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
rbio_pool_free(void * rbio,void * data)31 static void rbio_pool_free(void *rbio, void *data)
32 {
33 kfree(rbio);
34 }
35
resync_alloc_pages(struct resync_pages * rp,gfp_t gfp_flags)36 static inline int resync_alloc_pages(struct resync_pages *rp,
37 gfp_t gfp_flags)
38 {
39 int i;
40
41 for (i = 0; i < RESYNC_PAGES; i++) {
42 rp->pages[i] = alloc_page(gfp_flags);
43 if (!rp->pages[i])
44 goto out_free;
45 }
46
47 return 0;
48
49 out_free:
50 while (--i >= 0)
51 put_page(rp->pages[i]);
52 return -ENOMEM;
53 }
54
resync_free_pages(struct resync_pages * rp)55 static inline void resync_free_pages(struct resync_pages *rp)
56 {
57 int i;
58
59 for (i = 0; i < RESYNC_PAGES; i++)
60 put_page(rp->pages[i]);
61 }
62
resync_get_all_pages(struct resync_pages * rp)63 static inline void resync_get_all_pages(struct resync_pages *rp)
64 {
65 int i;
66
67 for (i = 0; i < RESYNC_PAGES; i++)
68 get_page(rp->pages[i]);
69 }
70
resync_fetch_page(struct resync_pages * rp,unsigned idx)71 static inline struct page *resync_fetch_page(struct resync_pages *rp,
72 unsigned idx)
73 {
74 if (WARN_ON_ONCE(idx >= RESYNC_PAGES))
75 return NULL;
76 return rp->pages[idx];
77 }
78
79 /*
80 * 'strct resync_pages' stores actual pages used for doing the resync
81 * IO, and it is per-bio, so make .bi_private points to it.
82 */
get_resync_pages(struct bio * bio)83 static inline struct resync_pages *get_resync_pages(struct bio *bio)
84 {
85 return bio->bi_private;
86 }
87
88 /* generally called after bio_reset() for reseting bvec */
md_bio_reset_resync_pages(struct bio * bio,struct resync_pages * rp,int size)89 static void md_bio_reset_resync_pages(struct bio *bio, struct resync_pages *rp,
90 int size)
91 {
92 int idx = 0;
93
94 /* initialize bvec table again */
95 do {
96 struct page *page = resync_fetch_page(rp, idx);
97 int len = min_t(int, size, PAGE_SIZE);
98
99 /*
100 * won't fail because the vec table is big
101 * enough to hold all these pages
102 */
103 bio_add_page(bio, page, len, 0);
104 size -= len;
105 } while (idx++ < RESYNC_PAGES && size > 0);
106 }
107