layer_vfsops.c revision 1.27
1 /* $NetBSD: layer_vfsops.c,v 1.27 2007/11/26 19:02:13 pooka Exp $ */ 2 3 /* 4 * Copyright (c) 1999 National Aeronautics & Space Administration 5 * All rights reserved. 6 * 7 * This software was written by William Studenmund of the 8 * Numerical Aerospace Simulation Facility, NASA Ames Research Center. 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 3. Neither the name of the National Aeronautics & Space Administration 19 * nor the names of its contributors may be used to endorse or promote 20 * products derived from this software without specific prior written 21 * permission. 22 * 23 * THIS SOFTWARE IS PROVIDED BY THE NATIONAL AERONAUTICS & SPACE ADMINISTRATION 24 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 25 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 26 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE ADMINISTRATION OR CONTRIB- 27 * UTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, 28 * OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 29 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 30 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 31 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 32 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 33 * POSSIBILITY OF SUCH DAMAGE. 34 */ 35 /* 36 * Copyright (c) 1992, 1993, 1995 37 * The Regents of the University of California. All rights reserved. 38 * 39 * This code is derived from software donated to Berkeley by 40 * Jan-Simon Pendry. 41 * 42 * Redistribution and use in source and binary forms, with or without 43 * modification, are permitted provided that the following conditions 44 * are met: 45 * 1. Redistributions of source code must retain the above copyright 46 * notice, this list of conditions and the following disclaimer. 47 * 2. Redistributions in binary form must reproduce the above copyright 48 * notice, this list of conditions and the following disclaimer in the 49 * documentation and/or other materials provided with the distribution. 50 * 3. Neither the name of the University nor the names of its contributors 51 * may be used to endorse or promote products derived from this software 52 * without specific prior written permission. 53 * 54 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 55 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 56 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 57 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 58 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 59 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 60 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 61 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 62 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 63 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 64 * SUCH DAMAGE. 65 * 66 * from: Id: lofs_vfsops.c,v 1.9 1992/05/30 10:26:24 jsp Exp 67 * from: @(#)lofs_vfsops.c 1.2 (Berkeley) 6/18/92 68 * @(#)null_vfsops.c 8.7 (Berkeley) 5/14/95 69 */ 70 71 /* 72 * generic layer vfs ops. 73 */ 74 75 #include <sys/cdefs.h> 76 __KERNEL_RCSID(0, "$NetBSD: layer_vfsops.c,v 1.27 2007/11/26 19:02:13 pooka Exp $"); 77 78 #include <sys/param.h> 79 #include <sys/sysctl.h> 80 #include <sys/systm.h> 81 #include <sys/time.h> 82 #include <sys/proc.h> 83 #include <sys/vnode.h> 84 #include <sys/mount.h> 85 #include <sys/namei.h> 86 #include <sys/malloc.h> 87 #include <sys/kauth.h> 88 89 #include <miscfs/genfs/layer.h> 90 #include <miscfs/genfs/layer_extern.h> 91 92 /* 93 * VFS start. Nothing needed here - the start routine 94 * on the underlying filesystem will have been called 95 * when that filesystem was mounted. 96 */ 97 int 98 layerfs_start(struct mount *mp, int flags) 99 { 100 101 #ifdef notyet 102 return VFS_START(MOUNTTOLAYERMOUNT(mp)->layerm_vfs, flags); 103 #else 104 return 0; 105 #endif 106 } 107 108 int 109 layerfs_root(mp, vpp) 110 struct mount *mp; 111 struct vnode **vpp; 112 { 113 struct vnode *vp; 114 115 #ifdef LAYERFS_DIAGNOSTIC 116 if (layerfs_debug) 117 printf("layerfs_root(mp = %p, vp = %p->%p)\n", mp, 118 MOUNTTOLAYERMOUNT(mp)->layerm_rootvp, 119 LAYERVPTOLOWERVP(MOUNTTOLAYERMOUNT(mp)->layerm_rootvp)); 120 #endif 121 122 /* 123 * Return locked reference to root. 124 */ 125 vp = MOUNTTOLAYERMOUNT(mp)->layerm_rootvp; 126 if (vp == NULL) { 127 *vpp = NULL; 128 return (EINVAL); 129 } 130 VREF(vp); 131 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 132 *vpp = vp; 133 return 0; 134 } 135 136 int 137 layerfs_quotactl(mp, cmd, uid, arg) 138 struct mount *mp; 139 int cmd; 140 uid_t uid; 141 void *arg; 142 { 143 144 return VFS_QUOTACTL(MOUNTTOLAYERMOUNT(mp)->layerm_vfs, cmd, uid, arg); 145 } 146 147 int 148 layerfs_statvfs(mp, sbp) 149 struct mount *mp; 150 struct statvfs *sbp; 151 { 152 int error; 153 struct statvfs *sbuf = malloc(sizeof(*sbuf), M_TEMP, M_WAITOK); 154 155 #ifdef LAYERFS_DIAGNOSTIC 156 if (layerfs_debug) 157 printf("layerfs_statvfs(mp = %p, vp = %p->%p)\n", mp, 158 MOUNTTOLAYERMOUNT(mp)->layerm_rootvp, 159 LAYERVPTOLOWERVP(MOUNTTOLAYERMOUNT(mp)->layerm_rootvp)); 160 #endif 161 162 (void)memset(sbuf, 0, sizeof(*sbuf)); 163 164 error = VFS_STATVFS(MOUNTTOLAYERMOUNT(mp)->layerm_vfs, sbuf); 165 if (error) 166 goto done; 167 168 /* now copy across the "interesting" information and fake the rest */ 169 sbp->f_flag = sbuf->f_flag; 170 sbp->f_bsize = sbuf->f_bsize; 171 sbp->f_frsize = sbuf->f_frsize; 172 sbp->f_iosize = sbuf->f_iosize; 173 sbp->f_blocks = sbuf->f_blocks; 174 sbp->f_bfree = sbuf->f_bfree; 175 sbp->f_bavail = sbuf->f_bavail; 176 sbp->f_bresvd = sbuf->f_bresvd; 177 sbp->f_files = sbuf->f_files; 178 sbp->f_ffree = sbuf->f_ffree; 179 sbp->f_favail = sbuf->f_favail; 180 sbp->f_fresvd = sbuf->f_fresvd; 181 sbp->f_namemax = sbuf->f_namemax; 182 copy_statvfs_info(sbp, mp); 183 done: 184 free(sbuf, M_TEMP); 185 return error; 186 } 187 188 int 189 layerfs_sync(struct mount *mp, int waitfor, 190 kauth_cred_t cred) 191 { 192 193 /* 194 * XXX - Assumes no data cached at layer. 195 */ 196 return (0); 197 } 198 199 int 200 layerfs_vget(mp, ino, vpp) 201 struct mount *mp; 202 ino_t ino; 203 struct vnode **vpp; 204 { 205 int error; 206 struct vnode *vp; 207 208 if ((error = VFS_VGET(MOUNTTOLAYERMOUNT(mp)->layerm_vfs, 209 ino, &vp))) { 210 *vpp = NULL; 211 return (error); 212 } 213 if ((error = layer_node_create(mp, vp, vpp))) { 214 vput(vp); 215 *vpp = NULL; 216 return (error); 217 } 218 219 return (0); 220 } 221 222 int 223 layerfs_fhtovp(mp, fidp, vpp) 224 struct mount *mp; 225 struct fid *fidp; 226 struct vnode **vpp; 227 { 228 int error; 229 struct vnode *vp; 230 231 if ((error = VFS_FHTOVP(MOUNTTOLAYERMOUNT(mp)->layerm_vfs, 232 fidp, &vp))) 233 return (error); 234 235 if ((error = layer_node_create(mp, vp, vpp))) { 236 vput(vp); 237 *vpp = NULL; 238 return (error); 239 } 240 241 return (0); 242 } 243 244 int 245 layerfs_vptofh(vp, fhp, fh_size) 246 struct vnode *vp; 247 struct fid *fhp; 248 size_t *fh_size; 249 { 250 251 return (VFS_VPTOFH(LAYERVPTOLOWERVP(vp), fhp, fh_size)); 252 } 253 254 /* 255 * layerfs_snapshot - handle a snapshot through a layered file system 256 * 257 * At present, we do NOT support snapshotting through a layered file 258 * system as the ffs implementation changes v_vnlock of the snapshot 259 * vnodes to point to one common lock. As there is no way for us to 260 * absolutely pass this change up the stack, a layered file system 261 * would end up referencing the wrong lock. 262 * 263 * This routine serves as a central resource for this behavior; all 264 * layered file systems don't need to worry about the above. Also, if 265 * things get fixed, all layers get the benefit. 266 */ 267 int 268 layerfs_snapshot(struct mount *mp, struct vnode *vp, 269 struct timespec *ts) 270 { 271 return (EOPNOTSUPP); 272 } 273 274 SYSCTL_SETUP(sysctl_vfs_layerfs_setup, "sysctl vfs.layerfs subtree setup") 275 { 276 const struct sysctlnode *layerfs_node = NULL; 277 278 sysctl_createv(clog, 0, NULL, NULL, 279 CTLFLAG_PERMANENT, 280 CTLTYPE_NODE, "vfs", NULL, 281 NULL, 0, NULL, 0, 282 CTL_VFS, CTL_EOL); 283 sysctl_createv(clog, 0, NULL, &layerfs_node, 284 CTLFLAG_PERMANENT, 285 CTLTYPE_NODE, "layerfs", 286 SYSCTL_DESCR("Generic layered file system"), 287 NULL, 0, NULL, 0, 288 CTL_VFS, CTL_CREATE); 289 290 #ifdef LAYERFS_DIAGNOSTIC 291 sysctl_createv(clog, 0, &layerfs_node, NULL, 292 CTLFLAG_PERMANENT|CTLFLAG_READWRITE, 293 CTLTYPE_INT, 294 "debug", 295 SYSCTL_DESCR("Verbose debugging messages"), 296 NULL, 0, &layerfs_debug, 0, 297 CTL_CREATE, CTL_EOL); 298 #endif 299 300 /* 301 * other subtrees should really be aliases to this, but since 302 * they can't tell if layerfs has been instantiated yet, they 303 * can't do that...not easily. not yet. :-) 304 */ 305 } 306
Indexes created Wed Sep 24 05:09:52 GMT 2025