From 2c43fd26e46734430122b8d2ad3024bb532df3ef Mon Sep 17 00:00:00 2001 From: Joe Thornber Date: Thu, 11 Dec 2014 11:12:19 +0000 Subject: [PATCH] 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 Signed-off-by: Mike Snitzer Cc: stable@vger.kernel.org --- drivers/md/dm-thin.c | 22 ++++++++++++++++++++-- 1 file changed, 20 insertions(+), 2 deletions(-) diff --git a/drivers/md/dm-thin.c b/drivers/md/dm-thin.c index 14b51a4fdf6b..922aa553e9e0 100644 --- a/drivers/md/dm-thin.c +++ b/drivers/md/dm-thin.c @@ -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;