1#ifndef _RAID10_H
2#define _RAID10_H
3
4struct 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
14struct 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             far_set_size; /* The number of devices in a set,
37					       * where a 'set' are devices that
38					       * contain far/offset copies of
39					       * each other.
40					       */
41		int		chunk_shift; /* shift from chunks to sectors */
42		sector_t	chunk_mask;
43	} prev, geo;
44	int			copies;	      /* near_copies * far_copies.
45					       * must be <= raid_disks
46					       */
47
48	sector_t		dev_sectors;  /* temp copy of
49					       * mddev->dev_sectors */
50	sector_t		reshape_progress;
51	sector_t		reshape_safe;
52	unsigned long		reshape_checkpoint;
53	sector_t		offset_diff;
54
55	struct list_head	retry_list;
56	/* queue pending writes and submit them on unplug */
57	struct bio_list		pending_bio_list;
58	int			pending_count;
59
60	spinlock_t		resync_lock;
61	int			nr_pending;
62	int			nr_waiting;
63	int			nr_queued;
64	int			barrier;
65	sector_t		next_resync;
66	int			fullsync;  /* set to 1 if a full sync is needed,
67					    * (fresh device added).
68					    * Cleared when a sync completes.
69					    */
70	int			have_replacement; /* There is at least one
71						   * replacement device.
72						   */
73	wait_queue_head_t	wait_barrier;
74
75	mempool_t		*r10bio_pool;
76	mempool_t		*r10buf_pool;
77	struct page		*tmppage;
78
79	/* When taking over an array from a different personality, we store
80	 * the new thread here until we fully activate the array.
81	 */
82	struct md_thread	*thread;
83};
84
85/*
86 * this is our 'private' RAID10 bio.
87 *
88 * it contains information about what kind of IO operations were started
89 * for this RAID10 operation, and about their status:
90 */
91
92struct r10bio {
93	atomic_t		remaining; /* 'have we finished' count,
94					    * used from IRQ handlers
95					    */
96	sector_t		sector;	/* virtual sector number */
97	int			sectors;
98	unsigned long		state;
99	struct mddev		*mddev;
100	/*
101	 * original bio going to /dev/mdx
102	 */
103	struct bio		*master_bio;
104	/*
105	 * if the IO is in READ direction, then this is where we read
106	 */
107	int			read_slot;
108
109	struct list_head	retry_list;
110	/*
111	 * if the IO is in WRITE direction, then multiple bios are used,
112	 * one for each copy.
113	 * When resyncing we also use one for each copy.
114	 * When reconstructing, we use 2 bios, one for read, one for write.
115	 * We choose the number when they are allocated.
116	 * We sometimes need an extra bio to write to the replacement.
117	 */
118	struct r10dev {
119		struct bio	*bio;
120		union {
121			struct bio	*repl_bio; /* used for resync and
122						    * writes */
123			struct md_rdev	*rdev;	   /* used for reads
124						    * (read_slot >= 0) */
125		};
126		sector_t	addr;
127		int		devnum;
128	} devs[0];
129};
130
131/* bits for r10bio.state */
132enum r10bio_state {
133	R10BIO_Uptodate,
134	R10BIO_IsSync,
135	R10BIO_IsRecover,
136	R10BIO_IsReshape,
137	R10BIO_Degraded,
138/* Set ReadError on bios that experience a read error
139 * so that raid10d knows what to do with them.
140 */
141	R10BIO_ReadError,
142/* If a write for this request means we can clear some
143 * known-bad-block records, we set this flag.
144 */
145	R10BIO_MadeGood,
146	R10BIO_WriteError,
147/* During a reshape we might be performing IO on the
148 * 'previous' part of the array, in which case this
149 * flag is set
150 */
151	R10BIO_Previous,
152};
153
154extern int md_raid10_congested(struct mddev *mddev, int bits);
155
156#endif
157