The dm-thin set_reserve_count() function is designed to control the current block reservation for a thin pool. It currently only provides the ability to increase the reservation.
Clients such as XFS will rely on over-reservation and thus require the ability to release excess reservation back to the pool. Update set_reserve_count() to return reserved blocks back to the pool. Signed-off-by: Brian Foster <[email protected]> --- drivers/md/dm-thin.c | 8 +++----- 1 file changed, 3 insertions(+), 5 deletions(-) diff --git a/drivers/md/dm-thin.c b/drivers/md/dm-thin.c index 31d36da..ac770d89 100644 --- a/drivers/md/dm-thin.c +++ b/drivers/md/dm-thin.c @@ -1429,7 +1429,8 @@ static bool dec_reserve_count(struct thin_c *tc, dm_block_t free_blocks) static int set_reserve_count(struct thin_c *tc, dm_block_t count) { int r; - dm_block_t free_blocks, delta; + dm_block_t free_blocks; + int64_t delta; unsigned long flags; r = get_free_blocks(tc->pool, &free_blocks); @@ -1437,8 +1438,6 @@ static int set_reserve_count(struct thin_c *tc, dm_block_t count) return r; spin_lock_irqsave(&tc->pool->lock, flags); - if (count <= tc->reserve_count) - goto out_unlock; /* nothing to do */ delta = count - tc->reserve_count; if (tc->pool->reserve_count + delta > free_blocks) r = -ENOSPC; @@ -1446,7 +1445,6 @@ static int set_reserve_count(struct thin_c *tc, dm_block_t count) tc->reserve_count = count; tc->pool->reserve_count += delta; } -out_unlock: spin_unlock_irqrestore(&tc->pool->lock, flags); return r; @@ -4369,7 +4367,7 @@ static int thin_reserve_space(struct dm_target *ti, sector_t nr_sects) * @nr_sects must always be a factor of the pool's blocksize; * upper layers can rely on the bdev's minimum_io_size for this. */ - if (!nr_sects || !is_factor(nr_sects, pool->sectors_per_block)) + if (!is_factor(nr_sects, pool->sectors_per_block)) return -EINVAL; blocks = nr_sects; -- 2.4.3 -- dm-devel mailing list [email protected] https://www.redhat.com/mailman/listinfo/dm-devel
