vfs_cwd.c revision 1.1.6.2
1 1.1.6.2 mjf /* $NetBSD: vfs_cwd.c,v 1.1.6.2 2009/01/17 13:29:20 mjf Exp $ */ 2 1.1.6.2 mjf 3 1.1.6.2 mjf /*- 4 1.1.6.2 mjf * Copyright (c) 2008 The NetBSD Foundation, Inc. 5 1.1.6.2 mjf * All rights reserved. 6 1.1.6.2 mjf * 7 1.1.6.2 mjf * Redistribution and use in source and binary forms, with or without 8 1.1.6.2 mjf * modification, are permitted provided that the following conditions 9 1.1.6.2 mjf * are met: 10 1.1.6.2 mjf * 1. Redistributions of source code must retain the above copyright 11 1.1.6.2 mjf * notice, this list of conditions and the following disclaimer. 12 1.1.6.2 mjf * 2. Redistributions in binary form must reproduce the above copyright 13 1.1.6.2 mjf * notice, this list of conditions and the following disclaimer in the 14 1.1.6.2 mjf * documentation and/or other materials provided with the distribution. 15 1.1.6.2 mjf * 16 1.1.6.2 mjf * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 17 1.1.6.2 mjf * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 18 1.1.6.2 mjf * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 19 1.1.6.2 mjf * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 20 1.1.6.2 mjf * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 21 1.1.6.2 mjf * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 22 1.1.6.2 mjf * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 23 1.1.6.2 mjf * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 24 1.1.6.2 mjf * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 25 1.1.6.2 mjf * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 26 1.1.6.2 mjf * POSSIBILITY OF SUCH DAMAGE. 27 1.1.6.2 mjf */ 28 1.1.6.2 mjf 29 1.1.6.2 mjf /* 30 1.1.6.2 mjf * Current working directory. 31 1.1.6.2 mjf */ 32 1.1.6.2 mjf 33 1.1.6.2 mjf #include <sys/cdefs.h> 34 1.1.6.2 mjf __KERNEL_RCSID(0, "$NetBSD: vfs_cwd.c,v 1.1.6.2 2009/01/17 13:29:20 mjf Exp $"); 35 1.1.6.2 mjf 36 1.1.6.2 mjf #include <sys/param.h> 37 1.1.6.2 mjf #include <sys/atomic.h> 38 1.1.6.2 mjf #include <sys/filedesc.h> 39 1.1.6.2 mjf #include <sys/proc.h> 40 1.1.6.2 mjf #include <sys/vnode.h> 41 1.1.6.2 mjf 42 1.1.6.2 mjf static int cwdi_ctor(void *, void *, int); 43 1.1.6.2 mjf static void cwdi_dtor(void *, void *); 44 1.1.6.2 mjf 45 1.1.6.2 mjf static pool_cache_t cwdi_cache; 46 1.1.6.2 mjf 47 1.1.6.2 mjf void 48 1.1.6.2 mjf cwd_sys_init(void) 49 1.1.6.2 mjf { 50 1.1.6.2 mjf 51 1.1.6.2 mjf cwdi_cache = pool_cache_init(sizeof(struct cwdinfo), coherency_unit, 52 1.1.6.2 mjf 0, 0, "cwdi", NULL, IPL_NONE, cwdi_ctor, cwdi_dtor, NULL); 53 1.1.6.2 mjf KASSERT(cwdi_cache != NULL); 54 1.1.6.2 mjf } 55 1.1.6.2 mjf 56 1.1.6.2 mjf /* 57 1.1.6.2 mjf * Create an initial cwdinfo structure, using the same current and root 58 1.1.6.2 mjf * directories as curproc. 59 1.1.6.2 mjf */ 60 1.1.6.2 mjf struct cwdinfo * 61 1.1.6.2 mjf cwdinit(void) 62 1.1.6.2 mjf { 63 1.1.6.2 mjf struct cwdinfo *cwdi; 64 1.1.6.2 mjf struct cwdinfo *copy; 65 1.1.6.2 mjf 66 1.1.6.2 mjf cwdi = pool_cache_get(cwdi_cache, PR_WAITOK); 67 1.1.6.2 mjf copy = curproc->p_cwdi; 68 1.1.6.2 mjf 69 1.1.6.2 mjf rw_enter(©->cwdi_lock, RW_READER); 70 1.1.6.2 mjf cwdi->cwdi_cdir = copy->cwdi_cdir; 71 1.1.6.2 mjf if (cwdi->cwdi_cdir) 72 1.1.6.2 mjf VREF(cwdi->cwdi_cdir); 73 1.1.6.2 mjf cwdi->cwdi_rdir = copy->cwdi_rdir; 74 1.1.6.2 mjf if (cwdi->cwdi_rdir) 75 1.1.6.2 mjf VREF(cwdi->cwdi_rdir); 76 1.1.6.2 mjf cwdi->cwdi_edir = copy->cwdi_edir; 77 1.1.6.2 mjf if (cwdi->cwdi_edir) 78 1.1.6.2 mjf VREF(cwdi->cwdi_edir); 79 1.1.6.2 mjf cwdi->cwdi_cmask = copy->cwdi_cmask; 80 1.1.6.2 mjf cwdi->cwdi_refcnt = 1; 81 1.1.6.2 mjf rw_exit(©->cwdi_lock); 82 1.1.6.2 mjf 83 1.1.6.2 mjf return (cwdi); 84 1.1.6.2 mjf } 85 1.1.6.2 mjf 86 1.1.6.2 mjf static int 87 1.1.6.2 mjf cwdi_ctor(void *arg, void *obj, int flags) 88 1.1.6.2 mjf { 89 1.1.6.2 mjf struct cwdinfo *cwdi = obj; 90 1.1.6.2 mjf 91 1.1.6.2 mjf rw_init(&cwdi->cwdi_lock); 92 1.1.6.2 mjf 93 1.1.6.2 mjf return 0; 94 1.1.6.2 mjf } 95 1.1.6.2 mjf 96 1.1.6.2 mjf static void 97 1.1.6.2 mjf cwdi_dtor(void *arg, void *obj) 98 1.1.6.2 mjf { 99 1.1.6.2 mjf struct cwdinfo *cwdi = obj; 100 1.1.6.2 mjf 101 1.1.6.2 mjf rw_destroy(&cwdi->cwdi_lock); 102 1.1.6.2 mjf } 103 1.1.6.2 mjf 104 1.1.6.2 mjf /* 105 1.1.6.2 mjf * Make p2 share p1's cwdinfo. 106 1.1.6.2 mjf */ 107 1.1.6.2 mjf void 108 1.1.6.2 mjf cwdshare(struct proc *p2) 109 1.1.6.2 mjf { 110 1.1.6.2 mjf struct cwdinfo *cwdi; 111 1.1.6.2 mjf 112 1.1.6.2 mjf cwdi = curproc->p_cwdi; 113 1.1.6.2 mjf 114 1.1.6.2 mjf atomic_inc_uint(&cwdi->cwdi_refcnt); 115 1.1.6.2 mjf p2->p_cwdi = cwdi; 116 1.1.6.2 mjf } 117 1.1.6.2 mjf 118 1.1.6.2 mjf /* 119 1.1.6.2 mjf * Make sure proc has only one reference to its cwdi, creating 120 1.1.6.2 mjf * a new one if necessary. 121 1.1.6.2 mjf */ 122 1.1.6.2 mjf void 123 1.1.6.2 mjf cwdunshare(struct proc *p) 124 1.1.6.2 mjf { 125 1.1.6.2 mjf struct cwdinfo *cwdi = p->p_cwdi; 126 1.1.6.2 mjf 127 1.1.6.2 mjf if (cwdi->cwdi_refcnt > 1) { 128 1.1.6.2 mjf cwdi = cwdinit(); 129 1.1.6.2 mjf cwdfree(p->p_cwdi); 130 1.1.6.2 mjf p->p_cwdi = cwdi; 131 1.1.6.2 mjf } 132 1.1.6.2 mjf } 133 1.1.6.2 mjf 134 1.1.6.2 mjf /* 135 1.1.6.2 mjf * Release a cwdinfo structure. 136 1.1.6.2 mjf */ 137 1.1.6.2 mjf void 138 1.1.6.2 mjf cwdfree(struct cwdinfo *cwdi) 139 1.1.6.2 mjf { 140 1.1.6.2 mjf 141 1.1.6.2 mjf if (atomic_dec_uint_nv(&cwdi->cwdi_refcnt) > 0) 142 1.1.6.2 mjf return; 143 1.1.6.2 mjf 144 1.1.6.2 mjf vrele(cwdi->cwdi_cdir); 145 1.1.6.2 mjf if (cwdi->cwdi_rdir) 146 1.1.6.2 mjf vrele(cwdi->cwdi_rdir); 147 1.1.6.2 mjf if (cwdi->cwdi_edir) 148 1.1.6.2 mjf vrele(cwdi->cwdi_edir); 149 1.1.6.2 mjf pool_cache_put(cwdi_cache, cwdi); 150 1.1.6.2 mjf } 151
Indexes created Thu Oct 02 07:10:07 GMT 2025