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1/* SPDX-License-Identifier: GPL-2.0 */
2/*
3 * Copyright (C) 2012 Fusion-io All rights reserved.
4 * Copyright (C) 2012 Intel Corp. All rights reserved.
5 */
6
7#ifndef BTRFS_RAID56_H
8#define BTRFS_RAID56_H
9
10#include <linux/workqueue.h>
11#include "volumes.h"
12
13enum btrfs_rbio_ops {
14 BTRFS_RBIO_WRITE,
15 BTRFS_RBIO_READ_REBUILD,
16 BTRFS_RBIO_PARITY_SCRUB,
17 BTRFS_RBIO_REBUILD_MISSING,
18};
19
20struct btrfs_raid_bio {
21 struct btrfs_io_context *bioc;
22
23 /*
24 * While we're doing RMW on a stripe we put it into a hash table so we
25 * can lock the stripe and merge more rbios into it.
26 */
27 struct list_head hash_list;
28
29 /* LRU list for the stripe cache */
30 struct list_head stripe_cache;
31
32 /* For scheduling work in the helper threads */
33 struct work_struct work;
34
35 /*
36 * bio_list and bio_list_lock are used to add more bios into the stripe
37 * in hopes of avoiding the full RMW
38 */
39 struct bio_list bio_list;
40 spinlock_t bio_list_lock;
41
42 /*
43 * Also protected by the bio_list_lock, the plug list is used by the
44 * plugging code to collect partial bios while plugged. The stripe
45 * locking code also uses it to hand off the stripe lock to the next
46 * pending IO.
47 */
48 struct list_head plug_list;
49
50 /* Flags that tell us if it is safe to merge with this bio. */
51 unsigned long flags;
52
53 /*
54 * Set if we're doing a parity rebuild for a read from higher up, which
55 * is handled differently from a parity rebuild as part of RMW.
56 */
57 enum btrfs_rbio_ops operation;
58
59 /* How many pages there are for the full stripe including P/Q */
60 u16 nr_pages;
61
62 /* How many sectors there are for the full stripe including P/Q */
63 u16 nr_sectors;
64
65 /* Number of data stripes (no p/q) */
66 u8 nr_data;
67
68 /* Numer of all stripes (including P/Q) */
69 u8 real_stripes;
70
71 /* How many pages there are for each stripe */
72 u8 stripe_npages;
73
74 /* How many sectors there are for each stripe */
75 u8 stripe_nsectors;
76
77 /* Stripe number that we're scrubbing */
78 u8 scrubp;
79
80 /*
81 * Size of all the bios in the bio_list. This helps us decide if the
82 * rbio maps to a full stripe or not.
83 */
84 int bio_list_bytes;
85
86 refcount_t refs;
87
88 atomic_t stripes_pending;
89
90 wait_queue_head_t io_wait;
91
92 /* Bitmap to record which horizontal stripe has data */
93 unsigned long dbitmap;
94
95 /* Allocated with stripe_nsectors-many bits for finish_*() calls */
96 unsigned long finish_pbitmap;
97
98 /*
99 * These are two arrays of pointers. We allocate the rbio big enough
100 * to hold them both and setup their locations when the rbio is
101 * allocated.
102 */
103
104 /*
105 * Pointers to pages that we allocated for reading/writing stripes
106 * directly from the disk (including P/Q).
107 */
108 struct page **stripe_pages;
109
110 /* Pointers to the sectors in the bio_list, for faster lookup */
111 struct sector_ptr *bio_sectors;
112
113 /*
114 * For subpage support, we need to map each sector to above
115 * stripe_pages.
116 */
117 struct sector_ptr *stripe_sectors;
118
119 /* Allocated with real_stripes-many pointers for finish_*() calls */
120 void **finish_pointers;
121
122 /*
123 * The bitmap recording where IO errors happened.
124 * Each bit is corresponding to one sector in either bio_sectors[] or
125 * stripe_sectors[] array.
126 *
127 * The reason we don't use another bit in sector_ptr is, we have two
128 * arrays of sectors, and a lot of IO can use sectors in both arrays.
129 * Thus making it much harder to iterate.
130 */
131 unsigned long *error_bitmap;
132
133 /*
134 * Checksum buffer if the rbio is for data. The buffer should cover
135 * all data sectors (exlcuding P/Q sectors).
136 */
137 u8 *csum_buf;
138
139 /*
140 * Each bit represents if the corresponding sector has data csum found.
141 * Should only cover data sectors (excluding P/Q sectors).
142 */
143 unsigned long *csum_bitmap;
144};
145
146/*
147 * For trace event usage only. Records useful debug info for each bio submitted
148 * by RAID56 to each physical device.
149 *
150 * No matter signed or not, (-1) is always the one indicating we can not grab
151 * the proper stripe number.
152 */
153struct raid56_bio_trace_info {
154 u64 devid;
155
156 /* The offset inside the stripe. (<= STRIPE_LEN) */
157 u32 offset;
158
159 /*
160 * Stripe number.
161 * 0 is the first data stripe, and nr_data for P stripe,
162 * nr_data + 1 for Q stripe.
163 * >= real_stripes for
164 */
165 u8 stripe_nr;
166};
167
168static inline int nr_data_stripes(const struct map_lookup *map)
169{
170 return map->num_stripes - btrfs_nr_parity_stripes(map->type);
171}
172
173#define RAID5_P_STRIPE ((u64)-2)
174#define RAID6_Q_STRIPE ((u64)-1)
175
176#define is_parity_stripe(x) (((x) == RAID5_P_STRIPE) || \
177 ((x) == RAID6_Q_STRIPE))
178
179struct btrfs_device;
180
181void raid56_parity_recover(struct bio *bio, struct btrfs_io_context *bioc,
182 int mirror_num);
183void raid56_parity_write(struct bio *bio, struct btrfs_io_context *bioc);
184
185void raid56_add_scrub_pages(struct btrfs_raid_bio *rbio, struct page *page,
186 unsigned int pgoff, u64 logical);
187
188struct btrfs_raid_bio *raid56_parity_alloc_scrub_rbio(struct bio *bio,
189 struct btrfs_io_context *bioc,
190 struct btrfs_device *scrub_dev,
191 unsigned long *dbitmap, int stripe_nsectors);
192void raid56_parity_submit_scrub_rbio(struct btrfs_raid_bio *rbio);
193
194struct btrfs_raid_bio *
195raid56_alloc_missing_rbio(struct bio *bio, struct btrfs_io_context *bioc);
196void raid56_submit_missing_rbio(struct btrfs_raid_bio *rbio);
197
198int btrfs_alloc_stripe_hash_table(struct btrfs_fs_info *info);
199void btrfs_free_stripe_hash_table(struct btrfs_fs_info *info);
200
201#endif
1/*
2 * Copyright (C) 2012 Fusion-io All rights reserved.
3 * Copyright (C) 2012 Intel Corp. All rights reserved.
4 *
5 * This program is free software; you can redistribute it and/or
6 * modify it under the terms of the GNU General Public
7 * License v2 as published by the Free Software Foundation.
8 *
9 * This program is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
12 * General Public License for more details.
13 *
14 * You should have received a copy of the GNU General Public
15 * License along with this program; if not, write to the
16 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
17 * Boston, MA 021110-1307, USA.
18 */
19
20#ifndef __BTRFS_RAID56__
21#define __BTRFS_RAID56__
22static inline int nr_parity_stripes(struct map_lookup *map)
23{
24 if (map->type & BTRFS_BLOCK_GROUP_RAID5)
25 return 1;
26 else if (map->type & BTRFS_BLOCK_GROUP_RAID6)
27 return 2;
28 else
29 return 0;
30}
31
32static inline int nr_data_stripes(struct map_lookup *map)
33{
34 return map->num_stripes - nr_parity_stripes(map);
35}
36#define RAID5_P_STRIPE ((u64)-2)
37#define RAID6_Q_STRIPE ((u64)-1)
38
39#define is_parity_stripe(x) (((x) == RAID5_P_STRIPE) || \
40 ((x) == RAID6_Q_STRIPE))
41
42struct btrfs_raid_bio;
43struct btrfs_device;
44
45int raid56_parity_recover(struct btrfs_root *root, struct bio *bio,
46 struct btrfs_bio *bbio, u64 stripe_len,
47 int mirror_num, int generic_io);
48int raid56_parity_write(struct btrfs_root *root, struct bio *bio,
49 struct btrfs_bio *bbio, u64 stripe_len);
50
51void raid56_add_scrub_pages(struct btrfs_raid_bio *rbio, struct page *page,
52 u64 logical);
53
54struct btrfs_raid_bio *
55raid56_parity_alloc_scrub_rbio(struct btrfs_root *root, struct bio *bio,
56 struct btrfs_bio *bbio, u64 stripe_len,
57 struct btrfs_device *scrub_dev,
58 unsigned long *dbitmap, int stripe_nsectors);
59void raid56_parity_submit_scrub_rbio(struct btrfs_raid_bio *rbio);
60
61struct btrfs_raid_bio *
62raid56_alloc_missing_rbio(struct btrfs_root *root, struct bio *bio,
63 struct btrfs_bio *bbio, u64 length);
64void raid56_submit_missing_rbio(struct btrfs_raid_bio *rbio);
65
66int btrfs_alloc_stripe_hash_table(struct btrfs_fs_info *info);
67void btrfs_free_stripe_hash_table(struct btrfs_fs_info *info);
68#endif