diff options
| author | Alex Elder <elder@inktank.com> | 2013-04-26 04:15:08 (GMT) |
|---|---|---|
| committer | Sage Weil <sage@inktank.com> | 2013-05-02 04:19:32 (GMT) |
| commit | a0cab924324fac8d6414009bc25ce31eeece038e (patch) | |
| tree | d8b180f239a010df65a11d80047be25b33626052 /drivers/block | |
| parent | f40eb349e032bee2b6f06e9b6f1dbfae561bd30a (diff) | |
| download | linux-fsl-qoriq-a0cab924324fac8d6414009bc25ce31eeece038e.tar.xz | |
rbd: avoid dropping extra reference in rbd_free_disk()
I found during some failure injection testing that the call to
rbd_free_disk() in the error path of rbd_dev_probe_finish() was
dropping an extra reference to the disk queue. The problem
occurred when put_disk tried to drop a reference to the disk's
queue. A call to blk_cleanup_queue() just prior to that will have
also dropped a reference to the queue.
The problem is that the reference dropped by put_disk() is assumed
to have been taken by add_disk(). Our code has error paths that can
occur after the disk and its queue are initialized, but before the
call to add_disk(), and in those paths we won't have that extra
reference.
The fix is easy though. In rbd_free_disk() we're already checking
the disk's GENHD_FL_UP flag. That flag is an indication that
add_disk() has been called, so just call blk_cleanup_queue()
conditional on that flag being set.
This resolves:
http://tracker.ceph.com/issues/4800
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
Diffstat (limited to 'drivers/block')
| -rw-r--r-- | drivers/block/rbd.c | 8 |
1 files changed, 5 insertions, 3 deletions
diff --git a/drivers/block/rbd.c b/drivers/block/rbd.c index 21e84a1..1704a3b 100644 --- a/drivers/block/rbd.c +++ b/drivers/block/rbd.c @@ -2844,10 +2844,12 @@ static void rbd_free_disk(struct rbd_device *rbd_dev) if (!disk) return; - if (disk->flags & GENHD_FL_UP) + rbd_dev->disk = NULL; + if (disk->flags & GENHD_FL_UP) { del_gendisk(disk); - if (disk->queue) - blk_cleanup_queue(disk->queue); + if (disk->queue) + blk_cleanup_queue(disk->queue); + } put_disk(disk); } |