Re: [PATCH 4/6] Btrfs: remove BUG() in print_extent_item

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

On Fri, May 26, 2017 at 08:18:22PM +0200, David Sterba wrote:
> On Thu, May 25, 2017 at 06:26:29PM -0600, Liu Bo wrote:
> > btrfs_print_leaf() is used in btrfs_get_extent_inline_ref_type, so
> > here we really want to print the invalid value of ref type instead of
> > causing a kernel panic.
> > 
> > Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
> > ---
> >  fs/btrfs/print-tree.c | 8 +++++++-
> >  1 file changed, 7 insertions(+), 1 deletion(-)
> > 
> > diff --git a/fs/btrfs/print-tree.c b/fs/btrfs/print-tree.c
> > index fcae61e..4448be6 100644
> > --- a/fs/btrfs/print-tree.c
> > +++ b/fs/btrfs/print-tree.c
> > @@ -63,6 +63,7 @@ static void print_extent_item(struct extent_buffer *eb, int slot, int type)
> >  	u32 item_size = btrfs_item_size_nr(eb, slot);
> >  	u64 flags;
> >  	u64 offset;
> > +	int is_data;
> >  
> >  	if (item_size < sizeof(*ei)) {
> >  #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
> > @@ -98,6 +99,8 @@ static void print_extent_item(struct extent_buffer *eb, int slot, int type)
> >  		iref = (struct btrfs_extent_inline_ref *)(ei + 1);
> >  	}
> >  
> > +	is_data = !!(flags & BTRFS_EXTENT_FLAG_DATA);
> > +
> >  	ptr = (unsigned long)iref;
> >  	end = (unsigned long)ei + item_size;
> >  	while (ptr < end) {
> > @@ -121,7 +124,10 @@ static void print_extent_item(struct extent_buffer *eb, int slot, int type)
> >  			       offset, btrfs_shared_data_ref_count(eb, sref));
> >  			break;
> >  		default:
> > -			BUG();
> > +			btrfs_err(eb->fs_info,
> > +				  "extent %llu has invalid ref type %d\n",
> > +				  eb->start, type);
> > +			return;
> 
> I don't see is_data used anywhere, also not in the followup patches.
> Please use a bool type in case it's valid here.
>

Good catch, I should remove is_data since it uses the original
btrfs_extent_inline_ref_type directly, will update it.

thanks,
-liubo


> >  		}
> >  		ptr += btrfs_extent_inline_ref_size(type);
> >  	}
> > -- 
> > 2.9.4
> > 
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