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 (c) 1988, 2010, Oracle and/or its affiliates. All rights reserved. 23 */ 24 25 /* Copyright (c) 1983, 1984, 1985, 1986, 1987, 1988, 1989 AT&T */ 26 /* All Rights Reserved */ 27 28 /* 29 * University Copyright- Copyright (c) 1982, 1986, 1988 30 * The Regents of the University of California 31 * All Rights Reserved 32 * 33 * University Acknowledgment- Portions of this document are derived from 34 * software developed by the University of California, Berkeley, and its 35 * contributors. 36 */ 37 38 39 #include <sys/types.h> 40 #include <sys/t_lock.h> 41 #include <sys/param.h> 42 #include <sys/buf.h> 43 #include <sys/cmn_err.h> 44 #include <sys/debug.h> 45 #include <sys/errno.h> 46 #include <sys/vfs.h> 47 #include <sys/swap.h> 48 #include <sys/vnode.h> 49 #include <sys/cred.h> 50 #include <sys/fs/snode.h> 51 #include <sys/thread.h> 52 53 #include <fs/fs_subr.h> 54 55 /* 56 * This is the loadable module wrapper. 57 */ 58 #include <sys/modctl.h> 59 60 static vfsdef_t vfw = { 61 VFSDEF_VERSION, 62 "specfs", 63 specinit, 64 VSW_ZMOUNT, 65 NULL 66 }; 67 68 extern struct mod_ops mod_fsops; 69 70 /* 71 * Module linkage information for the kernel. 72 */ 73 static struct modlfs modlfs = { 74 &mod_fsops, "filesystem for specfs", &vfw 75 }; 76 77 static struct modlinkage modlinkage = { 78 MODREV_1, (void *)&modlfs, NULL 79 }; 80 81 int 82 _init(void) 83 { 84 return (mod_install(&modlinkage)); 85 } 86 87 int 88 _info(struct modinfo *modinfop) 89 { 90 return (mod_info(&modlinkage, modinfop)); 91 } 92 93 /* 94 * N.B. 95 * No _fini routine. This module cannot be unloaded once loaded. 96 * The NO_UNLOAD_STUB in modstub.s must change if this module ever 97 * is modified to become unloadable. 98 */ 99 100 kmutex_t spec_syncbusy; /* initialized in specinit() */ 101 102 /* 103 * Run though all the snodes and force write-back 104 * of all dirty pages on the block devices. 105 */ 106 /*ARGSUSED*/ 107 int 108 spec_sync(struct vfs *vfsp, 109 short flag, 110 struct cred *cr) 111 { 112 struct snode *sync_list; 113 register struct snode **spp, *sp, *spnext; 114 register struct vnode *vp; 115 116 if (mutex_tryenter(&spec_syncbusy) == 0) 117 return (0); 118 119 if (flag & SYNC_ATTR) { 120 mutex_exit(&spec_syncbusy); 121 return (0); 122 } 123 mutex_enter(&stable_lock); 124 sync_list = NULL; 125 /* 126 * Find all the snodes that are dirty and add them to the sync_list 127 */ 128 for (spp = stable; spp < &stable[STABLESIZE]; spp++) { 129 for (sp = *spp; sp != NULL; sp = sp->s_next) { 130 vp = STOV(sp); 131 /* 132 * Don't bother sync'ing a vp if it's 133 * part of a virtual swap device. 134 */ 135 if (IS_SWAPVP(vp)) 136 continue; 137 138 if (vp->v_type == VBLK && vn_has_cached_data(vp)) { 139 /* 140 * Prevent vp from going away before we 141 * we get a chance to do a VOP_PUTPAGE 142 * via sync_list processing 143 */ 144 VN_HOLD(vp); 145 sp->s_list = sync_list; 146 sync_list = sp; 147 } 148 } 149 } 150 mutex_exit(&stable_lock); 151 /* 152 * Now write out all the snodes we marked asynchronously. 153 */ 154 for (sp = sync_list; sp != NULL; sp = spnext) { 155 spnext = sp->s_list; 156 vp = STOV(sp); 157 (void) VOP_PUTPAGE(vp, (offset_t)0, (uint_t)0, B_ASYNC, cr, 158 NULL); 159 VN_RELE(vp); /* Release our hold on vnode */ 160 } 161 mutex_exit(&spec_syncbusy); 162 return (0); 163 } 164