xref: /haiku/src/add-ons/kernel/file_systems/fat/bsd/kern/kern_lock.c (revision 342a1b221b5bb385410f758df2c625b70cafdd03)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
3  *
4  * Copyright (c) 2008 Attilio Rao <attilio@FreeBSD.org>
5  * All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice(s), this list of conditions and the following disclaimer as
12  *    the first lines of this file unmodified other than the possible
13  *    addition of one or more copyright notices.
14  * 2. Redistributions in binary form must reproduce the above copyright
15  *    notice(s), this list of conditions and the following disclaimer in the
16  *    documentation and/or other materials provided with the distribution.
17  *
18  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDER(S) ``AS IS'' AND ANY
19  * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
20  * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
21  * DISCLAIMED.  IN NO EVENT SHALL THE COPYRIGHT HOLDER(S) BE LIABLE FOR ANY
22  * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
23  * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
24  * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
25  * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
26  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
27  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH
28  * DAMAGE.
29  */
30 
31 
32 // Modified to support the Haiku FAT driver.
33 
34 #include "sys/param.h"
35 #include "sys/lockmgr.h"
36 #include "sys/mutex.h"
37 #include "sys/systm.h"
38 
39 
40 /*! @param flags LK_EXCLUSIVE or LK_SHARED by itself write- or read-locks the node, respectively.
41 	LK_RELEASE in combination with LK_EXCLUSIVE or LK_SHARED write- or read-unlocks the node,
42 	respectively.
43 	@param ilk Ignored in the Haiku port.
44 */
45 void
lockmgr(struct lock * lk,u_int flags,struct mtx * ilk)46 lockmgr(struct lock* lk, u_int flags, struct mtx* ilk)
47 {
48 	if ((flags & LK_RELEASE) != 0) {
49 		if ((flags & LK_SHARED) != 0)
50 			rw_lock_read_unlock(&lk->haikuRW);
51 		else
52 			rw_lock_write_unlock(&lk->haikuRW);
53 	} else if ((flags & LK_EXCLUSIVE) != 0) {
54 		rw_lock_write_lock(&lk->haikuRW);
55 	} else if ((flags & LK_SHARED) != 0) {
56 		rw_lock_read_lock(&lk->haikuRW);
57 	} else {
58 		panic("unrecognized lockmgr flag\n");
59 	}
60 
61 	return;
62 }
63