xref: /openbmc/linux/drivers/md/raid1.h (revision a0865368)
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 
52 	wait_queue_head_t	wait_barrier;
53 
54 	struct pool_info	*poolinfo;
55 
56 	struct page		*tmppage;
57 
58 	mempool_t *r1bio_pool;
59 	mempool_t *r1buf_pool;
60 
61 	/* When taking over an array from a different personality, we store
62 	 * the new thread here until we fully activate the array.
63 	 */
64 	struct mdk_thread_s	*thread;
65 };
66 
67 typedef struct r1_private_data_s conf_t;
68 
69 /*
70  * this is our 'private' RAID1 bio.
71  *
72  * it contains information about what kind of IO operations were started
73  * for this RAID1 operation, and about their status:
74  */
75 
76 struct r1bio_s {
77 	atomic_t		remaining; /* 'have we finished' count,
78 					    * used from IRQ handlers
79 					    */
80 	atomic_t		behind_remaining; /* number of write-behind ios remaining
81 						 * in this BehindIO request
82 						 */
83 	sector_t		sector;
84 	int			sectors;
85 	unsigned long		state;
86 	mddev_t			*mddev;
87 	/*
88 	 * original bio going to /dev/mdx
89 	 */
90 	struct bio		*master_bio;
91 	/*
92 	 * if the IO is in READ direction, then this is where we read
93 	 */
94 	int			read_disk;
95 
96 	struct list_head	retry_list;
97 	struct bitmap_update	*bitmap_update;
98 	/*
99 	 * if the IO is in WRITE direction, then multiple bios are used.
100 	 * We choose the number when they are allocated.
101 	 */
102 	struct bio		*bios[0];
103 	/* DO NOT PUT ANY NEW FIELDS HERE - bios array is contiguously alloced*/
104 };
105 
106 /* when we get a read error on a read-only array, we redirect to another
107  * device without failing the first device, or trying to over-write to
108  * correct the read error.  To keep track of bad blocks on a per-bio
109  * level, we store IO_BLOCKED in the appropriate 'bios' pointer
110  */
111 #define IO_BLOCKED ((struct bio*)1)
112 
113 /* bits for r1bio.state */
114 #define	R1BIO_Uptodate	0
115 #define	R1BIO_IsSync	1
116 #define	R1BIO_Degraded	2
117 #define	R1BIO_BehindIO	3
118 /* For write-behind requests, we call bi_end_io when
119  * the last non-write-behind device completes, providing
120  * any write was successful.  Otherwise we call when
121  * any write-behind write succeeds, otherwise we call
122  * with failure when last write completes (and all failed).
123  * Record that bi_end_io was called with this flag...
124  */
125 #define	R1BIO_Returned 6
126 
127 #endif
128