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 2007 Sun Microsystems, Inc. All rights reserved. 23 * Use is subject to license terms. 24 */ 25 26 /* Copyright (c) 1983, 1984, 1985, 1986, 1987, 1988, 1989 AT&T */ 27 /* All Rights Reserved */ 28 29 /* 30 * University Copyright- Copyright (c) 1982, 1986, 1988 31 * The Regents of the University of California 32 * All Rights Reserved 33 * 34 * University Acknowledgment- Portions of this document are derived from 35 * software developed by the University of California, Berkeley, and its 36 * contributors. 37 */ 38 39 40 #pragma ident "%Z%%M% %I% %E% SMI" 41 42 #include <sys/types.h> 43 #include <sys/t_lock.h> 44 #include <sys/param.h> 45 #include <sys/buf.h> 46 #include <sys/cmn_err.h> 47 #include <sys/debug.h> 48 #include <sys/errno.h> 49 #include <sys/vfs.h> 50 #include <sys/swap.h> 51 #include <sys/vnode.h> 52 #include <sys/cred.h> 53 #include <sys/fs/snode.h> 54 #include <sys/thread.h> 55 56 #include <fs/fs_subr.h> 57 58 /* 59 * This is the loadable module wrapper. 60 */ 61 #include <sys/modctl.h> 62 63 static vfsdef_t vfw = { 64 VFSDEF_VERSION, 65 "specfs", 66 specinit, 67 0, 68 NULL 69 }; 70 71 extern struct mod_ops mod_fsops; 72 73 /* 74 * Module linkage information for the kernel. 75 */ 76 static struct modlfs modlfs = { 77 &mod_fsops, "filesystem for specfs", &vfw 78 }; 79 80 static struct modlinkage modlinkage = { 81 MODREV_1, (void *)&modlfs, NULL 82 }; 83 84 int 85 _init(void) 86 { 87 return (mod_install(&modlinkage)); 88 } 89 90 int 91 _info(struct modinfo *modinfop) 92 { 93 return (mod_info(&modlinkage, modinfop)); 94 } 95 96 /* 97 * N.B. 98 * No _fini routine. This module cannot be unloaded once loaded. 99 * The NO_UNLOAD_STUB in modstub.s must change if this module ever 100 * is modified to become unloadable. 101 */ 102 103 kmutex_t spec_syncbusy; /* initialized in specinit() */ 104 105 /* 106 * Run though all the snodes and force write-back 107 * of all dirty pages on the block devices. 108 */ 109 /*ARGSUSED*/ 110 int 111 spec_sync(struct vfs *vfsp, 112 short flag, 113 struct cred *cr) 114 { 115 struct snode *sync_list; 116 register struct snode **spp, *sp, *spnext; 117 register struct vnode *vp; 118 119 if (mutex_tryenter(&spec_syncbusy) == 0) 120 return (0); 121 122 if (flag & SYNC_ATTR) { 123 mutex_exit(&spec_syncbusy); 124 return (0); 125 } 126 mutex_enter(&stable_lock); 127 sync_list = NULL; 128 /* 129 * Find all the snodes that are dirty and add them to the sync_list 130 */ 131 for (spp = stable; spp < &stable[STABLESIZE]; spp++) { 132 for (sp = *spp; sp != NULL; sp = sp->s_next) { 133 vp = STOV(sp); 134 /* 135 * Don't bother sync'ing a vp if it's 136 * part of a virtual swap device. 137 */ 138 if (IS_SWAPVP(vp)) 139 continue; 140 141 if (vp->v_type == VBLK && vn_has_cached_data(vp)) { 142 /* 143 * Prevent vp from going away before we 144 * we get a chance to do a VOP_PUTPAGE 145 * via sync_list processing 146 */ 147 VN_HOLD(vp); 148 sp->s_list = sync_list; 149 sync_list = sp; 150 } 151 } 152 } 153 mutex_exit(&stable_lock); 154 /* 155 * Now write out all the snodes we marked asynchronously. 156 */ 157 for (sp = sync_list; sp != NULL; sp = spnext) { 158 spnext = sp->s_list; 159 vp = STOV(sp); 160 (void) VOP_PUTPAGE(vp, (offset_t)0, (uint_t)0, B_ASYNC, cr, 161 NULL); 162 VN_RELE(vp); /* Release our hold on vnode */ 163 } 164 mutex_exit(&spec_syncbusy); 165 return (0); 166 } 167