Re: [PATCH] Btrfs: error out if generic_bin_search get invalid arguments

[Liu Bo <bo.li.liu@oracle.com>]

On Thu, Jun 23, 2016 at 10:51:52AM +0200, David Sterba wrote:
> On Wed, Jun 22, 2016 at 06:32:19PM -0700, Liu Bo wrote:
> > With btrfs-corrupt-block, one can set btree node/leaf's field, if
> > we assign a negative value to node/leaf, we can get various hangs,
> > eg. if extent_root's nritems is -2ULL, then we get stuck in
> >  btrfs_read_block_groups() because it has a while loop and
> > btrfs_search_slot() on extent_root will always return the first
> >  child.
> > 
> > This lets us know what's happening and returns a EINVAL to callers
> > instead of returning the first item.
> > 
> > Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
> > ---
> >  fs/btrfs/ctree.c | 8 ++++++++
> >  1 file changed, 8 insertions(+)
> > 
> > diff --git a/fs/btrfs/ctree.c b/fs/btrfs/ctree.c
> > index c49a500..915d224 100644
> > --- a/fs/btrfs/ctree.c
> > +++ b/fs/btrfs/ctree.c
> > @@ -1770,6 +1770,14 @@ static noinline int generic_bin_search(struct extent_buffer *eb,
> >  	unsigned long map_len = 0;
> >  	int err;
> >  
> > +	if (low > high) {
> > +		btrfs_err(eb->fs_info,
> > +		 "%s: low (%d) < high (%d) eb %llu owner %llu level %d",
> 
> Why is it '<' in the error message?

Err, my typo error.

Thanks,

-liubo