fdesc_vfsops.c revision 1.72
1 /* $NetBSD: fdesc_vfsops.c,v 1.72 2008/01/02 11:48:58 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 1.72 2008/01/02 11:48:58 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 { 74 struct lwp *l = curlwp; 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 { 112 return (0); 113 } 114 115 int 116 fdesc_unmount(struct mount *mp, int mntflags) 117 { 118 int error; 119 int flags = 0; 120 struct vnode *rtvp = VFSTOFDESC(mp)->f_root; 121 122 if (mntflags & MNT_FORCE) 123 flags |= FORCECLOSE; 124 125 if (rtvp->v_usecount > 1 && (mntflags & MNT_FORCE) == 0) 126 return (EBUSY); 127 if ((error = vflush(mp, rtvp, flags)) != 0) 128 return (error); 129 130 /* 131 * Blow it away for future re-use 132 */ 133 vgone(rtvp); 134 /* 135 * Finally, throw away the fdescmount structure 136 */ 137 free(mp->mnt_data, M_UFSMNT); /* XXX */ 138 mp->mnt_data = 0; 139 140 return (0); 141 } 142 143 int 144 fdesc_root(mp, vpp) 145 struct mount *mp; 146 struct vnode **vpp; 147 { 148 struct vnode *vp; 149 150 /* 151 * Return locked reference to root. 152 */ 153 vp = VFSTOFDESC(mp)->f_root; 154 VREF(vp); 155 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 156 *vpp = vp; 157 return (0); 158 } 159 160 int 161 fdesc_statvfs(mp, sbp) 162 struct mount *mp; 163 struct statvfs *sbp; 164 { 165 struct lwp *l = curlwp; 166 struct filedesc *fdp; 167 struct proc *p; 168 int lim; 169 int i; 170 int last; 171 int freefd; 172 173 /* 174 * Compute number of free file descriptors. 175 * [ Strange results will ensue if the open file 176 * limit is ever reduced below the current number 177 * of open files... ] 178 */ 179 p = l->l_proc; 180 lim = p->p_rlimit[RLIMIT_NOFILE].rlim_cur; 181 fdp = p->p_fd; 182 last = min(fdp->fd_nfiles, lim); 183 freefd = 0; 184 for (i = fdp->fd_freefile; i < last; i++) 185 if (fdp->fd_ofiles[i] == NULL) 186 freefd++; 187 188 /* 189 * Adjust for the fact that the fdesc array may not 190 * have been fully allocated yet. 191 */ 192 if (fdp->fd_nfiles < lim) 193 freefd += (lim - fdp->fd_nfiles); 194 195 sbp->f_bsize = DEV_BSIZE; 196 sbp->f_frsize = DEV_BSIZE; 197 sbp->f_iosize = DEV_BSIZE; 198 sbp->f_blocks = 2; /* 1K to keep df happy */ 199 sbp->f_bfree = 0; 200 sbp->f_bavail = 0; 201 sbp->f_bresvd = 0; 202 sbp->f_files = lim + 1; /* Allow for "." */ 203 sbp->f_ffree = freefd; /* See comments above */ 204 sbp->f_favail = freefd; /* See comments above */ 205 sbp->f_fresvd = 0; 206 copy_statvfs_info(sbp, mp); 207 return (0); 208 } 209 210 /*ARGSUSED*/ 211 int 212 fdesc_sync(struct mount *mp, int waitfor, 213 kauth_cred_t uc) 214 { 215 216 return (0); 217 } 218 219 /* 220 * Fdesc flat namespace lookup. 221 * Currently unsupported. 222 */ 223 int 224 fdesc_vget(struct mount *mp, ino_t ino, 225 struct vnode **vpp) 226 { 227 228 return (EOPNOTSUPP); 229 } 230 231 232 SYSCTL_SETUP(sysctl_vfs_fdesc_setup, "sysctl vfs.fdesc subtree setup") 233 { 234 235 sysctl_createv(clog, 0, NULL, NULL, 236 CTLFLAG_PERMANENT, 237 CTLTYPE_NODE, "vfs", NULL, 238 NULL, 0, NULL, 0, 239 CTL_VFS, CTL_EOL); 240 sysctl_createv(clog, 0, NULL, NULL, 241 CTLFLAG_PERMANENT, 242 CTLTYPE_NODE, "fdesc", 243 SYSCTL_DESCR("File-descriptor file system"), 244 NULL, 0, NULL, 0, 245 CTL_VFS, 7, CTL_EOL); 246 /* 247 * XXX the "7" above could be dynamic, thereby eliminating one 248 * more instance of the "number to vfs" mapping problem, but 249 * "7" is the order as taken from sys/mount.h 250 */ 251 } 252 253 extern const struct vnodeopv_desc fdesc_vnodeop_opv_desc; 254 255 const struct vnodeopv_desc * const fdesc_vnodeopv_descs[] = { 256 &fdesc_vnodeop_opv_desc, 257 NULL, 258 }; 259 260 struct vfsops fdesc_vfsops = { 261 MOUNT_FDESC, 262 0, 263 fdesc_mount, 264 fdesc_start, 265 fdesc_unmount, 266 fdesc_root, 267 (void *)eopnotsupp, /* vfs_quotactl */ 268 fdesc_statvfs, 269 fdesc_sync, 270 fdesc_vget, 271 (void *)eopnotsupp, /* vfs_fhtovp */ 272 (void *)eopnotsupp, /* vfs_vptofh */ 273 fdesc_init, 274 NULL, 275 fdesc_done, 276 NULL, /* vfs_mountroot */ 277 (int (*)(struct mount *, struct vnode *, struct timespec *)) eopnotsupp, 278 vfs_stdextattrctl, 279 (void *)eopnotsupp, /* vfs_suspendctl */ 280 fdesc_vnodeopv_descs, 281 0, 282 { NULL, NULL}, 283 }; 284 VFS_ATTACH(fdesc_vfsops); 285
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