[3.11.y.z extended stable] Patch "rbd: ignore unmapped snapshots that no longer exist" has been added to staging queue

[Luis Henriques]

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

    rbd: ignore unmapped snapshots that no longer exist

to the linux-3.11.y-queue branch of the 3.11.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-3.11.y-queue

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

For more information about the 3.11.y.z tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Luis

------

>From 2412adeef5a08c935e093a413d5d4bfa088b685f Mon Sep 17 00:00:00 2001
From: Josh Durgin <josh.durgin at inktank.com>
Date: Thu, 29 Aug 2013 19:16:42 -0700
Subject: rbd: ignore unmapped snapshots that no longer exist

commit efadc98aab674153709cc357ba565f04e3164fcd upstream.

This prevents erroring out while adding a device when a snapshot
unrelated to the current mapping is deleted between reading the
snapshot context and reading the snapshot names. If the mapped
snapshot name is not found an error still occurs as usual.

Signed-off-by: Josh Durgin <josh.durgin at inktank.com>
Reviewed-by: Alex Elder <elder at linaro.org>
Signed-off-by: Luis Henriques <luis.henriques at canonical.com>
---
 drivers/block/rbd.c | 9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/drivers/block/rbd.c b/drivers/block/rbd.c
index 0f5307f..9a2e922 100644
--- a/drivers/block/rbd.c
+++ b/drivers/block/rbd.c
@@ -4078,8 +4078,13 @@ static u64 rbd_v2_snap_id_by_name(struct rbd_device *rbd_dev, const char *name)

 		snap_id = snapc->snaps[which];
 		snap_name = rbd_dev_v2_snap_name(rbd_dev, snap_id);
-		if (IS_ERR(snap_name))
-			break;
+		if (IS_ERR(snap_name)) {
+			/* ignore no-longer existing snapshots */
+			if (PTR_ERR(snap_name) == -ENOENT)
+				continue;
+			else
+				break;
+		}
 		found = !strcmp(name, snap_name);
 		kfree(snap_name);
 	}
--
1.8.3.2