xfs: create a separate hashname function for extended attributes

Create a separate function to compute name hashvalues for extended
attributes.  When we get to parent pointers we'll be altering the rules
so that metadump obfuscation doesn't turn heinous.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>

fs/xfs/libxfs/xfs_attr.c

@@ -280,7 +280,7 @@ xfs_attr_get(
 		args->owner = args->dp->i_ino;
 	args->geo = args->dp->i_mount->m_attr_geo;
 	args->whichfork = XFS_ATTR_FORK;
-	args->hashval = xfs_da_hashname(args->name, args->namelen);
+	xfs_attr_sethash(args);
 
 	/* Entirely possible to look up a name which doesn't exist */
 	args->op_flags = XFS_DA_OP_OKNOENT;
@@ -415,6 +415,30 @@ xfs_attr_sf_addname(
 	return error;
 }
 
+/* Compute the hash value for a user/root/secure extended attribute */
+xfs_dahash_t
+xfs_attr_hashname(
+	const uint8_t		*name,
+	int			namelen)
+{
+	return xfs_da_hashname(name, namelen);
+}
+
+/* Compute the hash value for any extended attribute from any namespace. */
+xfs_dahash_t
+xfs_attr_hashval(
+	struct xfs_mount	*mp,
+	unsigned int		attr_flags,
+	const uint8_t		*name,
+	int			namelen,
+	const void		*value,
+	int			valuelen)
+{
+	ASSERT(xfs_attr_check_namespace(attr_flags));
+
+	return xfs_attr_hashname(name, namelen);
+}
+
 /*
  * Handle the state change on completion of a multi-state attr operation.
  *
@@ -925,7 +949,7 @@ xfs_attr_set(
 		args->owner = args->dp->i_ino;
 	args->geo = mp->m_attr_geo;
 	args->whichfork = XFS_ATTR_FORK;
-	args->hashval = xfs_da_hashname(args->name, args->namelen);
+	xfs_attr_sethash(args);
 
 	/*
 	 * We have no control over the attribute names that userspace passes us

fs/xfs/libxfs/xfs_attr.h

@@ -628,6 +628,20 @@ xfs_attr_init_replace_state(struct xfs_da_args *args)
 	return xfs_attr_init_add_state(args);
 }
 
+xfs_dahash_t xfs_attr_hashname(const uint8_t *name, int namelen);
+
+xfs_dahash_t xfs_attr_hashval(struct xfs_mount *mp, unsigned int attr_flags,
+		const uint8_t *name, int namelen, const void *value,
+		int valuelen);
+
+/* Set the hash value for any extended attribute from any namespace. */
+static inline void xfs_attr_sethash(struct xfs_da_args *args)
+{
+	args->hashval = xfs_attr_hashval(args->dp->i_mount, args->attr_filter,
+					 args->name, args->namelen,
+					 args->value, args->valuelen);
+}
+
 extern struct kmem_cache *xfs_attr_intent_cache;
 int __init xfs_attr_intent_init_cache(void);
 void xfs_attr_intent_destroy_cache(void);

fs/xfs/libxfs/xfs_attr_leaf.c

@@ -948,14 +948,13 @@ xfs_attr_shortform_to_leaf(
 		nargs.namelen = sfe->namelen;
 		nargs.value = &sfe->nameval[nargs.namelen];
 		nargs.valuelen = sfe->valuelen;
-		nargs.hashval = xfs_da_hashname(sfe->nameval,
-						sfe->namelen);
 		nargs.attr_filter = sfe->flags & XFS_ATTR_NSP_ONDISK_MASK;
 		if (!xfs_attr_check_namespace(sfe->flags)) {
 			xfs_da_mark_sick(args);
 			error = -EFSCORRUPTED;
 			goto out;
 		}
+		xfs_attr_sethash(&nargs);
 		error = xfs_attr3_leaf_lookup_int(bp, &nargs); /* set a->index */
 		ASSERT(error == -ENOATTR);
 		error = xfs_attr3_leaf_add(bp, &nargs);

fs/xfs/scrub/attr.c

@@ -179,7 +179,6 @@ xchk_xattr_actor(
 		.dp			= ip,
 		.name			= name,
 		.namelen		= namelen,
-		.hashval		= xfs_da_hashname(name, namelen),
 		.trans			= sc->tp,
 		.valuelen		= valuelen,
 		.owner			= ip->i_ino,
@@ -230,6 +229,7 @@ xchk_xattr_actor(
 
 	args.value = ab->value;
 
+	xfs_attr_sethash(&args);
 	error = xfs_attr_get_ilocked(&args);
 	/* ENODATA means the hash lookup failed and the attr is bad */
 	if (error == -ENODATA)
@@ -525,7 +525,10 @@ xchk_xattr_rec(
 			xchk_da_set_corrupt(ds, level);
 			goto out;
 		}
-		calc_hash = xfs_da_hashname(lentry->nameval, lentry->namelen);
+		calc_hash = xfs_attr_hashval(mp, ent->flags, lentry->nameval,
+					     lentry->namelen,
+					     lentry->nameval + lentry->namelen,
+					     be16_to_cpu(lentry->valuelen));
 	} else {
 		rentry = (struct xfs_attr_leaf_name_remote *)
 				(((char *)bp->b_addr) + nameidx);
@@ -533,7 +536,9 @@ xchk_xattr_rec(
 			xchk_da_set_corrupt(ds, level);
 			goto out;
 		}
-		calc_hash = xfs_da_hashname(rentry->name, rentry->namelen);
+		calc_hash = xfs_attr_hashval(mp, ent->flags, rentry->name,
+					     rentry->namelen, NULL,
+					     be32_to_cpu(rentry->valuelen));
 	}
 	if (calc_hash != hash)
 		xchk_da_set_corrupt(ds, level);

fs/xfs/xfs_attr_item.c

@@ -582,13 +582,13 @@ xfs_attri_recover_work(
 	args->whichfork = XFS_ATTR_FORK;
 	args->name = nv->name.i_addr;
 	args->namelen = nv->name.i_len;
-	args->hashval = xfs_da_hashname(args->name, args->namelen);
 	args->value = nv->value.i_addr;
 	args->valuelen = nv->value.i_len;
 	args->attr_filter = attrp->alfi_attr_filter & XFS_ATTRI_FILTER_MASK;
 	args->op_flags = XFS_DA_OP_RECOVERY | XFS_DA_OP_OKNOENT |
 			 XFS_DA_OP_LOGGED;
 	args->owner = args->dp->i_ino;
+	xfs_attr_sethash(args);
 
 	switch (xfs_attr_intent_op(attr)) {
 	case XFS_ATTRI_OP_FLAGS_SET:

fs/xfs/xfs_attr_list.c

@@ -135,12 +135,15 @@ xfs_attr_shortform_list(
 		}
 
 		sbp->entno = i;
-		sbp->hash = xfs_da_hashname(sfe->nameval, sfe->namelen);
 		sbp->name = sfe->nameval;
 		sbp->namelen = sfe->namelen;
 		/* These are bytes, and both on-disk, don't endian-flip */
 		sbp->valuelen = sfe->valuelen;
 		sbp->flags = sfe->flags;
+		sbp->hash = xfs_attr_hashval(dp->i_mount, sfe->flags,
+					     sfe->nameval, sfe->namelen,
+					     sfe->nameval + sfe->namelen,
+					     sfe->valuelen);
 		sfe = xfs_attr_sf_nextentry(sfe);
 		sbp++;
 		nsbuf++;