overlay_vfsops.c revision 1.34
1 /* $NetBSD: overlay_vfsops.c,v 1.34 2006/09/03 21:01:12 christos 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 1.34 2006/09/03 21:01:12 christos 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(struct mount *, const char *, void *, 92 struct nameidata *, struct lwp *); 93 int ov_unmount(struct mount *, int, struct lwp *); 94 95 #define NOVERLAYNODECACHE 16 96 97 /* 98 * Mount overlay layer 99 */ 100 int 101 ov_mount(mp, path, data, ndp, l) 102 struct mount *mp; 103 const char *path; 104 void *data; 105 struct nameidata *ndp; 106 struct lwp *l; 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 return copyout(&args, data, sizeof(args)); 124 } 125 /* 126 * Get argument 127 */ 128 error = copyin(data, &args, sizeof(struct overlay_args)); 129 if (error) 130 return (error); 131 132 /* 133 * Update is not supported 134 */ 135 if (mp->mnt_flag & MNT_UPDATE) 136 return EOPNOTSUPP; 137 138 /* 139 * Find lower node 140 */ 141 lowerrootvp = mp->mnt_vnodecovered; 142 if ((error = vget(lowerrootvp, LK_EXCLUSIVE | LK_RETRY))) 143 return (error); 144 145 /* 146 * First cut at fixing up upper mount point 147 */ 148 nmp = (struct overlay_mount *) malloc(sizeof(struct overlay_mount), 149 M_UFSMNT, M_WAITOK); /* XXX */ 150 memset(nmp, 0, sizeof(struct overlay_mount)); 151 152 mp->mnt_data = nmp; 153 mp->mnt_leaf = lowerrootvp->v_mount->mnt_leaf; 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 error = set_statvfs_info(path, UIO_USERSPACE, args.la.target, 198 UIO_USERSPACE, mp, l); 199 #ifdef OVERLAYFS_DIAGNOSTIC 200 printf("ov_mount: lower %s, alias at %s\n", 201 mp->mnt_stat.f_mntfromname, mp->mnt_stat.f_mntonname); 202 #endif 203 return error; 204 } 205 206 /* 207 * Free reference to overlay layer 208 */ 209 int 210 ov_unmount(mp, mntflags, l) 211 struct mount *mp; 212 int mntflags; 213 struct lwp *l; 214 { 215 struct vnode *overlay_rootvp = MOUNTTOOVERLAYMOUNT(mp)->ovm_rootvp; 216 int error; 217 int flags = 0; 218 219 #ifdef OVERLAYFS_DIAGNOSTIC 220 printf("ov_unmount(mp = %p)\n", mp); 221 #endif 222 223 if (mntflags & MNT_FORCE) 224 flags |= FORCECLOSE; 225 226 /* 227 * Clear out buffer cache. I don't think we 228 * ever get anything cached at this level at the 229 * moment, but who knows... 230 */ 231 #if 0 232 mntflushbuf(mp, 0); 233 if (mntinvalbuf(mp, 1)) 234 return (EBUSY); 235 #endif 236 if (overlay_rootvp->v_usecount > 1) 237 return (EBUSY); 238 if ((error = vflush(mp, overlay_rootvp, flags)) != 0) 239 return (error); 240 241 #ifdef OVERLAYFS_DIAGNOSTIC 242 vprint("alias root of lower", overlay_rootvp); 243 #endif 244 /* 245 * Release reference on underlying root vnode 246 */ 247 vrele(overlay_rootvp); 248 /* 249 * And blow it away for future re-use 250 */ 251 vgone(overlay_rootvp); 252 /* 253 * Finally, throw away the overlay_mount structure 254 */ 255 free(mp->mnt_data, M_UFSMNT); /* XXX */ 256 mp->mnt_data = 0; 257 return 0; 258 } 259 260 SYSCTL_SETUP(sysctl_vfs_overlay_setup, "sysctl vfs.overlay subtree setup") 261 { 262 263 sysctl_createv(clog, 0, NULL, NULL, 264 CTLFLAG_PERMANENT, CTLTYPE_NODE, "vfs", NULL, 265 NULL, 0, NULL, 0, 266 CTL_VFS, CTL_EOL); 267 sysctl_createv(clog, 0, NULL, NULL, 268 CTLFLAG_PERMANENT, CTLTYPE_NODE, "overlay", 269 SYSCTL_DESCR("Overlay file system"), 270 NULL, 0, NULL, 0, 271 CTL_VFS, CTL_CREATE, CTL_EOL); 272 } 273 274 extern const struct vnodeopv_desc overlay_vnodeop_opv_desc; 275 276 const struct vnodeopv_desc * const ov_vnodeopv_descs[] = { 277 &overlay_vnodeop_opv_desc, 278 NULL, 279 }; 280 281 struct vfsops overlay_vfsops = { 282 MOUNT_OVERLAY, 283 ov_mount, 284 layerfs_start, 285 ov_unmount, 286 layerfs_root, 287 layerfs_quotactl, 288 layerfs_statvfs, 289 layerfs_sync, 290 layerfs_vget, 291 layerfs_fhtovp, 292 layerfs_vptofh, 293 layerfs_init, 294 NULL, 295 layerfs_done, 296 NULL, /* vfs_mountroot */ 297 layerfs_snapshot, 298 vfs_stdextattrctl, 299 ov_vnodeopv_descs, 300 0, 301 { NULL, NULL }, 302 }; 303 VFS_ATTACH(overlay_vfsops); 304
Indexes created Tue Sep 30 11:09:46 GMT 2025