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 static void rbio_pool_free(void *rbio, void *data) 32 { 33 kfree(rbio); 34 } 35 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 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 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 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 */ 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 */ 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