[3.8.y.z extended stable] Patch "dm thin: fix the error path for the thin device constructor" has been added to staging queue

[Kamal Mostafa]

This is a note to let you know that I have just added a patch titled

    dm thin: fix the error path for the thin device constructor

to the linux-3.8.y-queue branch of the 3.8.y.z extended stable tree 
which can be found at:

 http://kernel.ubuntu.com/git?p=ubuntu/linux.git;a=shortlog;h=refs/heads/linux-3.8.y-queue

This patch is scheduled to be released in version 3.8.13.20.

If you, or anyone else, feels it should not be added to this tree, please 
reply to this email.

For more information about the 3.8.y.z tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Kamal

------

>From b21c9ad32a4a028ec4e5149c1de3e46ef20a998f Mon Sep 17 00:00:00 2001
From: Mike Snitzer <snitzer at redhat.com>
Date: Wed, 19 Feb 2014 20:32:33 -0500
Subject: dm thin: fix the error path for the thin device constructor

commit 1acacc0784aab45627b6009e0e9224886279ac0b upstream.

dm_pool_close_thin_device() must be called if dm_set_target_max_io_len()
fails in thin_ctr().  Otherwise __pool_destroy() will fail because the
pool will still have an open thin device:

 device-mapper: thin metadata: attempt to close pmd when 1 device(s) are still open
 device-mapper: thin: __pool_destroy: dm_pool_metadata_close() failed.

Also, must establish error code if failing thin_ctr() because the pool
is in fail_io mode.

Signed-off-by: Mike Snitzer <snitzer at redhat.com>
Acked-by: Joe Thornber <ejt at redhat.com>
Signed-off-by: Kamal Mostafa <kamal at canonical.com>
---
 drivers/md/dm-thin.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/drivers/md/dm-thin.c b/drivers/md/dm-thin.c
index e66e366..4d9659b 100644
--- a/drivers/md/dm-thin.c
+++ b/drivers/md/dm-thin.c
@@ -2623,6 +2623,7 @@ static int thin_ctr(struct dm_target *ti, unsigned argc, char **argv)

 	if (get_pool_mode(tc->pool) == PM_FAIL) {
 		ti->error = "Couldn't open thin device, Pool is in fail mode";
+		r = -EINVAL;
 		goto bad_thin_open;
 	}

@@ -2634,7 +2635,7 @@ static int thin_ctr(struct dm_target *ti, unsigned argc, char **argv)

 	r = dm_set_target_max_io_len(ti, tc->pool->sectors_per_block);
 	if (r)
-		goto bad_thin_open;
+		goto bad_target_max_io_len;

 	ti->num_flush_requests = 1;
 	ti->flush_supported = true;
@@ -2655,6 +2656,8 @@ static int thin_ctr(struct dm_target *ti, unsigned argc, char **argv)

 	return 0;

+bad_target_max_io_len:
+	dm_pool_close_thin_device(tc->td);
 bad_thin_open:
 	__pool_dec(tc->pool);
 bad_pool_lookup:
--
1.8.3.2