dm thin: fix missing out-of-data-space to write mode transition if blocks are released

Discard bios and thin device deletion have the potential to release data
blocks.  If the thin-pool is in out-of-data-space mode, and blocks were
released, transition the thin-pool back to full write mode.

The correct time to do this is just after the thin-pool metadata commit.
It cannot be done before the commit because the space maps will not
allow immediate reuse of the data blocks in case there's a rollback
following power failure.

Signed-off-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Cc: stable@vger.kernel.org
This commit is contained in:
Joe Thornber 2014-12-11 11:12:19 +00:00 committed by Mike Snitzer
parent 45ec9bd0fd
commit 2c43fd26e4

View File

@ -1127,6 +1127,24 @@ static void schedule_external_copy(struct thin_c *tc, dm_block_t virt_block,
schedule_zero(tc, virt_block, data_dest, cell, bio);
}
static void set_pool_mode(struct pool *pool, enum pool_mode new_mode);
static void check_for_space(struct pool *pool)
{
int r;
dm_block_t nr_free;
if (get_pool_mode(pool) != PM_OUT_OF_DATA_SPACE)
return;
r = dm_pool_get_free_block_count(pool->pmd, &nr_free);
if (r)
return;
if (nr_free)
set_pool_mode(pool, PM_WRITE);
}
/*
* A non-zero return indicates read_only or fail_io mode.
* Many callers don't care about the return value.
@ -1141,6 +1159,8 @@ static int commit(struct pool *pool)
r = dm_pool_commit_metadata(pool->pmd);
if (r)
metadata_operation_failed(pool, "dm_pool_commit_metadata", r);
else
check_for_space(pool);
return r;
}
@ -1159,8 +1179,6 @@ static void check_low_water_mark(struct pool *pool, dm_block_t free_blocks)
}
}
static void set_pool_mode(struct pool *pool, enum pool_mode new_mode);
static int alloc_data_block(struct thin_c *tc, dm_block_t *result)
{
int r;