1 // SPDX-License-Identifier: GPL-2.0
2 /* Maximum size of each resync request */
3 #define RESYNC_BLOCK_SIZE (64*1024)
4 #define RESYNC_PAGES ((RESYNC_BLOCK_SIZE + PAGE_SIZE-1) / PAGE_SIZE)
5
6 /*
7 * Number of guaranteed raid bios in case of extreme VM load:
8 */
9 #define NR_RAID_BIOS 256
10
11 /* when we get a read error on a read-only array, we redirect to another
12 * device without failing the first device, or trying to over-write to
13 * correct the read error. To keep track of bad blocks on a per-bio
14 * level, we store IO_BLOCKED in the appropriate 'bios' pointer
15 */
16 #define IO_BLOCKED ((struct bio *)1)
17 /* When we successfully write to a known bad-block, we need to remove the
18 * bad-block marking which must be done from process context. So we record
19 * the success by setting devs[n].bio to IO_MADE_GOOD
20 */
21 #define IO_MADE_GOOD ((struct bio *)2)
22
23 #define BIO_SPECIAL(bio) ((unsigned long)bio <= 2)
24
25 /* for managing resync I/O pages */
26 struct resync_pages {
27 void *raid_bio;
28 struct page *pages[RESYNC_PAGES];
29 };
30
31 struct raid1_plug_cb {
32 struct blk_plug_cb cb;
33 struct bio_list pending;
34 };
35
rbio_pool_free(void * rbio,void * data)36 static void rbio_pool_free(void *rbio, void *data)
37 {
38 kfree(rbio);
39 }
40
resync_alloc_pages(struct resync_pages * rp,gfp_t gfp_flags)41 static inline int resync_alloc_pages(struct resync_pages *rp,
42 gfp_t gfp_flags)
43 {
44 int i;
45
46 for (i = 0; i < RESYNC_PAGES; i++) {
47 rp->pages[i] = alloc_page(gfp_flags);
48 if (!rp->pages[i])
49 goto out_free;
50 }
51
52 return 0;
53
54 out_free:
55 while (--i >= 0)
56 put_page(rp->pages[i]);
57 return -ENOMEM;
58 }
59
resync_free_pages(struct resync_pages * rp)60 static inline void resync_free_pages(struct resync_pages *rp)
61 {
62 int i;
63
64 for (i = 0; i < RESYNC_PAGES; i++)
65 put_page(rp->pages[i]);
66 }
67
resync_get_all_pages(struct resync_pages * rp)68 static inline void resync_get_all_pages(struct resync_pages *rp)
69 {
70 int i;
71
72 for (i = 0; i < RESYNC_PAGES; i++)
73 get_page(rp->pages[i]);
74 }
75
resync_fetch_page(struct resync_pages * rp,unsigned idx)76 static inline struct page *resync_fetch_page(struct resync_pages *rp,
77 unsigned idx)
78 {
79 if (WARN_ON_ONCE(idx >= RESYNC_PAGES))
80 return NULL;
81 return rp->pages[idx];
82 }
83
84 /*
85 * 'strct resync_pages' stores actual pages used for doing the resync
86 * IO, and it is per-bio, so make .bi_private points to it.
87 */
get_resync_pages(struct bio * bio)88 static inline struct resync_pages *get_resync_pages(struct bio *bio)
89 {
90 return bio->bi_private;
91 }
92
93 /* generally called after bio_reset() for reseting bvec */
md_bio_reset_resync_pages(struct bio * bio,struct resync_pages * rp,int size)94 static void md_bio_reset_resync_pages(struct bio *bio, struct resync_pages *rp,
95 int size)
96 {
97 int idx = 0;
98
99 /* initialize bvec table again */
100 do {
101 struct page *page = resync_fetch_page(rp, idx);
102 int len = min_t(int, size, PAGE_SIZE);
103
104 /*
105 * won't fail because the vec table is big
106 * enough to hold all these pages
107 */
108 bio_add_page(bio, page, len, 0);
109 size -= len;
110 } while (idx++ < RESYNC_PAGES && size > 0);
111 }
112