overlay_vfsops.c revision 1.9
1 /* $NetBSD: overlay_vfsops.c,v 1.9 2001/11/10 13:33:43 lukem Exp $ */ 2 3 /* 4 * Copyright (c) 1999, 2000 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. All advertising materials mentioning features or use of this software 51 * must display the following acknowledgement: 52 * This product includes software developed by the University of 53 * California, Berkeley and its contributors. 54 * 4. Neither the name of the University nor the names of its contributors 55 * may be used to endorse or promote products derived from this software 56 * without specific prior written permission. 57 * 58 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 59 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 60 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 61 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 62 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 63 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 64 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 65 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 66 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 67 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 68 * SUCH DAMAGE. 69 * 70 * from: Id: lofs_vfsops.c,v 1.9 1992/05/30 10:26:24 jsp Exp 71 * from: @(#)lofs_vfsops.c 1.2 (Berkeley) 6/18/92 72 * @(#)null_vfsops.c 8.7 (Berkeley) 5/14/95 73 */ 74 75 /* 76 * Overlay Layer 77 * (See overlay_vnops.c for a description of what this does.) 78 */ 79 80 #include <sys/cdefs.h> 81 __KERNEL_RCSID(0, "$NetBSD: overlay_vfsops.c,v 1.9 2001/11/10 13:33:43 lukem Exp $"); 82 83 #include <sys/param.h> 84 #include <sys/systm.h> 85 #include <sys/time.h> 86 #include <sys/proc.h> 87 #include <sys/types.h> 88 #include <sys/vnode.h> 89 #include <sys/mount.h> 90 #include <sys/namei.h> 91 #include <sys/malloc.h> 92 #include <miscfs/overlay/overlay.h> 93 #include <miscfs/genfs/layer_extern.h> 94 95 int ov_mount __P((struct mount *, const char *, void *, 96 struct nameidata *, struct proc *)); 97 int ov_unmount __P((struct mount *, int, struct proc *)); 98 99 #define NOVERLAYNODECACHE 16 100 101 /* 102 * Mount overlay layer 103 */ 104 int 105 ov_mount(mp, path, data, ndp, p) 106 struct mount *mp; 107 const char *path; 108 void *data; 109 struct nameidata *ndp; 110 struct proc *p; 111 { 112 int error = 0; 113 struct overlay_args args; 114 struct vnode *lowerrootvp, *vp; 115 struct overlay_mount *nmp; 116 struct layer_mount *lmp; 117 size_t size; 118 119 #ifdef OVERLAYFS_DIAGNOSTIC 120 printf("ov_mount(mp = %p)\n", mp); 121 #endif 122 123 /* 124 * Get argument 125 */ 126 error = copyin(data, (caddr_t)&args, sizeof(struct overlay_args)); 127 if (error) 128 return (error); 129 130 /* 131 * Update only does export updating. 132 */ 133 if (mp->mnt_flag & MNT_UPDATE) { 134 lmp = MOUNTTOLAYERMOUNT(mp); 135 if (args.ova_target == 0) 136 return (vfs_export(mp, &lmp->layerm_export, 137 &args.la.export)); 138 else 139 return (EOPNOTSUPP); 140 } 141 142 /* 143 * Find lower node 144 */ 145 lowerrootvp = mp->mnt_vnodecovered; 146 if ((error = vget(lowerrootvp, LK_EXCLUSIVE | LK_RETRY))) 147 return (error); 148 149 /* 150 * First cut at fixing up upper mount point 151 */ 152 nmp = (struct overlay_mount *) malloc(sizeof(struct overlay_mount), 153 M_UFSMNT, M_WAITOK); /* XXX */ 154 memset((caddr_t)nmp, 0, sizeof(struct overlay_mount)); 155 156 mp->mnt_data = (qaddr_t) nmp; 157 nmp->ovm_vfs = lowerrootvp->v_mount; 158 if (nmp->ovm_vfs->mnt_flag & MNT_LOCAL) 159 mp->mnt_flag |= MNT_LOCAL; 160 161 /* 162 * Make sure that the mount point is sufficiently initialized 163 * that the node create call will work. 164 */ 165 vfs_getnewfsid(mp); 166 167 nmp->ovm_size = sizeof (struct overlay_node); 168 nmp->ovm_tag = VT_OVERLAY; 169 nmp->ovm_bypass = layer_bypass; 170 nmp->ovm_alloc = layer_node_alloc; /* the default alloc is fine */ 171 nmp->ovm_vnodeop_p = overlay_vnodeop_p; 172 simple_lock_init(&nmp->ovm_hashlock); 173 nmp->ovm_node_hashtbl = hashinit(NOVERLAYNODECACHE, HASH_LIST, M_CACHE, 174 M_WAITOK, &nmp->ovm_node_hash); 175 176 /* 177 * Fix up overlay node for root vnode 178 */ 179 error = layer_node_create(mp, lowerrootvp, &vp); 180 /* 181 * Make sure the fixup worked 182 */ 183 if (error) { 184 vput(lowerrootvp); 185 free(nmp, M_UFSMNT); /* XXX */ 186 return (error); 187 } 188 /* 189 * Unlock the node 190 */ 191 VOP_UNLOCK(vp, 0); 192 193 /* 194 * Keep a held reference to the root vnode. 195 * It is vrele'd in ov_unmount. 196 */ 197 vp->v_flag |= VROOT; 198 nmp->ovm_rootvp = vp; 199 200 (void) copyinstr(path, mp->mnt_stat.f_mntonname, MNAMELEN - 1, &size); 201 memset(mp->mnt_stat.f_mntonname + size, 0, MNAMELEN - size); 202 (void) copyinstr(args.la.target, mp->mnt_stat.f_mntfromname, MNAMELEN - 1, 203 &size); 204 memset(mp->mnt_stat.f_mntfromname + size, 0, MNAMELEN - size); 205 #ifdef OVERLAYFS_DIAGNOSTIC 206 printf("ov_mount: lower %s, alias at %s\n", 207 mp->mnt_stat.f_mntfromname, mp->mnt_stat.f_mntonname); 208 #endif 209 return (0); 210 } 211 212 /* 213 * Free reference to overlay layer 214 */ 215 int 216 ov_unmount(mp, mntflags, p) 217 struct mount *mp; 218 int mntflags; 219 struct proc *p; 220 { 221 struct vnode *overlay_rootvp = MOUNTTOOVERLAYMOUNT(mp)->ovm_rootvp; 222 int error; 223 int flags = 0; 224 225 #ifdef OVERLAYFS_DIAGNOSTIC 226 printf("ov_unmount(mp = %p)\n", mp); 227 #endif 228 229 if (mntflags & MNT_FORCE) 230 flags |= FORCECLOSE; 231 232 /* 233 * Clear out buffer cache. I don't think we 234 * ever get anything cached at this level at the 235 * moment, but who knows... 236 */ 237 #if 0 238 mntflushbuf(mp, 0); 239 if (mntinvalbuf(mp, 1)) 240 return (EBUSY); 241 #endif 242 if (overlay_rootvp->v_usecount > 1) 243 return (EBUSY); 244 if ((error = vflush(mp, overlay_rootvp, flags)) != 0) 245 return (error); 246 247 #ifdef OVERLAYFS_DIAGNOSTIC 248 vprint("alias root of lower", overlay_rootvp); 249 #endif 250 /* 251 * Release reference on underlying root vnode 252 */ 253 vrele(overlay_rootvp); 254 /* 255 * And blow it away for future re-use 256 */ 257 vgone(overlay_rootvp); 258 /* 259 * Finally, throw away the overlay_mount structure 260 */ 261 free(mp->mnt_data, M_UFSMNT); /* XXX */ 262 mp->mnt_data = 0; 263 return 0; 264 } 265 266 extern const struct vnodeopv_desc overlay_vnodeop_opv_desc; 267 268 const struct vnodeopv_desc * const ov_vnodeopv_descs[] = { 269 &overlay_vnodeop_opv_desc, 270 NULL, 271 }; 272 273 struct vfsops overlay_vfsops = { 274 MOUNT_OVERLAY, 275 ov_mount, 276 layerfs_start, 277 ov_unmount, 278 layerfs_root, 279 layerfs_quotactl, 280 layerfs_statfs, 281 layerfs_sync, 282 layerfs_vget, 283 layerfs_fhtovp, 284 layerfs_vptofh, 285 layerfs_init, 286 NULL, 287 layerfs_done, 288 layerfs_sysctl, 289 NULL, /* vfs_mountroot */ 290 layerfs_checkexp, 291 ov_vnodeopv_descs, 292 }; 293
Indexes created Mon Sep 29 21:09:56 GMT 2025