[PATCH] xfs: fix double IRELE in xfs_dqrele_inode

[Christoph Hellwig <hch@xxxxxxxxxxxxx>]

xfs_dqrele_inode calls xfs_iput to release the ilock and a reference
and then also calls IRELE which does a second decrement of the reference
count.  This leads to a premature freeing of inodes when quotas were turned
off while the filesystem was mounted.

Thanks to Utako Kusaka for reporting the bug and provinding a good testcase.

Signed-off-by: Christoph Hellwig <hch@xxxxxx>
Reported-by: Utako Kusaka <u-kusaka@xxxxxxxxxxxxx>

Index: xfs/fs/xfs/quota/xfs_qm_syscalls.c
===================================================================
--- xfs.orig/fs/xfs/quota/xfs_qm_syscalls.c     2009-10-11 13:41:52.932012023 
-0300
+++ xfs/fs/xfs/quota/xfs_qm_syscalls.c  2009-10-11 13:42:04.060016467 -0300
@@ -876,7 +876,6 @@ xfs_dqrele_inode(
                ip->i_gdquot = NULL;
        }
        xfs_iput(ip, XFS_ILOCK_EXCL);
-       IRELE(ip);
 
        return 0;
 }