projects / mirror_zfs-debian.git / blame
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|---|---|---|
| 34dc7c2f BB |
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 | #ifndef _SYS_FS_ZFS_RLOCK_H | |
| 27 | #define _SYS_FS_ZFS_RLOCK_H | |
| 28 | ||
| e5dc681a | 29 | |
| 34dc7c2f BB |
30 | |
| 31 | #ifdef __cplusplus | |
| 32 | extern "C" { | |
| 33 | #endif | |
| 34 | ||
| 35 | #ifdef _KERNEL | |
| 36 | ||
| 37 | #include <sys/zfs_znode.h> | |
| 38 | ||
| 39 | typedef enum { | |
| 40 | RL_READER, | |
| 41 | RL_WRITER, | |
| 42 | RL_APPEND | |
| 43 | } rl_type_t; | |
| 44 | ||
| 45 | typedef struct rl { | |
| 46 | znode_t *r_zp; /* znode this lock applies to */ | |
| 47 | avl_node_t r_node; /* avl node link */ | |
| 48 | uint64_t r_off; /* file range offset */ | |
| 49 | uint64_t r_len; /* file range length */ | |
| 50 | uint_t r_cnt; /* range reference count in tree */ | |
| 51 | rl_type_t r_type; /* range type */ | |
| 52 | kcondvar_t r_wr_cv; /* cv for waiting writers */ | |
| 53 | kcondvar_t r_rd_cv; /* cv for waiting readers */ | |
| 54 | uint8_t r_proxy; /* acting for original range */ | |
| 55 | uint8_t r_write_wanted; /* writer wants to lock this range */ | |
| 56 | uint8_t r_read_wanted; /* reader wants to lock this range */ | |
| 57 | } rl_t; | |
| 58 | ||
| 59 | /* | |
| 60 | * Lock a range (offset, length) as either shared (READER) | |
| 61 | * or exclusive (WRITER or APPEND). APPEND is a special type that | |
| 62 | * is converted to WRITER that specified to lock from the start of the | |
| 63 | * end of file. zfs_range_lock() returns the range lock structure. | |
| 64 | */ | |
| 65 | rl_t *zfs_range_lock(znode_t *zp, uint64_t off, uint64_t len, rl_type_t type); | |
| 66 | ||
| 67 | /* | |
| 68 | * Unlock range and destroy range lock structure. | |
| 69 | */ | |
| 70 | void zfs_range_unlock(rl_t *rl); | |
| 71 | ||
| 72 | /* | |
| 73 | * Reduce range locked as RW_WRITER from whole file to specified range. | |
| 74 | * Asserts the whole file was previously locked. | |
| 75 | */ | |
| 76 | void zfs_range_reduce(rl_t *rl, uint64_t off, uint64_t len); | |
| 77 | ||
| 78 | /* | |
| 79 | * AVL comparison function used to compare range locks | |
| 80 | */ | |
| 81 | int zfs_range_compare(const void *arg1, const void *arg2); | |
| 82 | ||
| 83 | #endif /* _KERNEL */ | |
| 84 | ||
| 85 | #ifdef __cplusplus | |
| 86 | } | |
| 87 | #endif | |
| 88 | ||
| 89 | #endif /* _SYS_FS_ZFS_RLOCK_H */ |