[PATCH v3 16/19] xfs: Add xfs_attr_set_deferred and xfs_attr_remove_deferred

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

From: Allison Henderson <allison.henderson@oracle.com>

These routines set up set and start a new deferred attribute
operation.  These functions are meant to be called by other
code needing to initiate a deferred attribute operation.
New helper function xfs_attr_item_init also added

Signed-off-by: Allison Henderson <allison.henderson@oracle.com>
Signed-off-by: Allison Collins <allison.henderson@oracle.com>
---
 fs/xfs/libxfs/xfs_attr.c | 85 ++++++++++++++++++++++++++++++++++++++++++++++++
 fs/xfs/libxfs/xfs_attr.h |  5 +++
 2 files changed, 90 insertions(+)

diff --git a/fs/xfs/libxfs/xfs_attr.c b/fs/xfs/libxfs/xfs_attr.c
index 7680789..f502396 100644
--- a/fs/xfs/libxfs/xfs_attr.c
+++ b/fs/xfs/libxfs/xfs_attr.c
@@ -25,6 +25,7 @@
 #include "xfs_trans_space.h"
 #include "xfs_trace.h"
 #include "xfs_attr_item.h"
+#include "xfs_attr.h"
 
 /*
  * xfs_attr.c
@@ -622,6 +623,70 @@ xfs_attr_set(
 	goto out_unlock;
 }
 
+STATIC int
+xfs_attr_item_init(
+	struct xfs_inode	*dp,		/* inode for attr operation */
+	struct xfs_trans	*tp,		/* transaction for attr op */
+	struct xfs_name		*name,		/* attr name, len and flags */
+	const unsigned char	*value,		/* attr value */
+	unsigned int		valuelen,	/* attr value len */
+	int			op_flags,	/* op flag (set or remove) */
+	struct xfs_attr_item	**attr)		/* new xfs_attr_item */
+{
+
+	struct xfs_attr_item	*new;
+	char			*name_value;
+
+	/*
+	 * All set operations must have a name but not necessarily a value.
+	 */
+	if (!name->len) {
+		ASSERT(0);
+		return -EINVAL;
+	}
+
+	new = kmem_alloc_large(XFS_ATTR_ITEM_SIZEOF(name->len, valuelen),
+			 KM_NOFS);
+	name_value = ((char *)new) + sizeof(struct xfs_attr_item);
+	memset(new, 0, XFS_ATTR_ITEM_SIZEOF(name->len, valuelen));
+	new->xattri_ip = dp;
+	new->xattri_op_flags = op_flags;
+	new->xattri_name_len = name->len;
+	new->xattri_value_len = valuelen;
+	new->xattri_flags = name->type;
+	memcpy(&name_value[0], name->name, name->len);
+	new->xattri_name = name_value;
+	new->xattri_value = name_value + name->len;
+
+	if (valuelen > 0)
+		memcpy(&name_value[name->len], value, valuelen);
+
+	*attr = new;
+	return 0;
+}
+
+/* Sets an attribute for an inode as a deferred operation */
+int
+xfs_attr_set_deferred(
+	struct xfs_inode	*dp,
+	struct xfs_trans	*tp,
+	struct xfs_name		*name,
+	const unsigned char	*value,
+	unsigned int		valuelen)
+{
+	struct xfs_attr_item	*new;
+	int			error = 0;
+
+	error = xfs_attr_item_init(dp, tp, name, value, valuelen,
+				 XFS_ATTR_OP_FLAGS_SET, &new);
+	if (error)
+		return error;
+
+	xfs_defer_add(tp, XFS_DEFER_OPS_TYPE_ATTR, &new->xattri_list);
+
+	return 0;
+}
+
 /*
  * Generic handler routine to remove a name from an attribute list.
  * Transitions attribute list from Btree to shortform as necessary.
@@ -703,6 +768,26 @@ xfs_attr_remove(
 	return error;
 }
 
+/* Removes an attribute for an inode as a deferred operation */
+int
+xfs_attr_remove_deferred(
+	struct xfs_inode        *dp,
+	struct xfs_trans	*tp,
+	struct xfs_name		*name)
+{
+
+	struct xfs_attr_item *new;
+
+	int error  = xfs_attr_item_init(dp, tp, name, NULL, 0,
+				  XFS_ATTR_OP_FLAGS_REMOVE, &new);
+	if (error)
+		return error;
+
+	xfs_defer_add(tp, XFS_DEFER_OPS_TYPE_ATTR, &new->xattri_list);
+
+	return 0;
+}
+
 /*========================================================================
  * External routines when attribute list is inside the inode
  *========================================================================*/
diff --git a/fs/xfs/libxfs/xfs_attr.h b/fs/xfs/libxfs/xfs_attr.h
index 1e0c25e..0dfec5c 100644
--- a/fs/xfs/libxfs/xfs_attr.h
+++ b/fs/xfs/libxfs/xfs_attr.h
@@ -190,5 +190,10 @@ bool xfs_attr_namecheck(const void *name, size_t length);
 int xfs_attr_args_init(struct xfs_da_args *args, struct xfs_inode *dp,
 		       struct xfs_name *name);
 int xfs_attr_calc_size(struct xfs_da_args *args, int *local);
+int xfs_attr_set_deferred(struct xfs_inode *dp, struct xfs_trans *tp,
+			  struct xfs_name *name, const unsigned char *value,
+			  unsigned int valuelen);
+int xfs_attr_remove_deferred(struct xfs_inode *dp, struct xfs_trans *tp,
+			    struct xfs_name *name);
 
 #endif	/* __XFS_ATTR_H__ */
-- 
2.7.4