/* * 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 #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 (RL_READER) * or exclusive (RL_WRITER or RL_APPEND). RL_APPEND is a special type that * is converted to RL_WRITER that specified to lock from the start of the * end of file. 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 order range locks * Locks are ordered on the start offset of the range. */ int zfs_range_compare(const void *arg1, const void *arg2); #endif /* _KERNEL */ #ifdef __cplusplus } #endif #endif /* _SYS_FS_ZFS_RLOCK_H */ |