1 /* 2 * Copyright (c) 1992 The Regents of the University of California 3 * Copyright (c) 1990, 1992 Jan-Simon Pendry 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 1.3 (Berkeley) 07/07/92 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 <lofs/lofs.h> 31 32 /* 33 * Mount null layer 34 */ 35 nullfs_mount(mp, path, data, ndp, p) 36 struct mount *mp; 37 char *path; 38 caddr_t data; 39 struct nameidata *ndp; 40 struct proc *p; 41 { 42 USES_VOP_UNLOCK; 43 int error = 0; 44 struct null_args args; 45 struct vnode *lowerrootvp, *vp; 46 struct vnode *nullm_rootvp; 47 struct null_mount *amp; 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 target 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 target vnode 78 */ 79 lowerrootvp = ndp->ni_vp; 80 #ifdef NULLFS_DIAGNOSTIC 81 printf("vp = %x, check for VDIR...\n", lowerrootvp); 82 #endif 83 vrele(ndp->ni_dvp); 84 ndp->ni_dvp = 0; 85 86 /* 87 * NEEDSWORK: Is this really bad, or just not 88 * the way it's been? 89 */ 90 if (lowerrootvp->v_type != VDIR) { 91 vput(lowerrootvp); 92 return (EINVAL); 93 } 94 95 #ifdef NULLFS_DIAGNOSTIC 96 printf("mp = %x\n", mp); 97 #endif 98 99 amp = (struct null_mount *) malloc(sizeof(struct null_mount), 100 M_UFSMNT, M_WAITOK); /* XXX */ 101 102 /* 103 * Save reference to underlying target FS 104 */ 105 amp->nullm_vfs = lowerrootvp->v_mount; 106 107 /* 108 * Save reference. Each mount also holds 109 * a reference on the root vnode. 110 */ 111 error = make_null_node(mp, lowerrootvp, &vp); 112 /* 113 * Unlock the node (either the target or the alias) 114 */ 115 VOP_UNLOCK(vp); 116 /* 117 * Make sure the node alias worked 118 */ 119 if (error) { 120 vrele(lowerrootvp); 121 free(amp, M_UFSMNT); /* XXX */ 122 return (error); 123 } 124 125 /* 126 * Keep a held reference to the root vnode. 127 * It is vrele'd in nullfs_unmount. 128 */ 129 nullm_rootvp = vp; 130 nullm_rootvp->v_flag |= VROOT; 131 amp->nullm_rootvp = nullm_rootvp; 132 if (NULLTOLOWERVP(nullm_rootvp)->v_mount->mnt_flag & MNT_LOCAL) 133 mp->mnt_flag |= MNT_LOCAL; 134 mp->mnt_data = (qaddr_t) amp; 135 getnewfsid(mp, MOUNT_LOFS); 136 137 (void) copyinstr(path, mp->mnt_stat.f_mntonname, MNAMELEN - 1, &size); 138 bzero(mp->mnt_stat.f_mntonname + size, MNAMELEN - size); 139 (void) copyinstr(args.target, mp->mnt_stat.f_mntfromname, MNAMELEN - 1, 140 &size); 141 bzero(mp->mnt_stat.f_mntfromname + size, MNAMELEN - size); 142 #ifdef NULLFS_DIAGNOSTIC 143 printf("nullfs_mount: target %s, alias at %s\n", 144 mp->mnt_stat.f_mntfromname, mp->mnt_stat.f_mntonname); 145 #endif 146 return (0); 147 } 148 149 /* 150 * VFS start. Nothing needed here - the start routine 151 * on the underlying filesystem will have been called 152 * when that filesystem was mounted. 153 */ 154 nullfs_start(mp, flags, p) 155 struct mount *mp; 156 int flags; 157 struct proc *p; 158 { 159 return (0); 160 /* return VFS_START(MOUNTTONULLMOUNT(mp)->nullm_vfs, flags, p); */ 161 } 162 163 /* 164 * Free reference to null layer 165 */ 166 nullfs_unmount(mp, mntflags, p) 167 struct mount *mp; 168 int mntflags; 169 struct proc *p; 170 { 171 struct vnode *nullm_rootvp = MOUNTTONULLMOUNT(mp)->nullm_rootvp; 172 int error; 173 int flags = 0; 174 extern int doforce; 175 176 #ifdef NULLFS_DIAGNOSTIC 177 printf("nullfs_unmount(mp = %x)\n", mp); 178 #endif 179 180 if (mntflags & MNT_FORCE) { 181 /* lofs can never be rootfs so don't check for it */ 182 if (!doforce) 183 return (EINVAL); 184 flags |= FORCECLOSE; 185 } 186 187 /* 188 * Clear out buffer cache. I don't think we 189 * ever get anything cached at this level at the 190 * moment, but who knows... 191 */ 192 mntflushbuf(mp, 0); 193 if (mntinvalbuf(mp, 1)) 194 return (EBUSY); 195 if (nullm_rootvp->v_usecount > 1) 196 return (EBUSY); 197 if (error = vflush(mp, nullm_rootvp, flags)) 198 return (error); 199 200 #ifdef NULLFS_DIAGNOSTIC 201 /* 202 * Flush any remaining vnode references 203 */ 204 null_node_flushmp (mp); 205 #endif 206 207 #ifdef NULLFS_DIAGNOSTIC 208 vprint("alias root of target", nullm_rootvp); 209 #endif 210 /* 211 * Release reference on underlying root vnode 212 */ 213 vrele(nullm_rootvp); 214 /* 215 * And blow it away for future re-use 216 */ 217 vgone(nullm_rootvp); 218 /* 219 * Finally, throw away the null_mount structure 220 */ 221 free(mp->mnt_data, M_UFSMNT); /* XXX */ 222 mp->mnt_data = 0; 223 return 0; 224 } 225 226 nullfs_root(mp, vpp) 227 struct mount *mp; 228 struct vnode **vpp; 229 { 230 USES_VOP_LOCK; 231 struct vnode *vp; 232 233 #ifdef NULLFS_DIAGNOSTIC 234 printf("nullfs_root(mp = %x, vp = %x->%x)\n", mp, 235 MOUNTTONULLMOUNT(mp)->nullm_rootvp, 236 NULLTOLOWERVP(MOUNTTONULLMOUNT(mp)->nullm_rootvp) 237 ); 238 #endif 239 240 /* 241 * Return locked reference to root. 242 */ 243 vp = MOUNTTONULLMOUNT(mp)->nullm_rootvp; 244 VREF(vp); 245 VOP_LOCK(vp); 246 *vpp = vp; 247 return 0; 248 } 249 250 nullfs_quotactl(mp, cmd, uid, arg, p) 251 struct mount *mp; 252 int cmd; 253 uid_t uid; 254 caddr_t arg; 255 struct proc *p; 256 { 257 return VFS_QUOTACTL(MOUNTTONULLMOUNT(mp)->nullm_vfs, cmd, uid, arg, p); 258 } 259 260 nullfs_statfs(mp, sbp, p) 261 struct mount *mp; 262 struct statfs *sbp; 263 struct proc *p; 264 { 265 int error; 266 struct statfs mstat; 267 268 #ifdef NULLFS_DIAGNOSTIC 269 printf("nullfs_statfs(mp = %x, vp = %x->%x)\n", mp, 270 MOUNTTONULLMOUNT(mp)->nullm_rootvp, 271 NULLTOLOWERVP(MOUNTTONULLMOUNT(mp)->nullm_rootvp) 272 ); 273 #endif 274 275 bzero(&mstat, sizeof(mstat)); 276 277 error = VFS_STATFS(MOUNTTONULLMOUNT(mp)->nullm_vfs, &mstat, p); 278 if (error) 279 return (error); 280 281 /* now copy across the "interesting" information and fake the rest */ 282 sbp->f_type = mstat.f_type; 283 sbp->f_flags = mstat.f_flags; 284 sbp->f_bsize = mstat.f_bsize; 285 sbp->f_iosize = mstat.f_iosize; 286 sbp->f_blocks = mstat.f_blocks; 287 sbp->f_bfree = mstat.f_bfree; 288 sbp->f_bavail = mstat.f_bavail; 289 sbp->f_files = mstat.f_files; 290 sbp->f_ffree = mstat.f_ffree; 291 if (sbp != &mp->mnt_stat) { 292 bcopy(&mp->mnt_stat.f_fsid, &sbp->f_fsid, sizeof(sbp->f_fsid)); 293 bcopy(mp->mnt_stat.f_mntonname, sbp->f_mntonname, MNAMELEN); 294 bcopy(mp->mnt_stat.f_mntfromname, sbp->f_mntfromname, MNAMELEN); 295 } 296 return (0); 297 } 298 299 nullfs_sync(mp, waitfor) 300 struct mount *mp; 301 int waitfor; 302 { 303 /* 304 * NEEDSWORK: Assumes no data cached at null layer. 305 * Is this true? 306 */ 307 return (0); 308 } 309 310 nullfs_fhtovp(mp, fhp, setgen, vpp) 311 struct mount *mp; 312 struct fid *fhp; 313 int setgen; 314 struct vnode **vpp; 315 { 316 return VFS_FHTOVP(MOUNTTONULLMOUNT(mp)->nullm_vfs, fhp, setgen, vpp); 317 } 318 319 nullfs_vptofh(vp, fhp) 320 struct vnode *vp; 321 struct fid *fhp; 322 { 323 return VFS_VPTOFH(NULLTOLOWERVP(vp), fhp); 324 } 325 326 int nullfs_init __P((void)); 327 328 struct vfsops null_vfsops = { 329 nullfs_mount, 330 nullfs_start, 331 nullfs_unmount, 332 nullfs_root, 333 nullfs_quotactl, 334 nullfs_statfs, 335 nullfs_sync, 336 nullfs_fhtovp, 337 nullfs_vptofh, 338 nullfs_init, 339 }; 340