xref: /openbmc/linux/drivers/md/raid10.h (revision 7e035230)
1 #ifndef _RAID10_H
2 #define _RAID10_H
3 
4 struct raid10_info {
5 	struct md_rdev	*rdev, *replacement;
6 	sector_t	head_position;
7 	int		recovery_disabled;	/* matches
8 						 * mddev->recovery_disabled
9 						 * when we shouldn't try
10 						 * recovering this device.
11 						 */
12 };
13 
14 struct r10conf {
15 	struct mddev		*mddev;
16 	struct raid10_info	*mirrors;
17 	struct raid10_info	*mirrors_new, *mirrors_old;
18 	spinlock_t		device_lock;
19 
20 	/* geometry */
21 	struct geom {
22 		int		raid_disks;
23 		int		near_copies;  /* number of copies laid out
24 					       * raid0 style */
25 		int		far_copies;   /* number of copies laid out
26 					       * at large strides across drives
27 					       */
28 		int		far_offset;   /* far_copies are offset by 1
29 					       * stripe instead of many
30 					       */
31 		sector_t	stride;	      /* distance between far copies.
32 					       * This is size / far_copies unless
33 					       * far_offset, in which case it is
34 					       * 1 stripe.
35 					       */
36 		int		chunk_shift; /* shift from chunks to sectors */
37 		sector_t	chunk_mask;
38 	} prev, geo;
39 	int			copies;	      /* near_copies * far_copies.
40 					       * must be <= raid_disks
41 					       */
42 
43 	sector_t		dev_sectors;  /* temp copy of
44 					       * mddev->dev_sectors */
45 	sector_t		reshape_progress;
46 	sector_t		reshape_safe;
47 	unsigned long		reshape_checkpoint;
48 	sector_t		offset_diff;
49 
50 	struct list_head	retry_list;
51 	/* queue pending writes and submit them on unplug */
52 	struct bio_list		pending_bio_list;
53 	int			pending_count;
54 
55 	spinlock_t		resync_lock;
56 	int			nr_pending;
57 	int			nr_waiting;
58 	int			nr_queued;
59 	int			barrier;
60 	sector_t		next_resync;
61 	int			fullsync;  /* set to 1 if a full sync is needed,
62 					    * (fresh device added).
63 					    * Cleared when a sync completes.
64 					    */
65 	int			have_replacement; /* There is at least one
66 						   * replacement device.
67 						   */
68 	wait_queue_head_t	wait_barrier;
69 
70 	mempool_t		*r10bio_pool;
71 	mempool_t		*r10buf_pool;
72 	struct page		*tmppage;
73 
74 	/* When taking over an array from a different personality, we store
75 	 * the new thread here until we fully activate the array.
76 	 */
77 	struct md_thread	*thread;
78 };
79 
80 /*
81  * this is our 'private' RAID10 bio.
82  *
83  * it contains information about what kind of IO operations were started
84  * for this RAID10 operation, and about their status:
85  */
86 
87 struct r10bio {
88 	atomic_t		remaining; /* 'have we finished' count,
89 					    * used from IRQ handlers
90 					    */
91 	sector_t		sector;	/* virtual sector number */
92 	int			sectors;
93 	unsigned long		state;
94 	struct mddev		*mddev;
95 	/*
96 	 * original bio going to /dev/mdx
97 	 */
98 	struct bio		*master_bio;
99 	/*
100 	 * if the IO is in READ direction, then this is where we read
101 	 */
102 	int			read_slot;
103 
104 	struct list_head	retry_list;
105 	/*
106 	 * if the IO is in WRITE direction, then multiple bios are used,
107 	 * one for each copy.
108 	 * When resyncing we also use one for each copy.
109 	 * When reconstructing, we use 2 bios, one for read, one for write.
110 	 * We choose the number when they are allocated.
111 	 * We sometimes need an extra bio to write to the replacement.
112 	 */
113 	struct {
114 		struct bio	*bio;
115 		union {
116 			struct bio	*repl_bio; /* used for resync and
117 						    * writes */
118 			struct md_rdev	*rdev;	   /* used for reads
119 						    * (read_slot >= 0) */
120 		};
121 		sector_t	addr;
122 		int		devnum;
123 	} devs[0];
124 };
125 
126 /* bits for r10bio.state */
127 enum r10bio_state {
128 	R10BIO_Uptodate,
129 	R10BIO_IsSync,
130 	R10BIO_IsRecover,
131 	R10BIO_IsReshape,
132 	R10BIO_Degraded,
133 /* Set ReadError on bios that experience a read error
134  * so that raid10d knows what to do with them.
135  */
136 	R10BIO_ReadError,
137 /* If a write for this request means we can clear some
138  * known-bad-block records, we set this flag.
139  */
140 	R10BIO_MadeGood,
141 	R10BIO_WriteError,
142 /* During a reshape we might be performing IO on the
143  * 'previous' part of the array, in which case this
144  * flag is set
145  */
146 	R10BIO_Previous,
147 };
148 
149 extern int md_raid10_congested(struct mddev *mddev, int bits);
150 
151 #endif
152