overlay_vfsops.c revision 1.43
1 /* $NetBSD: overlay_vfsops.c,v 1.43 2007/07/31 21:14:16 pooka 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 1.43 2007/07/31 21:14:16 pooka 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 VFS_PROTOS(ov); 92 93 #define NOVERLAYNODECACHE 16 94 95 /* 96 * Mount overlay layer 97 */ 98 int 99 ov_mount(struct mount *mp, const char *path, void *data, size_t *data_len, 100 struct lwp *l) 101 { 102 int error = 0; 103 struct overlay_args *args = data; 104 struct vnode *lowerrootvp, *vp; 105 struct overlay_mount *nmp; 106 struct layer_mount *lmp; 107 108 #ifdef OVERLAYFS_DIAGNOSTIC 109 printf("ov_mount(mp = %p)\n", mp); 110 #endif 111 112 if (*data_len < sizeof *args) 113 return EINVAL; 114 115 if (mp->mnt_flag & MNT_GETARGS) { 116 lmp = MOUNTTOLAYERMOUNT(mp); 117 if (lmp == NULL) 118 return EIO; 119 args->la.target = NULL; 120 *data_len = sizeof *args; 121 return 0; 122 } 123 124 /* 125 * Update is not supported 126 */ 127 if (mp->mnt_flag & MNT_UPDATE) 128 return EOPNOTSUPP; 129 130 /* 131 * Find lower node 132 */ 133 lowerrootvp = mp->mnt_vnodecovered; 134 if ((error = vget(lowerrootvp, LK_EXCLUSIVE | LK_RETRY))) 135 return (error); 136 137 /* 138 * First cut at fixing up upper mount point 139 */ 140 nmp = (struct overlay_mount *) malloc(sizeof(struct overlay_mount), 141 M_UFSMNT, M_WAITOK); /* XXX */ 142 memset(nmp, 0, sizeof(struct overlay_mount)); 143 144 mp->mnt_data = nmp; 145 nmp->ovm_vfs = lowerrootvp->v_mount; 146 if (nmp->ovm_vfs->mnt_flag & MNT_LOCAL) 147 mp->mnt_flag |= MNT_LOCAL; 148 149 /* 150 * Make sure that the mount point is sufficiently initialized 151 * that the node create call will work. 152 */ 153 vfs_getnewfsid(mp); 154 155 nmp->ovm_size = sizeof (struct overlay_node); 156 nmp->ovm_tag = VT_OVERLAY; 157 nmp->ovm_bypass = layer_bypass; 158 nmp->ovm_alloc = layer_node_alloc; /* the default alloc is fine */ 159 nmp->ovm_vnodeop_p = overlay_vnodeop_p; 160 simple_lock_init(&nmp->ovm_hashlock); 161 nmp->ovm_node_hashtbl = hashinit(NOVERLAYNODECACHE, HASH_LIST, M_CACHE, 162 M_WAITOK, &nmp->ovm_node_hash); 163 164 /* 165 * Fix up overlay node for root vnode 166 */ 167 error = layer_node_create(mp, lowerrootvp, &vp); 168 /* 169 * Make sure the fixup worked 170 */ 171 if (error) { 172 vput(lowerrootvp); 173 free(nmp, M_UFSMNT); /* XXX */ 174 return (error); 175 } 176 /* 177 * Unlock the node 178 */ 179 VOP_UNLOCK(vp, 0); 180 181 /* 182 * Keep a held reference to the root vnode. 183 * It is vrele'd in ov_unmount. 184 */ 185 vp->v_flag |= VROOT; 186 nmp->ovm_rootvp = vp; 187 188 error = set_statvfs_info(path, UIO_USERSPACE, args->la.target, 189 UIO_USERSPACE, mp->mnt_op->vfs_name, mp, l); 190 #ifdef OVERLAYFS_DIAGNOSTIC 191 printf("ov_mount: lower %s, alias at %s\n", 192 mp->mnt_stat.f_mntfromname, mp->mnt_stat.f_mntonname); 193 #endif 194 return error; 195 } 196 197 /* 198 * Free reference to overlay layer 199 */ 200 int 201 ov_unmount(struct mount *mp, int mntflags, struct lwp *l) 202 { 203 struct vnode *overlay_rootvp = MOUNTTOOVERLAYMOUNT(mp)->ovm_rootvp; 204 int error; 205 int flags = 0; 206 207 #ifdef OVERLAYFS_DIAGNOSTIC 208 printf("ov_unmount(mp = %p)\n", mp); 209 #endif 210 211 if (mntflags & MNT_FORCE) 212 flags |= FORCECLOSE; 213 214 if (overlay_rootvp->v_usecount > 1 && (mntflags & MNT_FORCE) == 0) 215 return (EBUSY); 216 if ((error = vflush(mp, overlay_rootvp, flags)) != 0) 217 return (error); 218 219 #ifdef OVERLAYFS_DIAGNOSTIC 220 vprint("alias root of lower", overlay_rootvp); 221 #endif 222 /* 223 * Release reference on underlying root vnode 224 */ 225 vrele(overlay_rootvp); 226 /* 227 * And blow it away for future re-use 228 */ 229 vgone(overlay_rootvp); 230 /* 231 * Finally, throw away the overlay_mount structure 232 */ 233 free(mp->mnt_data, M_UFSMNT); /* XXX */ 234 mp->mnt_data = 0; 235 return 0; 236 } 237 238 SYSCTL_SETUP(sysctl_vfs_overlay_setup, "sysctl vfs.overlay subtree setup") 239 { 240 241 sysctl_createv(clog, 0, NULL, NULL, 242 CTLFLAG_PERMANENT, CTLTYPE_NODE, "vfs", NULL, 243 NULL, 0, NULL, 0, 244 CTL_VFS, CTL_EOL); 245 sysctl_createv(clog, 0, NULL, NULL, 246 CTLFLAG_PERMANENT, CTLTYPE_NODE, "overlay", 247 SYSCTL_DESCR("Overlay file system"), 248 NULL, 0, NULL, 0, 249 CTL_VFS, CTL_CREATE, CTL_EOL); 250 } 251 252 extern const struct vnodeopv_desc overlay_vnodeop_opv_desc; 253 254 const struct vnodeopv_desc * const ov_vnodeopv_descs[] = { 255 &overlay_vnodeop_opv_desc, 256 NULL, 257 }; 258 259 struct vfsops overlay_vfsops = { 260 MOUNT_OVERLAY, 261 sizeof (struct overlay_args), 262 ov_mount, 263 layerfs_start, 264 ov_unmount, 265 layerfs_root, 266 layerfs_quotactl, 267 layerfs_statvfs, 268 layerfs_sync, 269 layerfs_vget, 270 layerfs_fhtovp, 271 layerfs_vptofh, 272 layerfs_init, 273 NULL, 274 layerfs_done, 275 NULL, /* vfs_mountroot */ 276 layerfs_snapshot, 277 vfs_stdextattrctl, 278 (void *)eopnotsupp, /* vfs_suspendctl */ 279 ov_vnodeopv_descs, 280 0, 281 { NULL, NULL }, 282 }; 283 VFS_ATTACH(overlay_vfsops); 284
Indexes created Mon Sep 29 21:09:56 GMT 2025