xfs: add parent attributes to link

This patch modifies xfs_link to add a parent pointer to the inode.
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Allison Henderson <allison.henderson@oracle.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
[djwong: minor rebase fixes]
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>

fs/xfs/libxfs/xfs_trans_space.c

@@ -50,3 +50,17 @@ xfs_mkdir_space_res(
 {
 	return xfs_create_space_res(mp, namelen);
 }
+
+unsigned int
+xfs_link_space_res(
+	struct xfs_mount	*mp,
+	unsigned int		namelen)
+{
+	unsigned int		ret;
+
+	ret = XFS_DIRENTER_SPACE_RES(mp, namelen);
+	if (xfs_has_parent(mp))
+		ret += xfs_parent_calc_space_res(mp, namelen);
+
+	return ret;
+}

fs/xfs/libxfs/xfs_trans_space.h

@@ -86,8 +86,6 @@
 	(2 * (mp)->m_alloc_maxlevels)
 #define	XFS_GROWFSRT_SPACE_RES(mp,b)	\
 	((b) + XFS_EXTENTADD_SPACE_RES(mp, XFS_DATA_FORK))
-#define	XFS_LINK_SPACE_RES(mp,nl)	\
-	XFS_DIRENTER_SPACE_RES(mp,nl)
 #define	XFS_QM_DQALLOC_SPACE_RES(mp)	\
 	(XFS_EXTENTADD_SPACE_RES(mp, XFS_DATA_FORK) + \
 	 XFS_DQUOT_CLUSTER_SIZE_FSB)
@@ -107,5 +105,6 @@ unsigned int xfs_parent_calc_space_res(struct xfs_mount *mp,
 
 unsigned int xfs_create_space_res(struct xfs_mount *mp, unsigned int namelen);
 unsigned int xfs_mkdir_space_res(struct xfs_mount *mp, unsigned int namelen);
+unsigned int xfs_link_space_res(struct xfs_mount *mp, unsigned int namelen);
 
 #endif	/* __XFS_TRANS_SPACE_H__ */

fs/xfs/scrub/dir_repair.c

@@ -704,7 +704,7 @@ xrep_dir_replay_update(
 	uint				resblks;
 	int				error;
 
-	resblks = XFS_LINK_SPACE_RES(mp, xname->len);
+	resblks = xfs_link_space_res(mp, xname->len);
 	error = xchk_trans_alloc(rd->sc, resblks);
 	if (error)
 		return error;

fs/xfs/scrub/orphanage.c

@@ -326,7 +326,7 @@ xrep_adoption_trans_alloc(
 
 	/* Compute the worst case space reservation that we need. */
 	adopt->sc = sc;
-	adopt->orphanage_blkres = XFS_LINK_SPACE_RES(mp, MAXNAMELEN);
+	adopt->orphanage_blkres = xfs_link_space_res(mp, MAXNAMELEN);
 	if (S_ISDIR(VFS_I(sc->ip)->i_mode))
 		child_blkres = XFS_RENAME_SPACE_RES(mp, xfs_name_dotdot.len);
 	adopt->child_blkres = child_blkres;

fs/xfs/xfs_inode.c

@@ -1299,14 +1299,15 @@ xfs_create_tmpfile(
 
 int
 xfs_link(
-	xfs_inode_t		*tdp,
-	xfs_inode_t		*sip,
+	struct xfs_inode	*tdp,
+	struct xfs_inode	*sip,
 	struct xfs_name		*target_name)
 {
-	xfs_mount_t		*mp = tdp->i_mount;
-	xfs_trans_t		*tp;
+	struct xfs_mount	*mp = tdp->i_mount;
+	struct xfs_trans	*tp;
 	int			error, nospace_error = 0;
 	int			resblks;
+	struct xfs_parent_args	*ppargs;
 
 	trace_xfs_link(tdp, target_name);
 
@@ -1325,11 +1326,25 @@ xfs_link(
 	if (error)
 		goto std_return;
 
-	resblks = XFS_LINK_SPACE_RES(mp, target_name->len);
+	error = xfs_parent_start(mp, &ppargs);
+	if (error)
+		goto std_return;
+
+	resblks = xfs_link_space_res(mp, target_name->len);
 	error = xfs_trans_alloc_dir(tdp, &M_RES(mp)->tr_link, sip, &resblks,
 			&tp, &nospace_error);
 	if (error)
-		goto std_return;
+		goto out_parent;
+
+	/*
+	 * We don't allow reservationless or quotaless hardlinking when parent
+	 * pointers are enabled because we can't back out if the xattrs must
+	 * grow.
+	 */
+	if (ppargs && nospace_error) {
+		error = nospace_error;
+		goto error_return;
+	}
 
 	/*
 	 * If we are using project inheritance, we only allow hard link
@@ -1380,6 +1395,19 @@ xfs_link(
 	xfs_trans_log_inode(tp, tdp, XFS_ILOG_CORE);
 
 	xfs_bumplink(tp, sip);
+
+	/*
+	 * If we have parent pointers, we now need to add the parent record to
+	 * the attribute fork of the inode. If this is the initial parent
+	 * attribute, we need to create it correctly, otherwise we can just add
+	 * the parent to the inode.
+	 */
+	if (ppargs) {
+		error = xfs_parent_addname(tp, ppargs, tdp, target_name, sip);
+		if (error)
+			goto error_return;
+	}
+
 	xfs_dir_update_hook(tdp, sip, 1, target_name);
 
 	/*
@@ -1393,12 +1421,15 @@ xfs_link(
 	error = xfs_trans_commit(tp);
 	xfs_iunlock(tdp, XFS_ILOCK_EXCL);
 	xfs_iunlock(sip, XFS_ILOCK_EXCL);
+	xfs_parent_finish(mp, ppargs);
 	return error;
 
  error_return:
 	xfs_trans_cancel(tp);
 	xfs_iunlock(tdp, XFS_ILOCK_EXCL);
 	xfs_iunlock(sip, XFS_ILOCK_EXCL);
+ out_parent:
+	xfs_parent_finish(mp, ppargs);
  std_return:
 	if (error == -ENOSPC && nospace_error)
 		error = nospace_error;