1 /* $NetBSD: fdesc_vfsops.c,v 1.82 2009/07/31 19:47:47 pooka Exp $ */ 2 3 /* 4 * Copyright (c) 1992, 1993, 1995 5 * The Regents of the University of California. All rights reserved. 6 * 7 * This code is derived from software donated to Berkeley by 8 * Jan-Simon Pendry. 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 3. Neither the name of the University nor the names of its contributors 19 * may be used to endorse or promote products derived from this software 20 * without specific prior written permission. 21 * 22 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 23 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 24 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 25 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 26 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 27 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 28 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 29 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 30 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 31 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 32 * SUCH DAMAGE. 33 * 34 * @(#)fdesc_vfsops.c 8.10 (Berkeley) 5/14/95 35 * 36 * #Id: fdesc_vfsops.c,v 1.9 1993/04/06 15:28:33 jsp Exp # 37 */ 38 39 /* 40 * /dev/fd Filesystem 41 */ 42 43 #include <sys/cdefs.h> 44 __KERNEL_RCSID(0, "$NetBSD: fdesc_vfsops.c,v 1.82 2009/07/31 19:47:47 pooka Exp $"); 45 46 #if defined(_KERNEL_OPT) 47 #include "opt_compat_netbsd.h" 48 #endif 49 50 #include <sys/param.h> 51 #include <sys/systm.h> 52 #include <sys/sysctl.h> 53 #include <sys/time.h> 54 #include <sys/proc.h> 55 #include <sys/resourcevar.h> 56 #include <sys/filedesc.h> 57 #include <sys/vnode.h> 58 #include <sys/mount.h> 59 #include <sys/dirent.h> 60 #include <sys/namei.h> 61 #include <sys/malloc.h> 62 #include <sys/kauth.h> 63 #include <sys/module.h> 64 65 #include <miscfs/genfs/genfs.h> 66 #include <miscfs/fdesc/fdesc.h> 67 68 MODULE(MODULE_CLASS_VFS, fdesc, NULL); 69 70 VFS_PROTOS(fdesc); 71 72 static struct sysctllog *fdesc_sysctl_log; 73 74 /* 75 * Mount the per-process file descriptors (/dev/fd) 76 */ 77 int 78 fdesc_mount(struct mount *mp, const char *path, void *data, size_t *data_len) 79 { 80 struct lwp *l = curlwp; 81 int error = 0; 82 struct vnode *rvp; 83 84 if (mp->mnt_flag & MNT_GETARGS) { 85 *data_len = 0; 86 return 0; 87 } 88 /* 89 * Update is a no-op 90 */ 91 if (mp->mnt_flag & MNT_UPDATE) 92 return (EOPNOTSUPP); 93 94 error = fdesc_allocvp(Froot, FD_ROOT, mp, &rvp); 95 if (error) 96 return (error); 97 98 rvp->v_type = VDIR; 99 rvp->v_vflag |= VV_ROOT; 100 mp->mnt_stat.f_namemax = MAXNAMLEN; 101 mp->mnt_flag |= MNT_LOCAL; 102 mp->mnt_data = rvp; 103 vfs_getnewfsid(mp); 104 105 error = set_statvfs_info(path, UIO_USERSPACE, "fdesc", UIO_SYSSPACE, 106 mp->mnt_op->vfs_name, mp, l); 107 VOP_UNLOCK(rvp, 0); 108 return error; 109 } 110 111 int 112 fdesc_start(struct mount *mp, int flags) 113 { 114 return (0); 115 } 116 117 int 118 fdesc_unmount(struct mount *mp, int mntflags) 119 { 120 int error; 121 int flags = 0; 122 struct vnode *rtvp = mp->mnt_data; 123 124 if (mntflags & MNT_FORCE) 125 flags |= FORCECLOSE; 126 127 if (rtvp->v_usecount > 1 && (mntflags & MNT_FORCE) == 0) 128 return (EBUSY); 129 if ((error = vflush(mp, rtvp, flags)) != 0) 130 return (error); 131 132 /* 133 * Blow it away for future re-use 134 */ 135 vgone(rtvp); 136 mp->mnt_data = NULL; 137 138 return (0); 139 } 140 141 int 142 fdesc_root(struct mount *mp, struct vnode **vpp) 143 { 144 struct vnode *vp; 145 146 /* 147 * Return locked reference to root. 148 */ 149 vp = mp->mnt_data; 150 VREF(vp); 151 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 152 *vpp = vp; 153 return (0); 154 } 155 156 int 157 fdesc_statvfs(struct mount *mp, struct statvfs *sbp) 158 { 159 160 sbp->f_bsize = DEV_BSIZE; 161 sbp->f_frsize = DEV_BSIZE; 162 sbp->f_iosize = DEV_BSIZE; 163 sbp->f_blocks = 2; /* 1K to keep df happy */ 164 sbp->f_bfree = 0; 165 sbp->f_bavail = 0; 166 sbp->f_bresvd = 0; 167 sbp->f_files = 0; 168 sbp->f_ffree = 0; 169 sbp->f_favail = 0; 170 sbp->f_fresvd = 0; 171 copy_statvfs_info(sbp, mp); 172 return (0); 173 } 174 175 /*ARGSUSED*/ 176 int 177 fdesc_sync(struct mount *mp, int waitfor, 178 kauth_cred_t uc) 179 { 180 181 return (0); 182 } 183 184 /* 185 * Fdesc flat namespace lookup. 186 * Currently unsupported. 187 */ 188 int 189 fdesc_vget(struct mount *mp, ino_t ino, 190 struct vnode **vpp) 191 { 192 193 return (EOPNOTSUPP); 194 } 195 196 extern const struct vnodeopv_desc fdesc_vnodeop_opv_desc; 197 198 const struct vnodeopv_desc * const fdesc_vnodeopv_descs[] = { 199 &fdesc_vnodeop_opv_desc, 200 NULL, 201 }; 202 203 struct vfsops fdesc_vfsops = { 204 MOUNT_FDESC, 205 0, 206 fdesc_mount, 207 fdesc_start, 208 fdesc_unmount, 209 fdesc_root, 210 (void *)eopnotsupp, /* vfs_quotactl */ 211 fdesc_statvfs, 212 fdesc_sync, 213 fdesc_vget, 214 (void *)eopnotsupp, /* vfs_fhtovp */ 215 (void *)eopnotsupp, /* vfs_vptofh */ 216 fdesc_init, 217 NULL, 218 fdesc_done, 219 NULL, /* vfs_mountroot */ 220 (int (*)(struct mount *, struct vnode *, struct timespec *)) eopnotsupp, 221 vfs_stdextattrctl, 222 (void *)eopnotsupp, /* vfs_suspendctl */ 223 genfs_renamelock_enter, 224 genfs_renamelock_exit, 225 (void *)eopnotsupp, 226 fdesc_vnodeopv_descs, 227 0, 228 { NULL, NULL}, 229 }; 230 231 static int 232 fdesc_modcmd(modcmd_t cmd, void *arg) 233 { 234 int error; 235 236 switch (cmd) { 237 case MODULE_CMD_INIT: 238 error = vfs_attach(&fdesc_vfsops); 239 if (error != 0) 240 break; 241 sysctl_createv(&fdesc_sysctl_log, 0, NULL, NULL, 242 CTLFLAG_PERMANENT, 243 CTLTYPE_NODE, "vfs", NULL, 244 NULL, 0, NULL, 0, 245 CTL_VFS, CTL_EOL); 246 sysctl_createv(&fdesc_sysctl_log, 0, NULL, NULL, 247 CTLFLAG_PERMANENT, 248 CTLTYPE_NODE, "fdesc", 249 SYSCTL_DESCR("File-descriptor file system"), 250 NULL, 0, NULL, 0, 251 CTL_VFS, 7, CTL_EOL); 252 /* 253 * XXX the "7" above could be dynamic, thereby eliminating one 254 * more instance of the "number to vfs" mapping problem, but 255 * "7" is the order as taken from sys/mount.h 256 */ 257 break; 258 case MODULE_CMD_FINI: 259 error = vfs_detach(&fdesc_vfsops); 260 if (error != 0) 261 break; 262 sysctl_teardown(&fdesc_sysctl_log); 263 break; 264 default: 265 error = ENOTTY; 266 break; 267 } 268 269 return (error); 270 } 271