layer_vfsops.c revision 1.30
1 /* $NetBSD: layer_vfsops.c,v 1.30 2008/12/05 13:05:37 ad 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 1.30 2008/12/05 13:05:37 ad 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 #include <sys/module.h> 89 90 #include <miscfs/genfs/layer.h> 91 #include <miscfs/genfs/layer_extern.h> 92 93 MODULE(MODULE_CLASS_MISC, layerfs, NULL); 94 95 static int 96 layerfs_modcmd(modcmd_t cmd, void *arg) 97 { 98 99 switch (cmd) { 100 case MODULE_CMD_INIT: 101 return 0; 102 case MODULE_CMD_FINI: 103 return 0; 104 default: 105 return ENOTTY; 106 } 107 108 return 0; 109 } 110 111 /* 112 * VFS start. Nothing needed here - the start routine 113 * on the underlying filesystem will have been called 114 * when that filesystem was mounted. 115 */ 116 int 117 layerfs_start(struct mount *mp, int flags) 118 { 119 120 #ifdef notyet 121 return VFS_START(MOUNTTOLAYERMOUNT(mp)->layerm_vfs, flags); 122 #else 123 return 0; 124 #endif 125 } 126 127 int 128 layerfs_root(mp, vpp) 129 struct mount *mp; 130 struct vnode **vpp; 131 { 132 struct vnode *vp; 133 134 #ifdef LAYERFS_DIAGNOSTIC 135 if (layerfs_debug) 136 printf("layerfs_root(mp = %p, vp = %p->%p)\n", mp, 137 MOUNTTOLAYERMOUNT(mp)->layerm_rootvp, 138 LAYERVPTOLOWERVP(MOUNTTOLAYERMOUNT(mp)->layerm_rootvp)); 139 #endif 140 141 /* 142 * Return locked reference to root. 143 */ 144 vp = MOUNTTOLAYERMOUNT(mp)->layerm_rootvp; 145 if (vp == NULL) { 146 *vpp = NULL; 147 return (EINVAL); 148 } 149 VREF(vp); 150 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 151 *vpp = vp; 152 return 0; 153 } 154 155 int 156 layerfs_quotactl(mp, cmd, uid, arg) 157 struct mount *mp; 158 int cmd; 159 uid_t uid; 160 void *arg; 161 { 162 163 return VFS_QUOTACTL(MOUNTTOLAYERMOUNT(mp)->layerm_vfs, cmd, uid, arg); 164 } 165 166 int 167 layerfs_statvfs(mp, sbp) 168 struct mount *mp; 169 struct statvfs *sbp; 170 { 171 int error; 172 struct statvfs *sbuf; 173 174 sbuf = kmem_alloc(sizeof(*sbuf), KM_SLEEP); 175 if (sbuf == NULL) 176 return ENOMEM; 177 178 #ifdef LAYERFS_DIAGNOSTIC 179 if (layerfs_debug) 180 printf("layerfs_statvfs(mp = %p, vp = %p->%p)\n", mp, 181 MOUNTTOLAYERMOUNT(mp)->layerm_rootvp, 182 LAYERVPTOLOWERVP(MOUNTTOLAYERMOUNT(mp)->layerm_rootvp)); 183 #endif 184 185 (void)memset(sbuf, 0, sizeof(*sbuf)); 186 187 error = VFS_STATVFS(MOUNTTOLAYERMOUNT(mp)->layerm_vfs, sbuf); 188 if (error) 189 goto done; 190 191 /* now copy across the "interesting" information and fake the rest */ 192 sbp->f_flag = sbuf->f_flag; 193 sbp->f_bsize = sbuf->f_bsize; 194 sbp->f_frsize = sbuf->f_frsize; 195 sbp->f_iosize = sbuf->f_iosize; 196 sbp->f_blocks = sbuf->f_blocks; 197 sbp->f_bfree = sbuf->f_bfree; 198 sbp->f_bavail = sbuf->f_bavail; 199 sbp->f_bresvd = sbuf->f_bresvd; 200 sbp->f_files = sbuf->f_files; 201 sbp->f_ffree = sbuf->f_ffree; 202 sbp->f_favail = sbuf->f_favail; 203 sbp->f_fresvd = sbuf->f_fresvd; 204 sbp->f_namemax = sbuf->f_namemax; 205 copy_statvfs_info(sbp, mp); 206 done: 207 kmem_free(sbuf, sizeof(*sbuf)); 208 return error; 209 } 210 211 int 212 layerfs_sync(struct mount *mp, int waitfor, 213 kauth_cred_t cred) 214 { 215 216 /* 217 * XXX - Assumes no data cached at layer. 218 */ 219 return (0); 220 } 221 222 int 223 layerfs_vget(mp, ino, vpp) 224 struct mount *mp; 225 ino_t ino; 226 struct vnode **vpp; 227 { 228 int error; 229 struct vnode *vp; 230 231 if ((error = VFS_VGET(MOUNTTOLAYERMOUNT(mp)->layerm_vfs, 232 ino, &vp))) { 233 *vpp = NULL; 234 return (error); 235 } 236 if ((error = layer_node_create(mp, vp, vpp))) { 237 vput(vp); 238 *vpp = NULL; 239 return (error); 240 } 241 242 return (0); 243 } 244 245 int 246 layerfs_fhtovp(mp, fidp, vpp) 247 struct mount *mp; 248 struct fid *fidp; 249 struct vnode **vpp; 250 { 251 int error; 252 struct vnode *vp; 253 254 if ((error = VFS_FHTOVP(MOUNTTOLAYERMOUNT(mp)->layerm_vfs, 255 fidp, &vp))) 256 return (error); 257 258 if ((error = layer_node_create(mp, vp, vpp))) { 259 vput(vp); 260 *vpp = NULL; 261 return (error); 262 } 263 264 return (0); 265 } 266 267 int 268 layerfs_vptofh(vp, fhp, fh_size) 269 struct vnode *vp; 270 struct fid *fhp; 271 size_t *fh_size; 272 { 273 274 return (VFS_VPTOFH(LAYERVPTOLOWERVP(vp), fhp, fh_size)); 275 } 276 277 /* 278 * layerfs_snapshot - handle a snapshot through a layered file system 279 * 280 * At present, we do NOT support snapshotting through a layered file 281 * system as the ffs implementation changes v_vnlock of the snapshot 282 * vnodes to point to one common lock. As there is no way for us to 283 * absolutely pass this change up the stack, a layered file system 284 * would end up referencing the wrong lock. 285 * 286 * This routine serves as a central resource for this behavior; all 287 * layered file systems don't need to worry about the above. Also, if 288 * things get fixed, all layers get the benefit. 289 */ 290 int 291 layerfs_snapshot(struct mount *mp, struct vnode *vp, 292 struct timespec *ts) 293 { 294 return (EOPNOTSUPP); 295 } 296 297 SYSCTL_SETUP(sysctl_vfs_layerfs_setup, "sysctl vfs.layerfs subtree setup") 298 { 299 const struct sysctlnode *layerfs_node = NULL; 300 301 sysctl_createv(clog, 0, NULL, NULL, 302 CTLFLAG_PERMANENT, 303 CTLTYPE_NODE, "vfs", NULL, 304 NULL, 0, NULL, 0, 305 CTL_VFS, CTL_EOL); 306 sysctl_createv(clog, 0, NULL, &layerfs_node, 307 CTLFLAG_PERMANENT, 308 CTLTYPE_NODE, "layerfs", 309 SYSCTL_DESCR("Generic layered file system"), 310 NULL, 0, NULL, 0, 311 CTL_VFS, CTL_CREATE); 312 313 #ifdef LAYERFS_DIAGNOSTIC 314 sysctl_createv(clog, 0, &layerfs_node, NULL, 315 CTLFLAG_PERMANENT|CTLFLAG_READWRITE, 316 CTLTYPE_INT, 317 "debug", 318 SYSCTL_DESCR("Verbose debugging messages"), 319 NULL, 0, &layerfs_debug, 0, 320 CTL_CREATE, CTL_EOL); 321 #endif 322 323 /* 324 * other subtrees should really be aliases to this, but since 325 * they can't tell if layerfs has been instantiated yet, they 326 * can't do that...not easily. not yet. :-) 327 */ 328 } 329 330 int 331 layerfs_renamelock_enter(struct mount *mp) 332 { 333 return VFS_RENAMELOCK_ENTER(MOUNTTOLAYERMOUNT(mp)->layerm_vfs); 334 } 335 336 void 337 layerfs_renamelock_exit(struct mount *mp) 338 { 339 VFS_RENAMELOCK_EXIT(MOUNTTOLAYERMOUNT(mp)->layerm_vfs); 340 } 341
Indexes created Tue Sep 23 07:09:52 GMT 2025