overlay_vfsops.c revision 1.16
1 /* $NetBSD: overlay_vfsops.c,v 1.16 2003/06/29 18:43:33 thorpej 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 1.16 2003/06/29 18:43:33 thorpej 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/vnode.h> 88 #include <sys/mount.h> 89 #include <sys/namei.h> 90 #include <sys/malloc.h> 91 #include <miscfs/overlay/overlay.h> 92 #include <miscfs/genfs/layer_extern.h> 93 94 int ov_mount __P((struct mount *, const char *, void *, 95 struct nameidata *, struct lwp *)); 96 int ov_unmount __P((struct mount *, int, struct lwp *)); 97 98 #define NOVERLAYNODECACHE 16 99 100 /* 101 * Mount overlay layer 102 */ 103 int 104 ov_mount(mp, path, data, ndp, l) 105 struct mount *mp; 106 const char *path; 107 void *data; 108 struct nameidata *ndp; 109 struct lwp *l; 110 { 111 int error = 0; 112 struct overlay_args args; 113 struct vnode *lowerrootvp, *vp; 114 struct overlay_mount *nmp; 115 struct layer_mount *lmp; 116 117 #ifdef OVERLAYFS_DIAGNOSTIC 118 printf("ov_mount(mp = %p)\n", mp); 119 #endif 120 121 if (mp->mnt_flag & MNT_GETARGS) { 122 lmp = MOUNTTOLAYERMOUNT(mp); 123 if (lmp == NULL) 124 return EIO; 125 args.la.target = NULL; 126 vfs_showexport(mp, &args.la.export, &lmp->layerm_export); 127 return copyout(&args, data, sizeof(args)); 128 } 129 /* 130 * Get argument 131 */ 132 error = copyin(data, (caddr_t)&args, sizeof(struct overlay_args)); 133 if (error) 134 return (error); 135 136 /* 137 * Update only does export updating. 138 */ 139 if (mp->mnt_flag & MNT_UPDATE) { 140 lmp = MOUNTTOLAYERMOUNT(mp); 141 if (args.ova_target == 0) 142 return (vfs_export(mp, &lmp->layerm_export, 143 &args.la.export)); 144 else 145 return (EOPNOTSUPP); 146 } 147 148 /* 149 * Find lower node 150 */ 151 lowerrootvp = mp->mnt_vnodecovered; 152 if ((error = vget(lowerrootvp, LK_EXCLUSIVE | LK_RETRY))) 153 return (error); 154 155 /* 156 * First cut at fixing up upper mount point 157 */ 158 nmp = (struct overlay_mount *) malloc(sizeof(struct overlay_mount), 159 M_UFSMNT, M_WAITOK); /* XXX */ 160 memset((caddr_t)nmp, 0, sizeof(struct overlay_mount)); 161 162 mp->mnt_data = nmp; 163 nmp->ovm_vfs = lowerrootvp->v_mount; 164 if (nmp->ovm_vfs->mnt_flag & MNT_LOCAL) 165 mp->mnt_flag |= MNT_LOCAL; 166 167 /* 168 * Make sure that the mount point is sufficiently initialized 169 * that the node create call will work. 170 */ 171 vfs_getnewfsid(mp); 172 173 nmp->ovm_size = sizeof (struct overlay_node); 174 nmp->ovm_tag = VT_OVERLAY; 175 nmp->ovm_bypass = layer_bypass; 176 nmp->ovm_alloc = layer_node_alloc; /* the default alloc is fine */ 177 nmp->ovm_vnodeop_p = overlay_vnodeop_p; 178 simple_lock_init(&nmp->ovm_hashlock); 179 nmp->ovm_node_hashtbl = hashinit(NOVERLAYNODECACHE, HASH_LIST, M_CACHE, 180 M_WAITOK, &nmp->ovm_node_hash); 181 182 /* 183 * Fix up overlay node for root vnode 184 */ 185 error = layer_node_create(mp, lowerrootvp, &vp); 186 /* 187 * Make sure the fixup worked 188 */ 189 if (error) { 190 vput(lowerrootvp); 191 free(nmp, M_UFSMNT); /* XXX */ 192 return (error); 193 } 194 /* 195 * Unlock the node 196 */ 197 VOP_UNLOCK(vp, 0); 198 199 /* 200 * Keep a held reference to the root vnode. 201 * It is vrele'd in ov_unmount. 202 */ 203 vp->v_flag |= VROOT; 204 nmp->ovm_rootvp = vp; 205 206 error = set_statfs_info(path, UIO_USERSPACE, args.la.target, 207 UIO_USERSPACE, mp, l); 208 #ifdef OVERLAYFS_DIAGNOSTIC 209 printf("ov_mount: lower %s, alias at %s\n", 210 mp->mnt_stat.f_mntfromname, mp->mnt_stat.f_mntonname); 211 #endif 212 return error; 213 } 214 215 /* 216 * Free reference to overlay layer 217 */ 218 int 219 ov_unmount(mp, mntflags, l) 220 struct mount *mp; 221 int mntflags; 222 struct lwp *l; 223 { 224 struct vnode *overlay_rootvp = MOUNTTOOVERLAYMOUNT(mp)->ovm_rootvp; 225 int error; 226 int flags = 0; 227 228 #ifdef OVERLAYFS_DIAGNOSTIC 229 printf("ov_unmount(mp = %p)\n", mp); 230 #endif 231 232 if (mntflags & MNT_FORCE) 233 flags |= FORCECLOSE; 234 235 /* 236 * Clear out buffer cache. I don't think we 237 * ever get anything cached at this level at the 238 * moment, but who knows... 239 */ 240 #if 0 241 mntflushbuf(mp, 0); 242 if (mntinvalbuf(mp, 1)) 243 return (EBUSY); 244 #endif 245 if (overlay_rootvp->v_usecount > 1) 246 return (EBUSY); 247 if ((error = vflush(mp, overlay_rootvp, flags)) != 0) 248 return (error); 249 250 #ifdef OVERLAYFS_DIAGNOSTIC 251 vprint("alias root of lower", overlay_rootvp); 252 #endif 253 /* 254 * Release reference on underlying root vnode 255 */ 256 vrele(overlay_rootvp); 257 /* 258 * And blow it away for future re-use 259 */ 260 vgone(overlay_rootvp); 261 /* 262 * Finally, throw away the overlay_mount structure 263 */ 264 free(mp->mnt_data, M_UFSMNT); /* XXX */ 265 mp->mnt_data = 0; 266 return 0; 267 } 268 269 extern const struct vnodeopv_desc overlay_vnodeop_opv_desc; 270 271 const struct vnodeopv_desc * const ov_vnodeopv_descs[] = { 272 &overlay_vnodeop_opv_desc, 273 NULL, 274 }; 275 276 struct vfsops overlay_vfsops = { 277 MOUNT_OVERLAY, 278 ov_mount, 279 layerfs_start, 280 ov_unmount, 281 layerfs_root, 282 layerfs_quotactl, 283 layerfs_statfs, 284 layerfs_sync, 285 layerfs_vget, 286 layerfs_fhtovp, 287 layerfs_vptofh, 288 layerfs_init, 289 NULL, 290 layerfs_done, 291 layerfs_sysctl, 292 NULL, /* vfs_mountroot */ 293 layerfs_checkexp, 294 ov_vnodeopv_descs, 295 }; 296
Indexes created Tue Sep 30 06:09:59 GMT 2025