1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * Some low level IO code, and hacks for various block layer limitations 4 * 5 * Copyright 2010, 2011 Kent Overstreet <kent.overstreet@gmail.com> 6 * Copyright 2012 Google, Inc. 7 */ 8 9 #include "bcache.h" 10 #include "bset.h" 11 #include "debug.h" 12 13 #include <linux/blkdev.h> 14 15 /* Bios with headers */ 16 17 void bch_bbio_free(struct bio *bio, struct cache_set *c) 18 { 19 struct bbio *b = container_of(bio, struct bbio, bio); 20 mempool_free(b, c->bio_meta); 21 } 22 23 struct bio *bch_bbio_alloc(struct cache_set *c) 24 { 25 struct bbio *b = mempool_alloc(c->bio_meta, GFP_NOIO); 26 struct bio *bio = &b->bio; 27 28 bio_init(bio, bio->bi_inline_vecs, bucket_pages(c)); 29 30 return bio; 31 } 32 33 void __bch_submit_bbio(struct bio *bio, struct cache_set *c) 34 { 35 struct bbio *b = container_of(bio, struct bbio, bio); 36 37 bio->bi_iter.bi_sector = PTR_OFFSET(&b->key, 0); 38 bio_set_dev(bio, PTR_CACHE(c, &b->key, 0)->bdev); 39 40 b->submit_time_us = local_clock_us(); 41 closure_bio_submit(bio, bio->bi_private); 42 } 43 44 void bch_submit_bbio(struct bio *bio, struct cache_set *c, 45 struct bkey *k, unsigned ptr) 46 { 47 struct bbio *b = container_of(bio, struct bbio, bio); 48 bch_bkey_copy_single_ptr(&b->key, k, ptr); 49 __bch_submit_bbio(bio, c); 50 } 51 52 /* IO errors */ 53 54 void bch_count_io_errors(struct cache *ca, blk_status_t error, const char *m) 55 { 56 /* 57 * The halflife of an error is: 58 * log2(1/2)/log2(127/128) * refresh ~= 88 * refresh 59 */ 60 61 if (ca->set->error_decay) { 62 unsigned count = atomic_inc_return(&ca->io_count); 63 64 while (count > ca->set->error_decay) { 65 unsigned errors; 66 unsigned old = count; 67 unsigned new = count - ca->set->error_decay; 68 69 /* 70 * First we subtract refresh from count; each time we 71 * succesfully do so, we rescale the errors once: 72 */ 73 74 count = atomic_cmpxchg(&ca->io_count, old, new); 75 76 if (count == old) { 77 count = new; 78 79 errors = atomic_read(&ca->io_errors); 80 do { 81 old = errors; 82 new = ((uint64_t) errors * 127) / 128; 83 errors = atomic_cmpxchg(&ca->io_errors, 84 old, new); 85 } while (old != errors); 86 } 87 } 88 } 89 90 if (error) { 91 char buf[BDEVNAME_SIZE]; 92 unsigned errors = atomic_add_return(1 << IO_ERROR_SHIFT, 93 &ca->io_errors); 94 errors >>= IO_ERROR_SHIFT; 95 96 if (errors < ca->set->error_limit) 97 pr_err("%s: IO error on %s, recovering", 98 bdevname(ca->bdev, buf), m); 99 else 100 bch_cache_set_error(ca->set, 101 "%s: too many IO errors %s", 102 bdevname(ca->bdev, buf), m); 103 } 104 } 105 106 void bch_bbio_count_io_errors(struct cache_set *c, struct bio *bio, 107 blk_status_t error, const char *m) 108 { 109 struct bbio *b = container_of(bio, struct bbio, bio); 110 struct cache *ca = PTR_CACHE(c, &b->key, 0); 111 112 unsigned threshold = op_is_write(bio_op(bio)) 113 ? c->congested_write_threshold_us 114 : c->congested_read_threshold_us; 115 116 if (threshold) { 117 unsigned t = local_clock_us(); 118 119 int us = t - b->submit_time_us; 120 int congested = atomic_read(&c->congested); 121 122 if (us > (int) threshold) { 123 int ms = us / 1024; 124 c->congested_last_us = t; 125 126 ms = min(ms, CONGESTED_MAX + congested); 127 atomic_sub(ms, &c->congested); 128 } else if (congested < 0) 129 atomic_inc(&c->congested); 130 } 131 132 bch_count_io_errors(ca, error, m); 133 } 134 135 void bch_bbio_endio(struct cache_set *c, struct bio *bio, 136 blk_status_t error, const char *m) 137 { 138 struct closure *cl = bio->bi_private; 139 140 bch_bbio_count_io_errors(c, bio, error, m); 141 bio_put(bio); 142 closure_put(cl); 143 } 144