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 36 static void rbio_pool_free(void *rbio, void *data) 37 { 38 kfree(rbio); 39 } 40 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 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 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 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 */ 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 */ 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