[PATCH 03/28] vfs: exit early from zero length remap operations

Darrick J. Wong
2018-10-22T00:30:21Z

If a remap caller asks us to remap to the source file's EOF and the
source file length leaves us with a zero byte request, exit early.

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

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. */