1 // SPDX-License-Identifier: GPL-2.0
3 * Some low level IO code, and hacks for various block layer limitations
5 * Copyright 2010, 2011 Kent Overstreet <kent.overstreet@gmail.com>
6 * Copyright 2012 Google, Inc.
13 #include <linux/blkdev.h>
15 /* Bios with headers */
17 void bch_bbio_free(struct bio *bio, struct cache_set *c)
19 struct bbio *b = container_of(bio, struct bbio, bio);
20 mempool_free(b, c->bio_meta);
23 struct bio *bch_bbio_alloc(struct cache_set *c)
25 struct bbio *b = mempool_alloc(c->bio_meta, GFP_NOIO);
26 struct bio *bio = &b->bio;
28 bio_init(bio, bio->bi_inline_vecs, bucket_pages(c));
33 void __bch_submit_bbio(struct bio *bio, struct cache_set *c)
35 struct bbio *b = container_of(bio, struct bbio, bio);
37 bio->bi_iter.bi_sector = PTR_OFFSET(&b->key, 0);
38 bio_set_dev(bio, PTR_CACHE(c, &b->key, 0)->bdev);
40 b->submit_time_us = local_clock_us();
41 closure_bio_submit(bio, bio->bi_private);
44 void bch_submit_bbio(struct bio *bio, struct cache_set *c,
45 struct bkey *k, unsigned ptr)
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);
54 void bch_count_io_errors(struct cache *ca, blk_status_t error, const char *m)
57 * The halflife of an error is:
58 * log2(1/2)/log2(127/128) * refresh ~= 88 * refresh
61 if (ca->set->error_decay) {
62 unsigned count = atomic_inc_return(&ca->io_count);
64 while (count > ca->set->error_decay) {
67 unsigned new = count - ca->set->error_decay;
70 * First we subtract refresh from count; each time we
71 * succesfully do so, we rescale the errors once:
74 count = atomic_cmpxchg(&ca->io_count, old, new);
79 errors = atomic_read(&ca->io_errors);
82 new = ((uint64_t) errors * 127) / 128;
83 errors = atomic_cmpxchg(&ca->io_errors,
85 } while (old != errors);
91 char buf[BDEVNAME_SIZE];
92 unsigned errors = atomic_add_return(1 << IO_ERROR_SHIFT,
94 errors >>= IO_ERROR_SHIFT;
96 if (errors < ca->set->error_limit)
97 pr_err("%s: IO error on %s, recovering",
98 bdevname(ca->bdev, buf), m);
100 bch_cache_set_error(ca->set,
101 "%s: too many IO errors %s",
102 bdevname(ca->bdev, buf), m);
106 void bch_bbio_count_io_errors(struct cache_set *c, struct bio *bio,
107 blk_status_t error, const char *m)
109 struct bbio *b = container_of(bio, struct bbio, bio);
110 struct cache *ca = PTR_CACHE(c, &b->key, 0);
112 unsigned threshold = op_is_write(bio_op(bio))
113 ? c->congested_write_threshold_us
114 : c->congested_read_threshold_us;
117 unsigned t = local_clock_us();
119 int us = t - b->submit_time_us;
120 int congested = atomic_read(&c->congested);
122 if (us > (int) threshold) {
124 c->congested_last_us = t;
126 ms = min(ms, CONGESTED_MAX + congested);
127 atomic_sub(ms, &c->congested);
128 } else if (congested < 0)
129 atomic_inc(&c->congested);
132 bch_count_io_errors(ca, error, m);
135 void bch_bbio_endio(struct cache_set *c, struct bio *bio,
136 blk_status_t error, const char *m)
138 struct closure *cl = bio->bi_private;
140 bch_bbio_count_io_errors(c, bio, error, m);