Linux 2.6.34-rc3
[pohmelfs.git] / drivers / md / raid1.h
blob5f2d443ae28af03cb31d6b16d30495abc73b45ff
1 #ifndef _RAID1_H
2 #define _RAID1_H
4 typedef struct mirror_info mirror_info_t;
6 struct mirror_info {
7 mdk_rdev_t *rdev;
8 sector_t head_position;
9 };
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.
19 struct pool_info {
20 mddev_t *mddev;
21 int raid_disks;
25 typedef struct r1bio_s r1bio_t;
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;
35 struct list_head retry_list;
36 /* queue pending writes and submit them on unplug */
37 struct bio_list pending_bio_list;
38 /* queue of writes that have been unplugged */
39 struct bio_list flushing_bio_list;
41 /* for use when syncing mirrors: */
43 spinlock_t resync_lock;
44 int nr_pending;
45 int nr_waiting;
46 int nr_queued;
47 int barrier;
48 sector_t next_resync;
49 int fullsync; /* set to 1 if a full sync is needed,
50 * (fresh device added).
51 * Cleared when a sync completes.
54 wait_queue_head_t wait_barrier;
56 struct pool_info *poolinfo;
58 struct page *tmppage;
60 mempool_t *r1bio_pool;
61 mempool_t *r1buf_pool;
63 /* When taking over an array from a different personality, we store
64 * the new thread here until we fully activate the array.
66 struct mdk_thread_s *thread;
69 typedef struct r1_private_data_s conf_t;
72 * this is our 'private' RAID1 bio.
74 * it contains information about what kind of IO operations were started
75 * for this RAID1 operation, and about their status:
78 struct r1bio_s {
79 atomic_t remaining; /* 'have we finished' count,
80 * used from IRQ handlers
82 atomic_t behind_remaining; /* number of write-behind ios remaining
83 * in this BehindIO request
85 sector_t sector;
86 int sectors;
87 unsigned long state;
88 mddev_t *mddev;
90 * original bio going to /dev/mdx
92 struct bio *master_bio;
94 * if the IO is in READ direction, then this is where we read
96 int read_disk;
98 struct list_head retry_list;
99 struct bitmap_update *bitmap_update;
101 * if the IO is in WRITE direction, then multiple bios are used.
102 * We choose the number when they are allocated.
104 struct bio *bios[0];
105 /* DO NOT PUT ANY NEW FIELDS HERE - bios array is contiguously alloced*/
108 /* when we get a read error on a read-only array, we redirect to another
109 * device without failing the first device, or trying to over-write to
110 * correct the read error. To keep track of bad blocks on a per-bio
111 * level, we store IO_BLOCKED in the appropriate 'bios' pointer
113 #define IO_BLOCKED ((struct bio*)1)
115 /* bits for r1bio.state */
116 #define R1BIO_Uptodate 0
117 #define R1BIO_IsSync 1
118 #define R1BIO_Degraded 2
119 #define R1BIO_BehindIO 3
120 #define R1BIO_Barrier 4
121 #define R1BIO_BarrierRetry 5
122 /* For write-behind requests, we call bi_end_io when
123 * the last non-write-behind device completes, providing
124 * any write was successful. Otherwise we call when
125 * any write-behind write succeeds, otherwise we call
126 * with failure when last write completes (and all failed).
127 * Record that bi_end_io was called with this flag...
129 #define R1BIO_Returned 6
131 #endif