fdesc_vfsops.c revision 38909
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 * 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 1.15 1998/05/06 05:29:33 msmith 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/proc.h> 49#include <sys/resourcevar.h> 50#include <sys/filedesc.h> 51#include <sys/vnode.h> 52#include <sys/mount.h> 53#include <sys/malloc.h> 54#include <miscfs/fdesc/fdesc.h> 55 56static MALLOC_DEFINE(M_FDESCMNT, "FDESC mount", "FDESC mount structure"); 57 58static int fdesc_fhtovp __P((struct mount *mp, struct fid *fhp, 59 struct mbuf *nam, struct vnode **vpp, 60 int *exflagsp, struct ucred **credanonp)); 61static int fdesc_mount __P((struct mount *mp, char *path, caddr_t data, 62 struct nameidata *ndp, struct proc *p)); 63static int fdesc_quotactl __P((struct mount *mp, int cmd, uid_t uid, 64 caddr_t arg, struct proc *p)); 65static int fdesc_start __P((struct mount *mp, int flags, struct proc *p)); 66static int fdesc_unmount __P((struct mount *mp, int mntflags, 67 struct proc *p)); 68static int fdesc_statfs __P((struct mount *mp, struct statfs *sbp, 69 struct proc *p)); 70static int fdesc_sync __P((struct mount *mp, int waitfor, 71 struct ucred *cred, struct proc *p)); 72static int fdesc_vget __P((struct mount *mp, ino_t ino, 73 struct vnode **vpp)); 74static int fdesc_vptofh __P((struct vnode *vp, struct fid *fhp)); 75 76/* 77 * Mount the per-process file descriptors (/dev/fd) 78 */ 79static int 80fdesc_mount(mp, path, data, ndp, p) 81 struct mount *mp; 82 char *path; 83 caddr_t data; 84 struct nameidata *ndp; 85 struct proc *p; 86{ 87 int error = 0; 88 u_int size; 89 struct fdescmount *fmp; 90 struct vnode *rvp; 91 92 /* 93 * Update is a no-op 94 */ 95 if (mp->mnt_flag & MNT_UPDATE) 96 return (EOPNOTSUPP); 97 98 error = fdesc_allocvp(Froot, FD_ROOT, mp, &rvp); 99 if (error) 100 return (error); 101 102 MALLOC(fmp, struct fdescmount *, sizeof(struct fdescmount), 103 M_FDESCMNT, M_WAITOK); /* XXX */ 104 rvp->v_type = VDIR; 105 rvp->v_flag |= VROOT; 106 fmp->f_root = rvp; 107 /* XXX -- don't mark as local to work around fts() problems */ 108 /*mp->mnt_flag |= MNT_LOCAL;*/ 109 mp->mnt_data = (qaddr_t) fmp; 110 vfs_getnewfsid(mp); 111 112 (void) copyinstr(path, mp->mnt_stat.f_mntonname, MNAMELEN - 1, &size); 113 bzero(mp->mnt_stat.f_mntonname + size, MNAMELEN - size); 114 bzero(mp->mnt_stat.f_mntfromname, MNAMELEN); 115 bcopy("fdesc", mp->mnt_stat.f_mntfromname, sizeof("fdesc")); 116 (void)fdesc_statfs(mp, &mp->mnt_stat, p); 117 return (0); 118} 119 120static int 121fdesc_start(mp, flags, p) 122 struct mount *mp; 123 int flags; 124 struct proc *p; 125{ 126 return (0); 127} 128 129static int 130fdesc_unmount(mp, mntflags, p) 131 struct mount *mp; 132 int mntflags; 133 struct proc *p; 134{ 135 int error; 136 int flags = 0; 137 struct vnode *rootvp = VFSTOFDESC(mp)->f_root; 138 139 if (mntflags & MNT_FORCE) 140 flags |= FORCECLOSE; 141 142 /* 143 * Clear out buffer cache. I don't think we 144 * ever get anything cached at this level at the 145 * moment, but who knows... 146 */ 147 if (rootvp->v_usecount > 1) 148 return (EBUSY); 149 if (error = vflush(mp, rootvp, flags)) 150 return (error); 151 152 /* 153 * Release reference on underlying root vnode 154 */ 155 vrele(rootvp); 156 /* 157 * And blow it away for future re-use 158 */ 159 vgone(rootvp); 160 /* 161 * Finally, throw away the fdescmount structure 162 */ 163 free(mp->mnt_data, M_FDESCMNT); /* XXX */ 164 mp->mnt_data = 0; 165 166 return (0); 167} 168 169int 170fdesc_root(mp, vpp) 171 struct mount *mp; 172 struct vnode **vpp; 173{ 174 struct proc *p = curproc; /* XXX */ 175 struct vnode *vp; 176 177 /* 178 * Return locked reference to root. 179 */ 180 vp = VFSTOFDESC(mp)->f_root; 181 VREF(vp); 182 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, p); 183 *vpp = vp; 184 return (0); 185} 186 187static int 188fdesc_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_flags = 0; 221 sbp->f_bsize = DEV_BSIZE; 222 sbp->f_iosize = DEV_BSIZE; 223 sbp->f_blocks = 2; /* 1K to keep df happy */ 224 sbp->f_bfree = 0; 225 sbp->f_bavail = 0; 226 sbp->f_files = lim + 1; /* Allow for "." */ 227 sbp->f_ffree = freefd; /* See comments above */ 228 if (sbp != &mp->mnt_stat) { 229 sbp->f_type = mp->mnt_vfc->vfc_typenum; 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 237static int 238fdesc_sync(mp, waitfor, cred, p) 239 struct mount *mp; 240 int waitfor; 241 struct ucred *cred; 242 struct proc *p; 243{ 244 245 return (0); 246} 247 248#define fdesc_fhtovp ((int (*) __P((struct mount *, struct fid *, \ 249 struct sockaddr *, struct vnode **, int *, struct ucred **)))eopnotsupp) 250#define fdesc_quotactl ((int (*) __P((struct mount *, int, uid_t, caddr_t, \ 251 struct proc *)))eopnotsupp) 252#define fdesc_sysctl ((int (*) __P((int *, u_int, void *, size_t *, void *, \ 253 size_t, struct proc *)))eopnotsupp) 254#define fdesc_vget ((int (*) __P((struct mount *, ino_t, struct vnode **))) \ 255 eopnotsupp) 256#define fdesc_vptofh ((int (*) __P((struct vnode *, struct fid *)))eopnotsupp) 257 258static struct vfsops fdesc_vfsops = { 259 fdesc_mount, 260 fdesc_start, 261 fdesc_unmount, 262 fdesc_root, 263 fdesc_quotactl, 264 fdesc_statfs, 265 fdesc_sync, 266 fdesc_vget, 267 fdesc_fhtovp, 268 fdesc_vptofh, 269 fdesc_init, 270}; 271 272VFS_SET(fdesc_vfsops, fdesc, VFCF_SYNTHETIC); 273