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/* for managing resync I/O pages */
7struct resync_pages {
8 void *raid_bio;
9 struct page *pages[RESYNC_PAGES];
10};
11
12static inline int resync_alloc_pages(struct resync_pages *rp,
13 gfp_t gfp_flags)
14{
15 int i;
16
17 for (i = 0; i < RESYNC_PAGES; i++) {
18 rp->pages[i] = alloc_page(gfp_flags);
19 if (!rp->pages[i])
20 goto out_free;
21 }
22
23 return 0;
24
25out_free:
26 while (--i >= 0)
27 put_page(rp->pages[i]);
28 return -ENOMEM;
29}
30
31static inline void resync_free_pages(struct resync_pages *rp)
32{
33 int i;
34
35 for (i = 0; i < RESYNC_PAGES; i++)
36 put_page(rp->pages[i]);
37}
38
39static inline void resync_get_all_pages(struct resync_pages *rp)
40{
41 int i;
42
43 for (i = 0; i < RESYNC_PAGES; i++)
44 get_page(rp->pages[i]);
45}
46
47static inline struct page *resync_fetch_page(struct resync_pages *rp,
48 unsigned idx)
49{
50 if (WARN_ON_ONCE(idx >= RESYNC_PAGES))
51 return NULL;
52 return rp->pages[idx];
53}
54
55/*
56 * 'strct resync_pages' stores actual pages used for doing the resync
57 * IO, and it is per-bio, so make .bi_private points to it.
58 */
59static inline struct resync_pages *get_resync_pages(struct bio *bio)
60{
61 return bio->bi_private;
62}
63
64/* generally called after bio_reset() for reseting bvec */
65static void md_bio_reset_resync_pages(struct bio *bio, struct resync_pages *rp,
66 int size)
67{
68 int idx = 0;
69
70 /* initialize bvec table again */
71 do {
72 struct page *page = resync_fetch_page(rp, idx);
73 int len = min_t(int, size, PAGE_SIZE);
74
75 /*
76 * won't fail because the vec table is big
77 * enough to hold all these pages
78 */
79 bio_add_page(bio, page, len, 0);
80 size -= len;
81 } while (idx++ < RESYNC_PAGES && size > 0);
82}
83