1 /* 2 * Copyright (c) 1992, 1993 3 * The Regents of the University of California. All rights reserved. 4 * All rights reserved. 5 * 6 * This code is derived from software donated to Berkeley by 7 * Jan-Simon Pendry. 8 * 9 * %sccs.include.redist.c% 10 * 11 * @(#)null_vfsops.c 8.1 (Berkeley) 06/10/93 12 * 13 * @(#)lofs_vfsops.c 1.2 (Berkeley) 6/18/92 14 * $Id: lofs_vfsops.c,v 1.9 1992/05/30 10:26:24 jsp Exp jsp $ 15 */ 16 17 /* 18 * Null Layer 19 * (See null_vnops.c for a description of what this does.) 20 */ 21 22 #include <sys/param.h> 23 #include <sys/systm.h> 24 #include <sys/time.h> 25 #include <sys/types.h> 26 #include <sys/vnode.h> 27 #include <sys/mount.h> 28 #include <sys/namei.h> 29 #include <sys/malloc.h> 30 #include <miscfs/nullfs/null.h> 31 32 /* 33 * Mount null layer 34 */ 35 int 36 nullfs_mount(mp, path, data, ndp, p) 37 struct mount *mp; 38 char *path; 39 caddr_t data; 40 struct nameidata *ndp; 41 struct proc *p; 42 { 43 int error = 0; 44 struct null_args args; 45 struct vnode *lowerrootvp, *vp; 46 struct vnode *nullm_rootvp; 47 struct null_mount *xmp; 48 u_int size; 49 50 #ifdef NULLFS_DIAGNOSTIC 51 printf("nullfs_mount(mp = %x)\n", mp); 52 #endif 53 54 /* 55 * Update is a no-op 56 */ 57 if (mp->mnt_flag & MNT_UPDATE) { 58 return (EOPNOTSUPP); 59 /* return VFS_MOUNT(MOUNTTONULLMOUNT(mp)->nullm_vfs, path, data, ndp, p);*/ 60 } 61 62 /* 63 * Get argument 64 */ 65 if (error = copyin(data, (caddr_t)&args, sizeof(struct null_args))) 66 return (error); 67 68 /* 69 * Find lower node 70 */ 71 NDINIT(ndp, LOOKUP, FOLLOW|WANTPARENT|LOCKLEAF, 72 UIO_USERSPACE, args.target, p); 73 if (error = namei(ndp)) 74 return (error); 75 76 /* 77 * Sanity check on lower vnode 78 */ 79 lowerrootvp = ndp->ni_vp; 80 81 vrele(ndp->ni_dvp); 82 ndp->ni_dvp = NULL; 83 84 xmp = (struct null_mount *) malloc(sizeof(struct null_mount), 85 M_UFSMNT, M_WAITOK); /* XXX */ 86 87 /* 88 * Save reference to underlying FS 89 */ 90 xmp->nullm_vfs = lowerrootvp->v_mount; 91 92 /* 93 * Save reference. Each mount also holds 94 * a reference on the root vnode. 95 */ 96 error = null_node_create(mp, lowerrootvp, &vp); 97 /* 98 * Unlock the node (either the lower or the alias) 99 */ 100 VOP_UNLOCK(vp); 101 /* 102 * Make sure the node alias worked 103 */ 104 if (error) { 105 vrele(lowerrootvp); 106 free(xmp, M_UFSMNT); /* XXX */ 107 return (error); 108 } 109 110 /* 111 * Keep a held reference to the root vnode. 112 * It is vrele'd in nullfs_unmount. 113 */ 114 nullm_rootvp = vp; 115 nullm_rootvp->v_flag |= VROOT; 116 xmp->nullm_rootvp = nullm_rootvp; 117 if (NULLVPTOLOWERVP(nullm_rootvp)->v_mount->mnt_flag & MNT_LOCAL) 118 mp->mnt_flag |= MNT_LOCAL; 119 mp->mnt_data = (qaddr_t) xmp; 120 getnewfsid(mp, MOUNT_LOFS); 121 122 (void) copyinstr(path, mp->mnt_stat.f_mntonname, MNAMELEN - 1, &size); 123 bzero(mp->mnt_stat.f_mntonname + size, MNAMELEN - size); 124 (void) copyinstr(args.target, mp->mnt_stat.f_mntfromname, MNAMELEN - 1, 125 &size); 126 bzero(mp->mnt_stat.f_mntfromname + size, MNAMELEN - size); 127 #ifdef NULLFS_DIAGNOSTIC 128 printf("nullfs_mount: lower %s, alias at %s\n", 129 mp->mnt_stat.f_mntfromname, mp->mnt_stat.f_mntonname); 130 #endif 131 return (0); 132 } 133 134 /* 135 * VFS start. Nothing needed here - the start routine 136 * on the underlying filesystem will have been called 137 * when that filesystem was mounted. 138 */ 139 int 140 nullfs_start(mp, flags, p) 141 struct mount *mp; 142 int flags; 143 struct proc *p; 144 { 145 return (0); 146 /* return VFS_START(MOUNTTONULLMOUNT(mp)->nullm_vfs, flags, p); */ 147 } 148 149 /* 150 * Free reference to null layer 151 */ 152 int 153 nullfs_unmount(mp, mntflags, p) 154 struct mount *mp; 155 int mntflags; 156 struct proc *p; 157 { 158 struct vnode *nullm_rootvp = MOUNTTONULLMOUNT(mp)->nullm_rootvp; 159 int error; 160 int flags = 0; 161 extern int doforce; 162 163 #ifdef NULLFS_DIAGNOSTIC 164 printf("nullfs_unmount(mp = %x)\n", mp); 165 #endif 166 167 if (mntflags & MNT_FORCE) { 168 /* lofs can never be rootfs so don't check for it */ 169 if (!doforce) 170 return (EINVAL); 171 flags |= FORCECLOSE; 172 } 173 174 /* 175 * Clear out buffer cache. I don't think we 176 * ever get anything cached at this level at the 177 * moment, but who knows... 178 */ 179 #if 0 180 mntflushbuf(mp, 0); 181 if (mntinvalbuf(mp, 1)) 182 return (EBUSY); 183 #endif 184 if (nullm_rootvp->v_usecount > 1) 185 return (EBUSY); 186 if (error = vflush(mp, nullm_rootvp, flags)) 187 return (error); 188 189 #ifdef NULLFS_DIAGNOSTIC 190 vprint("alias root of lower", nullm_rootvp); 191 #endif 192 /* 193 * Release reference on underlying root vnode 194 */ 195 vrele(nullm_rootvp); 196 /* 197 * And blow it away for future re-use 198 */ 199 vgone(nullm_rootvp); 200 /* 201 * Finally, throw away the null_mount structure 202 */ 203 free(mp->mnt_data, M_UFSMNT); /* XXX */ 204 mp->mnt_data = 0; 205 return 0; 206 } 207 208 int 209 nullfs_root(mp, vpp) 210 struct mount *mp; 211 struct vnode **vpp; 212 { 213 struct vnode *vp; 214 215 #ifdef NULLFS_DIAGNOSTIC 216 printf("nullfs_root(mp = %x, vp = %x->%x)\n", mp, 217 MOUNTTONULLMOUNT(mp)->nullm_rootvp, 218 NULLVPTOLOWERVP(MOUNTTONULLMOUNT(mp)->nullm_rootvp) 219 ); 220 #endif 221 222 /* 223 * Return locked reference to root. 224 */ 225 vp = MOUNTTONULLMOUNT(mp)->nullm_rootvp; 226 VREF(vp); 227 VOP_LOCK(vp); 228 *vpp = vp; 229 return 0; 230 } 231 232 int 233 nullfs_quotactl(mp, cmd, uid, arg, p) 234 struct mount *mp; 235 int cmd; 236 uid_t uid; 237 caddr_t arg; 238 struct proc *p; 239 { 240 return VFS_QUOTACTL(MOUNTTONULLMOUNT(mp)->nullm_vfs, cmd, uid, arg, p); 241 } 242 243 int 244 nullfs_statfs(mp, sbp, p) 245 struct mount *mp; 246 struct statfs *sbp; 247 struct proc *p; 248 { 249 int error; 250 struct statfs mstat; 251 252 #ifdef NULLFS_DIAGNOSTIC 253 printf("nullfs_statfs(mp = %x, vp = %x->%x)\n", mp, 254 MOUNTTONULLMOUNT(mp)->nullm_rootvp, 255 NULLVPTOLOWERVP(MOUNTTONULLMOUNT(mp)->nullm_rootvp) 256 ); 257 #endif 258 259 bzero(&mstat, sizeof(mstat)); 260 261 error = VFS_STATFS(MOUNTTONULLMOUNT(mp)->nullm_vfs, &mstat, p); 262 if (error) 263 return (error); 264 265 /* now copy across the "interesting" information and fake the rest */ 266 sbp->f_type = mstat.f_type; 267 sbp->f_flags = mstat.f_flags; 268 sbp->f_bsize = mstat.f_bsize; 269 sbp->f_iosize = mstat.f_iosize; 270 sbp->f_blocks = mstat.f_blocks; 271 sbp->f_bfree = mstat.f_bfree; 272 sbp->f_bavail = mstat.f_bavail; 273 sbp->f_files = mstat.f_files; 274 sbp->f_ffree = mstat.f_ffree; 275 if (sbp != &mp->mnt_stat) { 276 bcopy(&mp->mnt_stat.f_fsid, &sbp->f_fsid, sizeof(sbp->f_fsid)); 277 bcopy(mp->mnt_stat.f_mntonname, sbp->f_mntonname, MNAMELEN); 278 bcopy(mp->mnt_stat.f_mntfromname, sbp->f_mntfromname, MNAMELEN); 279 } 280 return (0); 281 } 282 283 int 284 nullfs_sync(mp, waitfor, cred, p) 285 struct mount *mp; 286 int waitfor; 287 struct ucred *cred; 288 struct proc *p; 289 { 290 /* 291 * XXX - Assumes no data cached at null layer. 292 */ 293 return (0); 294 } 295 296 int 297 nullfs_vget(mp, ino, vpp) 298 struct mount *mp; 299 ino_t ino; 300 struct vnode **vpp; 301 { 302 303 return VFS_VGET(MOUNTTONULLMOUNT(mp)->nullm_vfs, ino, vpp); 304 } 305 306 int 307 nullfs_fhtovp(mp, fidp, nam, vpp, exflagsp, credanonp) 308 struct mount *mp; 309 struct fid *fidp; 310 struct mbuf *nam; 311 struct vnode **vpp; 312 int *exflagsp; 313 struct ucred**credanonp; 314 { 315 316 return VFS_FHTOVP(MOUNTTONULLMOUNT(mp)->nullm_vfs, fidp, nam, vpp, exflagsp,credanonp); 317 } 318 319 int 320 nullfs_vptofh(vp, fhp) 321 struct vnode *vp; 322 struct fid *fhp; 323 { 324 return VFS_VPTOFH(NULLVPTOLOWERVP(vp), fhp); 325 } 326 327 int nullfs_init __P((void)); 328 329 struct vfsops null_vfsops = { 330 nullfs_mount, 331 nullfs_start, 332 nullfs_unmount, 333 nullfs_root, 334 nullfs_quotactl, 335 nullfs_statfs, 336 nullfs_sync, 337 nullfs_vget, 338 nullfs_fhtovp, 339 nullfs_vptofh, 340 nullfs_init, 341 }; 342