xfs: pass the attr value to put_listent when possible

Pass the attr value to put_listent when we have local xattrs or
shortform xattrs.  This will enable the GETPARENTS ioctl to use
xfs_attr_list as its backend.
Signed-off-by: Allison Henderson <allison.henderson@oracle.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>

fs/xfs/libxfs/xfs_attr.h

@@ -47,8 +47,9 @@ struct xfs_attrlist_cursor_kern {
 
 
 /* void; state communicated via *context */
-typedef void (*put_listent_func_t)(struct xfs_attr_list_context *, int,
-			      unsigned char *, int, int);
+typedef void (*put_listent_func_t)(struct xfs_attr_list_context *context,
+		int flags, unsigned char *name, int namelen, void *value,
+		int valuelen);
 
 struct xfs_attr_list_context {
 	struct xfs_trans	*tp;

fs/xfs/libxfs/xfs_attr_sf.h

@@ -16,6 +16,7 @@ typedef struct xfs_attr_sf_sort {
 	uint8_t		flags;		/* flags bits (see xfs_attr_leaf.h) */
 	xfs_dahash_t	hash;		/* this entry's hash value */
 	unsigned char	*name;		/* name value, pointer into buffer */
+	void		*value;
 } xfs_attr_sf_sort_t;
 
 #define XFS_ATTR_SF_ENTSIZE_MAX			/* max space for name&value */ \

fs/xfs/xfs_attr_list.c

@@ -92,6 +92,7 @@ xfs_attr_shortform_list(
 					     sfe->flags,
 					     sfe->nameval,
 					     (int)sfe->namelen,
+					     &sfe->nameval[sfe->namelen],
 					     (int)sfe->valuelen);
 			/*
 			 * Either search callback finished early or
@@ -138,6 +139,7 @@ xfs_attr_shortform_list(
 		sbp->name = sfe->nameval;
 		sbp->namelen = sfe->namelen;
 		/* These are bytes, and both on-disk, don't endian-flip */
+		sbp->value = &sfe->nameval[sfe->namelen],
 		sbp->valuelen = sfe->valuelen;
 		sbp->flags = sfe->flags;
 		sbp->hash = xfs_attr_hashval(dp->i_mount, sfe->flags,
@@ -192,6 +194,7 @@ xfs_attr_shortform_list(
 				     sbp->flags,
 				     sbp->name,
 				     sbp->namelen,
+				     sbp->value,
 				     sbp->valuelen);
 		if (context->seen_enough)
 			break;
@@ -479,6 +482,7 @@ xfs_attr3_leaf_list_int(
 	 */
 	for (; i < ichdr.count; entry++, i++) {
 		char *name;
+		void *value;
 		int namelen, valuelen;
 
 		if (be32_to_cpu(entry->hashval) != cursor->hashval) {
@@ -496,6 +500,7 @@ xfs_attr3_leaf_list_int(
 			name_loc = xfs_attr3_leaf_name_local(leaf, i);
 			name = name_loc->nameval;
 			namelen = name_loc->namelen;
+			value = &name_loc->nameval[name_loc->namelen];
 			valuelen = be16_to_cpu(name_loc->valuelen);
 		} else {
 			xfs_attr_leaf_name_remote_t *name_rmt;
@@ -503,6 +508,7 @@ xfs_attr3_leaf_list_int(
 			name_rmt = xfs_attr3_leaf_name_remote(leaf, i);
 			name = name_rmt->name;
 			namelen = name_rmt->namelen;
+			value = NULL;
 			valuelen = be32_to_cpu(name_rmt->valuelen);
 		}
 
@@ -513,7 +519,7 @@ xfs_attr3_leaf_list_int(
 			return -EFSCORRUPTED;
 		}
 		context->put_listent(context, entry->flags,
-					      name, namelen, valuelen);
+					      name, namelen, value, valuelen);
 		if (context->seen_enough)
 			break;
 		cursor->offset++;

fs/xfs/xfs_ioctl.c

@@ -310,6 +310,7 @@ xfs_ioc_attr_put_listent(
 	int			flags,
 	unsigned char		*name,
 	int			namelen,
+	void			*value,
 	int			valuelen)
 {
 	struct xfs_attrlist	*alist = context->buffer;

fs/xfs/xfs_xattr.c

@@ -222,6 +222,7 @@ xfs_xattr_put_listent(
 	int		flags,
 	unsigned char	*name,
 	int		namelen,
+	void		*value,
 	int		valuelen)
 {
 	char *prefix;