1 /* 2 * Copyright (c) 1992, 1993 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 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 2. Redistributions in binary form must reproduce the above copyright 14 * notice, this list of conditions and the following disclaimer in the 15 * documentation and/or other materials provided with the distribution. 16 * 3. All advertising materials mentioning features or use of this software 17 * must display the following acknowledgement: 18 * This product includes software developed by the University of 19 * California, Berkeley and its contributors. 20 * 4. Neither the name of the University nor the names of its contributors 21 * may be used to endorse or promote products derived from this software 22 * without specific prior written permission. 23 * 24 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 25 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 27 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 28 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 29 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 30 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 31 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 32 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 33 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 34 * SUCH DAMAGE. 35 * 36 * @(#)fdesc_vfsops.c 8.4 (Berkeley) 1/21/94 37 * 38 * $Id: fdesc_vfsops.c,v 1.6 1995/11/07 13:39:18 phk Exp $ 39 */ 40 41 /* 42 * /dev/fd Filesystem 43 */ 44 45 #include <sys/param.h> 46 #include <sys/systm.h> 47 #include <sys/kernel.h> 48 #include <sys/time.h> 49 #include <sys/types.h> 50 #include <sys/proc.h> 51 #include <sys/resourcevar.h> 52 #include <sys/filedesc.h> 53 #include <sys/vnode.h> 54 #include <sys/mount.h> 55 #include <sys/namei.h> 56 #include <sys/malloc.h> 57 #include <miscfs/fdesc/fdesc.h> 58 59 static int fdesc_fhtovp __P((struct mount *mp, struct fid *fhp, 60 struct mbuf *nam, struct vnode **vpp, 61 int *exflagsp, struct ucred **credanonp)); 62 static int fdesc_mount __P((struct mount *mp, char *path, caddr_t data, 63 struct nameidata *ndp, struct proc *p)); 64 static int fdesc_quotactl __P((struct mount *mp, int cmd, uid_t uid, 65 caddr_t arg, struct proc *p)); 66 static int fdesc_start __P((struct mount *mp, int flags, struct proc *p)); 67 static int fdesc_unmount __P((struct mount *mp, int mntflags, 68 struct proc *p)); 69 static int fdesc_statfs __P((struct mount *mp, struct statfs *sbp, 70 struct proc *p)); 71 static int fdesc_sync __P((struct mount *mp, int waitfor, 72 struct ucred *cred, struct proc *p)); 73 static int fdesc_vget __P((struct mount *mp, ino_t ino, 74 struct vnode **vpp)); 75 static int fdesc_vptofh __P((struct vnode *vp, struct fid *fhp)); 76 77 /* 78 * Mount the per-process file descriptors (/dev/fd) 79 */ 80 static int 81 fdesc_mount(mp, path, data, ndp, p) 82 struct mount *mp; 83 char *path; 84 caddr_t data; 85 struct nameidata *ndp; 86 struct proc *p; 87 { 88 int error = 0; 89 u_int size; 90 struct fdescmount *fmp; 91 struct vnode *rvp; 92 93 /* 94 * Update is a no-op 95 */ 96 if (mp->mnt_flag & MNT_UPDATE) 97 return (EOPNOTSUPP); 98 99 error = fdesc_allocvp(Froot, FD_ROOT, mp, &rvp); 100 if (error) 101 return (error); 102 103 MALLOC(fmp, struct fdescmount *, sizeof(struct fdescmount), 104 M_UFSMNT, M_WAITOK); /* XXX */ 105 rvp->v_type = VDIR; 106 rvp->v_flag |= VROOT; 107 fmp->f_root = rvp; 108 /* XXX -- don't mark as local to work around fts() problems */ 109 /*mp->mnt_flag |= MNT_LOCAL;*/ 110 mp->mnt_data = (qaddr_t) fmp; 111 getnewfsid(mp, MOUNT_FDESC); 112 113 (void) copyinstr(path, mp->mnt_stat.f_mntonname, MNAMELEN - 1, &size); 114 bzero(mp->mnt_stat.f_mntonname + size, MNAMELEN - size); 115 bzero(mp->mnt_stat.f_mntfromname, MNAMELEN); 116 bcopy("fdesc", mp->mnt_stat.f_mntfromname, sizeof("fdesc")); 117 (void)fdesc_statfs(mp, &mp->mnt_stat, p); 118 return (0); 119 } 120 121 static int 122 fdesc_start(mp, flags, p) 123 struct mount *mp; 124 int flags; 125 struct proc *p; 126 { 127 return (0); 128 } 129 130 static int 131 fdesc_unmount(mp, mntflags, p) 132 struct mount *mp; 133 int mntflags; 134 struct proc *p; 135 { 136 int error; 137 int flags = 0; 138 struct vnode *rootvp = VFSTOFDESC(mp)->f_root; 139 140 if (mntflags & MNT_FORCE) { 141 /* fdesc can never be rootfs so don't check for it */ 142 if (!doforce) 143 return (EINVAL); 144 flags |= FORCECLOSE; 145 } 146 147 /* 148 * Clear out buffer cache. I don't think we 149 * ever get anything cached at this level at the 150 * moment, but who knows... 151 */ 152 if (rootvp->v_usecount > 1) 153 return (EBUSY); 154 if (error = vflush(mp, rootvp, flags)) 155 return (error); 156 157 /* 158 * Release reference on underlying root vnode 159 */ 160 vrele(rootvp); 161 /* 162 * And blow it away for future re-use 163 */ 164 vgone(rootvp); 165 /* 166 * Finally, throw away the fdescmount structure 167 */ 168 free(mp->mnt_data, M_UFSMNT); /* XXX */ 169 mp->mnt_data = 0; 170 171 return (0); 172 } 173 174 int 175 fdesc_root(mp, vpp) 176 struct mount *mp; 177 struct vnode **vpp; 178 { 179 struct vnode *vp; 180 181 /* 182 * Return locked reference to root. 183 */ 184 vp = VFSTOFDESC(mp)->f_root; 185 VREF(vp); 186 VOP_LOCK(vp); 187 *vpp = vp; 188 return (0); 189 } 190 191 static int 192 fdesc_quotactl(mp, cmd, uid, arg, p) 193 struct mount *mp; 194 int cmd; 195 uid_t uid; 196 caddr_t arg; 197 struct proc *p; 198 { 199 200 return (EOPNOTSUPP); 201 } 202 203 static int 204 fdesc_statfs(mp, sbp, p) 205 struct mount *mp; 206 struct statfs *sbp; 207 struct proc *p; 208 { 209 struct filedesc *fdp; 210 int lim; 211 int i; 212 int last; 213 int freefd; 214 215 /* 216 * Compute number of free file descriptors. 217 * [ Strange results will ensue if the open file 218 * limit is ever reduced below the current number 219 * of open files... ] 220 */ 221 lim = p->p_rlimit[RLIMIT_NOFILE].rlim_cur; 222 fdp = p->p_fd; 223 last = min(fdp->fd_nfiles, lim); 224 freefd = 0; 225 for (i = fdp->fd_freefile; i < last; i++) 226 if (fdp->fd_ofiles[i] == NULL) 227 freefd++; 228 229 /* 230 * Adjust for the fact that the fdesc array may not 231 * have been fully allocated yet. 232 */ 233 if (fdp->fd_nfiles < lim) 234 freefd += (lim - fdp->fd_nfiles); 235 236 sbp->f_type = MOUNT_FDESC; 237 sbp->f_flags = 0; 238 sbp->f_bsize = DEV_BSIZE; 239 sbp->f_iosize = DEV_BSIZE; 240 sbp->f_blocks = 2; /* 1K to keep df happy */ 241 sbp->f_bfree = 0; 242 sbp->f_bavail = 0; 243 sbp->f_files = lim + 1; /* Allow for "." */ 244 sbp->f_ffree = freefd; /* See comments above */ 245 if (sbp != &mp->mnt_stat) { 246 bcopy(&mp->mnt_stat.f_fsid, &sbp->f_fsid, sizeof(sbp->f_fsid)); 247 bcopy(mp->mnt_stat.f_mntonname, sbp->f_mntonname, MNAMELEN); 248 bcopy(mp->mnt_stat.f_mntfromname, sbp->f_mntfromname, MNAMELEN); 249 } 250 return (0); 251 } 252 253 static int 254 fdesc_sync(mp, waitfor, cred, p) 255 struct mount *mp; 256 int waitfor; 257 struct ucred *cred; 258 struct proc *p; 259 { 260 261 return (0); 262 } 263 264 /* 265 * Fdesc flat namespace lookup. 266 * Currently unsupported. 267 */ 268 static int 269 fdesc_vget(mp, ino, vpp) 270 struct mount *mp; 271 ino_t ino; 272 struct vnode **vpp; 273 { 274 275 return (EOPNOTSUPP); 276 } 277 278 static int 279 fdesc_fhtovp(mp, fhp, nam, vpp, exflagsp, credanonp) 280 struct mount *mp; 281 struct fid *fhp; 282 struct mbuf *nam; 283 struct vnode **vpp; 284 int *exflagsp; 285 struct ucred **credanonp; 286 { 287 288 return (EOPNOTSUPP); 289 } 290 291 static int 292 fdesc_vptofh(vp, fhp) 293 struct vnode *vp; 294 struct fid *fhp; 295 { 296 297 return (EOPNOTSUPP); 298 } 299 300 static struct vfsops fdesc_vfsops = { 301 fdesc_mount, 302 fdesc_start, 303 fdesc_unmount, 304 fdesc_root, 305 fdesc_quotactl, 306 fdesc_statfs, 307 fdesc_sync, 308 fdesc_vget, 309 fdesc_fhtovp, 310 fdesc_vptofh, 311 fdesc_init, 312 }; 313 314 VFS_SET(fdesc_vfsops, fdesc, MOUNT_FDESC, VFCF_SYNTHETIC); 315