1 /* $NetBSD: layer_vfsops.c,v 1.22 2005/12/11 12:24:50 christos 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 1.22 2005/12/11 12:24:50 christos 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 <miscfs/genfs/layer.h> 88 #include <miscfs/genfs/layer_extern.h> 89 90 /* 91 * VFS start. Nothing needed here - the start routine 92 * on the underlying filesystem will have been called 93 * when that filesystem was mounted. 94 */ 95 int 96 layerfs_start(mp, flags, l) 97 struct mount *mp; 98 int flags; 99 struct lwp *l; 100 { 101 102 return (0); 103 /* return VFS_START(MOUNTTOLAYERMOUNT(mp)->layerm_vfs, flags, l); */ 104 } 105 106 int 107 layerfs_root(mp, vpp) 108 struct mount *mp; 109 struct vnode **vpp; 110 { 111 struct vnode *vp; 112 113 #ifdef LAYERFS_DIAGNOSTIC 114 if (layerfs_debug) 115 printf("layerfs_root(mp = %p, vp = %p->%p)\n", mp, 116 MOUNTTOLAYERMOUNT(mp)->layerm_rootvp, 117 LAYERVPTOLOWERVP(MOUNTTOLAYERMOUNT(mp)->layerm_rootvp)); 118 #endif 119 120 /* 121 * Return locked reference to root. 122 */ 123 vp = MOUNTTOLAYERMOUNT(mp)->layerm_rootvp; 124 if (vp == NULL) { 125 *vpp = NULL; 126 return (EINVAL); 127 } 128 VREF(vp); 129 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 130 *vpp = vp; 131 return 0; 132 } 133 134 int 135 layerfs_quotactl(mp, cmd, uid, arg, l) 136 struct mount *mp; 137 int cmd; 138 uid_t uid; 139 void *arg; 140 struct lwp *l; 141 { 142 143 return VFS_QUOTACTL(MOUNTTOLAYERMOUNT(mp)->layerm_vfs, 144 cmd, uid, arg, l); 145 } 146 147 int 148 layerfs_statvfs(mp, sbp, l) 149 struct mount *mp; 150 struct statvfs *sbp; 151 struct lwp *l; 152 { 153 int error; 154 struct statvfs *sbuf = malloc(sizeof(*sbuf), M_TEMP, M_WAITOK); 155 156 #ifdef LAYERFS_DIAGNOSTIC 157 if (layerfs_debug) 158 printf("layerfs_statvfs(mp = %p, vp = %p->%p)\n", mp, 159 MOUNTTOLAYERMOUNT(mp)->layerm_rootvp, 160 LAYERVPTOLOWERVP(MOUNTTOLAYERMOUNT(mp)->layerm_rootvp)); 161 #endif 162 163 (void)memset(sbuf, 0, sizeof(*sbuf)); 164 165 error = VFS_STATVFS(MOUNTTOLAYERMOUNT(mp)->layerm_vfs, sbuf, l); 166 if (error) 167 goto done; 168 169 /* now copy across the "interesting" information and fake the rest */ 170 sbp->f_flag = sbuf->f_flag; 171 sbp->f_bsize = sbuf->f_bsize; 172 sbp->f_frsize = sbuf->f_frsize; 173 sbp->f_iosize = sbuf->f_iosize; 174 sbp->f_blocks = sbuf->f_blocks; 175 sbp->f_bfree = sbuf->f_bfree; 176 sbp->f_bavail = sbuf->f_bavail; 177 sbp->f_bresvd = sbuf->f_bresvd; 178 sbp->f_files = sbuf->f_files; 179 sbp->f_ffree = sbuf->f_ffree; 180 sbp->f_favail = sbuf->f_favail; 181 sbp->f_fresvd = sbuf->f_fresvd; 182 sbp->f_namemax = sbuf->f_namemax; 183 copy_statvfs_info(sbp, mp); 184 done: 185 free(sbuf, M_TEMP); 186 return error; 187 } 188 189 int 190 layerfs_sync(mp, waitfor, cred, l) 191 struct mount *mp; 192 int waitfor; 193 struct ucred *cred; 194 struct lwp *l; 195 { 196 197 /* 198 * XXX - Assumes no data cached at layer. 199 */ 200 return (0); 201 } 202 203 int 204 layerfs_vget(mp, ino, vpp) 205 struct mount *mp; 206 ino_t ino; 207 struct vnode **vpp; 208 { 209 int error; 210 struct vnode *vp; 211 212 if ((error = VFS_VGET(MOUNTTOLAYERMOUNT(mp)->layerm_vfs, 213 ino, &vp))) { 214 *vpp = NULL; 215 return (error); 216 } 217 if ((error = layer_node_create(mp, vp, vpp))) { 218 vput(vp); 219 *vpp = NULL; 220 return (error); 221 } 222 223 return (0); 224 } 225 226 int 227 layerfs_fhtovp(mp, fidp, vpp) 228 struct mount *mp; 229 struct fid *fidp; 230 struct vnode **vpp; 231 { 232 int error; 233 struct vnode *vp; 234 235 if ((error = VFS_FHTOVP(MOUNTTOLAYERMOUNT(mp)->layerm_vfs, 236 fidp, &vp))) 237 return (error); 238 239 if ((error = layer_node_create(mp, vp, vpp))) { 240 vput(vp); 241 *vpp = NULL; 242 return (error); 243 } 244 245 return (0); 246 } 247 248 int 249 layerfs_vptofh(vp, fhp) 250 struct vnode *vp; 251 struct fid *fhp; 252 { 253 254 return (VFS_VPTOFH(LAYERVPTOLOWERVP(vp), fhp)); 255 } 256 257 /* 258 * layerfs_snapshot - handle a snapshot through a layered file system 259 * 260 * At present, we do NOT support snapshotting through a layered file 261 * system as the ffs implementation changes v_vnlock of the snapshot 262 * vnodes to point to one common lock. As there is no way for us to 263 * absolutely pass this change up the stack, a layered file system 264 * would end up referencing the wrong lock. 265 * 266 * This routine serves as a central resource for this behavior; all 267 * layered file systems don't need to worry about the above. Also, if 268 * things get fixed, all layers get the benefit. 269 */ 270 int 271 layerfs_snapshot(struct mount *mp, struct vnode *vp, struct timespec *ts) 272 { 273 return (EOPNOTSUPP); 274 } 275 276 SYSCTL_SETUP(sysctl_vfs_layerfs_setup, "sysctl vfs.layerfs subtree setup") 277 { 278 const struct sysctlnode *layerfs_node = NULL; 279 280 sysctl_createv(clog, 0, NULL, NULL, 281 CTLFLAG_PERMANENT, 282 CTLTYPE_NODE, "vfs", NULL, 283 NULL, 0, NULL, 0, 284 CTL_VFS, CTL_EOL); 285 sysctl_createv(clog, 0, NULL, &layerfs_node, 286 CTLFLAG_PERMANENT, 287 CTLTYPE_NODE, "layerfs", 288 SYSCTL_DESCR("Generic layered file system"), 289 NULL, 0, NULL, 0, 290 CTL_VFS, CTL_CREATE); 291 292 #ifdef LAYERFS_DIAGNOSTIC 293 sysctl_createv(clog, 0, &layerfs_node, NULL, 294 CTLFLAG_PERMANENT|CTLFLAG_READWRITE, 295 CTLTYPE_INT, 296 "debug", 297 SYSCTL_DESCR("Verbose debugging messages"), 298 NULL, 0, &layerfs_debug, 0, 299 CTL_CREATE, CTL_EOL); 300 #endif 301 302 /* 303 * other subtrees should really be aliases to this, but since 304 * they can't tell if layerfs has been instantiated yet, they 305 * can't do that...not easily. not yet. :-) 306 */ 307 } 308