         int                     new[MD_SB_DISKS];       /* buffer added since the last handle_stripe() */
  30         unsigned long           sector;                 /* sector of this row */
  31         int                     size;                   /* buffers size */
  32         int                     pd_idx;                 /* parity disk index */
  33         atomic_t                nr_pending;             /* nr of pending cmds */
  34         unsigned long           state;                  /* state flags */
  35         int                     cmd;                    /* stripe cmd */
  36         atomic_t                count;                  /* nr of waiters */
  37         int                     write_method;           /* reconstruct-write / read-modify-write */
  38         int                     phase;                  /* PHASE_BEGIN, ..., PHASE_COMPLETE */
  39         md_wait_queue_head_t    wait;                   /* processes waiting for this stripe */
  40
  41         int                     sync_redone;
  42 };
  43
  44 /*
  45  * Phase
  46  */
  47 #define PHASE_BEGIN             0
  48 #define PHASE_READ_OLD          1
  49 #define PHASE_WRITE             2
  50 #define PHASE_READ              3
  51 #define PHASE_COMPLETE          4
  52
  53 /*
  54  * Write method
  55  */
  56 #define METHOD_NONE             0
  57 #define RECONSTRUCT_WRITE       1
  58 #define READ_MODIFY_WRITE       2
  59
  60 /*
  61  * Stripe state
  62  */
  63 #define STRIPE_LOCKED           0
  64 #define STRIPE_ERROR            1
  65
  66 /*
  67  * Stripe commands
  68  */
  69 #define STRIPE_NONE             0
  70 #define STRIPE_WRITE            1
  71 #define STRIPE_READ             2
  72 #define STRIPE_SYNC             3
  73
  74 struct raid5_private_data {
  75         struct stripe_head      **stripe_hashtbl;
  76         mddev_t                 *mddev;
  77         mdk_thread_t            *thread, *resync_thread;
  78         struct disk_info        disks[MD_SB_DISKS];
  79         struct disk_info        *spare;
  80         int                     buffer_size;
  81         int                     chunk_size, level, algorithm;
  82         int                     raid_disks, working_disks, failed_disks;
  83         unsigned long           next_sector;
  84         atomic_t                nr_handle;
  85         struct stripe_head      *next_free_stripe;
  86         atomic_t                nr_stripes;
  87         int                     resync_parity;
  88         int                     max_nr_stripes;
  89         int                     clock;
  90         atomic_t                nr_hashed_stripes;
  91         atomic_t                nr_locked_stripes;
  92         atomic_t                nr_pending_stripes;
  93         atomic_t                nr_cached_stripes;
  94
  95         /*
  96          * Free stripes pool
  97          */
  98         atomic_t                nr_free_sh;
  99         struct stripe_head      *free_sh_list;
 100         md_wait_queue_head_t    wait_for_stripe;
 101
 102         md_spinlock_t           device_lock;
 103 };
 104
 105 typedef struct raid5_private_data raid5_conf_t;
 106
 107 #define mddev_to_conf(mddev) ((raid5_conf_t *) mddev->private)
 108
 109 /*
 110  * Our supported algorithms
 111  */
 112 #define ALGORITHM_LEFT_ASYMMETRIC       0
 113 #define ALGORITHM_RIGHT_ASYMMETRIC      1
 114 #define ALGORITHM_LEFT_SYMMETRIC        2
 115 #define ALGORITHM_RIGHT_SYMMETRIC       3
 116
 117 #endif