diff options
| author | Josh Durgin <josh.durgin@dreamhost.com> | 2011-12-05 10:47:13 -0800 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2012-11-26 11:38:10 -0800 |
| commit | 45739514727c294e843269d515b952d5dbd911bf (patch) | |
| tree | 96021d986c838adf85f6799d40e3583ce026eddf | |
| parent | 095cb2142dfb10daea5a3351ed9646d3178a6823 (diff) | |
rbd: protect read of snapshot sequence number
(cherry picked from commit 403f24d3d51760a8b9368d595fa5f48c309f1a0f)
This is updated whenever a snapshot is added or deleted, and the
snapc pointer is changed with every refresh of the header.
Signed-off-by: Josh Durgin <josh.durgin@dreamhost.com>
Reviewed-by: Alex Elder <elder@dreamhost.com>
Reviewed-by: Yehuda Sadeh <yehuda@hq.newdream.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | drivers/block/rbd.c | 4 |
1 files changed, 3 insertions, 1 deletions
diff --git a/drivers/block/rbd.c b/drivers/block/rbd.c index c1f770131654..ff224baf0ff6 100644 --- a/drivers/block/rbd.c +++ b/drivers/block/rbd.c @@ -1683,7 +1683,9 @@ static int rbd_header_add_snap(struct rbd_device *dev, if (ret < 0) return ret; - dev->header.snapc->seq = new_snapid; + down_write(&dev->header_rwsem); + dev->header.snapc->seq = new_snapid; + up_write(&dev->header_rwsem); return 0; bad: |