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)
7 * Number of guaranteed raid bios in case of extreme VM load:
9 #define NR_RAID_BIOS 256
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
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
21 #define IO_MADE_GOOD ((struct bio *)2)
23 #define BIO_SPECIAL(bio) ((unsigned long)bio <= 2)
25 /* When there are this many requests queue to be written by
26 * the raid thread, we become 'congested' to provide back-pressure
29 static int max_queued_requests = 1024;
31 /* for managing resync I/O pages */
34 struct page *pages[RESYNC_PAGES];
37 static void rbio_pool_free(void *rbio, void *data)
42 static inline int resync_alloc_pages(struct resync_pages *rp,
47 for (i = 0; i < RESYNC_PAGES; i++) {
48 rp->pages[i] = alloc_page(gfp_flags);
57 put_page(rp->pages[i]);
61 static inline void resync_free_pages(struct resync_pages *rp)
65 for (i = 0; i < RESYNC_PAGES; i++)
66 put_page(rp->pages[i]);
69 static inline void resync_get_all_pages(struct resync_pages *rp)
73 for (i = 0; i < RESYNC_PAGES; i++)
74 get_page(rp->pages[i]);
77 static inline struct page *resync_fetch_page(struct resync_pages *rp,
80 if (WARN_ON_ONCE(idx >= RESYNC_PAGES))
82 return rp->pages[idx];
86 * 'strct resync_pages' stores actual pages used for doing the resync
87 * IO, and it is per-bio, so make .bi_private points to it.
89 static inline struct resync_pages *get_resync_pages(struct bio *bio)
91 return bio->bi_private;
94 /* generally called after bio_reset() for reseting bvec */
95 static void md_bio_reset_resync_pages(struct bio *bio, struct resync_pages *rp,
100 /* initialize bvec table again */
102 struct page *page = resync_fetch_page(rp, idx);
103 int len = min_t(int, size, PAGE_SIZE);
106 * won't fail because the vec table is big
107 * enough to hold all these pages
109 bio_add_page(bio, page, len, 0);
111 } while (idx++ < RESYNC_PAGES && size > 0);