Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit f722063e authored by Joe Thornber's avatar Joe Thornber Committed by Mike Snitzer
Browse files

dm space map: optimise sm_ll_dec and sm_ll_inc 



Prior to this patch these methods did a lookup followed by an insert.
Instead they now call a common mutate function that adjusts the value
according to a callback function.  This avoids traversing the data
structures twice and hence improves performance.

Also factor out sm_ll_lookup_big_ref_count() for use by both
sm_ll_lookup() and sm_ll_mutate().

Signed-off-by: default avatarJoe Thornber <ejt@redhat.com>
Signed-off-by: default avatarMike Snitzer <snitzer@redhat.com>
Signed-off-by: default avatarAlasdair G Kergon <agk@redhat.com>
parent 04f17c80

drivers/md/persistent-data/dm-space-map-common.c

+49 −28
Original line number Diff line number Diff line
@@ -292,16 +292,11 @@ int sm_ll_lookup_bitmap(struct ll_disk *ll, dm_block_t b, uint32_t *result) 
	return dm_tm_unlock(ll->tm, blk);

}



int sm_ll_lookup(struct ll_disk *ll, dm_block_t b, uint32_t *result)

static int sm_ll_lookup_big_ref_count(struct ll_disk *ll, dm_block_t b,

				      uint32_t *result)

{

	__le32 le_rc;

	int r = sm_ll_lookup_bitmap(ll, b, result);



	if (r)

		return r;



	if (*result != 3)

		return r;

	int r;



	r = dm_btree_lookup(&ll->ref_count_info, ll->ref_count_root, &b, &le_rc);

	if (r < 0)
@@ -312,6 +307,19 @@ int sm_ll_lookup(struct ll_disk *ll, dm_block_t b, uint32_t *result) 
	return r;

}



int sm_ll_lookup(struct ll_disk *ll, dm_block_t b, uint32_t *result)

{

	int r = sm_ll_lookup_bitmap(ll, b, result);



	if (r)

		return r;



	if (*result != 3)

		return r;



	return sm_ll_lookup_big_ref_count(ll, b, result);

}



int sm_ll_find_free_block(struct ll_disk *ll, dm_block_t begin,

			  dm_block_t end, dm_block_t *result)

{
@@ -372,11 +380,12 @@ int sm_ll_find_free_block(struct ll_disk *ll, dm_block_t begin, 
	return -ENOSPC;

}



int sm_ll_insert(struct ll_disk *ll, dm_block_t b,

		 uint32_t ref_count, enum allocation_event *ev)

static int sm_ll_mutate(struct ll_disk *ll, dm_block_t b,

			uint32_t (*mutator)(void *context, uint32_t old),

			void *context, enum allocation_event *ev)

{

	int r;

	uint32_t bit, old;

	uint32_t bit, old, ref_count;

	struct dm_block *nb;

	dm_block_t index = b;

	struct disk_index_entry ie_disk;
@@ -399,6 +408,14 @@ int sm_ll_insert(struct ll_disk *ll, dm_block_t b, 
	bm_le = dm_bitmap_data(nb);

	old = sm_lookup_bitmap(bm_le, bit);



	if (old > 2) {

		r = sm_ll_lookup_big_ref_count(ll, b, &old);

		if (r < 0)

			return r;

	}



	ref_count = mutator(context, old);



	if (ref_count <= 2) {

		sm_set_bitmap(bm_le, bit, ref_count);
@@ -448,31 +465,35 @@ int sm_ll_insert(struct ll_disk *ll, dm_block_t b, 
	return ll->save_ie(ll, index, &ie_disk);

}



int sm_ll_inc(struct ll_disk *ll, dm_block_t b, enum allocation_event *ev)

static uint32_t set_ref_count(void *context, uint32_t old)

{

	int r;

	uint32_t rc;



	r = sm_ll_lookup(ll, b, &rc);

	if (r)

		return r;

	return *((uint32_t *) context);

}



	return sm_ll_insert(ll, b, rc + 1, ev);

int sm_ll_insert(struct ll_disk *ll, dm_block_t b,

		 uint32_t ref_count, enum allocation_event *ev)

{

	return sm_ll_mutate(ll, b, set_ref_count, &ref_count, ev);

}



int sm_ll_dec(struct ll_disk *ll, dm_block_t b, enum allocation_event *ev)

static uint32_t inc_ref_count(void *context, uint32_t old)

{

	int r;

	uint32_t rc;

	return old + 1;

}



	r = sm_ll_lookup(ll, b, &rc);

	if (r)

		return r;

int sm_ll_inc(struct ll_disk *ll, dm_block_t b, enum allocation_event *ev)

{

	return sm_ll_mutate(ll, b, inc_ref_count, NULL, ev);

}



	if (!rc)

		return -EINVAL;

static uint32_t dec_ref_count(void *context, uint32_t old)

{

	return old - 1;

}



	return sm_ll_insert(ll, b, rc - 1, ev);

int sm_ll_dec(struct ll_disk *ll, dm_block_t b, enum allocation_event *ev)

{

	return sm_ll_mutate(ll, b, dec_ref_count, NULL, ev);

}



int sm_ll_commit(struct ll_disk *ll)