Commit 172c2386 authored Nov 06, 2015 by Mike Snitzer

dm thin: restore requested 'error_if_no_space' setting on OODS to WRITE transition



A thin-pool that is in out-of-data-space (OODS) mode may transition back
to write mode -- without the admin adding more space to the thin-pool --
if/when blocks are released (either by deleting thin devices or
discarding provisioned blocks).

But as part of the thin-pool's earlier transition to out-of-data-space
mode the thin-pool may have set the 'error_if_no_space' flag to true if
the no_space_timeout expires without more space having been made
available.  That implementation detail, of changing the pool's
error_if_no_space setting, needs to be reset back to the default that
the user specified when the thin-pool's table was loaded.

Otherwise we'll drop the user requested behaviour on the floor when this
out-of-data-space to write mode transition occurs.

Reported-by: Vivek Goyal <vgoyal@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Acked-by: Joe Thornber <ejt@redhat.com>
Fixes: 2c43fd26 ("dm thin: fix missing out-of-data-space to write mode transition if blocks are released")
Cc: stable@vger.kernel.org

parent 8005c49d

drivers/md/dm-thin.c

+1 −0

Original line number	Diff line number	Diff line
		@@ -2432,6 +2432,7 @@ static void set_pool_mode(struct pool *pool, enum pool_mode new_mode)
		case PM_WRITE:
		if (old_mode != new_mode)
		notify_of_pool_mode_change(pool, "write");
		pool->pf.error_if_no_space = pt->requested_pf.error_if_no_space;
		dm_pool_metadata_read_write(pool->pmd);
		pool->process_bio = process_bio;
		pool->process_discard = process_discard_bio;

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