projects / linux.git / blame
| Commit | Line | Data |
|---|---|---|
| 1da177e4 | 1 | /* |
| 72c93bcc | 2 | * Copyright (c) 2000-2006 Silicon Graphics, Inc. |
| 7b718769 | 3 | * All Rights Reserved. |
| 1da177e4 | 4 | * |
| 7b718769 NS |
5 | * This program is free software; you can redistribute it and/or |
| 6 | * modify it under the terms of the GNU General Public License as | |
| 1da177e4 LT |
7 | * published by the Free Software Foundation. |
| 8 | * | |
| 7b718769 NS |
9 | * This program is distributed in the hope that it would be useful, |
| 10 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
| 11 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
| 12 | * GNU General Public License for more details. | |
| 1da177e4 | 13 | * |
| 7b718769 NS |
14 | * You should have received a copy of the GNU General Public License |
| 15 | * along with this program; if not, write the Free Software Foundation, | |
| 16 | * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA | |
| 1da177e4 LT |
17 | */ |
| 18 | #ifndef __XFS_SUPPORT_MRLOCK_H__ | |
| 19 | #define __XFS_SUPPORT_MRLOCK_H__ | |
| 20 | ||
| 21 | #include <linux/rwsem.h> | |
| 22 | ||
| 1da177e4 LT |
23 | typedef struct { |
| 24 | struct rw_semaphore mr_lock; | |
| 742ae1e3 | 25 | #if defined(DEBUG) || defined(XFS_WARN) |
| 1da177e4 | 26 | int mr_writer; |
| 579aa9ca | 27 | #endif |
| 1da177e4 LT |
28 | } mrlock_t; |
| 29 | ||
| 742ae1e3 | 30 | #if defined(DEBUG) || defined(XFS_WARN) |
| 1da177e4 | 31 | #define mrinit(mrp, name) \ |
| 72c93bcc | 32 | do { (mrp)->mr_writer = 0; init_rwsem(&(mrp)->mr_lock); } while (0) |
| 579aa9ca CH |
33 | #else |
| 34 | #define mrinit(mrp, name) \ | |
| 35 | do { init_rwsem(&(mrp)->mr_lock); } while (0) | |
| 36 | #endif | |
| 37 | ||
| 1da177e4 LT |
38 | #define mrlock_init(mrp, t,n,s) mrinit(mrp, n) |
| 39 | #define mrfree(mrp) do { } while (0) | |
| 1da177e4 | 40 | |
| f7c66ce3 LM |
41 | static inline void mraccess_nested(mrlock_t *mrp, int subclass) |
| 42 | { | |
| 43 | down_read_nested(&mrp->mr_lock, subclass); | |
| 44 | } | |
| 45 | ||
| 46 | static inline void mrupdate_nested(mrlock_t *mrp, int subclass) | |
| 47 | { | |
| 48 | down_write_nested(&mrp->mr_lock, subclass); | |
| 742ae1e3 | 49 | #if defined(DEBUG) || defined(XFS_WARN) |
| f7c66ce3 | 50 | mrp->mr_writer = 1; |
| 579aa9ca | 51 | #endif |
| f7c66ce3 LM |
52 | } |
| 53 | ||
| 1da177e4 LT |
54 | static inline int mrtryaccess(mrlock_t *mrp) |
| 55 | { | |
| 56 | return down_read_trylock(&mrp->mr_lock); | |
| 57 | } | |
| 58 | ||
| 59 | static inline int mrtryupdate(mrlock_t *mrp) | |
| 60 | { | |
| 61 | if (!down_write_trylock(&mrp->mr_lock)) | |
| 62 | return 0; | |
| 742ae1e3 | 63 | #if defined(DEBUG) || defined(XFS_WARN) |
| 1da177e4 | 64 | mrp->mr_writer = 1; |
| 579aa9ca | 65 | #endif |
| 1da177e4 LT |
66 | return 1; |
| 67 | } | |
| 68 | ||
| 579aa9ca | 69 | static inline void mrunlock_excl(mrlock_t *mrp) |
| 1da177e4 | 70 | { |
| 742ae1e3 | 71 | #if defined(DEBUG) || defined(XFS_WARN) |
| 579aa9ca CH |
72 | mrp->mr_writer = 0; |
| 73 | #endif | |
| 74 | up_write(&mrp->mr_lock); | |
| 1da177e4 LT |
75 | } |
| 76 | ||
| 579aa9ca | 77 | static inline void mrunlock_shared(mrlock_t *mrp) |
| 1da177e4 | 78 | { |
| 579aa9ca | 79 | up_read(&mrp->mr_lock); |
| 1da177e4 LT |
80 | } |
| 81 | ||
| 579aa9ca | 82 | static inline void mrdemote(mrlock_t *mrp) |
| 1da177e4 | 83 | { |
| 742ae1e3 | 84 | #if defined(DEBUG) || defined(XFS_WARN) |
| 579aa9ca | 85 | mrp->mr_writer = 0; |
| 1da177e4 | 86 | #endif |
| 579aa9ca CH |
87 | downgrade_write(&mrp->mr_lock); |
| 88 | } | |
| 1da177e4 LT |
89 | |
| 90 | #endif /* __XFS_SUPPORT_MRLOCK_H__ */ |