db2ac22ac1b42801a14e5eab8641109a3aa61505
[sfrench/cifs-2.6.git] / drivers / md / raid10.h
1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef _RAID10_H
3 #define _RAID10_H
4
5 struct raid10_info {
6         struct md_rdev  *rdev, *replacement;
7         sector_t        head_position;
8         int             recovery_disabled;      /* matches
9                                                  * mddev->recovery_disabled
10                                                  * when we shouldn't try
11                                                  * recovering this device.
12                                                  */
13 };
14
15 struct r10conf {
16         struct mddev            *mddev;
17         struct raid10_info      *mirrors;
18         struct raid10_info      *mirrors_new, *mirrors_old;
19         spinlock_t              device_lock;
20
21         /* geometry */
22         struct geom {
23                 int             raid_disks;
24                 int             near_copies;  /* number of copies laid out
25                                                * raid0 style */
26                 int             far_copies;   /* number of copies laid out
27                                                * at large strides across drives
28                                                */
29                 int             far_offset;   /* far_copies are offset by 1
30                                                * stripe instead of many
31                                                */
32                 sector_t        stride;       /* distance between far copies.
33                                                * This is size / far_copies unless
34                                                * far_offset, in which case it is
35                                                * 1 stripe.
36                                                */
37                 int             far_set_size; /* The number of devices in a set,
38                                                * where a 'set' are devices that
39                                                * contain far/offset copies of
40                                                * each other.
41                                                */
42                 int             chunk_shift; /* shift from chunks to sectors */
43                 sector_t        chunk_mask;
44         } prev, geo;
45         int                     copies;       /* near_copies * far_copies.
46                                                * must be <= raid_disks
47                                                */
48
49         sector_t                dev_sectors;  /* temp copy of
50                                                * mddev->dev_sectors */
51         sector_t                reshape_progress;
52         sector_t                reshape_safe;
53         unsigned long           reshape_checkpoint;
54         sector_t                offset_diff;
55
56         struct list_head        retry_list;
57         /* A separate list of r1bio which just need raid_end_bio_io called.
58          * This mustn't happen for writes which had any errors if the superblock
59          * needs to be written.
60          */
61         struct list_head        bio_end_io_list;
62
63         /* queue pending writes and submit them on unplug */
64         struct bio_list         pending_bio_list;
65         int                     pending_count;
66
67         spinlock_t              resync_lock;
68         atomic_t                nr_pending;
69         int                     nr_waiting;
70         int                     nr_queued;
71         int                     barrier;
72         int                     array_freeze_pending;
73         sector_t                next_resync;
74         int                     fullsync;  /* set to 1 if a full sync is needed,
75                                             * (fresh device added).
76                                             * Cleared when a sync completes.
77                                             */
78         int                     have_replacement; /* There is at least one
79                                                    * replacement device.
80                                                    */
81         wait_queue_head_t       wait_barrier;
82
83         mempool_t               *r10bio_pool;
84         mempool_t               *r10buf_pool;
85         struct page             *tmppage;
86         struct bio_set          *bio_split;
87
88         /* When taking over an array from a different personality, we store
89          * the new thread here until we fully activate the array.
90          */
91         struct md_thread        *thread;
92
93         /*
94          * Keep track of cluster resync window to send to other nodes.
95          */
96         sector_t                cluster_sync_low;
97         sector_t                cluster_sync_high;
98 };
99
100 /*
101  * this is our 'private' RAID10 bio.
102  *
103  * it contains information about what kind of IO operations were started
104  * for this RAID10 operation, and about their status:
105  */
106
107 struct r10bio {
108         atomic_t                remaining; /* 'have we finished' count,
109                                             * used from IRQ handlers
110                                             */
111         sector_t                sector; /* virtual sector number */
112         int                     sectors;
113         unsigned long           state;
114         struct mddev            *mddev;
115         /*
116          * original bio going to /dev/mdx
117          */
118         struct bio              *master_bio;
119         /*
120          * if the IO is in READ direction, then this is where we read
121          */
122         int                     read_slot;
123
124         struct list_head        retry_list;
125         /*
126          * if the IO is in WRITE direction, then multiple bios are used,
127          * one for each copy.
128          * When resyncing we also use one for each copy.
129          * When reconstructing, we use 2 bios, one for read, one for write.
130          * We choose the number when they are allocated.
131          * We sometimes need an extra bio to write to the replacement.
132          */
133         struct r10dev {
134                 struct bio      *bio;
135                 union {
136                         struct bio      *repl_bio; /* used for resync and
137                                                     * writes */
138                         struct md_rdev  *rdev;     /* used for reads
139                                                     * (read_slot >= 0) */
140                 };
141                 sector_t        addr;
142                 int             devnum;
143         } devs[0];
144 };
145
146 /* bits for r10bio.state */
147 enum r10bio_state {
148         R10BIO_Uptodate,
149         R10BIO_IsSync,
150         R10BIO_IsRecover,
151         R10BIO_IsReshape,
152         R10BIO_Degraded,
153 /* Set ReadError on bios that experience a read error
154  * so that raid10d knows what to do with them.
155  */
156         R10BIO_ReadError,
157 /* If a write for this request means we can clear some
158  * known-bad-block records, we set this flag.
159  */
160         R10BIO_MadeGood,
161         R10BIO_WriteError,
162 /* During a reshape we might be performing IO on the
163  * 'previous' part of the array, in which case this
164  * flag is set
165  */
166         R10BIO_Previous,
167 /* failfast devices did receive failfast requests. */
168         R10BIO_FailFast,
169 };
170 #endif