[PATCH v3 02/10] NFS: Move the flock open mode check into nfs_flock()

[Benjamin Coddington <bcodding@redhat.com>]

We only need to check lock exclusive/shared types against open mode when
flock() is used on NFS, so move it into the flock-specific path instead of
checking it for all locks.

Signed-off-by: Benjamin Coddington <bcodding@redhat.com>
---
 fs/nfs/file.c     |   16 ++++++++++++++++
 fs/nfs/nfs4proc.c |   13 -------------
 2 files changed, 16 insertions(+), 13 deletions(-)

diff --git a/fs/nfs/file.c b/fs/nfs/file.c
index 93e2364..1e4804b 100644
--- a/fs/nfs/file.c
+++ b/fs/nfs/file.c
@@ -893,6 +893,22 @@ int nfs_flock(struct file *filp, int cmd, struct file_lock *fl)
 	/* We're simulating flock() locks using posix locks on the server */
 	if (fl->fl_type == F_UNLCK)
 		return do_unlk(filp, cmd, fl, is_local);
+
+	/*
+	 * VFS doesn't require the open mode to match a flock() lock's type.
+	 * NFS, however, may simulate flock() locking with posix locking which
+	 * requires the open mode to match the lock type.
+	 */
+	switch (fl->fl_type) {
+	case F_RDLCK:
+		if (!(filp->f_mode & FMODE_READ))
+			return -EBADF;
+		break;
+	case F_WRLCK:
+		if (!(filp->f_mode & FMODE_WRITE))
+			return -EBADF;
+	}
+
 	return do_setlk(filp, cmd, fl, is_local);
 }
 EXPORT_SYMBOL_GPL(nfs_flock);
diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c
index 2231d7d..05ea1e1 100644
--- a/fs/nfs/nfs4proc.c
+++ b/fs/nfs/nfs4proc.c
@@ -6125,19 +6125,6 @@ nfs4_proc_lock(struct file *filp, int cmd, struct file_lock *request)
 
 	if (state == NULL)
 		return -ENOLCK;
-	/*
-	 * Don't rely on the VFS having checked the file open mode,
-	 * since it won't do this for flock() locks.
-	 */
-	switch (request->fl_type) {
-	case F_RDLCK:
-		if (!(filp->f_mode & FMODE_READ))
-			return -EBADF;
-		break;
-	case F_WRLCK:
-		if (!(filp->f_mode & FMODE_WRITE))
-			return -EBADF;
-	}
 
 	do {
 		status = nfs4_proc_setlk(state, cmd, request);
-- 
1.7.1