On 3/19/18 10:08 PM, Darrick J. Wong wrote:
> From: Darrick J. Wong <darrick.wong@xxxxxxxxxx>
>
> There are a few cases where an early stage of xfs_repair will write an
> invalid inode fork buffer to signal to a later stage that it needs to
> correct the value. This happens in phase 4 when we detect an inline
> format directory with an invalid .. pointer. To avoid triggering the
> ifork verifiers on this, inject a custom verifier for phase 6 that lets
> this pass for now.
>
> Signed-off-by: Darrick J. Wong <darrick.wong@xxxxxxxxxx>
> ---
> libxfs/libxfs_api_defs.h | 2 +
> repair/phase6.c | 66 +++++++++++++++++++++++++++++++++++++++++++++-
> 2 files changed, 67 insertions(+), 1 deletion(-)
>
>
> diff --git a/libxfs/libxfs_api_defs.h b/libxfs/libxfs_api_defs.h
> index 5d56340..78daca0 100644
> --- a/libxfs/libxfs_api_defs.h
> +++ b/libxfs/libxfs_api_defs.h
> @@ -150,5 +150,7 @@
> #define xfs_rmap_lookup_le_range libxfs_rmap_lookup_le_range
> #define xfs_refc_block libxfs_refc_block
> #define xfs_rmap_compare libxfs_rmap_compare
> +#define xfs_dir_get_ops libxfs_dir_get_ops
> +#define xfs_default_ifork_ops libxfs_default_ifork_ops
>
> #endif /* __LIBXFS_API_DEFS_H__ */
> diff --git a/repair/phase6.c b/repair/phase6.c
> index aff83bc..e9189af 100644
> --- a/repair/phase6.c
> +++ b/repair/phase6.c
> @@ -39,6 +39,70 @@ static struct xfs_name xfs_name_dot = {(unsigned char *)".",
> XFS_DIR3_FT_DIR};
>
> /*
> + * When we're checking directory inodes, we're allowed to set a directory's
(a shortform directory only?)
> + * dotdot entry to zero to signal that the parent needs to be reconnected
> + * during phase 6. The ifork verifiers would normally fail that, but we'll
> + * accept this canary so that we can fix the dir.
hm we actually just replace it temporarily, potato/potahto?
> + */
> +static xfs_failaddr_t
> +phase6_verify_dir(
> + struct xfs_inode *ip)
> +{
> + struct xfs_mount *mp = ip->i_mount;
> + const struct xfs_dir_ops *dops;
> + struct xfs_ifork *ifp;
> + struct xfs_dir2_sf_hdr *sfp;
> + xfs_failaddr_t fa;
> + xfs_ino_t old_parent;
> + bool parent_bypass = false;
> + int size;
> +
> + dops = libxfs_dir_get_ops(mp, NULL);
> +
> + ifp = XFS_IFORK_PTR(ip, XFS_DATA_FORK);
> + sfp = (struct xfs_dir2_sf_hdr *)ifp->if_u1.if_data;
> + size = ifp->if_bytes;
> +
> + /* Don't let the NULLFSINO .. entry blow everything up. */
NULLFSINO is ((xfs_ino_t)-1) not zero, so is this comment accurate?
Maybe an explicit comment here about this being for shortform dirs?
/*
* If this is a shortform directory, phase4 may have set the parent
* inode to zero to indicate that it must be fixed. Temporarily
* set a valid parent so that the directory verifier will pass.
*/
> + if (size > offsetof(struct xfs_dir2_sf_hdr, parent) &&
> + size >= xfs_dir2_sf_hdr_size(sfp->i8count)) {
> + old_parent = dops->sf_get_parent_ino(sfp);
> + if (old_parent == 0) {
> + dops->sf_put_parent_ino(sfp, mp->m_sb.sb_rootino);
> + parent_bypass = true;
> + }
> + }
> +
> + fa = libxfs_default_ifork_ops.verify_dir(ip);
> +
> + /* Put it back. */
/* Put the special parent == 0 back in place */
> + if (parent_bypass)
> + dops->sf_put_parent_ino(sfp, old_parent);
> +
> + return fa;
> +}
> +
> +static xfs_failaddr_t
> +phase6_verify_attr(
> + struct xfs_inode *ip)
> +{
> + return libxfs_default_ifork_ops.verify_attr(ip);
> +}
Is there a reason for these wrappers vs. just populating the
custom ifork_ops with xfs_attr_shortform_verify and
xfs_symlink_shortform_verify?
> +
> +static xfs_failaddr_t
> +phase6_verify_symlink(
> + struct xfs_inode *ip)
> +{
> + return libxfs_default_ifork_ops.verify_symlink(ip);
> +}
> +
> +struct xfs_ifork_ops phase6_default_ifork_ops = {
Naming a "custom" verifier "default" seems counterintuitive,
is there a reason for the "default" semantics I'm missing? Not
a huge deal, just makes me go "hmmm...."
> + .verify_attr = phase6_verify_attr,
> + .verify_dir = phase6_verify_dir,
> + .verify_symlink = phase6_verify_symlink,
> +};
> +
> +/*
> * Data structures used to keep track of directories where the ".."
> * entries are updated. These must be rebuilt after the initial pass
> */
> @@ -2833,7 +2897,7 @@ process_dir_inode(
>
> ASSERT(!is_inode_refchecked(irec, ino_offset) || dotdot_update);
>
> - error = -libxfs_iget(mp, NULL, ino, 0, &ip, NULL);
> + error = -libxfs_iget(mp, NULL, ino, 0, &ip, &phase6_default_ifork_ops);
> if (error) {
> if (!no_modify)
> do_error(
>
> --
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