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-rw-r--r--uts/common/fs/zfs/sys/zfs_rlock.h89
1 files changed, 89 insertions, 0 deletions
diff --git a/uts/common/fs/zfs/sys/zfs_rlock.h b/uts/common/fs/zfs/sys/zfs_rlock.h
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+++ b/uts/common/fs/zfs/sys/zfs_rlock.h
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+/*
+ * CDDL HEADER START
+ *
+ * The contents of this file are subject to the terms of the
+ * Common Development and Distribution License (the "License").
+ * You may not use this file except in compliance with the License.
+ *
+ * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
+ * or http://www.opensolaris.org/os/licensing.
+ * See the License for the specific language governing permissions
+ * and limitations under the License.
+ *
+ * When distributing Covered Code, include this CDDL HEADER in each
+ * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
+ * If applicable, add the following below this CDDL HEADER, with the
+ * fields enclosed by brackets "[]" replaced with your own identifying
+ * information: Portions Copyright [yyyy] [name of copyright owner]
+ *
+ * CDDL HEADER END
+ */
+/*
+ * Copyright 2006 Sun Microsystems, Inc. All rights reserved.
+ * Use is subject to license terms.
+ */
+
+#ifndef _SYS_FS_ZFS_RLOCK_H
+#define _SYS_FS_ZFS_RLOCK_H
+
+#pragma ident "%Z%%M% %I% %E% SMI"
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#ifdef _KERNEL
+
+#include <sys/zfs_znode.h>
+
+typedef enum {
+ RL_READER,
+ RL_WRITER,
+ RL_APPEND
+} rl_type_t;
+
+typedef struct rl {
+ znode_t *r_zp; /* znode this lock applies to */
+ avl_node_t r_node; /* avl node link */
+ uint64_t r_off; /* file range offset */
+ uint64_t r_len; /* file range length */
+ uint_t r_cnt; /* range reference count in tree */
+ rl_type_t r_type; /* range type */
+ kcondvar_t r_wr_cv; /* cv for waiting writers */
+ kcondvar_t r_rd_cv; /* cv for waiting readers */
+ uint8_t r_proxy; /* acting for original range */
+ uint8_t r_write_wanted; /* writer wants to lock this range */
+ uint8_t r_read_wanted; /* reader wants to lock this range */
+} rl_t;
+
+/*
+ * Lock a range (offset, length) as either shared (READER)
+ * or exclusive (WRITER or APPEND). APPEND is a special type that
+ * is converted to WRITER that specified to lock from the start of the
+ * end of file. zfs_range_lock() returns the range lock structure.
+ */
+rl_t *zfs_range_lock(znode_t *zp, uint64_t off, uint64_t len, rl_type_t type);
+
+/*
+ * Unlock range and destroy range lock structure.
+ */
+void zfs_range_unlock(rl_t *rl);
+
+/*
+ * Reduce range locked as RW_WRITER from whole file to specified range.
+ * Asserts the whole file was previously locked.
+ */
+void zfs_range_reduce(rl_t *rl, uint64_t off, uint64_t len);
+
+/*
+ * AVL comparison function used to compare range locks
+ */
+int zfs_range_compare(const void *arg1, const void *arg2);
+
+#endif /* _KERNEL */
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* _SYS_FS_ZFS_RLOCK_H */