Commit 279afbad authored by Kent Overstreet's avatar Kent Overstreet
Browse files

bcache: Track dirty data by stripe 



To make background writeback aware of raid5/6 stripes, we first need to
track the amount of dirty data within each stripe - we do this by
breaking up the existing sectors_dirty into per stripe atomic_ts

Signed-off-by: default avatarKent Overstreet <koverstreet@google.com>
parent 444fc0b6

drivers/md/bcache/bcache.h

+4 −6
Original line number Diff line number Diff line
@@ -437,7 +437,10 @@ struct bcache_device { 
	/* If nonzero, we're detaching/unregistering from cache set */

	atomic_t		detaching;



	atomic_long_t		sectors_dirty;

	uint64_t		nr_stripes;

	unsigned		stripe_size_bits;

	atomic_t		*stripe_sectors_dirty;



	unsigned long		sectors_dirty_last;

	long			sectors_dirty_derivative;
@@ -1159,9 +1162,6 @@ static inline void wake_up_allocators(struct cache_set *c) 


/* Forward declarations */



void bch_writeback_queue(struct cached_dev *);

void bch_writeback_add(struct cached_dev *, unsigned);



void bch_count_io_errors(struct cache *, int, const char *);

void bch_bbio_count_io_errors(struct cache_set *, struct bio *,

			      int, const char *);
@@ -1224,8 +1224,6 @@ void bch_cache_set_stop(struct cache_set *); 
struct cache_set *bch_cache_set_alloc(struct cache_sb *);

void bch_btree_cache_free(struct cache_set *);

int bch_btree_cache_alloc(struct cache_set *);

void bch_sectors_dirty_init(struct cached_dev *);

void bch_cached_dev_writeback_init(struct cached_dev *);

void bch_moving_init_cache_set(struct cache_set *);



int bch_cache_allocator_start(struct cache *ca);

drivers/md/bcache/btree.c

+13 −7
Original line number Diff line number Diff line
@@ -24,6 +24,7 @@ 
#include "btree.h"

#include "debug.h"

#include "request.h"

#include "writeback.h"



#include <linux/slab.h>

#include <linux/bitops.h>
@@ -1599,14 +1600,14 @@ static bool fix_overlapping_extents(struct btree *b, 
				    struct btree_iter *iter,

				    struct btree_op *op)

{

	void subtract_dirty(struct bkey *k, int sectors)

	void subtract_dirty(struct bkey *k, uint64_t offset, int sectors)

	{

		struct bcache_device *d = b->c->devices[KEY_INODE(k)];



		if (KEY_DIRTY(k) && d)

			atomic_long_sub(sectors, &d->sectors_dirty);

		if (KEY_DIRTY(k))

			bcache_dev_sectors_dirty_add(b->c, KEY_INODE(k),

						     offset, -sectors);

	}



	uint64_t old_offset;

	unsigned old_size, sectors_found = 0;



	while (1) {
@@ -1618,6 +1619,7 @@ static bool fix_overlapping_extents(struct btree *b, 
		if (bkey_cmp(k, &START_KEY(insert)) <= 0)

			continue;



		old_offset = KEY_START(k);

		old_size = KEY_SIZE(k);



		/*
@@ -1673,7 +1675,7 @@ static bool fix_overlapping_extents(struct btree *b, 


			struct bkey *top;



			subtract_dirty(k, KEY_SIZE(insert));

			subtract_dirty(k, KEY_START(insert), KEY_SIZE(insert));



			if (bkey_written(b, k)) {

				/*
@@ -1720,7 +1722,7 @@ static bool fix_overlapping_extents(struct btree *b, 
			}

		}



		subtract_dirty(k, old_size - KEY_SIZE(k));

		subtract_dirty(k, old_offset, old_size - KEY_SIZE(k));

	}



check_failed:
@@ -1796,6 +1798,10 @@ static bool btree_insert_key(struct btree *b, struct btree_op *op, 
insert:	shift_keys(b, m, k);

copy:	bkey_copy(m, k);

merged:

	if (KEY_DIRTY(k))

		bcache_dev_sectors_dirty_add(b->c, KEY_INODE(k),

					     KEY_START(k), KEY_SIZE(k));



	bch_check_keys(b, "%u for %s", status, op_type(op));



	if (b->level && !KEY_OFFSET(k))

drivers/md/bcache/request.c

+2 −1
Original line number Diff line number Diff line
@@ -10,6 +10,7 @@ 
#include "btree.h"

#include "debug.h"

#include "request.h"

#include "writeback.h"



#include <linux/cgroup.h>

#include <linux/module.h>
@@ -1044,7 +1045,7 @@ static void request_write(struct cached_dev *dc, struct search *s) 
		closure_bio_submit(bio, cl, s->d);

	} else {

		s->op.cache_bio = bio;

		bch_writeback_add(dc, bio_sectors(bio));

		bch_writeback_add(dc);

	}

out:

	closure_call(&s->op.cl, bch_insert_data, NULL, cl);

drivers/md/bcache/super.c

+28 −4
Original line number Diff line number Diff line
@@ -10,6 +10,7 @@ 
#include "btree.h"

#include "debug.h"

#include "request.h"

#include "writeback.h"



#include <linux/blkdev.h>

#include <linux/buffer_head.h>
@@ -744,13 +745,35 @@ static void bcache_device_free(struct bcache_device *d) 
		mempool_destroy(d->unaligned_bvec);

	if (d->bio_split)

		bioset_free(d->bio_split);

	if (is_vmalloc_addr(d->stripe_sectors_dirty))

		vfree(d->stripe_sectors_dirty);

	else

		kfree(d->stripe_sectors_dirty);



	closure_debug_destroy(&d->cl);

}



static int bcache_device_init(struct bcache_device *d, unsigned block_size)

static int bcache_device_init(struct bcache_device *d, unsigned block_size,

			      sector_t sectors)

{

	struct request_queue *q;

	size_t n;



	if (!d->stripe_size_bits)

		d->stripe_size_bits = 31;



	d->nr_stripes = round_up(sectors, 1 << d->stripe_size_bits) >>

		d->stripe_size_bits;



	if (!d->nr_stripes || d->nr_stripes > SIZE_MAX / sizeof(atomic_t))

		return -ENOMEM;



	n = d->nr_stripes * sizeof(atomic_t);

	d->stripe_sectors_dirty = n < PAGE_SIZE << 6

		? kzalloc(n, GFP_KERNEL)

		: vzalloc(n);

	if (!d->stripe_sectors_dirty)

		return -ENOMEM;



	if (!(d->bio_split = bioset_create(4, offsetof(struct bbio, bio))) ||

	    !(d->unaligned_bvec = mempool_create_kmalloc_pool(1,
@@ -760,6 +783,7 @@ static int bcache_device_init(struct bcache_device *d, unsigned block_size) 
	    !(q = blk_alloc_queue(GFP_KERNEL)))

		return -ENOMEM;



	set_capacity(d->disk, sectors);

	snprintf(d->disk->disk_name, DISK_NAME_LEN, "bcache%i", bcache_minor);



	d->disk->major		= bcache_major;
@@ -1047,7 +1071,8 @@ static int cached_dev_init(struct cached_dev *dc, unsigned block_size) 
		hlist_add_head(&io->hash, dc->io_hash + RECENT_IO);

	}



	ret = bcache_device_init(&dc->disk, block_size);

	ret = bcache_device_init(&dc->disk, block_size,

			 dc->bdev->bd_part->nr_sects - dc->sb.data_offset);

	if (ret)

		return ret;
@@ -1146,11 +1171,10 @@ static int flash_dev_run(struct cache_set *c, struct uuid_entry *u) 


	kobject_init(&d->kobj, &bch_flash_dev_ktype);



	if (bcache_device_init(d, block_bytes(c)))

	if (bcache_device_init(d, block_bytes(c), u->sectors))

		goto err;



	bcache_device_attach(d, c, u - c->uuids);

	set_capacity(d->disk, u->sectors);

	bch_flash_dev_request_init(d);

	add_disk(d->disk);

drivers/md/bcache/sysfs.c

+3 −2
Original line number Diff line number Diff line
@@ -9,6 +9,7 @@ 
#include "sysfs.h"

#include "btree.h"

#include "request.h"

#include "writeback.h"



#include <linux/blkdev.h>

#include <linux/sort.h>
@@ -128,7 +129,7 @@ SHOW(__bch_cached_dev) 
		char derivative[20];

		char target[20];

		bch_hprint(dirty,

		       atomic_long_read(&dc->disk.sectors_dirty) << 9);

			   bcache_dev_sectors_dirty(&dc->disk) << 9);

		bch_hprint(derivative,	dc->writeback_rate_derivative << 9);

		bch_hprint(target,	dc->writeback_rate_target << 9);
@@ -144,7 +145,7 @@ SHOW(__bch_cached_dev) 
	}



	sysfs_hprint(dirty_data,

		     atomic_long_read(&dc->disk.sectors_dirty) << 9);

		     bcache_dev_sectors_dirty(&dc->disk) << 9);



	var_printf(sequential_merge,	"%i");

	var_hprint(sequential_cutoff);

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