xref: /openbmc/linux/drivers/md/raid1.h (revision e8e0929d)
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 	/* queue of writes that have been unplugged */
39 	struct bio_list		flushing_bio_list;
40 
41 	/* for use when syncing mirrors: */
42 
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.
52 					    */
53 
54 	wait_queue_head_t	wait_barrier;
55 
56 	struct pool_info	*poolinfo;
57 
58 	struct page		*tmppage;
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 our 'private' RAID1 bio.
68  *
69  * it contains information about what kind of IO operations were started
70  * for this RAID1 operation, and about their status:
71  */
72 
73 struct r1bio_s {
74 	atomic_t		remaining; /* 'have we finished' count,
75 					    * used from IRQ handlers
76 					    */
77 	atomic_t		behind_remaining; /* number of write-behind ios remaining
78 						 * in this BehindIO request
79 						 */
80 	sector_t		sector;
81 	int			sectors;
82 	unsigned long		state;
83 	mddev_t			*mddev;
84 	/*
85 	 * original bio going to /dev/mdx
86 	 */
87 	struct bio		*master_bio;
88 	/*
89 	 * if the IO is in READ direction, then this is where we read
90 	 */
91 	int			read_disk;
92 
93 	struct list_head	retry_list;
94 	struct bitmap_update	*bitmap_update;
95 	/*
96 	 * if the IO is in WRITE direction, then multiple bios are used.
97 	 * We choose the number when they are allocated.
98 	 */
99 	struct bio		*bios[0];
100 	/* DO NOT PUT ANY NEW FIELDS HERE - bios array is contiguously alloced*/
101 };
102 
103 /* when we get a read error on a read-only array, we redirect to another
104  * device without failing the first device, or trying to over-write to
105  * correct the read error.  To keep track of bad blocks on a per-bio
106  * level, we store IO_BLOCKED in the appropriate 'bios' pointer
107  */
108 #define IO_BLOCKED ((struct bio*)1)
109 
110 /* bits for r1bio.state */
111 #define	R1BIO_Uptodate	0
112 #define	R1BIO_IsSync	1
113 #define	R1BIO_Degraded	2
114 #define	R1BIO_BehindIO	3
115 #define	R1BIO_Barrier	4
116 #define R1BIO_BarrierRetry 5
117 /* For write-behind requests, we call bi_end_io when
118  * the last non-write-behind device completes, providing
119  * any write was successful.  Otherwise we call when
120  * any write-behind write succeeds, otherwise we call
121  * with failure when last write completes (and all failed).
122  * Record that bi_end_io was called with this flag...
123  */
124 #define	R1BIO_Returned 6
125 
126 #endif
127