1 /* 2 * Copyright (c) 1992, 1993, 1995 3 * The Regents of the University of California. All rights reserved. 4 * 5 * This code is derived from software donated to Berkeley by 6 * Jan-Simon Pendry. 7 * 8 * %sccs.include.redist.c% 9 * 10 * @(#)null_vfsops.c 8.7 (Berkeley) 05/14/95 11 * 12 * @(#)lofs_vfsops.c 1.2 (Berkeley) 6/18/92 13 * $Id: lofs_vfsops.c,v 1.9 1992/05/30 10:26:24 jsp Exp jsp $ 14 */ 15 16 /* 17 * Null Layer 18 * (See null_vnops.c for a description of what this does.) 19 */ 20 21 #include <sys/param.h> 22 #include <sys/systm.h> 23 #include <sys/proc.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, 0, p); 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 vfs_getnewfsid(mp); 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; 161 162 #ifdef NULLFS_DIAGNOSTIC 163 printf("nullfs_unmount(mp = %x)\n", mp); 164 #endif 165 166 if (mntflags & MNT_FORCE) 167 flags |= FORCECLOSE; 168 169 /* 170 * Clear out buffer cache. I don't think we 171 * ever get anything cached at this level at the 172 * moment, but who knows... 173 */ 174 #if 0 175 mntflushbuf(mp, 0); 176 if (mntinvalbuf(mp, 1)) 177 return (EBUSY); 178 #endif 179 if (nullm_rootvp->v_usecount > 1) 180 return (EBUSY); 181 if (error = vflush(mp, nullm_rootvp, flags)) 182 return (error); 183 184 #ifdef NULLFS_DIAGNOSTIC 185 vprint("alias root of lower", nullm_rootvp); 186 #endif 187 /* 188 * Release reference on underlying root vnode 189 */ 190 vrele(nullm_rootvp); 191 /* 192 * And blow it away for future re-use 193 */ 194 vgone(nullm_rootvp); 195 /* 196 * Finally, throw away the null_mount structure 197 */ 198 free(mp->mnt_data, M_UFSMNT); /* XXX */ 199 mp->mnt_data = 0; 200 return 0; 201 } 202 203 int 204 nullfs_root(mp, vpp) 205 struct mount *mp; 206 struct vnode **vpp; 207 { 208 struct proc *p = curproc; /* XXX */ 209 struct vnode *vp; 210 211 #ifdef NULLFS_DIAGNOSTIC 212 printf("nullfs_root(mp = %x, vp = %x->%x)\n", mp, 213 MOUNTTONULLMOUNT(mp)->nullm_rootvp, 214 NULLVPTOLOWERVP(MOUNTTONULLMOUNT(mp)->nullm_rootvp) 215 ); 216 #endif 217 218 /* 219 * Return locked reference to root. 220 */ 221 vp = MOUNTTONULLMOUNT(mp)->nullm_rootvp; 222 VREF(vp); 223 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, p); 224 *vpp = vp; 225 return 0; 226 } 227 228 int 229 nullfs_quotactl(mp, cmd, uid, arg, p) 230 struct mount *mp; 231 int cmd; 232 uid_t uid; 233 caddr_t arg; 234 struct proc *p; 235 { 236 return VFS_QUOTACTL(MOUNTTONULLMOUNT(mp)->nullm_vfs, cmd, uid, arg, p); 237 } 238 239 int 240 nullfs_statfs(mp, sbp, p) 241 struct mount *mp; 242 struct statfs *sbp; 243 struct proc *p; 244 { 245 int error; 246 struct statfs mstat; 247 248 #ifdef NULLFS_DIAGNOSTIC 249 printf("nullfs_statfs(mp = %x, vp = %x->%x)\n", mp, 250 MOUNTTONULLMOUNT(mp)->nullm_rootvp, 251 NULLVPTOLOWERVP(MOUNTTONULLMOUNT(mp)->nullm_rootvp) 252 ); 253 #endif 254 255 bzero(&mstat, sizeof(mstat)); 256 257 error = VFS_STATFS(MOUNTTONULLMOUNT(mp)->nullm_vfs, &mstat, p); 258 if (error) 259 return (error); 260 261 /* now copy across the "interesting" information and fake the rest */ 262 sbp->f_type = mstat.f_type; 263 sbp->f_flags = mstat.f_flags; 264 sbp->f_bsize = mstat.f_bsize; 265 sbp->f_iosize = mstat.f_iosize; 266 sbp->f_blocks = mstat.f_blocks; 267 sbp->f_bfree = mstat.f_bfree; 268 sbp->f_bavail = mstat.f_bavail; 269 sbp->f_files = mstat.f_files; 270 sbp->f_ffree = mstat.f_ffree; 271 if (sbp != &mp->mnt_stat) { 272 bcopy(&mp->mnt_stat.f_fsid, &sbp->f_fsid, sizeof(sbp->f_fsid)); 273 bcopy(mp->mnt_stat.f_mntonname, sbp->f_mntonname, MNAMELEN); 274 bcopy(mp->mnt_stat.f_mntfromname, sbp->f_mntfromname, MNAMELEN); 275 } 276 return (0); 277 } 278 279 int 280 nullfs_sync(mp, waitfor, cred, p) 281 struct mount *mp; 282 int waitfor; 283 struct ucred *cred; 284 struct proc *p; 285 { 286 /* 287 * XXX - Assumes no data cached at null layer. 288 */ 289 return (0); 290 } 291 292 int 293 nullfs_vget(mp, ino, vpp) 294 struct mount *mp; 295 ino_t ino; 296 struct vnode **vpp; 297 { 298 299 return VFS_VGET(MOUNTTONULLMOUNT(mp)->nullm_vfs, ino, vpp); 300 } 301 302 int 303 nullfs_fhtovp(mp, fidp, nam, vpp, exflagsp, credanonp) 304 struct mount *mp; 305 struct fid *fidp; 306 struct mbuf *nam; 307 struct vnode **vpp; 308 int *exflagsp; 309 struct ucred**credanonp; 310 { 311 312 return VFS_FHTOVP(MOUNTTONULLMOUNT(mp)->nullm_vfs, fidp, nam, vpp, exflagsp,credanonp); 313 } 314 315 int 316 nullfs_vptofh(vp, fhp) 317 struct vnode *vp; 318 struct fid *fhp; 319 { 320 return VFS_VPTOFH(NULLVPTOLOWERVP(vp), fhp); 321 } 322 323 int nullfs_init __P((struct vfsconf *)); 324 325 #define nullfs_sysctl ((int (*) __P((int *, u_int, void *, size_t *, void *, \ 326 size_t, struct proc *)))eopnotsupp) 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_vget, 337 nullfs_fhtovp, 338 nullfs_vptofh, 339 nullfs_init, 340 nullfs_sysctl, 341 }; 342