fdesc_vfsops.c revision 1.70
1 /* $NetBSD: fdesc_vfsops.c,v 1.70 2007/10/10 20:42:28 ad 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 1.70 2007/10/10 20:42:28 ad 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 64 #include <miscfs/fdesc/fdesc.h> 65 66 VFS_PROTOS(fdesc); 67 68 /* 69 * Mount the per-process file descriptors (/dev/fd) 70 */ 71 int 72 fdesc_mount(struct mount *mp, const char *path, void *data, size_t *data_len, 73 struct lwp *l) 74 { 75 int error = 0; 76 struct fdescmount *fmp; 77 struct vnode *rvp; 78 79 if (mp->mnt_flag & MNT_GETARGS) { 80 *data_len = 0; 81 return 0; 82 } 83 /* 84 * Update is a no-op 85 */ 86 if (mp->mnt_flag & MNT_UPDATE) 87 return (EOPNOTSUPP); 88 89 error = fdesc_allocvp(Froot, FD_ROOT, mp, &rvp); 90 if (error) 91 return (error); 92 93 MALLOC(fmp, struct fdescmount *, sizeof(struct fdescmount), 94 M_UFSMNT, M_WAITOK); /* XXX */ 95 rvp->v_type = VDIR; 96 rvp->v_vflag |= VV_ROOT; 97 fmp->f_root = rvp; 98 mp->mnt_stat.f_namemax = MAXNAMLEN; 99 mp->mnt_flag |= MNT_LOCAL; 100 mp->mnt_data = fmp; 101 vfs_getnewfsid(mp); 102 103 error = set_statvfs_info(path, UIO_USERSPACE, "fdesc", UIO_SYSSPACE, 104 mp->mnt_op->vfs_name, mp, l); 105 VOP_UNLOCK(rvp, 0); 106 return error; 107 } 108 109 int 110 fdesc_start(struct mount *mp, int flags, 111 struct lwp *l) 112 { 113 return (0); 114 } 115 116 int 117 fdesc_unmount(struct mount *mp, int mntflags, struct lwp *l) 118 { 119 int error; 120 int flags = 0; 121 struct vnode *rtvp = VFSTOFDESC(mp)->f_root; 122 123 if (mntflags & MNT_FORCE) 124 flags |= FORCECLOSE; 125 126 if (rtvp->v_usecount > 1 && (mntflags & MNT_FORCE) == 0) 127 return (EBUSY); 128 if ((error = vflush(mp, rtvp, flags)) != 0) 129 return (error); 130 131 /* 132 * Release reference on underlying root vnode 133 */ 134 vrele(rtvp); 135 /* 136 * And blow it away for future re-use 137 */ 138 vgone(rtvp); 139 /* 140 * Finally, throw away the fdescmount structure 141 */ 142 free(mp->mnt_data, M_UFSMNT); /* XXX */ 143 mp->mnt_data = 0; 144 145 return (0); 146 } 147 148 int 149 fdesc_root(mp, vpp) 150 struct mount *mp; 151 struct vnode **vpp; 152 { 153 struct vnode *vp; 154 155 /* 156 * Return locked reference to root. 157 */ 158 vp = VFSTOFDESC(mp)->f_root; 159 VREF(vp); 160 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 161 *vpp = vp; 162 return (0); 163 } 164 165 int 166 fdesc_quotactl(struct mount *mp, int cmd, uid_t uid, 167 void *arg, struct lwp *l) 168 { 169 170 return (EOPNOTSUPP); 171 } 172 173 int 174 fdesc_statvfs(mp, sbp, l) 175 struct mount *mp; 176 struct statvfs *sbp; 177 struct lwp *l; 178 { 179 struct filedesc *fdp; 180 struct proc *p; 181 int lim; 182 int i; 183 int last; 184 int freefd; 185 186 /* 187 * Compute number of free file descriptors. 188 * [ Strange results will ensue if the open file 189 * limit is ever reduced below the current number 190 * of open files... ] 191 */ 192 p = l->l_proc; 193 lim = p->p_rlimit[RLIMIT_NOFILE].rlim_cur; 194 fdp = p->p_fd; 195 last = min(fdp->fd_nfiles, lim); 196 freefd = 0; 197 for (i = fdp->fd_freefile; i < last; i++) 198 if (fdp->fd_ofiles[i] == NULL) 199 freefd++; 200 201 /* 202 * Adjust for the fact that the fdesc array may not 203 * have been fully allocated yet. 204 */ 205 if (fdp->fd_nfiles < lim) 206 freefd += (lim - fdp->fd_nfiles); 207 208 sbp->f_bsize = DEV_BSIZE; 209 sbp->f_frsize = DEV_BSIZE; 210 sbp->f_iosize = DEV_BSIZE; 211 sbp->f_blocks = 2; /* 1K to keep df happy */ 212 sbp->f_bfree = 0; 213 sbp->f_bavail = 0; 214 sbp->f_bresvd = 0; 215 sbp->f_files = lim + 1; /* Allow for "." */ 216 sbp->f_ffree = freefd; /* See comments above */ 217 sbp->f_favail = freefd; /* See comments above */ 218 sbp->f_fresvd = 0; 219 copy_statvfs_info(sbp, mp); 220 return (0); 221 } 222 223 /*ARGSUSED*/ 224 int 225 fdesc_sync(struct mount *mp, int waitfor, 226 kauth_cred_t uc, struct lwp *l) 227 { 228 229 return (0); 230 } 231 232 /* 233 * Fdesc flat namespace lookup. 234 * Currently unsupported. 235 */ 236 int 237 fdesc_vget(struct mount *mp, ino_t ino, 238 struct vnode **vpp) 239 { 240 241 return (EOPNOTSUPP); 242 } 243 244 245 SYSCTL_SETUP(sysctl_vfs_fdesc_setup, "sysctl vfs.fdesc subtree setup") 246 { 247 248 sysctl_createv(clog, 0, NULL, NULL, 249 CTLFLAG_PERMANENT, 250 CTLTYPE_NODE, "vfs", NULL, 251 NULL, 0, NULL, 0, 252 CTL_VFS, CTL_EOL); 253 sysctl_createv(clog, 0, NULL, NULL, 254 CTLFLAG_PERMANENT, 255 CTLTYPE_NODE, "fdesc", 256 SYSCTL_DESCR("File-descriptor file system"), 257 NULL, 0, NULL, 0, 258 CTL_VFS, 7, CTL_EOL); 259 /* 260 * XXX the "7" above could be dynamic, thereby eliminating one 261 * more instance of the "number to vfs" mapping problem, but 262 * "7" is the order as taken from sys/mount.h 263 */ 264 } 265 266 extern const struct vnodeopv_desc fdesc_vnodeop_opv_desc; 267 268 const struct vnodeopv_desc * const fdesc_vnodeopv_descs[] = { 269 &fdesc_vnodeop_opv_desc, 270 NULL, 271 }; 272 273 struct vfsops fdesc_vfsops = { 274 MOUNT_FDESC, 275 0, 276 fdesc_mount, 277 fdesc_start, 278 fdesc_unmount, 279 fdesc_root, 280 fdesc_quotactl, 281 fdesc_statvfs, 282 fdesc_sync, 283 fdesc_vget, 284 (void *)eopnotsupp, /* vfs_fhtovp */ 285 (void *)eopnotsupp, /* vfs_vptofh */ 286 fdesc_init, 287 NULL, 288 fdesc_done, 289 NULL, /* vfs_mountroot */ 290 (int (*)(struct mount *, struct vnode *, struct timespec *)) eopnotsupp, 291 vfs_stdextattrctl, 292 (void *)eopnotsupp, /* vfs_suspendctl */ 293 fdesc_vnodeopv_descs, 294 0, 295 { NULL, NULL}, 296 }; 297 VFS_ATTACH(fdesc_vfsops); 298
Indexes created Fri Sep 26 08:10:20 GMT 2025