[PATCH 1/1] NFSD: fix leak referent count of nfsd4_ssc_umount_item in nfsd4_copy

[Dai Ngo <dai.ngo@xxxxxxxxxx>]

The reference count of nfsd4_ssc_umount_item is not decremented
on error conditions. This prevents the laundromat from unmounting
the vfsmount of the source file.

This patch decrements the reference count of nfsd4_ssc_umount_item
on error.

Fixes: f4e44b393389 ("NFSD: delay unmount source's export after inter-server copy completed.")
Signed-off-by: Dai Ngo <dai.ngo@xxxxxxxxxx>
---
 fs/nfsd/nfs4proc.c | 12 ++++++++----
 1 file changed, 8 insertions(+), 4 deletions(-)

diff --git a/fs/nfsd/nfs4proc.c b/fs/nfsd/nfs4proc.c
index b4e7e18e1761..889b603619c3 100644
--- a/fs/nfsd/nfs4proc.c
+++ b/fs/nfsd/nfs4proc.c
@@ -1821,13 +1821,17 @@ nfsd4_copy(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
 out:
 	return status;
 out_err:
+	if (nfsd4_ssc_is_inter(copy)) {
+		/*
+		 * Source's vfsmount of inter-copy will be unmounted
+		 * by the laundromat. Use copy instead of async_copy
+		 * since async_copy->ss_nsui might not be set yet.
+	 	*/
+		refcount_dec(&copy->ss_nsui->nsui_refcnt);
+	}
 	if (async_copy)
 		cleanup_async_copy(async_copy);
 	status = nfserrno(-ENOMEM);
-	/*
-	 * source's vfsmount of inter-copy will be unmounted
-	 * by the laundromat
-	 */
 	goto out;
 }
 
-- 
2.9.5