176 lines · c
1// SPDX-License-Identifier: GPL-2.02/*3 * Some low level IO code, and hacks for various block layer limitations4 *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 17void bch_bbio_free(struct bio *bio, struct cache_set *c)18{19 struct bbio *b = container_of(bio, struct bbio, bio);20 21 mempool_free(b, &c->bio_meta);22}23 24struct bio *bch_bbio_alloc(struct cache_set *c)25{26 struct bbio *b = mempool_alloc(&c->bio_meta, GFP_NOIO);27 struct bio *bio = &b->bio;28 29 bio_init(bio, NULL, bio->bi_inline_vecs,30 meta_bucket_pages(&c->cache->sb), 0);31 32 return bio;33}34 35void __bch_submit_bbio(struct bio *bio, struct cache_set *c)36{37 struct bbio *b = container_of(bio, struct bbio, bio);38 39 bio->bi_iter.bi_sector = PTR_OFFSET(&b->key, 0);40 bio_set_dev(bio, c->cache->bdev);41 42 b->submit_time_us = local_clock_us();43 closure_bio_submit(c, bio, bio->bi_private);44}45 46void bch_submit_bbio(struct bio *bio, struct cache_set *c,47 struct bkey *k, unsigned int ptr)48{49 struct bbio *b = container_of(bio, struct bbio, bio);50 51 bch_bkey_copy_single_ptr(&b->key, k, ptr);52 __bch_submit_bbio(bio, c);53}54 55/* IO errors */56void bch_count_backing_io_errors(struct cached_dev *dc, struct bio *bio)57{58 unsigned int errors;59 60 WARN_ONCE(!dc, "NULL pointer of struct cached_dev");61 62 /*63 * Read-ahead requests on a degrading and recovering md raid64 * (e.g. raid6) device might be failured immediately by md65 * raid code, which is not a real hardware media failure. So66 * we shouldn't count failed REQ_RAHEAD bio to dc->io_errors.67 */68 if (bio->bi_opf & REQ_RAHEAD) {69 pr_warn_ratelimited("%pg: Read-ahead I/O failed on backing device, ignore\n",70 dc->bdev);71 return;72 }73 74 errors = atomic_add_return(1, &dc->io_errors);75 if (errors < dc->error_limit)76 pr_err("%pg: IO error on backing device, unrecoverable\n",77 dc->bdev);78 else79 bch_cached_dev_error(dc);80}81 82void bch_count_io_errors(struct cache *ca,83 blk_status_t error,84 int is_read,85 const char *m)86{87 /*88 * The halflife of an error is:89 * log2(1/2)/log2(127/128) * refresh ~= 88 * refresh90 */91 92 if (ca->set->error_decay) {93 unsigned int count = atomic_inc_return(&ca->io_count);94 95 while (count > ca->set->error_decay) {96 unsigned int errors;97 unsigned int old = count;98 unsigned int new = count - ca->set->error_decay;99 100 /*101 * First we subtract refresh from count; each time we102 * successfully do so, we rescale the errors once:103 */104 105 count = atomic_cmpxchg(&ca->io_count, old, new);106 107 if (count == old) {108 count = new;109 110 errors = atomic_read(&ca->io_errors);111 do {112 old = errors;113 new = ((uint64_t) errors * 127) / 128;114 errors = atomic_cmpxchg(&ca->io_errors,115 old, new);116 } while (old != errors);117 }118 }119 }120 121 if (error) {122 unsigned int errors = atomic_add_return(1 << IO_ERROR_SHIFT,123 &ca->io_errors);124 errors >>= IO_ERROR_SHIFT;125 126 if (errors < ca->set->error_limit)127 pr_err("%pg: IO error on %s%s\n",128 ca->bdev, m,129 is_read ? ", recovering." : ".");130 else131 bch_cache_set_error(ca->set,132 "%pg: too many IO errors %s\n",133 ca->bdev, m);134 }135}136 137void bch_bbio_count_io_errors(struct cache_set *c, struct bio *bio,138 blk_status_t error, const char *m)139{140 struct bbio *b = container_of(bio, struct bbio, bio);141 struct cache *ca = c->cache;142 int is_read = (bio_data_dir(bio) == READ ? 1 : 0);143 144 unsigned int threshold = op_is_write(bio_op(bio))145 ? c->congested_write_threshold_us146 : c->congested_read_threshold_us;147 148 if (threshold) {149 unsigned int t = local_clock_us();150 int us = t - b->submit_time_us;151 int congested = atomic_read(&c->congested);152 153 if (us > (int) threshold) {154 int ms = us / 1024;155 156 c->congested_last_us = t;157 158 ms = min(ms, CONGESTED_MAX + congested);159 atomic_sub(ms, &c->congested);160 } else if (congested < 0)161 atomic_inc(&c->congested);162 }163 164 bch_count_io_errors(ca, error, is_read, m);165}166 167void bch_bbio_endio(struct cache_set *c, struct bio *bio,168 blk_status_t error, const char *m)169{170 struct closure *cl = bio->bi_private;171 172 bch_bbio_count_io_errors(c, bio, error, m);173 bio_put(bio);174 closure_put(cl);175}176