Re: [PATCH] xfs_db: teach the frag command about sparse inode chunks

[Brian Foster <bfoster@redhat.com>]

On Mon, Dec 03, 2018 at 05:01:33PM -0600, Eric Sandeen wrote:
> This is the equivalent of:
> 
> ea8a48f xfs_check: process sparse inode chunks correctly
> 
> for the frag_f() command in xfs_db.
> 
> Without this, the xfs_db frag command shows corruption as it
> wanders into blocks that are not inodes.
> 
> Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=201823
> Signed-off-by: Eric Sandeen <sandeen@redhat.com>
> ---

Looks good to me, thanks.

Reviewed-by: Brian Foster <bfoster@redhat.com>

> 
> diff --git a/db/frag.c b/db/frag.c
> index 6792d47..5f33cb7 100644
> --- a/db/frag.c
> +++ b/db/frag.c
> @@ -466,29 +466,56 @@ scanfunc_ino(
>  	int			off;
>  	xfs_inobt_ptr_t		*pp;
>  	xfs_inobt_rec_t		*rp;
> +	xfs_agblock_t		agbno;
> +	xfs_agblock_t		end_agbno;
> +	struct xfs_dinode	*dip;
> +	int			blks_per_buf;
> +	int			inodes_per_buf;
> +	int			ioff;
> +
> +	if (xfs_sb_version_hassparseinodes(&mp->m_sb))
> +		blks_per_buf = xfs_icluster_size_fsb(mp);
> +	else
> +		blks_per_buf = mp->m_ialloc_blks;
> +	inodes_per_buf = min(blks_per_buf << mp->m_sb.sb_inopblog,
> +			     XFS_INODES_PER_CHUNK);
>  
>  	if (level == 0) {
>  		rp = XFS_INOBT_REC_ADDR(mp, block, 1);
>  		for (i = 0; i < be16_to_cpu(block->bb_numrecs); i++) {
>  			agino = be32_to_cpu(rp[i].ir_startino);
> -			off = XFS_INO_TO_OFFSET(mp, agino);
> +			agbno = XFS_AGINO_TO_AGBNO(mp, agino);
> +			off = XFS_AGINO_TO_OFFSET(mp, agino);
> +			end_agbno = agbno + mp->m_ialloc_blks;
> +
>  			push_cur();
> -			set_cur(&typtab[TYP_INODE],
> -				XFS_AGB_TO_DADDR(mp, seqno,
> -						 XFS_AGINO_TO_AGBNO(mp, agino)),
> -				XFS_FSB_TO_BB(mp, mp->m_ialloc_blks),
> -				DB_RING_IGN, NULL);
> -			if (iocur_top->data == NULL) {
> -				dbprintf(_("can't read inode block %u/%u\n"),
> -					seqno, XFS_AGINO_TO_AGBNO(mp, agino));
> -				continue;
> -			}
> -			for (j = 0; j < XFS_INODES_PER_CHUNK; j++) {
> -				if (XFS_INOBT_IS_FREE_DISK(&rp[i], j))
> -					continue;
> -				process_inode(agf, agino + j, (xfs_dinode_t *)
> -					((char *)iocur_top->data +
> -					((off + j) << mp->m_sb.sb_inodelog)));
> +			ioff = 0;
> +			while (agbno < end_agbno &&
> +			       ioff < XFS_INODES_PER_CHUNK) {
> +				if (xfs_inobt_is_sparse_disk(&rp[i], ioff))
> +					goto next_buf;
> +
> +				set_cur(&typtab[TYP_INODE],
> +					XFS_AGB_TO_DADDR(mp, seqno, agbno),
> +					XFS_FSB_TO_BB(mp, blks_per_buf),
> +					DB_RING_IGN, NULL);
> +				if (iocur_top->data == NULL) {
> +					dbprintf(_("can't read inode block %u/%u\n"),
> +						 seqno, agbno);
> +					goto next_buf;
> +				}
> +
> +				for (j = 0; j < inodes_per_buf; j++) {
> +					if (XFS_INOBT_IS_FREE_DISK(&rp[i], ioff + j))
> +						goto next_buf;
> +					dip = (xfs_dinode_t *)((char *)iocur_top->data +
> +						((off + j) << mp->m_sb.sb_inodelog));
> +					process_inode(agf, agino + ioff + j, dip);
> +				}
> +
> +next_buf:
> +				agbno += blks_per_buf;
> +				ioff += inodes_per_buf;
>  			}
>  			pop_cur();
>  		}
>