Btrfs: return error when we specify wrong start to defrag
We need such a sanity check for wrong start when we defrag a file, otherwise,
even with a wrong start that's larger than file size, we can end up changing
not only inode's force compress flag but also FS's incompat flags.
Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.cz>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c
index ace88c1..a74edc7 100644
--- a/fs/btrfs/ioctl.c
+++ b/fs/btrfs/ioctl.c
@@ -1154,8 +1154,11 @@
u64 new_align = ~((u64)128 * 1024 - 1);
struct page **pages = NULL;
- if (extent_thresh == 0)
- extent_thresh = 256 * 1024;
+ if (isize == 0)
+ return 0;
+
+ if (range->start >= isize)
+ return -EINVAL;
if (range->flags & BTRFS_DEFRAG_RANGE_COMPRESS) {
if (range->compress_type > BTRFS_COMPRESS_TYPES)
@@ -1164,8 +1167,8 @@
compress_type = range->compress_type;
}
- if (isize == 0)
- return 0;
+ if (extent_thresh == 0)
+ extent_thresh = 256 * 1024;
/*
* if we were not given a file, allocate a readahead