fdesc_vfsops.c revision 22521
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 * $FreeBSD: head/sys/fs/fdescfs/fdesc_vfsops.c 22521 1997-02-10 02:22:35Z dyson $ 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 59static int fdesc_fhtovp __P((struct mount *mp, struct fid *fhp, 60 struct mbuf *nam, struct vnode **vpp, 61 int *exflagsp, struct ucred **credanonp)); 62static int fdesc_mount __P((struct mount *mp, char *path, caddr_t data, 63 struct nameidata *ndp, struct proc *p)); 64static int fdesc_quotactl __P((struct mount *mp, int cmd, uid_t uid, 65 caddr_t arg, struct proc *p)); 66static int fdesc_start __P((struct mount *mp, int flags, struct proc *p)); 67static int fdesc_unmount __P((struct mount *mp, int mntflags, 68 struct proc *p)); 69static int fdesc_statfs __P((struct mount *mp, struct statfs *sbp, 70 struct proc *p)); 71static int fdesc_sync __P((struct mount *mp, int waitfor, 72 struct ucred *cred, struct proc *p)); 73static int fdesc_vget __P((struct mount *mp, ino_t ino, 74 struct vnode **vpp)); 75static int fdesc_vptofh __P((struct vnode *vp, struct fid *fhp)); 76 77/* 78 * Mount the per-process file descriptors (/dev/fd) 79 */ 80static int 81fdesc_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 vfs_getnewfsid(mp); 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 121static int 122fdesc_start(mp, flags, p) 123 struct mount *mp; 124 int flags; 125 struct proc *p; 126{ 127 return (0); 128} 129 130static int 131fdesc_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 flags |= FORCECLOSE; 142 143 /* 144 * Clear out buffer cache. I don't think we 145 * ever get anything cached at this level at the 146 * moment, but who knows... 147 */ 148 if (rootvp->v_usecount > 1) 149 return (EBUSY); 150 if (error = vflush(mp, rootvp, flags)) 151 return (error); 152 153 /* 154 * Release reference on underlying root vnode 155 */ 156 vrele(rootvp); 157 /* 158 * And blow it away for future re-use 159 */ 160 vgone(rootvp); 161 /* 162 * Finally, throw away the fdescmount structure 163 */ 164 free(mp->mnt_data, M_UFSMNT); /* XXX */ 165 mp->mnt_data = 0; 166 167 return (0); 168} 169 170int 171fdesc_root(mp, vpp) 172 struct mount *mp; 173 struct vnode **vpp; 174{ 175 struct proc *p = curproc; /* XXX */ 176 struct vnode *vp; 177 178 /* 179 * Return locked reference to root. 180 */ 181 vp = VFSTOFDESC(mp)->f_root; 182 VREF(vp); 183 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, p); 184 *vpp = vp; 185 return (0); 186} 187 188static int 189fdesc_statfs(mp, sbp, p) 190 struct mount *mp; 191 struct statfs *sbp; 192 struct proc *p; 193{ 194 struct filedesc *fdp; 195 int lim; 196 int i; 197 int last; 198 int freefd; 199 200 /* 201 * Compute number of free file descriptors. 202 * [ Strange results will ensue if the open file 203 * limit is ever reduced below the current number 204 * of open files... ] 205 */ 206 lim = p->p_rlimit[RLIMIT_NOFILE].rlim_cur; 207 fdp = p->p_fd; 208 last = min(fdp->fd_nfiles, lim); 209 freefd = 0; 210 for (i = fdp->fd_freefile; i < last; i++) 211 if (fdp->fd_ofiles[i] == NULL) 212 freefd++; 213 214 /* 215 * Adjust for the fact that the fdesc array may not 216 * have been fully allocated yet. 217 */ 218 if (fdp->fd_nfiles < lim) 219 freefd += (lim - fdp->fd_nfiles); 220 221 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 sbp->f_type = mp->mnt_vfc->vfc_typenum; 231 bcopy(&mp->mnt_stat.f_fsid, &sbp->f_fsid, sizeof(sbp->f_fsid)); 232 bcopy(mp->mnt_stat.f_mntonname, sbp->f_mntonname, MNAMELEN); 233 bcopy(mp->mnt_stat.f_mntfromname, sbp->f_mntfromname, MNAMELEN); 234 } 235 return (0); 236} 237 238static int 239fdesc_sync(mp, waitfor, cred, p) 240 struct mount *mp; 241 int waitfor; 242 struct ucred *cred; 243 struct proc *p; 244{ 245 246 return (0); 247} 248 249#define fdesc_fhtovp ((int (*) __P((struct mount *, struct fid *, \ 250 struct mbuf *, struct vnode **, int *, struct ucred **)))eopnotsupp) 251#define fdesc_quotactl ((int (*) __P((struct mount *, int, uid_t, caddr_t, \ 252 struct proc *)))eopnotsupp) 253#define fdesc_sysctl ((int (*) __P((int *, u_int, void *, size_t *, void *, \ 254 size_t, struct proc *)))eopnotsupp) 255#define fdesc_vget ((int (*) __P((struct mount *, ino_t, struct vnode **))) \ 256 eopnotsupp) 257#define fdesc_vptofh ((int (*) __P((struct vnode *, struct fid *)))eopnotsupp) 258 259static struct vfsops fdesc_vfsops = { 260 fdesc_mount, 261 fdesc_start, 262 fdesc_unmount, 263 fdesc_root, 264 fdesc_quotactl, 265 fdesc_statfs, 266 fdesc_sync, 267 fdesc_vget, 268 fdesc_fhtovp, 269 fdesc_vptofh, 270 fdesc_init, 271}; 272 273VFS_SET(fdesc_vfsops, fdesc, MOUNT_FDESC, VFCF_SYNTHETIC); 274