From d54cdc8ca7aabc69e145a62155855db42b04ed0b Mon Sep 17 00:00:00 2001 From: Josef Bacik <josef@redhat.com> Date: Tue, 1 Feb 2011 15:52:47 -0800 Subject: [PATCH] fs: make block fiemap mapping length at least blocksize long Some filesystems don't deal well with being asked to map less than blocksize blocks (GFS2 for example). Since we are always mapping at least blocksize sections anyway, just make sure len is at least as big as a blocksize so we don't trip up any filesystems. Thanks, Signed-off-by: Josef Bacik <josef@redhat.com> Cc: Steven Whitehouse <swhiteho@redhat.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> --- fs/ioctl.c | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/fs/ioctl.c b/fs/ioctl.c index a59635e295fa..1eebeb72b202 100644 --- a/fs/ioctl.c +++ b/fs/ioctl.c @@ -273,6 +273,13 @@ int __generic_block_fiemap(struct inode *inode, len = isize; } + /* + * Some filesystems can't deal with being asked to map less than + * blocksize, so make sure our len is at least block length. + */ + if (logical_to_blk(inode, len) == 0) + len = blk_to_logical(inode, 1); + start_blk = logical_to_blk(inode, start); last_blk = logical_to_blk(inode, start + len - 1);