[PATCH 3.14 43/44] btrfs: incorrect handling for fiemap_fill_next_extent return

Greg Kroah-Hartman
2015-06-19T21:00:13Z

From: Chengyu Song <csong84@gatech.edu>

commit 26e726afe01c1c82072cf23a5ed89ce25f39d9f2 upstream.

fiemap_fill_next_extent returns 0 on success, -errno on error, 1 if this was
the last extent that will fit in user array. If 1 is returned, the return
value may eventually returned to user space, which should not happen, according
to manpage of ioctl.

Signed-off-by: Chengyu Song <csong84@gatech.edu>
Reviewed-by: David Sterba <dsterba@suse.cz>
Reviewed-by: Liu Bo <bo.li.liu@oracle.com>
Signed-off-by: Chris Mason <clm@fb.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
fs/btrfs/extent_io.c | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)

--- a/fs/btrfs/extent_io.c
+++ b/fs/btrfs/extent_io.c
@@ -4289,8 +4289,11 @@ int extent_fiemap(struct inode *inode, s
}
ret = fiemap_fill_next_extent(fieinfo, em_start, disko,
em_len, flags);
- if (ret)
+ if (ret) {
+ if (ret == 1)
+ ret = 0;
goto out_free;
+ }
}
out_free:
free_extent_map(em);