[mirror_ubuntu-jammy-kernel.git] / drivers / md / bcache / io.c

// SPDX-License-Identifier: GPL-2.0
/*
 * Some low level IO code, and hacks for various block layer limitations
 *
 * Copyright 2010, 2011 Kent Overstreet <kent.overstreet@gmail.com>
 * Copyright 2012 Google, Inc.
 */

#include "bcache.h"
#include "bset.h"
#include "debug.h"

#include <linux/blkdev.h>

/* Bios with headers */

void bch_bbio_free(struct bio *bio, struct cache_set *c)
{
	struct bbio *b = container_of(bio, struct bbio, bio);
	mempool_free(b, c->bio_meta);
}

struct bio *bch_bbio_alloc(struct cache_set *c)
{
	struct bbio *b = mempool_alloc(c->bio_meta, GFP_NOIO);
	struct bio *bio = &b->bio;

	bio_init(bio, bio->bi_inline_vecs, bucket_pages(c));

	return bio;
}

void __bch_submit_bbio(struct bio *bio, struct cache_set *c)
{
	struct bbio *b = container_of(bio, struct bbio, bio);

	bio->bi_iter.bi_sector	= PTR_OFFSET(&b->key, 0);
	bio_set_dev(bio, PTR_CACHE(c, &b->key, 0)->bdev);

	b->submit_time_us = local_clock_us();
	closure_bio_submit(bio, bio->bi_private);
}

void bch_submit_bbio(struct bio *bio, struct cache_set *c,
		     struct bkey *k, unsigned ptr)
{
	struct bbio *b = container_of(bio, struct bbio, bio);
	bch_bkey_copy_single_ptr(&b->key, k, ptr);
	__bch_submit_bbio(bio, c);
}

/* IO errors */

void bch_count_io_errors(struct cache *ca,
			 blk_status_t error,
			 int is_read,
			 const char *m)
{
	/*
	 * The halflife of an error is:
	 * log2(1/2)/log2(127/128) * refresh ~= 88 * refresh
	 */

	if (ca->set->error_decay) {
		unsigned count = atomic_inc_return(&ca->io_count);

		while (count > ca->set->error_decay) {
			unsigned errors;
			unsigned old = count;
			unsigned new = count - ca->set->error_decay;

			/*
			 * First we subtract refresh from count; each time we
			 * succesfully do so, we rescale the errors once:
			 */

			count = atomic_cmpxchg(&ca->io_count, old, new);

			if (count == old) {
				count = new;

				errors = atomic_read(&ca->io_errors);
				do {
					old = errors;
					new = ((uint64_t) errors * 127) / 128;
					errors = atomic_cmpxchg(&ca->io_errors,
								old, new);
				} while (old != errors);
			}
		}
	}

	if (error) {
		char buf[BDEVNAME_SIZE];
		unsigned errors = atomic_add_return(1 << IO_ERROR_SHIFT,
						    &ca->io_errors);
		errors >>= IO_ERROR_SHIFT;

		if (errors < ca->set->error_limit)
			pr_err("%s: IO error on %s%s",
			       bdevname(ca->bdev, buf), m,
			       is_read ? ", recovering." : ".");
		else
			bch_cache_set_error(ca->set,
					    "%s: too many IO errors %s",
					    bdevname(ca->bdev, buf), m);
	}
}

void bch_bbio_count_io_errors(struct cache_set *c, struct bio *bio,
			      blk_status_t error, const char *m)
{
	struct bbio *b = container_of(bio, struct bbio, bio);
	struct cache *ca = PTR_CACHE(c, &b->key, 0);
	int is_read = (bio_data_dir(bio) == READ ? 1 : 0);

	unsigned threshold = op_is_write(bio_op(bio))
		? c->congested_write_threshold_us
		: c->congested_read_threshold_us;

	if (threshold) {
		unsigned t = local_clock_us();

		int us = t - b->submit_time_us;
		int congested = atomic_read(&c->congested);

		if (us > (int) threshold) {
			int ms = us / 1024;
			c->congested_last_us = t;

			ms = min(ms, CONGESTED_MAX + congested);
			atomic_sub(ms, &c->congested);
		} else if (congested < 0)
			atomic_inc(&c->congested);
	}

	bch_count_io_errors(ca, error, is_read, m);
}

void bch_bbio_endio(struct cache_set *c, struct bio *bio,
		    blk_status_t error, const char *m)
{
	struct closure *cl = bio->bi_private;

	bch_bbio_count_io_errors(c, bio, error, m);
	bio_put(bio);
	closure_put(cl);
}
Commit	Line	Data
b2441318	1	// SPDX-License-Identifier: GPL-2.0
cafe5635 KO	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
c37511b8 KO	13	#include <linux/blkdev.h>
c37511b8 KO	14
cafe5635 KO	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
3a83f467	28	bio_init(bio, bio->bi_inline_vecs, bucket_pages(c));
cafe5635 KO	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
4f024f37	37	bio->bi_iter.bi_sector = PTR_OFFSET(&b->key, 0);
74d46992	38	bio_set_dev(bio, PTR_CACHE(c, &b->key, 0)->bdev);
cafe5635 KO	39
cafe5635 KO	40	b->submit_time_us = local_clock_us();
749b61da	41	closure_bio_submit(bio, bio->bi_private);
cafe5635 KO	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
5138ac67 CL	54	void bch_count_io_errors(struct cache *ca,
	55	blk_status_t error,
	56	int is_read,
	57	const char *m)
cafe5635 KO	58	{
	59	/*
	60	* The halflife of an error is:
	61	* log2(1/2)/log2(127/128) * refresh ~= 88 * refresh
	62	*/
	63
	64	if (ca->set->error_decay) {
	65	unsigned count = atomic_inc_return(&ca->io_count);
	66
	67	while (count > ca->set->error_decay) {
	68	unsigned errors;
	69	unsigned old = count;
	70	unsigned new = count - ca->set->error_decay;
	71
	72	/*
	73	* First we subtract refresh from count; each time we
	74	* succesfully do so, we rescale the errors once:
	75	*/
	76
	77	count = atomic_cmpxchg(&ca->io_count, old, new);
	78
	79	if (count == old) {
	80	count = new;
	81
	82	errors = atomic_read(&ca->io_errors);
	83	do {
	84	old = errors;
	85	new = ((uint64_t) errors * 127) / 128;
	86	errors = atomic_cmpxchg(&ca->io_errors,
	87	old, new);
	88	} while (old != errors);
	89	}
	90	}
	91	}
	92
	93	if (error) {
	94	char buf[BDEVNAME_SIZE];
	95	unsigned errors = atomic_add_return(1 << IO_ERROR_SHIFT,
	96	&ca->io_errors);
	97	errors >>= IO_ERROR_SHIFT;
	98
	99	if (errors < ca->set->error_limit)
5138ac67 CL	100	pr_err("%s: IO error on %s%s",
	101	bdevname(ca->bdev, buf), m,
	102	is_read ? ", recovering." : ".");
cafe5635 KO	103	else
	104	bch_cache_set_error(ca->set,
	105	"%s: too many IO errors %s",
	106	bdevname(ca->bdev, buf), m);
	107	}
	108	}
	109
	110	void bch_bbio_count_io_errors(struct cache_set c, struct bio bio,
4e4cbee9	111	blk_status_t error, const char *m)
cafe5635 KO	112	{
	113	struct bbio *b = container_of(bio, struct bbio, bio);
	114	struct cache *ca = PTR_CACHE(c, &b->key, 0);
5138ac67	115	int is_read = (bio_data_dir(bio) == READ ? 1 : 0);
cafe5635	116
c8d93247	117	unsigned threshold = op_is_write(bio_op(bio))
cafe5635 KO	118	? c->congested_write_threshold_us
	119	: c->congested_read_threshold_us;
	120
	121	if (threshold) {
	122	unsigned t = local_clock_us();
	123
	124	int us = t - b->submit_time_us;
	125	int congested = atomic_read(&c->congested);
	126
	127	if (us > (int) threshold) {
	128	int ms = us / 1024;
	129	c->congested_last_us = t;
	130
	131	ms = min(ms, CONGESTED_MAX + congested);
	132	atomic_sub(ms, &c->congested);
	133	} else if (congested < 0)
	134	atomic_inc(&c->congested);
	135	}
	136
5138ac67	137	bch_count_io_errors(ca, error, is_read, m);
cafe5635 KO	138	}
	139
	140	void bch_bbio_endio(struct cache_set c, struct bio bio,
4e4cbee9	141	blk_status_t error, const char *m)
cafe5635 KO	142	{
	143	struct closure *cl = bio->bi_private;
	144
	145	bch_bbio_count_io_errors(c, bio, error, m);
	146	bio_put(bio);
	147	closure_put(cl);
	148	}