Re: [PATCH] xfs_db: use correct inode to set inode type

[Gao Xiang <hsiangkao@redhat.com>]

Hi,

On Thu, Aug 13, 2020 at 02:03:24PM +0800, Zorro Lang wrote:
> A test fails as:
>   # xfs_db -c "inode 133" -c "addr" -c "p core.size" -c "type inode" -c "addr" -c "p core.size" /dev/sdb1
>   current
>           byte offset 68096, length 512
>           buffer block 128 (fsbno 16), 32 bbs
>           inode 133, dir inode -1, type inode
>   core.size = 123142
>   current
>           byte offset 65536, length 512
>           buffer block 128 (fsbno 16), 32 bbs
>           inode 128, dir inode 128, type inode
>   core.size = 42
> 
> The "type inode" get wrong inode addr due to it trys to get the
> beginning of an inode chunk, refer to "533d1d229 xfs_db: properly set
> inode type".

From the kernel side, the prefered way is
commit id ("subject")

> 
> We don't need to get the beginning of a chunk in set_iocur_type, due
> to set_cur_inode(ino) will help to do all of that and make a proper
> verification. We just need to give it a correct inode.
> 
> Reported-by: Jianhong Yin <jiyin@redhat.com>
> Signed-off-by: Zorro Lang <zlang@redhat.com>
> ---
>  db/io.c | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
> 
> diff --git a/db/io.c b/db/io.c
> index 6628d061..61940a07 100644
> --- a/db/io.c
> +++ b/db/io.c
> @@ -591,6 +591,7 @@ set_iocur_type(
>  	/* Inodes are special; verifier checks all inodes in the chunk */
>  	if (type->typnm == TYP_INODE) {
>  		xfs_daddr_t	b = iocur_top->bb;
> +		int		bo = iocur_top->boff;
>  		xfs_ino_t	ino;
>  
>  		/*
> @@ -598,7 +599,7 @@ set_iocur_type(
>   		 * which contains the current disk location; daddr may change.
>   		 */
>  		ino = XFS_AGINO_TO_INO(mp, xfs_daddr_to_agno(mp, b),
> -			((b << BBSHIFT) >> mp->m_sb.sb_inodelog) %
> +			(((b << BBSHIFT) + bo) >> mp->m_sb.sb_inodelog) %
>  			XFS_AGB_TO_AGINO(mp, mp->m_sb.sb_agblocks));
>  		set_cur_inode(ino);
>  		return;

Not familar with such code, but after looking into a bit, (my premature
thought is that) I'm wondering if we need to reverify original buffer in

if (type->fields) {
	...
	set_cur()
}

iocur_top->typ = type;

/* verify the buffer if the type has one. */
...

since set_cur() already verified the buffer in
set_cur->libxfs_buf_read->...->libxfs_readbuf_verify?

Not related to this patchset but I'm a bit curious about it now...

Thanks,
Gao Xiang

> -- 
> 2.20.1
>