Commit 2d679fc7 authored by Kent Overstreet's avatar Kent Overstreet
Browse files

bcache: Stripe size isn't necessarily a power of two 



Originally I got this right... except that the divides didn't use
do_div(), which broke 32 bit kernels. When I went to fix that, I forgot
that the raid stripe size usually isn't a power of two... doh

Signed-off-by: default avatarKent Overstreet <kmo@daterainc.com>
parent 77c320eb

drivers/md/bcache/bcache.h

+1 −1
Original line number Diff line number Diff line
@@ -437,7 +437,7 @@ struct bcache_device { 
	int			flush_done;



	uint64_t		nr_stripes;

	unsigned		stripe_size_bits;

	unsigned		stripe_size;

	atomic_t		*stripe_sectors_dirty;



	unsigned long		sectors_dirty_last;

drivers/md/bcache/super.c

+3 −4
Original line number Diff line number Diff line
@@ -761,11 +761,10 @@ static int bcache_device_init(struct bcache_device *d, unsigned block_size, 
	struct request_queue *q;

	size_t n;



	if (!d->stripe_size_bits)

		d->stripe_size_bits = 31;

	if (!d->stripe_size)

		d->stripe_size = 1 << 31;



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

		d->stripe_size_bits;

	d->nr_stripes = DIV_ROUND_UP_ULL(sectors, d->stripe_size);



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

		return -ENOMEM;

drivers/md/bcache/sysfs.c

+1 −1
Original line number Diff line number Diff line
@@ -157,7 +157,7 @@ SHOW(__bch_cached_dev) 
	sysfs_hprint(dirty_data,

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



	sysfs_hprint(stripe_size,	(1 << dc->disk.stripe_size_bits) << 9);

	sysfs_hprint(stripe_size,	dc->disk.stripe_size << 9);

	var_printf(partial_stripes_expensive,	"%u");



	var_printf(sequential_merge,	"%i");

drivers/md/bcache/writeback.c

+17 −16
Original line number Diff line number Diff line
@@ -114,25 +114,25 @@ static bool dirty_pred(struct keybuf *buf, struct bkey *k) 


static bool dirty_full_stripe_pred(struct keybuf *buf, struct bkey *k)

{

	uint64_t stripe;

	uint64_t stripe = KEY_START(k);

	unsigned nr_sectors = KEY_SIZE(k);

	struct cached_dev *dc = container_of(buf, struct cached_dev,

					     writeback_keys);

	unsigned stripe_size = 1 << dc->disk.stripe_size_bits;



	if (!KEY_DIRTY(k))

		return false;



	stripe = KEY_START(k) >> dc->disk.stripe_size_bits;

	while (1) {

		if (atomic_read(dc->disk.stripe_sectors_dirty + stripe) !=

		    stripe_size)

			return false;

	do_div(stripe, dc->disk.stripe_size);



		if (nr_sectors <= stripe_size)

	while (1) {

		if (atomic_read(dc->disk.stripe_sectors_dirty + stripe) ==

		    dc->disk.stripe_size)

			return true;



		nr_sectors -= stripe_size;

		if (nr_sectors <= dc->disk.stripe_size)

			return false;



		nr_sectors -= dc->disk.stripe_size;

		stripe++;

	}

}
@@ -186,11 +186,12 @@ static void refill_dirty(struct closure *cl) 


		for (i = 0; i < dc->disk.nr_stripes; i++)

			if (atomic_read(dc->disk.stripe_sectors_dirty + i) ==

			    1 << dc->disk.stripe_size_bits)

			    dc->disk.stripe_size)

				goto full_stripes;



		goto normal_refill;

full_stripes:

		searched_from_start = false;	/* not searching entire btree */

		bch_refill_keybuf(dc->disk.c, buf, &end,

				  dirty_full_stripe_pred);

	} else {
@@ -252,19 +253,19 @@ void bcache_dev_sectors_dirty_add(struct cache_set *c, unsigned inode, 
				  uint64_t offset, int nr_sectors)

{

	struct bcache_device *d = c->devices[inode];

	unsigned stripe_size, stripe_offset;

	uint64_t stripe;

	unsigned stripe_offset;

	uint64_t stripe = offset;



	if (!d)

		return;



	stripe_size = 1 << d->stripe_size_bits;

	stripe = offset >> d->stripe_size_bits;

	stripe_offset = offset & (stripe_size - 1);

	do_div(stripe, d->stripe_size);



	stripe_offset = offset & (d->stripe_size - 1);



	while (nr_sectors) {

		int s = min_t(unsigned, abs(nr_sectors),

			      stripe_size - stripe_offset);

			      d->stripe_size - stripe_offset);



		if (nr_sectors < 0)

			s = -s;

drivers/md/bcache/writeback.h

+5 −3
Original line number Diff line number Diff line
@@ -18,16 +18,18 @@ static inline bool bcache_dev_stripe_dirty(struct bcache_device *d, 
					   uint64_t offset,

					   unsigned nr_sectors)

{

	uint64_t stripe = offset >> d->stripe_size_bits;

	uint64_t stripe = offset;



	do_div(stripe, d->stripe_size);



	while (1) {

		if (atomic_read(d->stripe_sectors_dirty + stripe))

			return true;



		if (nr_sectors <= 1 << d->stripe_size_bits)

		if (nr_sectors <= d->stripe_size)

			return false;



		nr_sectors -= 1 << d->stripe_size_bits;

		nr_sectors -= d->stripe_size;

		stripe++;

	}

}

CRA Git | Maintained and supported by SUSTech CRA and CCSE