Partially revert "locks: fix file locking on overlayfs"

This partially reverts commit c568d68341be7030f5647def68851e469b21ca11.

Overlayfs files will now automatically get the correct locks, no need to
hack overlay support in VFS.

It is a partial revert, because it leaves the locks_inode() calls in place
and defines locks_inode() to file_inode().  We could revert those as well,
but it would be unnecessary code churn and it makes sense to document that
we are getting the inode for locking purposes.

Don't revert MS_NOREMOTELOCK yet since that has been part of the userspace
API for some time (though not in a useful way).  Will try to remove
internal flags later when the dust around the new mount API settles.

Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Acked-by: Jeff Layton <jlayton@kernel.org>

1 files changed, 6 insertions, 11 deletions

diff --git a/fs/locks.c b/fs/locks.c
index baa564841c03..dab4e72f8bff 100644
--- a/fs/locks.c
+++ b/fs/locks.c
@@ -139,11 +139,6 @@
 #define IS_OFDLCK(fl)	(fl->fl_flags & FL_OFDLCK)
 #define IS_REMOTELCK(fl)	(fl->fl_pid <= 0)
 
-static inline bool is_remote_lock(struct file *filp)
-{
-	return likely(!(filp->f_path.dentry->d_sb->s_flags & SB_NOREMOTELOCK));
-}
-
 static bool lease_breaking(struct file_lock *fl)
 {
 	return fl->fl_flags & (FL_UNLOCK_PENDING | FL_DOWNGRADE_PENDING);
@@ -1875,7 +1870,7 @@ EXPORT_SYMBOL(generic_setlease);
 int
 vfs_setlease(struct file *filp, long arg, struct file_lock **lease, void **priv)
 {
-	if (filp->f_op->setlease && is_remote_lock(filp))
+	if (filp->f_op->setlease)
 		return filp->f_op->setlease(filp, arg, lease, priv);
 	else
 		return generic_setlease(filp, arg, lease, priv);
@@ -2022,7 +2017,7 @@ SYSCALL_DEFINE2(flock, unsigned int, fd, unsigned int, cmd)
 	if (error)
 		goto out_free;
 
-	if (f.file->f_op->flock && is_remote_lock(f.file))
+	if (f.file->f_op->flock)
 		error = f.file->f_op->flock(f.file,
 					  (can_sleep) ? F_SETLKW : F_SETLK,
 					  lock);
@@ -2048,7 +2043,7 @@ SYSCALL_DEFINE2(flock, unsigned int, fd, unsigned int, cmd)
  */
 int vfs_test_lock(struct file *filp, struct file_lock *fl)
 {
-	if (filp->f_op->lock && is_remote_lock(filp))
+	if (filp->f_op->lock)
 		return filp->f_op->lock(filp, F_GETLK, fl);
 	posix_test_lock(filp, fl);
 	return 0;
@@ -2191,7 +2186,7 @@ out:
  */
 int vfs_lock_file(struct file *filp, unsigned int cmd, struct file_lock *fl, struct file_lock *conf)
 {
-	if (filp->f_op->lock && is_remote_lock(filp))
+	if (filp->f_op->lock)
 		return filp->f_op->lock(filp, cmd, fl);
 	else
 		return posix_lock_file(filp, fl, conf);
@@ -2513,7 +2508,7 @@ locks_remove_flock(struct file *filp, struct file_lock_context *flctx)
 	if (list_empty(&flctx->flc_flock))
 		return;
 
-	if (filp->f_op->flock && is_remote_lock(filp))
+	if (filp->f_op->flock)
 		filp->f_op->flock(filp, F_SETLKW, &fl);
 	else
 		flock_lock_inode(inode, &fl);
@@ -2600,7 +2595,7 @@ EXPORT_SYMBOL(posix_unblock_lock);
  */
 int vfs_cancel_lock(struct file *filp, struct file_lock *fl)
 {
-	if (filp->f_op->lock && is_remote_lock(filp))
+	if (filp->f_op->lock)
 		return filp->f_op->lock(filp, F_CANCELLK, fl);
 	return 0;
 }