[PATCH v2 03/13] OverlayFS: add cross-device check for copy_file_range

From: Olga Kornievskaia <olga.kornievskaia@gmail.com>
To: trond.myklebust@hammerspace.com, anna.schumaker@netapp.com,
	viro@zeniv.linux.org.uk, smfrench@gmail.com, miklos@szeredi.hu
Cc: linux-nfs@vger.kernel.org, linux-fsdevel@vger.kernel.org,
	linux-cifs@vger.kernel.org, linux-unionfs@vger.kernel.org,
	linux-man@vger.kernel.org
Subject: [PATCH v2 03/13] OverlayFS: add cross-device check for copy_file_range
Date: Wed, 24 Oct 2018 15:58:27 -0400	[thread overview]
Message-ID: <20181024195837.35532-5-olga.kornievskaia@gmail.com> (raw)
In-Reply-To: <20181024195837.35532-1-olga.kornievskaia@gmail.com>

From: Olga Kornievskaia <kolga@netapp.com>

VFS copy_file_range was relaxed to allow for cross-device copy.
Add a check for now, to disallow cross-device copy offload until
appropriate support is added.

Signed-off-by: Olga Kornievskaia <kolga@netapp.com>
`
---
 fs/overlayfs/file.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/fs/overlayfs/file.c b/fs/overlayfs/file.c
index aeaefd2..5282853 100644
--- a/fs/overlayfs/file.c
+++ b/fs/overlayfs/file.c
@@ -483,6 +483,9 @@ static ssize_t ovl_copy_file_range(struct file *file_in, loff_t pos_in,
 				   struct file *file_out, loff_t pos_out,
 				   size_t len, unsigned int flags)
 {
+	if (file_in->f_inode->i_sb != file_out->f_inode->i_sb)
+		return -EXDEV;
+
 	return ovl_copyfile(file_in, pos_in, file_out, pos_out, len, flags,
 			    OVL_COPY);
 }
-- 
1.8.3.1
