overlay_vfsops.c revision 1.7
1 /* $NetBSD: overlay_vfsops.c,v 1.7 2001/06/07 13:44:48 wiz 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/param.h> 81 #include <sys/systm.h> 82 #include <sys/time.h> 83 #include <sys/proc.h> 84 #include <sys/types.h> 85 #include <sys/vnode.h> 86 #include <sys/mount.h> 87 #include <sys/namei.h> 88 #include <sys/malloc.h> 89 #include <miscfs/overlay/overlay.h> 90 #include <miscfs/genfs/layer_extern.h> 91 92 int ov_mount __P((struct mount *, const char *, void *, 93 struct nameidata *, struct proc *)); 94 int ov_unmount __P((struct mount *, int, struct proc *)); 95 96 #define NOVERLAYNODECACHE 16 97 98 /* 99 * Mount overlay layer 100 */ 101 int 102 ov_mount(mp, path, data, ndp, p) 103 struct mount *mp; 104 const char *path; 105 void *data; 106 struct nameidata *ndp; 107 struct proc *p; 108 { 109 int error = 0; 110 struct overlay_args args; 111 struct vnode *lowerrootvp, *vp; 112 struct overlay_mount *nmp; 113 struct layer_mount *lmp; 114 size_t size; 115 116 #ifdef OVERLAYFS_DIAGNOSTIC 117 printf("ov_mount(mp = %p)\n", mp); 118 #endif 119 120 /* 121 * Get argument 122 */ 123 error = copyin(data, (caddr_t)&args, sizeof(struct overlay_args)); 124 if (error) 125 return (error); 126 127 /* 128 * Update only does export updating. 129 */ 130 if (mp->mnt_flag & MNT_UPDATE) { 131 lmp = MOUNTTOLAYERMOUNT(mp); 132 if (args.ova_target == 0) 133 return (vfs_export(mp, &lmp->layerm_export, 134 &args.la.export)); 135 else 136 return (EOPNOTSUPP); 137 } 138 139 /* 140 * Find lower node 141 */ 142 lowerrootvp = mp->mnt_vnodecovered; 143 if ((error = vget(lowerrootvp, LK_EXCLUSIVE | LK_RETRY))) 144 return (error); 145 146 /* 147 * First cut at fixing up upper mount point 148 */ 149 nmp = (struct overlay_mount *) malloc(sizeof(struct overlay_mount), 150 M_UFSMNT, M_WAITOK); /* XXX */ 151 memset((caddr_t)nmp, 0, sizeof(struct overlay_mount)); 152 153 mp->mnt_data = (qaddr_t) nmp; 154 nmp->ovm_vfs = lowerrootvp->v_mount; 155 if (nmp->ovm_vfs->mnt_flag & MNT_LOCAL) 156 mp->mnt_flag |= MNT_LOCAL; 157 158 /* 159 * Make sure that the mount point is sufficiently initialized 160 * that the node create call will work. 161 */ 162 vfs_getnewfsid(mp); 163 164 nmp->ovm_size = sizeof (struct overlay_node); 165 nmp->ovm_tag = VT_OVERLAY; 166 nmp->ovm_bypass = layer_bypass; 167 nmp->ovm_alloc = layer_node_alloc; /* the default alloc is fine */ 168 nmp->ovm_vnodeop_p = overlay_vnodeop_p; 169 simple_lock_init(&nmp->ovm_hashlock); 170 nmp->ovm_node_hashtbl = hashinit(NOVERLAYNODECACHE, HASH_LIST, M_CACHE, 171 M_WAITOK, &nmp->ovm_node_hash); 172 173 /* 174 * Fix up overlay node for root vnode 175 */ 176 error = layer_node_create(mp, lowerrootvp, &vp); 177 /* 178 * Make sure the fixup worked 179 */ 180 if (error) { 181 vput(lowerrootvp); 182 free(nmp, M_UFSMNT); /* XXX */ 183 return (error); 184 } 185 /* 186 * Unlock the node 187 */ 188 VOP_UNLOCK(vp, 0); 189 190 /* 191 * Keep a held reference to the root vnode. 192 * It is vrele'd in ov_unmount. 193 */ 194 vp->v_flag |= VROOT; 195 nmp->ovm_rootvp = vp; 196 197 (void) copyinstr(path, mp->mnt_stat.f_mntonname, MNAMELEN - 1, &size); 198 memset(mp->mnt_stat.f_mntonname + size, 0, MNAMELEN - size); 199 (void) copyinstr(args.la.target, mp->mnt_stat.f_mntfromname, MNAMELEN - 1, 200 &size); 201 memset(mp->mnt_stat.f_mntfromname + size, 0, MNAMELEN - size); 202 #ifdef OVERLAYFS_DIAGNOSTIC 203 printf("ov_mount: lower %s, alias at %s\n", 204 mp->mnt_stat.f_mntfromname, mp->mnt_stat.f_mntonname); 205 #endif 206 return (0); 207 } 208 209 /* 210 * Free reference to overlay layer 211 */ 212 int 213 ov_unmount(mp, mntflags, p) 214 struct mount *mp; 215 int mntflags; 216 struct proc *p; 217 { 218 struct vnode *overlay_rootvp = MOUNTTOOVERLAYMOUNT(mp)->ovm_rootvp; 219 int error; 220 int flags = 0; 221 222 #ifdef OVERLAYFS_DIAGNOSTIC 223 printf("ov_unmount(mp = %p)\n", mp); 224 #endif 225 226 if (mntflags & MNT_FORCE) 227 flags |= FORCECLOSE; 228 229 /* 230 * Clear out buffer cache. I don't think we 231 * ever get anything cached at this level at the 232 * moment, but who knows... 233 */ 234 #if 0 235 mntflushbuf(mp, 0); 236 if (mntinvalbuf(mp, 1)) 237 return (EBUSY); 238 #endif 239 if (overlay_rootvp->v_usecount > 1) 240 return (EBUSY); 241 if ((error = vflush(mp, overlay_rootvp, flags)) != 0) 242 return (error); 243 244 #ifdef OVERLAYFS_DIAGNOSTIC 245 vprint("alias root of lower", overlay_rootvp); 246 #endif 247 /* 248 * Release reference on underlying root vnode 249 */ 250 vrele(overlay_rootvp); 251 /* 252 * And blow it away for future re-use 253 */ 254 vgone(overlay_rootvp); 255 /* 256 * Finally, throw away the overlay_mount structure 257 */ 258 free(mp->mnt_data, M_UFSMNT); /* XXX */ 259 mp->mnt_data = 0; 260 return 0; 261 } 262 263 extern const struct vnodeopv_desc overlay_vnodeop_opv_desc; 264 265 const struct vnodeopv_desc * const ov_vnodeopv_descs[] = { 266 &overlay_vnodeop_opv_desc, 267 NULL, 268 }; 269 270 struct vfsops overlay_vfsops = { 271 MOUNT_OVERLAY, 272 ov_mount, 273 layerfs_start, 274 ov_unmount, 275 layerfs_root, 276 layerfs_quotactl, 277 layerfs_statfs, 278 layerfs_sync, 279 layerfs_vget, 280 layerfs_fhtovp, 281 layerfs_vptofh, 282 layerfs_init, 283 layerfs_done, 284 layerfs_sysctl, 285 NULL, /* vfs_mountroot */ 286 layerfs_checkexp, 287 ov_vnodeopv_descs, 288 }; 289
Indexes created Mon Sep 29 21:09:56 GMT 2025