overlay_vfsops.c revision 1.18
1 /* $NetBSD: overlay_vfsops.c,v 1.18 2003/08/07 16:32:39 agc 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. 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 * Overlay Layer 73 * (See overlay_vnops.c for a description of what this does.) 74 */ 75 76 #include <sys/cdefs.h> 77 __KERNEL_RCSID(0, "$NetBSD: overlay_vfsops.c,v 1.18 2003/08/07 16:32:39 agc Exp $"); 78 79 #include <sys/param.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/overlay/overlay.h> 88 #include <miscfs/genfs/layer_extern.h> 89 90 int ov_mount __P((struct mount *, const char *, void *, 91 struct nameidata *, struct proc *)); 92 int ov_unmount __P((struct mount *, int, struct proc *)); 93 94 #define NOVERLAYNODECACHE 16 95 96 /* 97 * Mount overlay layer 98 */ 99 int 100 ov_mount(mp, path, data, ndp, p) 101 struct mount *mp; 102 const char *path; 103 void *data; 104 struct nameidata *ndp; 105 struct proc *p; 106 { 107 int error = 0; 108 struct overlay_args args; 109 struct vnode *lowerrootvp, *vp; 110 struct overlay_mount *nmp; 111 struct layer_mount *lmp; 112 113 #ifdef OVERLAYFS_DIAGNOSTIC 114 printf("ov_mount(mp = %p)\n", mp); 115 #endif 116 117 if (mp->mnt_flag & MNT_GETARGS) { 118 lmp = MOUNTTOLAYERMOUNT(mp); 119 if (lmp == NULL) 120 return EIO; 121 args.la.target = NULL; 122 vfs_showexport(mp, &args.la.export, &lmp->layerm_export); 123 return copyout(&args, data, sizeof(args)); 124 } 125 /* 126 * Get argument 127 */ 128 error = copyin(data, (caddr_t)&args, sizeof(struct overlay_args)); 129 if (error) 130 return (error); 131 132 /* 133 * Update only does export updating. 134 */ 135 if (mp->mnt_flag & MNT_UPDATE) { 136 lmp = MOUNTTOLAYERMOUNT(mp); 137 if (args.ova_target == 0) 138 return (vfs_export(mp, &lmp->layerm_export, 139 &args.la.export)); 140 else 141 return (EOPNOTSUPP); 142 } 143 144 /* 145 * Find lower node 146 */ 147 lowerrootvp = mp->mnt_vnodecovered; 148 if ((error = vget(lowerrootvp, LK_EXCLUSIVE | LK_RETRY))) 149 return (error); 150 151 /* 152 * First cut at fixing up upper mount point 153 */ 154 nmp = (struct overlay_mount *) malloc(sizeof(struct overlay_mount), 155 M_UFSMNT, M_WAITOK); /* XXX */ 156 memset((caddr_t)nmp, 0, sizeof(struct overlay_mount)); 157 158 mp->mnt_data = nmp; 159 nmp->ovm_vfs = lowerrootvp->v_mount; 160 if (nmp->ovm_vfs->mnt_flag & MNT_LOCAL) 161 mp->mnt_flag |= MNT_LOCAL; 162 163 /* 164 * Make sure that the mount point is sufficiently initialized 165 * that the node create call will work. 166 */ 167 vfs_getnewfsid(mp); 168 169 nmp->ovm_size = sizeof (struct overlay_node); 170 nmp->ovm_tag = VT_OVERLAY; 171 nmp->ovm_bypass = layer_bypass; 172 nmp->ovm_alloc = layer_node_alloc; /* the default alloc is fine */ 173 nmp->ovm_vnodeop_p = overlay_vnodeop_p; 174 simple_lock_init(&nmp->ovm_hashlock); 175 nmp->ovm_node_hashtbl = hashinit(NOVERLAYNODECACHE, HASH_LIST, M_CACHE, 176 M_WAITOK, &nmp->ovm_node_hash); 177 178 /* 179 * Fix up overlay node for root vnode 180 */ 181 error = layer_node_create(mp, lowerrootvp, &vp); 182 /* 183 * Make sure the fixup worked 184 */ 185 if (error) { 186 vput(lowerrootvp); 187 free(nmp, M_UFSMNT); /* XXX */ 188 return (error); 189 } 190 /* 191 * Unlock the node 192 */ 193 VOP_UNLOCK(vp, 0); 194 195 /* 196 * Keep a held reference to the root vnode. 197 * It is vrele'd in ov_unmount. 198 */ 199 vp->v_flag |= VROOT; 200 nmp->ovm_rootvp = vp; 201 202 error = set_statfs_info(path, UIO_USERSPACE, args.la.target, 203 UIO_USERSPACE, mp, p); 204 #ifdef OVERLAYFS_DIAGNOSTIC 205 printf("ov_mount: lower %s, alias at %s\n", 206 mp->mnt_stat.f_mntfromname, mp->mnt_stat.f_mntonname); 207 #endif 208 return error; 209 } 210 211 /* 212 * Free reference to overlay layer 213 */ 214 int 215 ov_unmount(mp, mntflags, p) 216 struct mount *mp; 217 int mntflags; 218 struct proc *p; 219 { 220 struct vnode *overlay_rootvp = MOUNTTOOVERLAYMOUNT(mp)->ovm_rootvp; 221 int error; 222 int flags = 0; 223 224 #ifdef OVERLAYFS_DIAGNOSTIC 225 printf("ov_unmount(mp = %p)\n", mp); 226 #endif 227 228 if (mntflags & MNT_FORCE) 229 flags |= FORCECLOSE; 230 231 /* 232 * Clear out buffer cache. I don't think we 233 * ever get anything cached at this level at the 234 * moment, but who knows... 235 */ 236 #if 0 237 mntflushbuf(mp, 0); 238 if (mntinvalbuf(mp, 1)) 239 return (EBUSY); 240 #endif 241 if (overlay_rootvp->v_usecount > 1) 242 return (EBUSY); 243 if ((error = vflush(mp, overlay_rootvp, flags)) != 0) 244 return (error); 245 246 #ifdef OVERLAYFS_DIAGNOSTIC 247 vprint("alias root of lower", overlay_rootvp); 248 #endif 249 /* 250 * Release reference on underlying root vnode 251 */ 252 vrele(overlay_rootvp); 253 /* 254 * And blow it away for future re-use 255 */ 256 vgone(overlay_rootvp); 257 /* 258 * Finally, throw away the overlay_mount structure 259 */ 260 free(mp->mnt_data, M_UFSMNT); /* XXX */ 261 mp->mnt_data = 0; 262 return 0; 263 } 264 265 extern const struct vnodeopv_desc overlay_vnodeop_opv_desc; 266 267 const struct vnodeopv_desc * const ov_vnodeopv_descs[] = { 268 &overlay_vnodeop_opv_desc, 269 NULL, 270 }; 271 272 struct vfsops overlay_vfsops = { 273 MOUNT_OVERLAY, 274 ov_mount, 275 layerfs_start, 276 ov_unmount, 277 layerfs_root, 278 layerfs_quotactl, 279 layerfs_statfs, 280 layerfs_sync, 281 layerfs_vget, 282 layerfs_fhtovp, 283 layerfs_vptofh, 284 layerfs_init, 285 NULL, 286 layerfs_done, 287 layerfs_sysctl, 288 NULL, /* vfs_mountroot */ 289 layerfs_checkexp, 290 ov_vnodeopv_descs, 291 }; 292
Indexes created Mon Sep 29 21:09:56 GMT 2025