[PATCH 01/13] xfs: make xfs_attr_set require XFS_DA_OP_REMOVE

["Darrick J. Wong" <djwong@xxxxxxxxxx>]

From: Darrick J. Wong <djwong@xxxxxxxxxx>

In the next patch we're going to add the ability to look up local/sf
xattrs based on the attr name and value matching.  As a result, we need
callers of xfs_attr_set to declare explicitly that they want to remove
an xattr.  Passing in NULL value will no longer suffice.

Signed-off-by: Darrick J. Wong <djwong@xxxxxxxxxx>
---
 fs/xfs/libxfs/xfs_attr.c   |    9 +++++----
 fs/xfs/libxfs/xfs_parent.c |    1 +
 fs/xfs/xfs_xattr.c         |    5 +++++
 3 files changed, 11 insertions(+), 4 deletions(-)


diff --git a/fs/xfs/libxfs/xfs_attr.c b/fs/xfs/libxfs/xfs_attr.c
index 3065dd622102..756d93526075 100644
--- a/fs/xfs/libxfs/xfs_attr.c
+++ b/fs/xfs/libxfs/xfs_attr.c
@@ -977,6 +977,7 @@ xfs_attr_set(
 	struct xfs_inode	*dp = args->dp;
 	struct xfs_mount	*mp = dp->i_mount;
 	struct xfs_trans_res	tres;
+	bool			is_remove = args->op_flags & XFS_DA_OP_REMOVE;
 	bool			rsvd;
 	int			error, local;
 	int			rmt_blks = 0;
@@ -1004,7 +1005,7 @@ xfs_attr_set(
 	args->op_flags = XFS_DA_OP_OKNOENT |
 					(args->op_flags & XFS_DA_OP_LOGGED);
 
-	if (args->value) {
+	if (!is_remove) {
 		XFS_STATS_INC(mp, xs_attr_set);
 		args->total = xfs_attr_calc_size(args, &local);
 
@@ -1038,7 +1039,7 @@ xfs_attr_set(
 	if (error)
 		return error;
 
-	if (args->value || xfs_inode_hasattr(dp)) {
+	if (!is_remove || xfs_inode_hasattr(dp)) {
 		error = xfs_iext_count_may_overflow(dp, XFS_ATTR_FORK,
 				XFS_IEXT_ATTR_MANIP_CNT(rmt_blks));
 		if (error == -EFBIG)
@@ -1052,7 +1053,7 @@ xfs_attr_set(
 	switch (error) {
 	case -EEXIST:
 		/* if no value, we are performing a remove operation */
-		if (!args->value) {
+		if (is_remove) {
 			error = xfs_attr_defer_remove(args);
 			break;
 		}
@@ -1064,7 +1065,7 @@ xfs_attr_set(
 		break;
 	case -ENOATTR:
 		/* Can't remove what isn't there. */
-		if (!args->value)
+		if (is_remove)
 			goto out_trans_cancel;
 
 		/* Pure replace fails if no existing attr to replace. */
diff --git a/fs/xfs/libxfs/xfs_parent.c b/fs/xfs/libxfs/xfs_parent.c
index f7fecee93894..387f3c65287f 100644
--- a/fs/xfs/libxfs/xfs_parent.c
+++ b/fs/xfs/libxfs/xfs_parent.c
@@ -460,6 +460,7 @@ xfs_parent_unset(
 	scr->args.geo		= ip->i_mount->m_attr_geo;
 	scr->args.name		= (const unsigned char *)&scr->rec;
 	scr->args.namelen	= reclen;
+	scr->args.op_flags	= XFS_DA_OP_REMOVE;
 	scr->args.whichfork	= XFS_ATTR_FORK;
 
 	return xfs_attr_set(&scr->args);
diff --git a/fs/xfs/xfs_xattr.c b/fs/xfs/xfs_xattr.c
index 85edd7e05fde..8f8aa13bf7eb 100644
--- a/fs/xfs/xfs_xattr.c
+++ b/fs/xfs/xfs_xattr.c
@@ -103,6 +103,11 @@ xfs_attr_change(
 		use_logging = true;
 	}
 
+	if (args->value)
+		args->op_flags &= ~XFS_DA_OP_REMOVE;
+	else
+		args->op_flags |= XFS_DA_OP_REMOVE;
+
 	error = xfs_attr_set(args);
 
 	if (use_logging)