On Tue, Apr 16, 2013 at 05:20:28PM +0800, Liu Bo wrote: > 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. The range->start check is good, but why are you worried about the incompat flag? LZO support has been around for more than 2 years. > --- a/fs/btrfs/ioctl.c > +++ b/fs/btrfs/ioctl.c > @@ -1152,8 +1152,11 @@ int btrfs_defrag_file(struct inode *inode, struct file *file, > 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 (isize == 0) > - return 0; > + if (extent_thresh == 0) > + extent_thresh = 256 * 1024; That's a more logical order of the checks, good. Reviewed-by: David Sterba <dsterba@xxxxxxx> -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
