overlay_vfsops.c revision 1.37
1 /* $NetBSD: overlay_vfsops.c,v 1.37 2007/01/19 14:49:11 hannken 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 1.37 2007/01/19 14:49:11 hannken 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(struct mount *mp, const char *path, void *data, 102 struct nameidata *ndp, struct lwp *l) 103 { 104 int error = 0; 105 struct overlay_args args; 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 (mp->mnt_flag & MNT_GETARGS) { 115 lmp = MOUNTTOLAYERMOUNT(mp); 116 if (lmp == NULL) 117 return EIO; 118 args.la.target = NULL; 119 return copyout(&args, data, sizeof(args)); 120 } 121 /* 122 * Get argument 123 */ 124 error = copyin(data, &args, sizeof(struct overlay_args)); 125 if (error) 126 return (error); 127 128 /* 129 * Update is not supported 130 */ 131 if (mp->mnt_flag & MNT_UPDATE) 132 return EOPNOTSUPP; 133 134 /* 135 * Find lower node 136 */ 137 lowerrootvp = mp->mnt_vnodecovered; 138 if ((error = vget(lowerrootvp, LK_EXCLUSIVE | LK_RETRY))) 139 return (error); 140 141 /* 142 * First cut at fixing up upper mount point 143 */ 144 nmp = (struct overlay_mount *) malloc(sizeof(struct overlay_mount), 145 M_UFSMNT, M_WAITOK); /* XXX */ 146 memset(nmp, 0, sizeof(struct overlay_mount)); 147 148 mp->mnt_data = nmp; 149 mp->mnt_leaf = lowerrootvp->v_mount->mnt_leaf; 150 nmp->ovm_vfs = lowerrootvp->v_mount; 151 if (nmp->ovm_vfs->mnt_flag & MNT_LOCAL) 152 mp->mnt_flag |= MNT_LOCAL; 153 154 /* 155 * Make sure that the mount point is sufficiently initialized 156 * that the node create call will work. 157 */ 158 vfs_getnewfsid(mp); 159 160 nmp->ovm_size = sizeof (struct overlay_node); 161 nmp->ovm_tag = VT_OVERLAY; 162 nmp->ovm_bypass = layer_bypass; 163 nmp->ovm_alloc = layer_node_alloc; /* the default alloc is fine */ 164 nmp->ovm_vnodeop_p = overlay_vnodeop_p; 165 simple_lock_init(&nmp->ovm_hashlock); 166 nmp->ovm_node_hashtbl = hashinit(NOVERLAYNODECACHE, HASH_LIST, M_CACHE, 167 M_WAITOK, &nmp->ovm_node_hash); 168 169 /* 170 * Fix up overlay node for root vnode 171 */ 172 error = layer_node_create(mp, lowerrootvp, &vp); 173 /* 174 * Make sure the fixup worked 175 */ 176 if (error) { 177 vput(lowerrootvp); 178 free(nmp, M_UFSMNT); /* XXX */ 179 return (error); 180 } 181 /* 182 * Unlock the node 183 */ 184 VOP_UNLOCK(vp, 0); 185 186 /* 187 * Keep a held reference to the root vnode. 188 * It is vrele'd in ov_unmount. 189 */ 190 vp->v_flag |= VROOT; 191 nmp->ovm_rootvp = vp; 192 193 error = set_statvfs_info(path, UIO_USERSPACE, args.la.target, 194 UIO_USERSPACE, mp, l); 195 #ifdef OVERLAYFS_DIAGNOSTIC 196 printf("ov_mount: lower %s, alias at %s\n", 197 mp->mnt_stat.f_mntfromname, mp->mnt_stat.f_mntonname); 198 #endif 199 return error; 200 } 201 202 /* 203 * Free reference to overlay layer 204 */ 205 int 206 ov_unmount(struct mount *mp, int mntflags, struct lwp *l) 207 { 208 struct vnode *overlay_rootvp = MOUNTTOOVERLAYMOUNT(mp)->ovm_rootvp; 209 int error; 210 int flags = 0; 211 212 #ifdef OVERLAYFS_DIAGNOSTIC 213 printf("ov_unmount(mp = %p)\n", mp); 214 #endif 215 216 if (mntflags & MNT_FORCE) 217 flags |= FORCECLOSE; 218 219 /* 220 * Clear out buffer cache. I don't think we 221 * ever get anything cached at this level at the 222 * moment, but who knows... 223 */ 224 #if 0 225 mntflushbuf(mp, 0); 226 if (mntinvalbuf(mp, 1)) 227 return (EBUSY); 228 #endif 229 if (overlay_rootvp->v_usecount > 1) 230 return (EBUSY); 231 if ((error = vflush(mp, overlay_rootvp, flags)) != 0) 232 return (error); 233 234 #ifdef OVERLAYFS_DIAGNOSTIC 235 vprint("alias root of lower", overlay_rootvp); 236 #endif 237 /* 238 * Release reference on underlying root vnode 239 */ 240 vrele(overlay_rootvp); 241 /* 242 * And blow it away for future re-use 243 */ 244 vgone(overlay_rootvp); 245 /* 246 * Finally, throw away the overlay_mount structure 247 */ 248 free(mp->mnt_data, M_UFSMNT); /* XXX */ 249 mp->mnt_data = 0; 250 return 0; 251 } 252 253 SYSCTL_SETUP(sysctl_vfs_overlay_setup, "sysctl vfs.overlay subtree setup") 254 { 255 256 sysctl_createv(clog, 0, NULL, NULL, 257 CTLFLAG_PERMANENT, CTLTYPE_NODE, "vfs", NULL, 258 NULL, 0, NULL, 0, 259 CTL_VFS, CTL_EOL); 260 sysctl_createv(clog, 0, NULL, NULL, 261 CTLFLAG_PERMANENT, CTLTYPE_NODE, "overlay", 262 SYSCTL_DESCR("Overlay file system"), 263 NULL, 0, NULL, 0, 264 CTL_VFS, CTL_CREATE, CTL_EOL); 265 } 266 267 extern const struct vnodeopv_desc overlay_vnodeop_opv_desc; 268 269 const struct vnodeopv_desc * const ov_vnodeopv_descs[] = { 270 &overlay_vnodeop_opv_desc, 271 NULL, 272 }; 273 274 struct vfsops overlay_vfsops = { 275 MOUNT_OVERLAY, 276 ov_mount, 277 layerfs_start, 278 ov_unmount, 279 layerfs_root, 280 layerfs_quotactl, 281 layerfs_statvfs, 282 layerfs_sync, 283 layerfs_vget, 284 layerfs_fhtovp, 285 layerfs_vptofh, 286 layerfs_init, 287 NULL, 288 layerfs_done, 289 NULL, /* vfs_mountroot */ 290 layerfs_snapshot, 291 vfs_stdextattrctl, 292 vfs_stdsuspendctl, 293 ov_vnodeopv_descs, 294 0, 295 { NULL, NULL }, 296 }; 297 VFS_ATTACH(overlay_vfsops); 298
Indexes created Tue Sep 30 06:09:59 GMT 2025