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authorAlex Elder <elder@inktank.com>2013-06-01 02:40:44 +0400
committerSage Weil <sage@inktank.com>2013-07-04 02:32:41 +0400
commit82a442d239695a242c4d584464c9606322cd02aa (patch)
tree50ce1f9db9ecede73a92fc6ce1680e340495fee1 /drivers
parent751cc0e3cfabdda87c4c21519253c6751e97a8d4 (diff)
downloadlinux-82a442d239695a242c4d584464c9606322cd02aa.tar.xz
rbd: protect against concurrent unmaps
Make sure two concurrent unmap operations on the same rbd device won't collide, by only proceeding with the removal and cleanup of a device if is not already underway. Signed-off-by: Alex Elder <elder@inktank.com> Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
Diffstat (limited to 'drivers')
-rw-r--r--drivers/block/rbd.c6
1 files changed, 4 insertions, 2 deletions
diff --git a/drivers/block/rbd.c b/drivers/block/rbd.c
index 9eead4879c90..305c740778c6 100644
--- a/drivers/block/rbd.c
+++ b/drivers/block/rbd.c
@@ -5137,6 +5137,7 @@ static ssize_t rbd_remove(struct bus_type *bus,
struct list_head *tmp;
int dev_id;
unsigned long ul;
+ bool already = false;
int ret;
ret = strict_strtoul(buf, 10, &ul);
@@ -5164,11 +5165,12 @@ static ssize_t rbd_remove(struct bus_type *bus,
if (rbd_dev->open_count)
ret = -EBUSY;
else
- set_bit(RBD_DEV_FLAG_REMOVING, &rbd_dev->flags);
+ already = test_and_set_bit(RBD_DEV_FLAG_REMOVING,
+ &rbd_dev->flags);
spin_unlock_irq(&rbd_dev->lock);
}
spin_unlock(&rbd_dev_list_lock);
- if (ret < 0)
+ if (ret < 0 || already)
goto done;
rbd_bus_del_dev(rbd_dev);