diff options
| author | Alex Elder <elder@inktank.com> | 2013-05-31 17:40:44 -0500 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2014-01-09 12:24:25 -0800 |
| commit | 7aa73ee13251af1534de166ea5379f32a6bf7793 (patch) | |
| tree | fbd0161f39acac30d75737a5c0e6aab2c080b75f | |
| parent | c4d00f5b3e1f48f99d99d813fe8071c719e1790b (diff) | |
rbd: protect against concurrent unmaps
commit 82a442d239695a242c4d584464c9606322cd02aa upstream.
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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | drivers/block/rbd.c | 6 |
1 files changed, 4 insertions, 2 deletions
diff --git a/drivers/block/rbd.c b/drivers/block/rbd.c index afdbd558485..8326b39b057 100644 --- a/drivers/block/rbd.c +++ b/drivers/block/rbd.c @@ -5108,6 +5108,7 @@ 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); @@ -5135,11 +5136,12 @@ 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); |