overlay_vfsops.c revision 1.40
1 /* $NetBSD: overlay_vfsops.c,v 1.40 2007/07/12 19:35:35 dsl 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 1.40 2007/07/12 19:35:35 dsl 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 *, size_t *, 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(struct mount *mp, const char *path, void *data, size_t *data_len, 102 struct nameidata *ndp, struct lwp *l) 103 { 104 int error = 0; 105 struct overlay_args *args = data; 106 struct vnode *lowerrootvp, *vp; 107 struct overlay_mount *nmp; 108 struct layer_mount *lmp; 109 110 #ifdef OVERLAYFS_DIAGNOSTIC 111 printf("ov_mount(mp = %p)\n", mp); 112 #endif 113 114 if (*data_len < sizeof *args) 115 return EINVAL; 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 *data_len = sizeof *args; 123 return 0; 124 } 125 126 /* 127 * Update is not supported 128 */ 129 if (mp->mnt_flag & MNT_UPDATE) 130 return EOPNOTSUPP; 131 132 /* 133 * Find lower node 134 */ 135 lowerrootvp = mp->mnt_vnodecovered; 136 if ((error = vget(lowerrootvp, LK_EXCLUSIVE | LK_RETRY))) 137 return (error); 138 139 /* 140 * First cut at fixing up upper mount point 141 */ 142 nmp = (struct overlay_mount *) malloc(sizeof(struct overlay_mount), 143 M_UFSMNT, M_WAITOK); /* XXX */ 144 memset(nmp, 0, sizeof(struct overlay_mount)); 145 146 mp->mnt_data = nmp; 147 nmp->ovm_vfs = lowerrootvp->v_mount; 148 if (nmp->ovm_vfs->mnt_flag & MNT_LOCAL) 149 mp->mnt_flag |= MNT_LOCAL; 150 151 /* 152 * Make sure that the mount point is sufficiently initialized 153 * that the node create call will work. 154 */ 155 vfs_getnewfsid(mp); 156 157 nmp->ovm_size = sizeof (struct overlay_node); 158 nmp->ovm_tag = VT_OVERLAY; 159 nmp->ovm_bypass = layer_bypass; 160 nmp->ovm_alloc = layer_node_alloc; /* the default alloc is fine */ 161 nmp->ovm_vnodeop_p = overlay_vnodeop_p; 162 simple_lock_init(&nmp->ovm_hashlock); 163 nmp->ovm_node_hashtbl = hashinit(NOVERLAYNODECACHE, HASH_LIST, M_CACHE, 164 M_WAITOK, &nmp->ovm_node_hash); 165 166 /* 167 * Fix up overlay node for root vnode 168 */ 169 error = layer_node_create(mp, lowerrootvp, &vp); 170 /* 171 * Make sure the fixup worked 172 */ 173 if (error) { 174 vput(lowerrootvp); 175 free(nmp, M_UFSMNT); /* XXX */ 176 return (error); 177 } 178 /* 179 * Unlock the node 180 */ 181 VOP_UNLOCK(vp, 0); 182 183 /* 184 * Keep a held reference to the root vnode. 185 * It is vrele'd in ov_unmount. 186 */ 187 vp->v_flag |= VROOT; 188 nmp->ovm_rootvp = vp; 189 190 error = set_statvfs_info(path, UIO_USERSPACE, args->la.target, 191 UIO_USERSPACE, mp, l); 192 #ifdef OVERLAYFS_DIAGNOSTIC 193 printf("ov_mount: lower %s, alias at %s\n", 194 mp->mnt_stat.f_mntfromname, mp->mnt_stat.f_mntonname); 195 #endif 196 return error; 197 } 198 199 /* 200 * Free reference to overlay layer 201 */ 202 int 203 ov_unmount(struct mount *mp, int mntflags, struct lwp *l) 204 { 205 struct vnode *overlay_rootvp = MOUNTTOOVERLAYMOUNT(mp)->ovm_rootvp; 206 int error; 207 int flags = 0; 208 209 #ifdef OVERLAYFS_DIAGNOSTIC 210 printf("ov_unmount(mp = %p)\n", mp); 211 #endif 212 213 if (mntflags & MNT_FORCE) 214 flags |= FORCECLOSE; 215 216 if (overlay_rootvp->v_usecount > 1 && (mntflags & MNT_FORCE) == 0) 217 return (EBUSY); 218 if ((error = vflush(mp, overlay_rootvp, flags)) != 0) 219 return (error); 220 221 #ifdef OVERLAYFS_DIAGNOSTIC 222 vprint("alias root of lower", overlay_rootvp); 223 #endif 224 /* 225 * Release reference on underlying root vnode 226 */ 227 vrele(overlay_rootvp); 228 /* 229 * And blow it away for future re-use 230 */ 231 vgone(overlay_rootvp); 232 /* 233 * Finally, throw away the overlay_mount structure 234 */ 235 free(mp->mnt_data, M_UFSMNT); /* XXX */ 236 mp->mnt_data = 0; 237 return 0; 238 } 239 240 SYSCTL_SETUP(sysctl_vfs_overlay_setup, "sysctl vfs.overlay subtree setup") 241 { 242 243 sysctl_createv(clog, 0, NULL, NULL, 244 CTLFLAG_PERMANENT, CTLTYPE_NODE, "vfs", NULL, 245 NULL, 0, NULL, 0, 246 CTL_VFS, CTL_EOL); 247 sysctl_createv(clog, 0, NULL, NULL, 248 CTLFLAG_PERMANENT, CTLTYPE_NODE, "overlay", 249 SYSCTL_DESCR("Overlay file system"), 250 NULL, 0, NULL, 0, 251 CTL_VFS, CTL_CREATE, CTL_EOL); 252 } 253 254 extern const struct vnodeopv_desc overlay_vnodeop_opv_desc; 255 256 const struct vnodeopv_desc * const ov_vnodeopv_descs[] = { 257 &overlay_vnodeop_opv_desc, 258 NULL, 259 }; 260 261 struct vfsops overlay_vfsops = { 262 MOUNT_OVERLAY, 263 sizeof (struct overlay_args), 264 ov_mount, 265 layerfs_start, 266 ov_unmount, 267 layerfs_root, 268 layerfs_quotactl, 269 layerfs_statvfs, 270 layerfs_sync, 271 layerfs_vget, 272 layerfs_fhtovp, 273 layerfs_vptofh, 274 layerfs_init, 275 NULL, 276 layerfs_done, 277 NULL, /* vfs_mountroot */ 278 layerfs_snapshot, 279 vfs_stdextattrctl, 280 vfs_stdsuspendctl, 281 ov_vnodeopv_descs, 282 0, 283 { NULL, NULL }, 284 }; 285 VFS_ATTACH(overlay_vfsops); 286
Indexes created Mon Sep 29 21:09:56 GMT 2025