From: Sage Weil <sage@newdream.net>
Date: Thu, 21 Aug 2008 18:21:38 +0000 (-0700)
Subject: kclient: fix i_lock/snap_rwsem lock inversion (read, not write)
X-Git-Tag: v0.4~189
X-Git-Url: http://git-server-git.apps.pok.os.sepia.ceph.com/?a=commitdiff_plain;h=5614170e6eb0a512dd9b15db81e6ff84438748cd;p=ceph.git

kclient: fix i_lock/snap_rwsem lock inversion (read, not write)
---

diff --git a/src/kernel/caps.c b/src/kernel/caps.c
index dc563aaf1fd2..83351b7092a5 100644
--- a/src/kernel/caps.c
+++ b/src/kernel/caps.c
@@ -454,7 +454,7 @@ ack:
 				dout(10, "inverting snap/in locks on %p\n",
 				     inode);
 				spin_unlock(&inode->i_lock);
-				down_write(&mdsc->snap_rwsem);
+				down_read(&mdsc->snap_rwsem);
 				took_snap_rwsem = 1;
 				goto retry;
 			}
@@ -492,7 +492,7 @@ ack:
 	if (session)
 		mutex_unlock(&session->s_mutex);
 	if (took_snap_rwsem)
-		up_write(&mdsc->snap_rwsem);
+		up_read(&mdsc->snap_rwsem);
 }