Re: [PATCH 2/2] xfs_db: consolidate set_iocur_type behavior

["Darrick J. Wong" <darrick.wong@oracle.com>]

On Thu, Aug 20, 2020 at 07:09:45PM -0500, Eric Sandeen wrote:
> Right now there are 3 cases to type_f: inode type, type with fields,
> and a default.  The first two were added to address issues with handling
> V5 metadata.
> 
> The first two already use some version of set_cur, which handles all
> of the validation etc. There's no reason to leave the open-coded bits
> at the end, just send every non-inode type through set_cur and be done
> with it.
> 
> Signed-off-by: Eric Sandeen <sandeen@redhat.com>
> ---
> 
>  io.c |   28 +++++-----------------------
>  1 file changed, 5 insertions(+), 23 deletions(-)
> 
> diff --git a/db/io.c b/db/io.c
> index 884da599..235191f5 100644
> --- a/db/io.c
> +++ b/db/io.c
> @@ -603,33 +603,15 @@ set_iocur_type(
>  				iocur_top->boff / mp->m_sb.sb_inodesize);
>  		ino = XFS_AGINO_TO_INO(mp, xfs_daddr_to_agno(mp, b), agino);
>  		set_cur_inode(ino);
> -		return;
> -	}
> -
> -	/* adjust buffer size for types with fields & hence fsize() */
> -	if (type->fields) {
> -		int bb_count;	/* type's size in basic blocks */
> +	} else  {

Two spaces    ^^ between the else and the paren.

I also wonder, why not leave the "return;" at the end of the
"if (type->typnm == TYP_INODE)" part and then you can reduce the
indenting level of the rest of the function?

<shrug> maintainer's prerogative on that one though.
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>

/me also wonders why dquots don't get the same "save the buffer offset"
treatment as inodes, but that's a separate question. :)

--D

> +		int bb_count = 1;	/* type's size in basic blocks */
>  
> -		bb_count = BTOBB(byteize(fsize(type->fields,
> +		/* adjust buffer size for types with fields & hence fsize() */
> +		if (type->fields)
> +			bb_count = BTOBB(byteize(fsize(type->fields,
>  					       iocur_top->data, 0, 0)));
>  		set_cur(type, iocur_top->bb, bb_count, DB_RING_IGN, NULL);
>  	}
> -	iocur_top->typ = type;
> -
> -	/* verify the buffer if the type has one. */
> -	if (!bp)
> -		return;
> -	if (!type->bops) {
> -		bp->b_ops = NULL;
> -		bp->b_flags |= LIBXFS_B_UNCHECKED;
> -		return;
> -	}
> -	if (!(bp->b_flags & LIBXFS_B_UPTODATE))
> -		return;
> -	bp->b_error = 0;
> -	bp->b_ops = type->bops;
> -	bp->b_ops->verify_read(bp);
> -	bp->b_flags &= ~LIBXFS_B_UNCHECKED;
>  }
>  
>  static void
>