fdesc_vfsops.c revision 1.68
1 /* $NetBSD: fdesc_vfsops.c,v 1.68 2007/07/26 22:57:39 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 1.68 2007/07/26 22:57:39 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 64 #include <miscfs/fdesc/fdesc.h> 65 66 int fdesc_mount(struct mount *, const char *, void *, size_t *, 67 struct nameidata *, struct lwp *); 68 int fdesc_start(struct mount *, int, struct lwp *); 69 int fdesc_unmount(struct mount *, int, struct lwp *); 70 int fdesc_quotactl(struct mount *, int, uid_t, void *, 71 struct lwp *); 72 int fdesc_statvfs(struct mount *, struct statvfs *, struct lwp *); 73 int fdesc_sync(struct mount *, int, kauth_cred_t, struct lwp *); 74 int fdesc_vget(struct mount *, ino_t, struct vnode **); 75 76 /* 77 * Mount the per-process file descriptors (/dev/fd) 78 */ 79 int 80 fdesc_mount(struct mount *mp, const char *path, void *data, size_t *data_len, 81 struct nameidata *ndp, struct lwp *l) 82 { 83 int error = 0; 84 struct fdescmount *fmp; 85 struct vnode *rvp; 86 87 if (mp->mnt_flag & MNT_GETARGS) { 88 *data_len = 0; 89 return 0; 90 } 91 /* 92 * Update is a no-op 93 */ 94 if (mp->mnt_flag & MNT_UPDATE) 95 return (EOPNOTSUPP); 96 97 error = fdesc_allocvp(Froot, FD_ROOT, mp, &rvp); 98 if (error) 99 return (error); 100 101 MALLOC(fmp, struct fdescmount *, sizeof(struct fdescmount), 102 M_UFSMNT, M_WAITOK); /* XXX */ 103 rvp->v_type = VDIR; 104 rvp->v_flag |= VROOT; 105 fmp->f_root = rvp; 106 mp->mnt_stat.f_namemax = MAXNAMLEN; 107 mp->mnt_flag |= MNT_LOCAL; 108 mp->mnt_data = fmp; 109 vfs_getnewfsid(mp); 110 111 error = set_statvfs_info(path, UIO_USERSPACE, "fdesc", UIO_SYSSPACE, 112 mp->mnt_op->vfs_name, mp, l); 113 VOP_UNLOCK(rvp, 0); 114 return error; 115 } 116 117 int 118 fdesc_start(struct mount *mp, int flags, 119 struct lwp *l) 120 { 121 return (0); 122 } 123 124 int 125 fdesc_unmount(struct mount *mp, int mntflags, struct lwp *l) 126 { 127 int error; 128 int flags = 0; 129 struct vnode *rtvp = VFSTOFDESC(mp)->f_root; 130 131 if (mntflags & MNT_FORCE) 132 flags |= FORCECLOSE; 133 134 if (rtvp->v_usecount > 1 && (mntflags & MNT_FORCE) == 0) 135 return (EBUSY); 136 if ((error = vflush(mp, rtvp, flags)) != 0) 137 return (error); 138 139 /* 140 * Release reference on underlying root vnode 141 */ 142 vrele(rtvp); 143 /* 144 * And blow it away for future re-use 145 */ 146 vgone(rtvp); 147 /* 148 * Finally, throw away the fdescmount structure 149 */ 150 free(mp->mnt_data, M_UFSMNT); /* XXX */ 151 mp->mnt_data = 0; 152 153 return (0); 154 } 155 156 int 157 fdesc_root(mp, vpp) 158 struct mount *mp; 159 struct vnode **vpp; 160 { 161 struct vnode *vp; 162 163 /* 164 * Return locked reference to root. 165 */ 166 vp = VFSTOFDESC(mp)->f_root; 167 VREF(vp); 168 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 169 *vpp = vp; 170 return (0); 171 } 172 173 int 174 fdesc_quotactl(struct mount *mp, int cmd, uid_t uid, 175 void *arg, struct lwp *l) 176 { 177 178 return (EOPNOTSUPP); 179 } 180 181 int 182 fdesc_statvfs(mp, sbp, l) 183 struct mount *mp; 184 struct statvfs *sbp; 185 struct lwp *l; 186 { 187 struct filedesc *fdp; 188 struct proc *p; 189 int lim; 190 int i; 191 int last; 192 int freefd; 193 194 /* 195 * Compute number of free file descriptors. 196 * [ Strange results will ensue if the open file 197 * limit is ever reduced below the current number 198 * of open files... ] 199 */ 200 p = l->l_proc; 201 lim = p->p_rlimit[RLIMIT_NOFILE].rlim_cur; 202 fdp = p->p_fd; 203 last = min(fdp->fd_nfiles, lim); 204 freefd = 0; 205 for (i = fdp->fd_freefile; i < last; i++) 206 if (fdp->fd_ofiles[i] == NULL) 207 freefd++; 208 209 /* 210 * Adjust for the fact that the fdesc array may not 211 * have been fully allocated yet. 212 */ 213 if (fdp->fd_nfiles < lim) 214 freefd += (lim - fdp->fd_nfiles); 215 216 sbp->f_bsize = DEV_BSIZE; 217 sbp->f_frsize = DEV_BSIZE; 218 sbp->f_iosize = DEV_BSIZE; 219 sbp->f_blocks = 2; /* 1K to keep df happy */ 220 sbp->f_bfree = 0; 221 sbp->f_bavail = 0; 222 sbp->f_bresvd = 0; 223 sbp->f_files = lim + 1; /* Allow for "." */ 224 sbp->f_ffree = freefd; /* See comments above */ 225 sbp->f_favail = freefd; /* See comments above */ 226 sbp->f_fresvd = 0; 227 copy_statvfs_info(sbp, mp); 228 return (0); 229 } 230 231 /*ARGSUSED*/ 232 int 233 fdesc_sync(struct mount *mp, int waitfor, 234 kauth_cred_t uc, struct lwp *l) 235 { 236 237 return (0); 238 } 239 240 /* 241 * Fdesc flat namespace lookup. 242 * Currently unsupported. 243 */ 244 int 245 fdesc_vget(struct mount *mp, ino_t ino, 246 struct vnode **vpp) 247 { 248 249 return (EOPNOTSUPP); 250 } 251 252 253 SYSCTL_SETUP(sysctl_vfs_fdesc_setup, "sysctl vfs.fdesc subtree setup") 254 { 255 256 sysctl_createv(clog, 0, NULL, NULL, 257 CTLFLAG_PERMANENT, 258 CTLTYPE_NODE, "vfs", NULL, 259 NULL, 0, NULL, 0, 260 CTL_VFS, CTL_EOL); 261 sysctl_createv(clog, 0, NULL, NULL, 262 CTLFLAG_PERMANENT, 263 CTLTYPE_NODE, "fdesc", 264 SYSCTL_DESCR("File-descriptor file system"), 265 NULL, 0, NULL, 0, 266 CTL_VFS, 7, CTL_EOL); 267 /* 268 * XXX the "7" above could be dynamic, thereby eliminating one 269 * more instance of the "number to vfs" mapping problem, but 270 * "7" is the order as taken from sys/mount.h 271 */ 272 } 273 274 extern const struct vnodeopv_desc fdesc_vnodeop_opv_desc; 275 276 const struct vnodeopv_desc * const fdesc_vnodeopv_descs[] = { 277 &fdesc_vnodeop_opv_desc, 278 NULL, 279 }; 280 281 struct vfsops fdesc_vfsops = { 282 MOUNT_FDESC, 283 0, 284 fdesc_mount, 285 fdesc_start, 286 fdesc_unmount, 287 fdesc_root, 288 fdesc_quotactl, 289 fdesc_statvfs, 290 fdesc_sync, 291 fdesc_vget, 292 (void *)eopnotsupp, /* vfs_fhtovp */ 293 (void *)eopnotsupp, /* vfs_vptofh */ 294 fdesc_init, 295 NULL, 296 fdesc_done, 297 NULL, /* vfs_mountroot */ 298 (int (*)(struct mount *, struct vnode *, struct timespec *)) eopnotsupp, 299 vfs_stdextattrctl, 300 (void *)eopnotsupp, /* vfs_suspendctl */ 301 fdesc_vnodeopv_descs, 302 0, 303 { NULL, NULL}, 304 }; 305 VFS_ATTACH(fdesc_vfsops); 306
Indexes created Fri Sep 26 20:09:58 GMT 2025