xfs: enable the xfs_defer mechanism to process extents to free

Connect the xfs_defer mechanism with the pieces that we'll need to
handle deferred extent freeing.  We'll wire up the existing code to
our new deferred mechanism later.
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>

fs/xfs/libxfs/xfs_defer.h

@@ -51,6 +51,7 @@ struct xfs_defer_pending {
  * find all the space it needs.
  */
 enum xfs_defer_ops_type {
+	XFS_DEFER_OPS_TYPE_FREE,
 	XFS_DEFER_OPS_TYPE_MAX,
 };
 

fs/xfs/xfs_super.c

@@ -1854,6 +1854,8 @@ init_xfs_fs(void)
 	printk(KERN_INFO XFS_VERSION_STRING " with "
 			 XFS_BUILD_OPTIONS " enabled\n");
 
+	xfs_extent_free_init_defer_op();
+
 	xfs_dir_startup();
 
 	error = xfs_init_zones();

fs/xfs/xfs_trans.h

@@ -210,6 +210,8 @@ void		xfs_trans_ichgtime(struct xfs_trans *, struct xfs_inode *, int);
 void		xfs_trans_ijoin(struct xfs_trans *, struct xfs_inode *, uint);
 void		xfs_trans_log_buf(xfs_trans_t *, struct xfs_buf *, uint, uint);
 void		xfs_trans_log_inode(xfs_trans_t *, struct xfs_inode *, uint);
+
+void		xfs_extent_free_init_defer_op(void);
 struct xfs_efi_log_item	*xfs_trans_get_efi(struct xfs_trans *, uint);
 void		xfs_trans_log_efi_extent(struct xfs_trans *,
 					 struct xfs_efi_log_item *,

fs/xfs/xfs_trans_extfree.c

@@ -22,10 +22,12 @@
 #include "xfs_log_format.h"
 #include "xfs_trans_resv.h"
 #include "xfs_mount.h"
+#include "xfs_defer.h"
 #include "xfs_trans.h"
 #include "xfs_trans_priv.h"
 #include "xfs_extfree_item.h"
 #include "xfs_alloc.h"
+#include "xfs_bmap.h"
 
 /*
  * This routine is called to allocate an "extent free intention"
@@ -145,3 +147,111 @@ xfs_trans_free_extent(
 
 	return error;
 }
+
+/* Sort bmap items by AG. */
+static int
+xfs_extent_free_diff_items(
+	void				*priv,
+	struct list_head		*a,
+	struct list_head		*b)
+{
+	struct xfs_mount		*mp = priv;
+	struct xfs_bmap_free_item	*ra;
+	struct xfs_bmap_free_item	*rb;
+
+	ra = container_of(a, struct xfs_bmap_free_item, xbfi_list);
+	rb = container_of(b, struct xfs_bmap_free_item, xbfi_list);
+	return  XFS_FSB_TO_AGNO(mp, ra->xbfi_startblock) -
+		XFS_FSB_TO_AGNO(mp, rb->xbfi_startblock);
+}
+
+/* Get an EFI. */
+STATIC void *
+xfs_extent_free_create_intent(
+	struct xfs_trans		*tp,
+	unsigned int			count)
+{
+	return xfs_trans_get_efi(tp, count);
+}
+
+/* Log a free extent to the intent item. */
+STATIC void
+xfs_extent_free_log_item(
+	struct xfs_trans		*tp,
+	void				*intent,
+	struct list_head		*item)
+{
+	struct xfs_bmap_free_item	*free;
+
+	free = container_of(item, struct xfs_bmap_free_item, xbfi_list);
+	xfs_trans_log_efi_extent(tp, intent, free->xbfi_startblock,
+			free->xbfi_blockcount);
+}
+
+/* Get an EFD so we can process all the free extents. */
+STATIC void *
+xfs_extent_free_create_done(
+	struct xfs_trans		*tp,
+	void				*intent,
+	unsigned int			count)
+{
+	return xfs_trans_get_efd(tp, intent, count);
+}
+
+/* Process a free extent. */
+STATIC int
+xfs_extent_free_finish_item(
+	struct xfs_trans		*tp,
+	struct xfs_defer_ops		*dop,
+	struct list_head		*item,
+	void				*done_item,
+	void				**state)
+{
+	struct xfs_bmap_free_item	*free;
+	int				error;
+
+	free = container_of(item, struct xfs_bmap_free_item, xbfi_list);
+	error = xfs_trans_free_extent(tp, done_item,
+			free->xbfi_startblock,
+			free->xbfi_blockcount);
+	kmem_free(free);
+	return error;
+}
+
+/* Abort all pending EFIs. */
+STATIC void
+xfs_extent_free_abort_intent(
+	void				*intent)
+{
+	xfs_efi_release(intent);
+}
+
+/* Cancel a free extent. */
+STATIC void
+xfs_extent_free_cancel_item(
+	struct list_head		*item)
+{
+	struct xfs_bmap_free_item	*free;
+
+	free = container_of(item, struct xfs_bmap_free_item, xbfi_list);
+	kmem_free(free);
+}
+
+static const struct xfs_defer_op_type xfs_extent_free_defer_type = {
+	.type		= XFS_DEFER_OPS_TYPE_FREE,
+	.max_items	= XFS_EFI_MAX_FAST_EXTENTS,
+	.diff_items	= xfs_extent_free_diff_items,
+	.create_intent	= xfs_extent_free_create_intent,
+	.abort_intent	= xfs_extent_free_abort_intent,
+	.log_item	= xfs_extent_free_log_item,
+	.create_done	= xfs_extent_free_create_done,
+	.finish_item	= xfs_extent_free_finish_item,
+	.cancel_item	= xfs_extent_free_cancel_item,
+};
+
+/* Register the deferred op type. */
+void
+xfs_extent_free_init_defer_op(void)
+{
+	xfs_defer_init_op_type(&xfs_extent_free_defer_type);
+}