1 files changed, 97 insertions, 0 deletions

diff --git a/fs/xfs/libxfs/xfs_defer.h b/fs/xfs/libxfs/xfs_defer.h
new file mode 100644
index 000000000000..cc3981c48296
--- /dev/null
+++ b/fs/xfs/libxfs/xfs_defer.h
@@ -0,0 +1,97 @@
+/*
+ * Copyright (C) 2016 Oracle.  All Rights Reserved.
+ *
+ * Author: Darrick J. Wong <darrick.wong@oracle.com>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it would be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write the Free Software Foundation,
+ * Inc.,  51 Franklin St, Fifth Floor, Boston, MA  02110-1301, USA.
+ */
+#ifndef __XFS_DEFER_H__
+#define __XFS_DEFER_H__
+
+struct xfs_defer_op_type;
+
+/*
+ * Save a log intent item and a list of extents, so that we can replay
+ * whatever action had to happen to the extent list and file the log done
+ * item.
+ */
+struct xfs_defer_pending {
+        const struct xfs_defer_op_type  *dfp_type;      /* function pointers */
+        struct list_head                dfp_list;       /* pending items */
+        bool                            dfp_committed;  /* committed trans? */
+        void                            *dfp_intent;    /* log intent item */
+        struct list_head                dfp_work;       /* work items */
+        unsigned int                    dfp_count;      /* # extent items */
+};
+
+/*
+ * Header for deferred operation list.
+ *
+ * dop_low is used by the allocator to activate the lowspace algorithm -
+ * when free space is running low the extent allocator may choose to
+ * allocate an extent from an AG without leaving sufficient space for
+ * a btree split when inserting the new extent.  In this case the allocator
+ * will enable the lowspace algorithm which is supposed to allow further
+ * allocations (such as btree splits and newroots) to allocate from
+ * sequential AGs.  In order to avoid locking AGs out of order the lowspace
+ * algorithm will start searching for free space from AG 0.  If the correct
+ * transaction reservations have been made then this algorithm will eventually
+ * find all the space it needs.
+ */
+enum xfs_defer_ops_type {
+        XFS_DEFER_OPS_TYPE_RMAP,
+        XFS_DEFER_OPS_TYPE_FREE,
+        XFS_DEFER_OPS_TYPE_MAX,
+};
+
+#define XFS_DEFER_OPS_NR_INODES 2       /* join up to two inodes */
+
+struct xfs_defer_ops {
+        bool                    dop_committed;  /* did any trans commit? */
+        bool                    dop_low;        /* alloc in low mode */
+        struct list_head        dop_intake;     /* unlogged pending work */
+        struct list_head        dop_pending;    /* logged pending work */
+
+        /* relog these inodes with each roll */
+        struct xfs_inode        *dop_inodes[XFS_DEFER_OPS_NR_INODES];
+};
+
+void xfs_defer_add(struct xfs_defer_ops *dop, enum xfs_defer_ops_type type,
+                struct list_head *h);
+int xfs_defer_finish(struct xfs_trans **tp, struct xfs_defer_ops *dop,
+                struct xfs_inode *ip);
+void xfs_defer_cancel(struct xfs_defer_ops *dop);
+void xfs_defer_init(struct xfs_defer_ops *dop, xfs_fsblock_t *fbp);
+bool xfs_defer_has_unfinished_work(struct xfs_defer_ops *dop);
+int xfs_defer_join(struct xfs_defer_ops *dop, struct xfs_inode *ip);
+
+/* Description of a deferred type. */
+struct xfs_defer_op_type {
+        enum xfs_defer_ops_type type;
+        unsigned int            max_items;
+        void (*abort_intent)(void *);
+        void *(*create_done)(struct xfs_trans *, void *, unsigned int);
+        int (*finish_item)(struct xfs_trans *, struct xfs_defer_ops *,
+                        struct list_head *, void *, void **);
+        void (*finish_cleanup)(struct xfs_trans *, void *, int);
+        void (*cancel_item)(struct list_head *);
+        int (*diff_items)(void *, struct list_head *, struct list_head *);
+        void *(*create_intent)(struct xfs_trans *, uint);
+        void (*log_item)(struct xfs_trans *, void *, struct list_head *);
+};
+
+void xfs_defer_init_op_type(const struct xfs_defer_op_type *type);
+
+#endif /* __XFS_DEFER_H__ */