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1 #ifndef _RAID1_H
2 #define _RAID1_H
3 
4 #include <linux/raid/md.h>
5 
6 typedef struct mirror_info mirror_info_t;
7 
8 struct mirror_info {
9 	mdk_rdev_t	*rdev;
10 	sector_t	head_position;
11 };
12 
13 /*
14  * memory pools need a pointer to the mddev, so they can force an unplug
15  * when memory is tight, and a count of the number of drives that the
16  * pool was allocated for, so they know how much to allocate and free.
17  * mddev->raid_disks cannot be used, as it can change while a pool is active
18  * These two datums are stored in a kmalloced struct.
19  */
20 
21 struct pool_info {
22 	mddev_t *mddev;
23 	int	raid_disks;
24 };
25 
26 
27 typedef struct r1bio_s r1bio_t;
28 
29 struct r1_private_data_s {
30 	mddev_t			*mddev;
31 	mirror_info_t		*mirrors;
32 	int			raid_disks;
33 	int			last_used;
34 	sector_t		next_seq_sect;
35 	spinlock_t		device_lock;
36 
37 	struct list_head	retry_list;
38 	/* queue pending writes and submit them on unplug */
39 	struct bio_list		pending_bio_list;
40 	/* queue of writes that have been unplugged */
41 	struct bio_list		flushing_bio_list;
42 
43 	/* for use when syncing mirrors: */
44 
45 	spinlock_t		resync_lock;
46 	int			nr_pending;
47 	int			nr_waiting;
48 	int			nr_queued;
49 	int			barrier;
50 	sector_t		next_resync;
51 	int			fullsync;  /* set to 1 if a full sync is needed,
52 					    * (fresh device added).
53 					    * Cleared when a sync completes.
54 					    */
55 
56 	wait_queue_head_t	wait_barrier;
57 
58 	struct pool_info	*poolinfo;
59 
60 	struct page		*tmppage;
61 
62 	mempool_t *r1bio_pool;
63 	mempool_t *r1buf_pool;
64 };
65 
66 typedef struct r1_private_data_s conf_t;
67 
68 /*
69  * this is the only point in the RAID code where we violate
70  * C type safety. mddev->private is an 'opaque' pointer.
71  */
72 #define mddev_to_conf(mddev) ((conf_t *) mddev->private)
73 
74 /*
75  * this is our 'private' RAID1 bio.
76  *
77  * it contains information about what kind of IO operations were started
78  * for this RAID1 operation, and about their status:
79  */
80 
81 struct r1bio_s {
82 	atomic_t		remaining; /* 'have we finished' count,
83 					    * used from IRQ handlers
84 					    */
85 	atomic_t		behind_remaining; /* number of write-behind ios remaining
86 						 * in this BehindIO request
87 						 */
88 	sector_t		sector;
89 	int			sectors;
90 	unsigned long		state;
91 	mddev_t			*mddev;
92 	/*
93 	 * original bio going to /dev/mdx
94 	 */
95 	struct bio		*master_bio;
96 	/*
97 	 * if the IO is in READ direction, then this is where we read
98 	 */
99 	int			read_disk;
100 
101 	struct list_head	retry_list;
102 	struct bitmap_update	*bitmap_update;
103 	/*
104 	 * if the IO is in WRITE direction, then multiple bios are used.
105 	 * We choose the number when they are allocated.
106 	 */
107 	struct bio		*bios[0];
108 	/* DO NOT PUT ANY NEW FIELDS HERE - bios array is contiguously alloced*/
109 };
110 
111 /* when we get a read error on a read-only array, we redirect to another
112  * device without failing the first device, or trying to over-write to
113  * correct the read error.  To keep track of bad blocks on a per-bio
114  * level, we store IO_BLOCKED in the appropriate 'bios' pointer
115  */
116 #define IO_BLOCKED ((struct bio*)1)
117 
118 /* bits for r1bio.state */
119 #define	R1BIO_Uptodate	0
120 #define	R1BIO_IsSync	1
121 #define	R1BIO_Degraded	2
122 #define	R1BIO_BehindIO	3
123 #define	R1BIO_Barrier	4
124 #define R1BIO_BarrierRetry 5
125 /* For write-behind requests, we call bi_end_io when
126  * the last non-write-behind device completes, providing
127  * any write was successful.  Otherwise we call when
128  * any write-behind write succeeds, otherwise we call
129  * with failure when last write completes (and all failed).
130  * Record that bi_end_io was called with this flag...
131  */
132 #define	R1BIO_Returned 6
133 
134 #endif
135