overlay_vfsops.c revision 1.20
1 /* $NetBSD: overlay_vfsops.c,v 1.20 2004/03/09 03:16:09 atatat 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 1.20 2004/03/09 03:16:09 atatat Exp $"); 78 79 #include <sys/param.h> 80 #include <sys/systm.h> 81 #include <sys/sysctl.h> 82 #include <sys/time.h> 83 #include <sys/proc.h> 84 #include <sys/vnode.h> 85 #include <sys/mount.h> 86 #include <sys/namei.h> 87 #include <sys/malloc.h> 88 #include <miscfs/overlay/overlay.h> 89 #include <miscfs/genfs/layer_extern.h> 90 91 int ov_mount __P((struct mount *, const char *, void *, 92 struct nameidata *, struct proc *)); 93 int ov_unmount __P((struct mount *, int, struct proc *)); 94 95 #define NOVERLAYNODECACHE 16 96 97 /* 98 * Mount overlay layer 99 */ 100 int 101 ov_mount(mp, path, data, ndp, p) 102 struct mount *mp; 103 const char *path; 104 void *data; 105 struct nameidata *ndp; 106 struct proc *p; 107 { 108 int error = 0; 109 struct overlay_args args; 110 struct vnode *lowerrootvp, *vp; 111 struct overlay_mount *nmp; 112 struct layer_mount *lmp; 113 114 #ifdef OVERLAYFS_DIAGNOSTIC 115 printf("ov_mount(mp = %p)\n", mp); 116 #endif 117 118 if (mp->mnt_flag & MNT_GETARGS) { 119 lmp = MOUNTTOLAYERMOUNT(mp); 120 if (lmp == NULL) 121 return EIO; 122 args.la.target = NULL; 123 vfs_showexport(mp, &args.la.export, &lmp->layerm_export); 124 return copyout(&args, data, sizeof(args)); 125 } 126 /* 127 * Get argument 128 */ 129 error = copyin(data, (caddr_t)&args, sizeof(struct overlay_args)); 130 if (error) 131 return (error); 132 133 /* 134 * Update only does export updating. 135 */ 136 if (mp->mnt_flag & MNT_UPDATE) { 137 lmp = MOUNTTOLAYERMOUNT(mp); 138 if (args.ova_target == 0) 139 return (vfs_export(mp, &lmp->layerm_export, 140 &args.la.export)); 141 else 142 return (EOPNOTSUPP); 143 } 144 145 /* 146 * Find lower node 147 */ 148 lowerrootvp = mp->mnt_vnodecovered; 149 if ((error = vget(lowerrootvp, LK_EXCLUSIVE | LK_RETRY))) 150 return (error); 151 152 /* 153 * First cut at fixing up upper mount point 154 */ 155 nmp = (struct overlay_mount *) malloc(sizeof(struct overlay_mount), 156 M_UFSMNT, M_WAITOK); /* XXX */ 157 memset((caddr_t)nmp, 0, sizeof(struct overlay_mount)); 158 159 mp->mnt_data = nmp; 160 nmp->ovm_vfs = lowerrootvp->v_mount; 161 if (nmp->ovm_vfs->mnt_flag & MNT_LOCAL) 162 mp->mnt_flag |= MNT_LOCAL; 163 164 /* 165 * Make sure that the mount point is sufficiently initialized 166 * that the node create call will work. 167 */ 168 vfs_getnewfsid(mp); 169 170 nmp->ovm_size = sizeof (struct overlay_node); 171 nmp->ovm_tag = VT_OVERLAY; 172 nmp->ovm_bypass = layer_bypass; 173 nmp->ovm_alloc = layer_node_alloc; /* the default alloc is fine */ 174 nmp->ovm_vnodeop_p = overlay_vnodeop_p; 175 simple_lock_init(&nmp->ovm_hashlock); 176 nmp->ovm_node_hashtbl = hashinit(NOVERLAYNODECACHE, HASH_LIST, M_CACHE, 177 M_WAITOK, &nmp->ovm_node_hash); 178 179 /* 180 * Fix up overlay node for root vnode 181 */ 182 error = layer_node_create(mp, lowerrootvp, &vp); 183 /* 184 * Make sure the fixup worked 185 */ 186 if (error) { 187 vput(lowerrootvp); 188 free(nmp, M_UFSMNT); /* XXX */ 189 return (error); 190 } 191 /* 192 * Unlock the node 193 */ 194 VOP_UNLOCK(vp, 0); 195 196 /* 197 * Keep a held reference to the root vnode. 198 * It is vrele'd in ov_unmount. 199 */ 200 vp->v_flag |= VROOT; 201 nmp->ovm_rootvp = vp; 202 203 error = set_statfs_info(path, UIO_USERSPACE, args.la.target, 204 UIO_USERSPACE, mp, p); 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 error; 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 SYSCTL_SETUP(sysctl_vfs_overlay_setup, "sysctl vfs.overlay subtree setup") 267 { 268 269 sysctl_createv(SYSCTL_PERMANENT, 270 CTLTYPE_NODE, "vfs", NULL, 271 NULL, 0, NULL, 0, 272 CTL_VFS, CTL_EOL); 273 sysctl_createv(SYSCTL_PERMANENT, 274 CTLTYPE_NODE, "overlay", NULL, 275 NULL, 0, NULL, 0, 276 CTL_VFS, CTL_CREATE, CTL_EOL); 277 } 278 279 extern const struct vnodeopv_desc overlay_vnodeop_opv_desc; 280 281 const struct vnodeopv_desc * const ov_vnodeopv_descs[] = { 282 &overlay_vnodeop_opv_desc, 283 NULL, 284 }; 285 286 struct vfsops overlay_vfsops = { 287 MOUNT_OVERLAY, 288 ov_mount, 289 layerfs_start, 290 ov_unmount, 291 layerfs_root, 292 layerfs_quotactl, 293 layerfs_statfs, 294 layerfs_sync, 295 layerfs_vget, 296 layerfs_fhtovp, 297 layerfs_vptofh, 298 layerfs_init, 299 NULL, 300 layerfs_done, 301 NULL, 302 NULL, /* vfs_mountroot */ 303 layerfs_checkexp, 304 ov_vnodeopv_descs, 305 }; 306
Indexes created Tue Sep 30 06:09:59 GMT 2025