zfs-builds-mm/zfs-0.8.1/include/sys/zfs_rlock.h

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2019-07-06 23:40:11 +02:00
/*
* 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.
*/
/*
* Copyright (c) 2018 by Delphix. All rights reserved.
*/
#ifndef _SYS_FS_ZFS_RLOCK_H
#define _SYS_FS_ZFS_RLOCK_H
#ifdef __cplusplus
extern "C" {
#endif
#include <sys/avl.h>
typedef enum {
RL_READER,
RL_WRITER,
RL_APPEND
} rangelock_type_t;
struct locked_range;
typedef void (rangelock_cb_t)(struct locked_range *, void *);
typedef struct rangelock {
avl_tree_t rl_tree; /* contains locked_range_t */
kmutex_t rl_lock;
rangelock_cb_t *rl_cb;
void *rl_arg;
} rangelock_t;
typedef struct locked_range {
rangelock_t *lr_rangelock; /* rangelock that this lock applies to */
avl_node_t lr_node; /* avl node link */
uint64_t lr_offset; /* file range offset */
uint64_t lr_length; /* file range length */
uint_t lr_count; /* range reference count in tree */
rangelock_type_t lr_type; /* range type */
kcondvar_t lr_write_cv; /* cv for waiting writers */
kcondvar_t lr_read_cv; /* cv for waiting readers */
uint8_t lr_proxy; /* acting for original range */
uint8_t lr_write_wanted; /* writer wants to lock this range */
uint8_t lr_read_wanted; /* reader wants to lock this range */
} locked_range_t;
void rangelock_init(rangelock_t *, rangelock_cb_t *, void *);
void rangelock_fini(rangelock_t *);
locked_range_t *rangelock_enter(rangelock_t *,
uint64_t, uint64_t, rangelock_type_t);
void rangelock_exit(locked_range_t *);
void rangelock_reduce(locked_range_t *, uint64_t, uint64_t);
#ifdef __cplusplus
}
#endif
#endif /* _SYS_FS_ZFS_RLOCK_H */