fdesc_vfsops.c revision 1.65
1 /* $NetBSD: fdesc_vfsops.c,v 1.65 2007/07/08 23:58:53 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 1.65 2007/07/08 23:58:53 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 *, 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, 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 return 0; 89 /* 90 * Update is a no-op 91 */ 92 if (mp->mnt_flag & MNT_UPDATE) 93 return (EOPNOTSUPP); 94 95 error = fdesc_allocvp(Froot, FD_ROOT, mp, &rvp); 96 if (error) 97 return (error); 98 99 MALLOC(fmp, struct fdescmount *, sizeof(struct fdescmount), 100 M_UFSMNT, M_WAITOK); /* XXX */ 101 rvp->v_type = VDIR; 102 rvp->v_flag |= VROOT; 103 fmp->f_root = rvp; 104 mp->mnt_stat.f_namemax = MAXNAMLEN; 105 mp->mnt_flag |= MNT_LOCAL; 106 mp->mnt_data = fmp; 107 vfs_getnewfsid(mp); 108 109 error = set_statvfs_info(path, UIO_USERSPACE, "fdesc", UIO_SYSSPACE, 110 mp, l); 111 VOP_UNLOCK(rvp, 0); 112 return error; 113 } 114 115 int 116 fdesc_start(struct mount *mp, int flags, 117 struct lwp *l) 118 { 119 return (0); 120 } 121 122 int 123 fdesc_unmount(struct mount *mp, int mntflags, struct lwp *l) 124 { 125 int error; 126 int flags = 0; 127 struct vnode *rtvp = VFSTOFDESC(mp)->f_root; 128 129 if (mntflags & MNT_FORCE) 130 flags |= FORCECLOSE; 131 132 if (rtvp->v_usecount > 1 && (mntflags & MNT_FORCE) == 0) 133 return (EBUSY); 134 if ((error = vflush(mp, rtvp, flags)) != 0) 135 return (error); 136 137 /* 138 * Release reference on underlying root vnode 139 */ 140 vrele(rtvp); 141 /* 142 * And blow it away for future re-use 143 */ 144 vgone(rtvp); 145 /* 146 * Finally, throw away the fdescmount structure 147 */ 148 free(mp->mnt_data, M_UFSMNT); /* XXX */ 149 mp->mnt_data = 0; 150 151 return (0); 152 } 153 154 int 155 fdesc_root(mp, vpp) 156 struct mount *mp; 157 struct vnode **vpp; 158 { 159 struct vnode *vp; 160 161 /* 162 * Return locked reference to root. 163 */ 164 vp = VFSTOFDESC(mp)->f_root; 165 VREF(vp); 166 vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); 167 *vpp = vp; 168 return (0); 169 } 170 171 int 172 fdesc_quotactl(struct mount *mp, int cmd, uid_t uid, 173 void *arg, struct lwp *l) 174 { 175 176 return (EOPNOTSUPP); 177 } 178 179 int 180 fdesc_statvfs(mp, sbp, l) 181 struct mount *mp; 182 struct statvfs *sbp; 183 struct lwp *l; 184 { 185 struct filedesc *fdp; 186 struct proc *p; 187 int lim; 188 int i; 189 int last; 190 int freefd; 191 192 /* 193 * Compute number of free file descriptors. 194 * [ Strange results will ensue if the open file 195 * limit is ever reduced below the current number 196 * of open files... ] 197 */ 198 p = l->l_proc; 199 lim = p->p_rlimit[RLIMIT_NOFILE].rlim_cur; 200 fdp = p->p_fd; 201 last = min(fdp->fd_nfiles, lim); 202 freefd = 0; 203 for (i = fdp->fd_freefile; i < last; i++) 204 if (fdp->fd_ofiles[i] == NULL) 205 freefd++; 206 207 /* 208 * Adjust for the fact that the fdesc array may not 209 * have been fully allocated yet. 210 */ 211 if (fdp->fd_nfiles < lim) 212 freefd += (lim - fdp->fd_nfiles); 213 214 sbp->f_bsize = DEV_BSIZE; 215 sbp->f_frsize = DEV_BSIZE; 216 sbp->f_iosize = DEV_BSIZE; 217 sbp->f_blocks = 2; /* 1K to keep df happy */ 218 sbp->f_bfree = 0; 219 sbp->f_bavail = 0; 220 sbp->f_bresvd = 0; 221 sbp->f_files = lim + 1; /* Allow for "." */ 222 sbp->f_ffree = freefd; /* See comments above */ 223 sbp->f_favail = freefd; /* See comments above */ 224 sbp->f_fresvd = 0; 225 copy_statvfs_info(sbp, mp); 226 return (0); 227 } 228 229 /*ARGSUSED*/ 230 int 231 fdesc_sync(struct mount *mp, int waitfor, 232 kauth_cred_t uc, struct lwp *l) 233 { 234 235 return (0); 236 } 237 238 /* 239 * Fdesc flat namespace lookup. 240 * Currently unsupported. 241 */ 242 int 243 fdesc_vget(struct mount *mp, ino_t ino, 244 struct vnode **vpp) 245 { 246 247 return (EOPNOTSUPP); 248 } 249 250 251 SYSCTL_SETUP(sysctl_vfs_fdesc_setup, "sysctl vfs.fdesc subtree setup") 252 { 253 254 sysctl_createv(clog, 0, NULL, NULL, 255 CTLFLAG_PERMANENT, 256 CTLTYPE_NODE, "vfs", NULL, 257 NULL, 0, NULL, 0, 258 CTL_VFS, CTL_EOL); 259 sysctl_createv(clog, 0, NULL, NULL, 260 CTLFLAG_PERMANENT, 261 CTLTYPE_NODE, "fdesc", 262 SYSCTL_DESCR("File-descriptor file system"), 263 NULL, 0, NULL, 0, 264 CTL_VFS, 7, CTL_EOL); 265 /* 266 * XXX the "7" above could be dynamic, thereby eliminating one 267 * more instance of the "number to vfs" mapping problem, but 268 * "7" is the order as taken from sys/mount.h 269 */ 270 } 271 272 extern const struct vnodeopv_desc fdesc_vnodeop_opv_desc; 273 274 const struct vnodeopv_desc * const fdesc_vnodeopv_descs[] = { 275 &fdesc_vnodeop_opv_desc, 276 NULL, 277 }; 278 279 struct vfsops fdesc_vfsops = { 280 MOUNT_FDESC, 281 fdesc_mount, 282 fdesc_start, 283 fdesc_unmount, 284 fdesc_root, 285 fdesc_quotactl, 286 fdesc_statvfs, 287 fdesc_sync, 288 fdesc_vget, 289 (void *)eopnotsupp, /* vfs_fhtovp */ 290 (void *)eopnotsupp, /* vfs_vptofh */ 291 fdesc_init, 292 NULL, 293 fdesc_done, 294 NULL, /* vfs_mountroot */ 295 (int (*)(struct mount *, struct vnode *, struct timespec *)) eopnotsupp, 296 vfs_stdextattrctl, 297 vfs_stdsuspendctl, 298 fdesc_vnodeopv_descs, 299 0, 300 { NULL, NULL}, 301 }; 302 VFS_ATTACH(fdesc_vfsops); 303
Indexes created Fri Sep 26 20:09:58 GMT 2025