layer_vfsops.c revision 1.32
1 /* $NetBSD: layer_vfsops.c,v 1.32 2010/01/08 11:35:10 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 1.32 2010/01/08 11:35:10 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 #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(struct mount *mp, struct vnode **vpp) 129 { 130 struct vnode *vp; 131 132 #ifdef LAYERFS_DIAGNOSTIC 133 if (layerfs_debug) 134 printf("layerfs_root(mp = %p, vp = %p->%p)\n", mp, 135 MOUNTTOLAYERMOUNT(mp)->layerm_rootvp, 136 LAYERVPTOLOWERVP(MOUNTTOLAYERMOUNT(mp)->layerm_rootvp)); 137 #endif 138 139 /* 140 * Return locked reference to root. 141 */ 142 vp = MOUNTTOLAYERMOUNT(mp)->layerm_rootvp; 143 if (vp == NULL) { 144 *vpp = NULL; 145 return (EINVAL); 146 } 147 vref(vp); 148 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 149 *vpp = vp; 150 return 0; 151 } 152 153 int 154 layerfs_quotactl(struct mount *mp, int cmd, uid_t uid, void *arg) 155 { 156 157 return VFS_QUOTACTL(MOUNTTOLAYERMOUNT(mp)->layerm_vfs, cmd, uid, arg); 158 } 159 160 int 161 layerfs_statvfs(struct mount *mp, struct statvfs *sbp) 162 { 163 int error; 164 struct statvfs *sbuf; 165 166 sbuf = kmem_alloc(sizeof(*sbuf), KM_SLEEP); 167 if (sbuf == NULL) 168 return ENOMEM; 169 170 #ifdef LAYERFS_DIAGNOSTIC 171 if (layerfs_debug) 172 printf("layerfs_statvfs(mp = %p, vp = %p->%p)\n", mp, 173 MOUNTTOLAYERMOUNT(mp)->layerm_rootvp, 174 LAYERVPTOLOWERVP(MOUNTTOLAYERMOUNT(mp)->layerm_rootvp)); 175 #endif 176 177 (void)memset(sbuf, 0, sizeof(*sbuf)); 178 179 error = VFS_STATVFS(MOUNTTOLAYERMOUNT(mp)->layerm_vfs, sbuf); 180 if (error) 181 goto done; 182 183 /* now copy across the "interesting" information and fake the rest */ 184 sbp->f_flag = sbuf->f_flag; 185 sbp->f_bsize = sbuf->f_bsize; 186 sbp->f_frsize = sbuf->f_frsize; 187 sbp->f_iosize = sbuf->f_iosize; 188 sbp->f_blocks = sbuf->f_blocks; 189 sbp->f_bfree = sbuf->f_bfree; 190 sbp->f_bavail = sbuf->f_bavail; 191 sbp->f_bresvd = sbuf->f_bresvd; 192 sbp->f_files = sbuf->f_files; 193 sbp->f_ffree = sbuf->f_ffree; 194 sbp->f_favail = sbuf->f_favail; 195 sbp->f_fresvd = sbuf->f_fresvd; 196 sbp->f_namemax = sbuf->f_namemax; 197 copy_statvfs_info(sbp, mp); 198 done: 199 kmem_free(sbuf, sizeof(*sbuf)); 200 return error; 201 } 202 203 int 204 layerfs_sync(struct mount *mp, int waitfor, 205 kauth_cred_t cred) 206 { 207 208 /* 209 * XXX - Assumes no data cached at layer. 210 */ 211 return (0); 212 } 213 214 int 215 layerfs_vget(struct mount *mp, ino_t ino, struct vnode **vpp) 216 { 217 int error; 218 struct vnode *vp; 219 220 if ((error = VFS_VGET(MOUNTTOLAYERMOUNT(mp)->layerm_vfs, 221 ino, &vp))) { 222 *vpp = NULL; 223 return (error); 224 } 225 if ((error = layer_node_create(mp, vp, vpp))) { 226 vput(vp); 227 *vpp = NULL; 228 return (error); 229 } 230 231 return (0); 232 } 233 234 int 235 layerfs_fhtovp(struct mount *mp, struct fid *fidp, struct vnode **vpp) 236 { 237 int error; 238 struct vnode *vp; 239 240 if ((error = VFS_FHTOVP(MOUNTTOLAYERMOUNT(mp)->layerm_vfs, 241 fidp, &vp))) 242 return (error); 243 244 if ((error = layer_node_create(mp, vp, vpp))) { 245 vput(vp); 246 *vpp = NULL; 247 return (error); 248 } 249 250 return (0); 251 } 252 253 int 254 layerfs_vptofh(struct vnode *vp, struct fid *fhp, size_t *fh_size) 255 { 256 257 return (VFS_VPTOFH(LAYERVPTOLOWERVP(vp), fhp, fh_size)); 258 } 259 260 /* 261 * layerfs_snapshot - handle a snapshot through a layered file system 262 * 263 * At present, we do NOT support snapshotting through a layered file 264 * system as the ffs implementation changes v_vnlock of the snapshot 265 * vnodes to point to one common lock. As there is no way for us to 266 * absolutely pass this change up the stack, a layered file system 267 * would end up referencing the wrong lock. 268 * 269 * This routine serves as a central resource for this behavior; all 270 * layered file systems don't need to worry about the above. Also, if 271 * things get fixed, all layers get the benefit. 272 */ 273 int 274 layerfs_snapshot(struct mount *mp, struct vnode *vp, 275 struct timespec *ts) 276 { 277 return (EOPNOTSUPP); 278 } 279 280 SYSCTL_SETUP(sysctl_vfs_layerfs_setup, "sysctl vfs.layerfs subtree setup") 281 { 282 const struct sysctlnode *layerfs_node = NULL; 283 284 sysctl_createv(clog, 0, NULL, NULL, 285 CTLFLAG_PERMANENT, 286 CTLTYPE_NODE, "vfs", NULL, 287 NULL, 0, NULL, 0, 288 CTL_VFS, CTL_EOL); 289 sysctl_createv(clog, 0, NULL, &layerfs_node, 290 CTLFLAG_PERMANENT, 291 CTLTYPE_NODE, "layerfs", 292 SYSCTL_DESCR("Generic layered file system"), 293 NULL, 0, NULL, 0, 294 CTL_VFS, CTL_CREATE); 295 296 #ifdef LAYERFS_DIAGNOSTIC 297 sysctl_createv(clog, 0, &layerfs_node, NULL, 298 CTLFLAG_PERMANENT|CTLFLAG_READWRITE, 299 CTLTYPE_INT, 300 "debug", 301 SYSCTL_DESCR("Verbose debugging messages"), 302 NULL, 0, &layerfs_debug, 0, 303 CTL_CREATE, CTL_EOL); 304 #endif 305 306 /* 307 * other subtrees should really be aliases to this, but since 308 * they can't tell if layerfs has been instantiated yet, they 309 * can't do that...not easily. not yet. :-) 310 */ 311 } 312 313 int 314 layerfs_renamelock_enter(struct mount *mp) 315 { 316 return VFS_RENAMELOCK_ENTER(MOUNTTOLAYERMOUNT(mp)->layerm_vfs); 317 } 318 319 void 320 layerfs_renamelock_exit(struct mount *mp) 321 { 322 VFS_RENAMELOCK_EXIT(MOUNTTOLAYERMOUNT(mp)->layerm_vfs); 323 } 324
Indexes created Tue Sep 23 14:10:03 GMT 2025