1 /* 2 * CDDL HEADER START 3 * 4 * The contents of this file are subject to the terms of the 5 * Common Development and Distribution License (the "License"). 6 * You may not use this file except in compliance with the License. 7 * 8 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE 9 * or http://www.opensolaris.org/os/licensing. 10 * See the License for the specific language governing permissions 11 * and limitations under the License. 12 * 13 * When distributing Covered Code, include this CDDL HEADER in each 14 * file and include the License file at usr/src/OPENSOLARIS.LICENSE. 15 * If applicable, add the following below this CDDL HEADER, with the 16 * fields enclosed by brackets "[]" replaced with your own identifying 17 * information: Portions Copyright [yyyy] [name of copyright owner] 18 * 19 * CDDL HEADER END 20 */ 21 /* 22 * Copyright 2006 Sun Microsystems, Inc. All rights reserved. 23 * Use is subject to license terms. 24 */ 25 /* 26 * Copyright (c) 2018 by Delphix. All rights reserved. 27 */ 28 29 #ifndef _SYS_FS_ZFS_RLOCK_H 30 #define _SYS_FS_ZFS_RLOCK_H 31 32 #ifdef __cplusplus 33 extern "C" { 34 #endif 35 36 #include <sys/avl.h> 37 38 typedef enum { 39 RL_READER, 40 RL_WRITER, 41 RL_APPEND 42 } zfs_rangelock_type_t; 43 44 struct zfs_locked_range; 45 46 typedef void (zfs_rangelock_cb_t)(struct zfs_locked_range *, void *); 47 48 typedef struct zfs_rangelock { 49 avl_tree_t rl_tree; /* contains locked_range_t */ 50 kmutex_t rl_lock; 51 zfs_rangelock_cb_t *rl_cb; 52 void *rl_arg; 53 } zfs_rangelock_t; 54 55 typedef struct zfs_locked_range { 56 zfs_rangelock_t *lr_rangelock; /* rangelock that this lock applies to */ 57 avl_node_t lr_node; /* avl node link */ 58 uint64_t lr_offset; /* file range offset */ 59 uint64_t lr_length; /* file range length */ 60 uint_t lr_count; /* range reference count in tree */ 61 zfs_rangelock_type_t lr_type; /* range type */ 62 kcondvar_t lr_write_cv; /* cv for waiting writers */ 63 kcondvar_t lr_read_cv; /* cv for waiting readers */ 64 uint8_t lr_proxy; /* acting for original range */ 65 uint8_t lr_write_wanted; /* writer wants to lock this range */ 66 uint8_t lr_read_wanted; /* reader wants to lock this range */ 67 } zfs_locked_range_t; 68 69 void zfs_rangelock_init(zfs_rangelock_t *, zfs_rangelock_cb_t *, void *); 70 void zfs_rangelock_fini(zfs_rangelock_t *); 71 72 zfs_locked_range_t *zfs_rangelock_enter(zfs_rangelock_t *, 73 uint64_t, uint64_t, zfs_rangelock_type_t); 74 zfs_locked_range_t *zfs_rangelock_tryenter(zfs_rangelock_t *, 75 uint64_t, uint64_t, zfs_rangelock_type_t); 76 void zfs_rangelock_exit(zfs_locked_range_t *); 77 void zfs_rangelock_reduce(zfs_locked_range_t *, uint64_t, uint64_t); 78 79 #ifdef __cplusplus 80 } 81 #endif 82 83 #endif /* _SYS_FS_ZFS_RLOCK_H */ 84