Re: [PATCH 2/2] btrfs: pretty print leaked root name

[David Sterba <dsterba@suse.cz>]

On Fri, Aug 21, 2020 at 10:35:38AM +0300, Nikolay Borisov wrote:
> 
> 
> On 20.08.20 г. 23:00 ч., Josef Bacik wrote:
> > I'm a actual human being so am incapable of converting u64 to s64 in my
> > head, so add a helper to get the pretty name of a root objectid and use
> > that helper to spit out the name for any special roots for leaked roots,
> > so I don't have to scratch my head and figure out which root I messed up
> > the refs for.
> > 
> > Signed-off-by: Josef Bacik <josef@toxicpanda.com>
> > ---
> >  fs/btrfs/disk-io.c    |  8 +++++---
> >  fs/btrfs/print-tree.c | 37 +++++++++++++++++++++++++++++++++++++
> >  fs/btrfs/print-tree.h |  1 +
> >  3 files changed, 43 insertions(+), 3 deletions(-)
> > 
> > diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
> > index ac6d6fddd5f4..a7358e0f59de 100644
> > --- a/fs/btrfs/disk-io.c
> > +++ b/fs/btrfs/disk-io.c
> > @@ -1506,11 +1506,13 @@ void btrfs_check_leaked_roots(struct btrfs_fs_info *fs_info)
> >  	struct btrfs_root *root;
> >  
> >  	while (!list_empty(&fs_info->allocated_roots)) {
> > +		const char *name = btrfs_root_name(root->root_key.objectid);
> > +
> >  		root = list_first_entry(&fs_info->allocated_roots,
> >  					struct btrfs_root, leak_list);
> > -		btrfs_err(fs_info, "leaked root %llu-%llu refcount %d",
> > -			  root->root_key.objectid, root->root_key.offset,
> > -			  refcount_read(&root->refs));
> > +		btrfs_err(fs_info, "leaked root %s%lld-%llu refcount %d",
> 
> nit: Won't this string result in some rather awkward looking strings,
> such as:
> 
> "leaked root ROOT_TREE<objectid>-<offset>..." i.e shouldn't the
> (objectid,offset) pair be marked with parentheses?

I don't understand why need/want to print the offset here. It is from
the key.offset but for a message we should print it in an understandable
way.