summaryrefslogtreecommitdiff
path: root/fs/xfs/xfs_refcount_item.h
diff options
context:
space:
mode:
Diffstat (limited to 'fs/xfs/xfs_refcount_item.h')
-rw-r--r--fs/xfs/xfs_refcount_item.h100
1 files changed, 100 insertions, 0 deletions
diff --git a/fs/xfs/xfs_refcount_item.h b/fs/xfs/xfs_refcount_item.h
new file mode 100644
index 000000000000..34b6f7a8c149
--- /dev/null
+++ b/fs/xfs/xfs_refcount_item.h
@@ -0,0 +1,100 @@
+/*
+ * 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_REFCOUNT_ITEM_H__
+#define __XFS_REFCOUNT_ITEM_H__
+
+/*
+ * There are (currently) two pairs of refcount btree redo item types:
+ * increase and decrease. The log items for these are CUI (refcount
+ * update intent) and CUD (refcount update done). The redo item type
+ * is encoded in the flags field of each xfs_map_extent.
+ *
+ * *I items should be recorded in the *first* of a series of rolled
+ * transactions, and the *D items should be recorded in the same
+ * transaction that records the associated refcountbt updates.
+ *
+ * Should the system crash after the commit of the first transaction
+ * but before the commit of the final transaction in a series, log
+ * recovery will use the redo information recorded by the intent items
+ * to replay the refcountbt metadata updates.
+ */
+
+/* kernel only CUI/CUD definitions */
+
+struct xfs_mount;
+struct kmem_zone;
+
+/*
+ * Max number of extents in fast allocation path.
+ */
+#define XFS_CUI_MAX_FAST_EXTENTS 16
+
+/*
+ * Define CUI flag bits. Manipulated by set/clear/test_bit operators.
+ */
+#define XFS_CUI_RECOVERED 1
+
+/*
+ * This is the "refcount update intent" log item. It is used to log
+ * the fact that some reverse mappings need to change. It is used in
+ * conjunction with the "refcount update done" log item described
+ * below.
+ *
+ * These log items follow the same rules as struct xfs_efi_log_item;
+ * see the comments about that structure (in xfs_extfree_item.h) for
+ * more details.
+ */
+struct xfs_cui_log_item {
+ struct xfs_log_item cui_item;
+ atomic_t cui_refcount;
+ atomic_t cui_next_extent;
+ unsigned long cui_flags; /* misc flags */
+ struct xfs_cui_log_format cui_format;
+};
+
+static inline size_t
+xfs_cui_log_item_sizeof(
+ unsigned int nr)
+{
+ return offsetof(struct xfs_cui_log_item, cui_format) +
+ xfs_cui_log_format_sizeof(nr);
+}
+
+/*
+ * This is the "refcount update done" log item. It is used to log the
+ * fact that some refcountbt updates mentioned in an earlier cui item
+ * have been performed.
+ */
+struct xfs_cud_log_item {
+ struct xfs_log_item cud_item;
+ struct xfs_cui_log_item *cud_cuip;
+ struct xfs_cud_log_format cud_format;
+};
+
+extern struct kmem_zone *xfs_cui_zone;
+extern struct kmem_zone *xfs_cud_zone;
+
+struct xfs_cui_log_item *xfs_cui_init(struct xfs_mount *, uint);
+struct xfs_cud_log_item *xfs_cud_init(struct xfs_mount *,
+ struct xfs_cui_log_item *);
+void xfs_cui_item_free(struct xfs_cui_log_item *);
+void xfs_cui_release(struct xfs_cui_log_item *);
+
+#endif /* __XFS_REFCOUNT_ITEM_H__ */