diff mbox series

[04/26] vfs: exit early from zero length remap operations

Message ID 153965942391.1256.1491987046439132016.stgit@magnolia (mailing list archive)
State New, archived
Headers show
Series fs: fixes for serious clone/dedupe problems | expand

Commit Message

Darrick J. Wong Oct. 16, 2018, 3:10 a.m. UTC 
From: Darrick J. Wong <darrick.wong@oracle.com>

If a remap caller asks us to remap to the source file's EOF and the
source file has zero bytes, exit early.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
---
 fs/read_write.c |    2 ++
 1 file changed, 2 insertions(+)

Comments

Christoph Hellwig Oct. 17, 2018, 8:26 a.m. UTC | #1 
On Mon, Oct 15, 2018 at 08:10:23PM -0700, Darrick J. Wong wrote:
> From: Darrick J. Wong <darrick.wong@oracle.com>
> 
> If a remap caller asks us to remap to the source file's EOF and the
> source file has zero bytes, exit early.
> 
> Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>

Looks good,

Reviewed-by: Christoph Hellwig <hch@lst.de>
diff mbox series

Patch

diff --git a/fs/read_write.c b/fs/read_write.c
index d6e8e242a15f..2456da3f8a41 100644
--- a/fs/read_write.c
+++ b/fs/read_write.c
@@ -1748,6 +1748,8 @@  int vfs_clone_file_prep(struct file *file_in, loff_t pos_in,
 		if (pos_in > isize)
 			return -EINVAL;
 		*len = isize - pos_in;
+		if (*len == 0)
+			return 0;
 	}
 
 	/* Check that we don't violate system file offset limits. */