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 1.4 1995/03/16 20:23:38 wollman 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 int fdesc_statfs __P((struct mount *, struct statfs *, struct proc *)); 60 61 /* 62 * Mount the per-process file descriptors (/dev/fd) 63 */ 64 int 65 fdesc_mount(mp, path, data, ndp, p) 66 struct mount *mp; 67 char *path; 68 caddr_t data; 69 struct nameidata *ndp; 70 struct proc *p; 71 { 72 int error = 0; 73 u_int size; 74 struct fdescmount *fmp; 75 struct vnode *rvp; 76 77 /* 78 * Update is a no-op 79 */ 80 if (mp->mnt_flag & MNT_UPDATE) 81 return (EOPNOTSUPP); 82 83 error = fdesc_allocvp(Froot, FD_ROOT, mp, &rvp); 84 if (error) 85 return (error); 86 87 MALLOC(fmp, struct fdescmount *, sizeof(struct fdescmount), 88 M_UFSMNT, M_WAITOK); /* XXX */ 89 rvp->v_type = VDIR; 90 rvp->v_flag |= VROOT; 91 fmp->f_root = rvp; 92 /* XXX -- don't mark as local to work around fts() problems */ 93 /*mp->mnt_flag |= MNT_LOCAL;*/ 94 mp->mnt_data = (qaddr_t) fmp; 95 getnewfsid(mp, MOUNT_FDESC); 96 97 (void) copyinstr(path, mp->mnt_stat.f_mntonname, MNAMELEN - 1, &size); 98 bzero(mp->mnt_stat.f_mntonname + size, MNAMELEN - size); 99 bzero(mp->mnt_stat.f_mntfromname, MNAMELEN); 100 bcopy("fdesc", mp->mnt_stat.f_mntfromname, sizeof("fdesc")); 101 (void)fdesc_statfs(mp, &mp->mnt_stat, p); 102 return (0); 103 } 104 105 int 106 fdesc_start(mp, flags, p) 107 struct mount *mp; 108 int flags; 109 struct proc *p; 110 { 111 return (0); 112 } 113 114 int 115 fdesc_unmount(mp, mntflags, p) 116 struct mount *mp; 117 int mntflags; 118 struct proc *p; 119 { 120 int error; 121 int flags = 0; 122 struct vnode *rootvp = VFSTOFDESC(mp)->f_root; 123 124 if (mntflags & MNT_FORCE) { 125 /* fdesc can never be rootfs so don't check for it */ 126 if (!doforce) 127 return (EINVAL); 128 flags |= FORCECLOSE; 129 } 130 131 /* 132 * Clear out buffer cache. I don't think we 133 * ever get anything cached at this level at the 134 * moment, but who knows... 135 */ 136 if (rootvp->v_usecount > 1) 137 return (EBUSY); 138 if (error = vflush(mp, rootvp, flags)) 139 return (error); 140 141 /* 142 * Release reference on underlying root vnode 143 */ 144 vrele(rootvp); 145 /* 146 * And blow it away for future re-use 147 */ 148 vgone(rootvp); 149 /* 150 * Finally, throw away the fdescmount structure 151 */ 152 free(mp->mnt_data, M_UFSMNT); /* XXX */ 153 mp->mnt_data = 0; 154 155 return (0); 156 } 157 158 int 159 fdesc_root(mp, vpp) 160 struct mount *mp; 161 struct vnode **vpp; 162 { 163 struct vnode *vp; 164 165 /* 166 * Return locked reference to root. 167 */ 168 vp = VFSTOFDESC(mp)->f_root; 169 VREF(vp); 170 VOP_LOCK(vp); 171 *vpp = vp; 172 return (0); 173 } 174 175 int 176 fdesc_quotactl(mp, cmd, uid, arg, p) 177 struct mount *mp; 178 int cmd; 179 uid_t uid; 180 caddr_t arg; 181 struct proc *p; 182 { 183 184 return (EOPNOTSUPP); 185 } 186 187 int 188 fdesc_statfs(mp, sbp, p) 189 struct mount *mp; 190 struct statfs *sbp; 191 struct proc *p; 192 { 193 struct filedesc *fdp; 194 int lim; 195 int i; 196 int last; 197 int freefd; 198 199 /* 200 * Compute number of free file descriptors. 201 * [ Strange results will ensue if the open file 202 * limit is ever reduced below the current number 203 * of open files... ] 204 */ 205 lim = p->p_rlimit[RLIMIT_NOFILE].rlim_cur; 206 fdp = p->p_fd; 207 last = min(fdp->fd_nfiles, lim); 208 freefd = 0; 209 for (i = fdp->fd_freefile; i < last; i++) 210 if (fdp->fd_ofiles[i] == NULL) 211 freefd++; 212 213 /* 214 * Adjust for the fact that the fdesc array may not 215 * have been fully allocated yet. 216 */ 217 if (fdp->fd_nfiles < lim) 218 freefd += (lim - fdp->fd_nfiles); 219 220 sbp->f_type = MOUNT_FDESC; 221 sbp->f_flags = 0; 222 sbp->f_bsize = DEV_BSIZE; 223 sbp->f_iosize = DEV_BSIZE; 224 sbp->f_blocks = 2; /* 1K to keep df happy */ 225 sbp->f_bfree = 0; 226 sbp->f_bavail = 0; 227 sbp->f_files = lim + 1; /* Allow for "." */ 228 sbp->f_ffree = freefd; /* See comments above */ 229 if (sbp != &mp->mnt_stat) { 230 bcopy(&mp->mnt_stat.f_fsid, &sbp->f_fsid, sizeof(sbp->f_fsid)); 231 bcopy(mp->mnt_stat.f_mntonname, sbp->f_mntonname, MNAMELEN); 232 bcopy(mp->mnt_stat.f_mntfromname, sbp->f_mntfromname, MNAMELEN); 233 } 234 return (0); 235 } 236 237 int 238 fdesc_sync(mp, waitfor) 239 struct mount *mp; 240 int waitfor; 241 { 242 243 return (0); 244 } 245 246 /* 247 * Fdesc flat namespace lookup. 248 * Currently unsupported. 249 */ 250 int 251 fdesc_vget(mp, ino, vpp) 252 struct mount *mp; 253 ino_t ino; 254 struct vnode **vpp; 255 { 256 257 return (EOPNOTSUPP); 258 } 259 260 int 261 fdesc_fhtovp(mp, fhp, setgen, vpp) 262 struct mount *mp; 263 struct fid *fhp; 264 int setgen; 265 struct vnode **vpp; 266 { 267 return (EOPNOTSUPP); 268 } 269 270 int 271 fdesc_vptofh(vp, fhp) 272 struct vnode *vp; 273 struct fid *fhp; 274 { 275 276 return (EOPNOTSUPP); 277 } 278 279 struct vfsops fdesc_vfsops = { 280 fdesc_mount, 281 fdesc_start, 282 fdesc_unmount, 283 fdesc_root, 284 fdesc_quotactl, 285 fdesc_statfs, 286 fdesc_sync, 287 fdesc_vget, 288 fdesc_fhtovp, 289 fdesc_vptofh, 290 fdesc_init, 291 }; 292 293 VFS_SET(fdesc_vfsops, fdesc, MOUNT_FDESC, VFCF_SYNTHETIC); 294