[PATCH v9 21/28] xfs: add parent attributes to link

[Allison Henderson <allison.henderson@oracle.com>]

From: Dave Chinner <dchinner@redhat.com>

This patch modifies xfs_link to add a parent pointer to the inode.
xfs_link will also need to create an attribute fork if the inode does
not already have one.

[bfoster: rebase, use VFS inode fields, fix xfs_bmap_finish() usage]
[achender: rebased, changed __unint32_t to xfs_dir2_dataptr_t,
	   fixed null pointer bugs]

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Allison Henderson <allison.henderson@oracle.com>
---
 fs/xfs/xfs_inode.c | 37 +++++++++++++++++++++++++++++--------
 1 file changed, 29 insertions(+), 8 deletions(-)

diff --git a/fs/xfs/xfs_inode.c b/fs/xfs/xfs_inode.c
index 3f722e6..4a32eb1 100644
--- a/fs/xfs/xfs_inode.c
+++ b/fs/xfs/xfs_inode.c
@@ -1409,6 +1409,7 @@ xfs_link(
 	xfs_trans_t		*tp;
 	int			error;
 	int			resblks;
+	xfs_dir2_dataptr_t	diroffset;
 
 	trace_xfs_link(tdp, target_name);
 
@@ -1436,8 +1437,8 @@ xfs_link(
 
 	xfs_lock_two_inodes(sip, XFS_ILOCK_EXCL, tdp, XFS_ILOCK_EXCL);
 
-	xfs_trans_ijoin(tp, sip, XFS_ILOCK_EXCL);
-	xfs_trans_ijoin(tp, tdp, XFS_ILOCK_EXCL);
+	xfs_trans_ijoin(tp, sip, 0);
+	xfs_trans_ijoin(tp, tdp, 0);
 
 	/*
 	 * If we are using project inheritance, we only allow hard link
@@ -1466,15 +1467,28 @@ xfs_link(
 	}
 
 	error = xfs_dir_createname(tp, tdp, target_name, sip->i_ino,
-				   resblks, NULL);
+				   resblks, &diroffset);
 	if (error)
-		goto error_return;
+		goto out_defer_cancel;
 	xfs_trans_ichgtime(tp, tdp, XFS_ICHGTIME_MOD | XFS_ICHGTIME_CHG);
 	xfs_trans_log_inode(tp, tdp, XFS_ILOG_CORE);
 
 	error = xfs_bumplink(tp, sip);
 	if (error)
-		goto error_return;
+		goto out_defer_cancel;
+
+	/*
+	 * 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 (xfs_sb_version_hasparent(&mp->m_sb)) {
+		error = xfs_parent_add_deferred(tdp, tp, sip, target_name,
+				       diroffset);
+		if (error)
+			goto out_defer_cancel;
+	}
 
 	/*
 	 * If this is a synchronous mount, make sure that the
@@ -1484,11 +1498,18 @@ xfs_link(
 	if (mp->m_flags & (XFS_MOUNT_WSYNC|XFS_MOUNT_DIRSYNC))
 		xfs_trans_set_sync(tp);
 
-	return xfs_trans_commit(tp);
+	error = xfs_trans_commit(tp);
+	xfs_iunlock(tdp, XFS_ILOCK_EXCL);
+	xfs_iunlock(sip, XFS_ILOCK_EXCL);
+	return error;
 
- error_return:
+out_defer_cancel:
+	xfs_defer_cancel(tp);
+error_return:
 	xfs_trans_cancel(tp);
- std_return:
+	xfs_iunlock(tdp, XFS_ILOCK_EXCL);
+	xfs_iunlock(sip, XFS_ILOCK_EXCL);
+std_return:
 	return error;
 }
 
-- 
2.7.4