fdesc_vfsops.c revision 1.76
1 /* $NetBSD: fdesc_vfsops.c,v 1.76 2008/05/13 08:31:13 simonb 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 1.76 2008/05/13 08:31:13 simonb 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 /* 73 * Mount the per-process file descriptors (/dev/fd) 74 */ 75 int 76 fdesc_mount(struct mount *mp, const char *path, void *data, size_t *data_len) 77 { 78 struct lwp *l = curlwp; 79 int error = 0; 80 struct fdescmount *fmp; 81 struct vnode *rvp; 82 83 if (mp->mnt_flag & MNT_GETARGS) { 84 *data_len = 0; 85 return 0; 86 } 87 /* 88 * Update is a no-op 89 */ 90 if (mp->mnt_flag & MNT_UPDATE) 91 return (EOPNOTSUPP); 92 93 error = fdesc_allocvp(Froot, FD_ROOT, mp, &rvp); 94 if (error) 95 return (error); 96 97 MALLOC(fmp, struct fdescmount *, sizeof(struct fdescmount), 98 M_UFSMNT, M_WAITOK); /* XXX */ 99 rvp->v_type = VDIR; 100 rvp->v_vflag |= VV_ROOT; 101 fmp->f_root = rvp; 102 mp->mnt_stat.f_namemax = MAXNAMLEN; 103 mp->mnt_flag |= MNT_LOCAL; 104 mp->mnt_data = fmp; 105 vfs_getnewfsid(mp); 106 107 error = set_statvfs_info(path, UIO_USERSPACE, "fdesc", UIO_SYSSPACE, 108 mp->mnt_op->vfs_name, mp, l); 109 VOP_UNLOCK(rvp, 0); 110 return error; 111 } 112 113 int 114 fdesc_start(struct mount *mp, int flags) 115 { 116 return (0); 117 } 118 119 int 120 fdesc_unmount(struct mount *mp, int mntflags) 121 { 122 int error; 123 int flags = 0; 124 struct vnode *rtvp = VFSTOFDESC(mp)->f_root; 125 126 if (mntflags & MNT_FORCE) 127 flags |= FORCECLOSE; 128 129 if (rtvp->v_usecount > 1 && (mntflags & MNT_FORCE) == 0) 130 return (EBUSY); 131 if ((error = vflush(mp, rtvp, flags)) != 0) 132 return (error); 133 134 /* 135 * Blow it away for future re-use 136 */ 137 vgone(rtvp); 138 /* 139 * Finally, throw away the fdescmount structure 140 */ 141 free(mp->mnt_data, M_UFSMNT); /* XXX */ 142 mp->mnt_data = NULL; 143 144 return (0); 145 } 146 147 int 148 fdesc_root(mp, vpp) 149 struct mount *mp; 150 struct vnode **vpp; 151 { 152 struct vnode *vp; 153 154 /* 155 * Return locked reference to root. 156 */ 157 vp = VFSTOFDESC(mp)->f_root; 158 VREF(vp); 159 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 160 *vpp = vp; 161 return (0); 162 } 163 164 int 165 fdesc_statvfs(mp, sbp) 166 struct mount *mp; 167 struct statvfs *sbp; 168 { 169 struct lwp *l = curlwp; 170 struct filedesc *fdp; 171 struct proc *p; 172 int lim; 173 int i; 174 int last; 175 int freefd; 176 177 /* 178 * Compute number of free file descriptors. 179 * [ Strange results will ensue if the open file 180 * limit is ever reduced below the current number 181 * of open files... ] 182 */ 183 p = l->l_proc; 184 lim = p->p_rlimit[RLIMIT_NOFILE].rlim_cur; 185 fdp = p->p_fd; 186 last = min(fdp->fd_nfiles, lim); 187 freefd = 0; 188 for (i = fdp->fd_freefile; i < last; i++) 189 if (fdp->fd_ofiles[i] == NULL) 190 freefd++; 191 192 /* 193 * Adjust for the fact that the fdesc array may not 194 * have been fully allocated yet. 195 */ 196 if (fdp->fd_nfiles < lim) 197 freefd += (lim - fdp->fd_nfiles); 198 199 sbp->f_bsize = DEV_BSIZE; 200 sbp->f_frsize = DEV_BSIZE; 201 sbp->f_iosize = DEV_BSIZE; 202 sbp->f_blocks = 2; /* 1K to keep df happy */ 203 sbp->f_bfree = 0; 204 sbp->f_bavail = 0; 205 sbp->f_bresvd = 0; 206 sbp->f_files = lim + 1; /* Allow for "." */ 207 sbp->f_ffree = freefd; /* See comments above */ 208 sbp->f_favail = freefd; /* See comments above */ 209 sbp->f_fresvd = 0; 210 copy_statvfs_info(sbp, mp); 211 return (0); 212 } 213 214 /*ARGSUSED*/ 215 int 216 fdesc_sync(struct mount *mp, int waitfor, 217 kauth_cred_t uc) 218 { 219 220 return (0); 221 } 222 223 /* 224 * Fdesc flat namespace lookup. 225 * Currently unsupported. 226 */ 227 int 228 fdesc_vget(struct mount *mp, ino_t ino, 229 struct vnode **vpp) 230 { 231 232 return (EOPNOTSUPP); 233 } 234 235 236 SYSCTL_SETUP(sysctl_vfs_fdesc_setup, "sysctl vfs.fdesc subtree setup") 237 { 238 239 sysctl_createv(clog, 0, NULL, NULL, 240 CTLFLAG_PERMANENT, 241 CTLTYPE_NODE, "vfs", NULL, 242 NULL, 0, NULL, 0, 243 CTL_VFS, CTL_EOL); 244 sysctl_createv(clog, 0, NULL, NULL, 245 CTLFLAG_PERMANENT, 246 CTLTYPE_NODE, "fdesc", 247 SYSCTL_DESCR("File-descriptor file system"), 248 NULL, 0, NULL, 0, 249 CTL_VFS, 7, CTL_EOL); 250 /* 251 * XXX the "7" above could be dynamic, thereby eliminating one 252 * more instance of the "number to vfs" mapping problem, but 253 * "7" is the order as taken from sys/mount.h 254 */ 255 } 256 257 extern const struct vnodeopv_desc fdesc_vnodeop_opv_desc; 258 259 const struct vnodeopv_desc * const fdesc_vnodeopv_descs[] = { 260 &fdesc_vnodeop_opv_desc, 261 NULL, 262 }; 263 264 struct vfsops fdesc_vfsops = { 265 MOUNT_FDESC, 266 0, 267 fdesc_mount, 268 fdesc_start, 269 fdesc_unmount, 270 fdesc_root, 271 (void *)eopnotsupp, /* vfs_quotactl */ 272 fdesc_statvfs, 273 fdesc_sync, 274 fdesc_vget, 275 (void *)eopnotsupp, /* vfs_fhtovp */ 276 (void *)eopnotsupp, /* vfs_vptofh */ 277 fdesc_init, 278 NULL, 279 fdesc_done, 280 NULL, /* vfs_mountroot */ 281 (int (*)(struct mount *, struct vnode *, struct timespec *)) eopnotsupp, 282 vfs_stdextattrctl, 283 (void *)eopnotsupp, /* vfs_suspendctl */ 284 genfs_renamelock_enter, 285 genfs_renamelock_exit, 286 (void *)eopnotsupp, 287 fdesc_vnodeopv_descs, 288 0, 289 { NULL, NULL}, 290 }; 291 292 static int 293 fdesc_modcmd(modcmd_t cmd, void *arg) 294 { 295 296 switch (cmd) { 297 case MODULE_CMD_INIT: 298 return vfs_attach(&fdesc_vfsops); 299 case MODULE_CMD_FINI: 300 return vfs_detach(&fdesc_vfsops); 301 default: 302 return ENOTTY; 303 } 304 } 305
Indexes created Fri Sep 26 20:09:58 GMT 2025