/* $NetBSD: fdesc_vfsops.c,v 1.79 2009/03/14 15:36:22 dsl Exp $ */ /* * Copyright (c) 1992, 1993, 1995 * The Regents of the University of California. All rights reserved. * * This code is derived from software donated to Berkeley by * Jan-Simon Pendry. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 3. Neither the name of the University nor the names of its contributors * may be used to endorse or promote products derived from this software * without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. * * @(#)fdesc_vfsops.c 8.10 (Berkeley) 5/14/95 * * #Id: fdesc_vfsops.c,v 1.9 1993/04/06 15:28:33 jsp Exp # */ /* * /dev/fd Filesystem */ #include __KERNEL_RCSID(0, "$NetBSD: fdesc_vfsops.c,v 1.79 2009/03/14 15:36:22 dsl Exp $"); #if defined(_KERNEL_OPT) #include "opt_compat_netbsd.h" #endif #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include MODULE(MODULE_CLASS_VFS, fdesc, NULL); VFS_PROTOS(fdesc); static struct sysctllog *fdesc_sysctl_log; /* * Mount the per-process file descriptors (/dev/fd) */ int fdesc_mount(struct mount *mp, const char *path, void *data, size_t *data_len) { struct lwp *l = curlwp; int error = 0; struct fdescmount *fmp; struct vnode *rvp; if (mp->mnt_flag & MNT_GETARGS) { *data_len = 0; return 0; } /* * Update is a no-op */ if (mp->mnt_flag & MNT_UPDATE) return (EOPNOTSUPP); error = fdesc_allocvp(Froot, FD_ROOT, mp, &rvp); if (error) return (error); fmp = (struct fdescmount *)malloc(sizeof(struct fdescmount), M_UFSMNT, M_WAITOK); /* XXX */ rvp->v_type = VDIR; rvp->v_vflag |= VV_ROOT; fmp->f_root = rvp; mp->mnt_stat.f_namemax = MAXNAMLEN; mp->mnt_flag |= MNT_LOCAL; mp->mnt_data = fmp; vfs_getnewfsid(mp); error = set_statvfs_info(path, UIO_USERSPACE, "fdesc", UIO_SYSSPACE, mp->mnt_op->vfs_name, mp, l); VOP_UNLOCK(rvp, 0); return error; } int fdesc_start(struct mount *mp, int flags) { return (0); } int fdesc_unmount(struct mount *mp, int mntflags) { int error; int flags = 0; struct vnode *rtvp = VFSTOFDESC(mp)->f_root; if (mntflags & MNT_FORCE) flags |= FORCECLOSE; if (rtvp->v_usecount > 1 && (mntflags & MNT_FORCE) == 0) return (EBUSY); if ((error = vflush(mp, rtvp, flags)) != 0) return (error); /* * Blow it away for future re-use */ vgone(rtvp); /* * Finally, throw away the fdescmount structure */ free(mp->mnt_data, M_UFSMNT); /* XXX */ mp->mnt_data = NULL; return (0); } int fdesc_root(struct mount *mp, struct vnode **vpp) { struct vnode *vp; /* * Return locked reference to root. */ vp = VFSTOFDESC(mp)->f_root; VREF(vp); vn_lock(vp, LK_EXCLUSIVE | LK_RETRY); *vpp = vp; return (0); } int fdesc_statvfs(struct mount *mp, struct statvfs *sbp) { struct lwp *l = curlwp; struct filedesc *fdp; struct proc *p; int lim; int i; int last; int freefd; /* * Compute number of free file descriptors. * [ Strange results will ensue if the open file * limit is ever reduced below the current number * of open files... ] */ p = l->l_proc; lim = p->p_rlimit[RLIMIT_NOFILE].rlim_cur; fdp = p->p_fd; last = min(fdp->fd_nfiles, lim); freefd = 0; for (i = fdp->fd_freefile; i < last; i++) if (fdp->fd_ofiles[i] == NULL) freefd++; /* * Adjust for the fact that the fdesc array may not * have been fully allocated yet. */ if (fdp->fd_nfiles < lim) freefd += (lim - fdp->fd_nfiles); sbp->f_bsize = DEV_BSIZE; sbp->f_frsize = DEV_BSIZE; sbp->f_iosize = DEV_BSIZE; sbp->f_blocks = 2; /* 1K to keep df happy */ sbp->f_bfree = 0; sbp->f_bavail = 0; sbp->f_bresvd = 0; sbp->f_files = lim + 1; /* Allow for "." */ sbp->f_ffree = freefd; /* See comments above */ sbp->f_favail = freefd; /* See comments above */ sbp->f_fresvd = 0; copy_statvfs_info(sbp, mp); return (0); } /*ARGSUSED*/ int fdesc_sync(struct mount *mp, int waitfor, kauth_cred_t uc) { return (0); } /* * Fdesc flat namespace lookup. * Currently unsupported. */ int fdesc_vget(struct mount *mp, ino_t ino, struct vnode **vpp) { return (EOPNOTSUPP); } extern const struct vnodeopv_desc fdesc_vnodeop_opv_desc; const struct vnodeopv_desc * const fdesc_vnodeopv_descs[] = { &fdesc_vnodeop_opv_desc, NULL, }; struct vfsops fdesc_vfsops = { MOUNT_FDESC, 0, fdesc_mount, fdesc_start, fdesc_unmount, fdesc_root, (void *)eopnotsupp, /* vfs_quotactl */ fdesc_statvfs, fdesc_sync, fdesc_vget, (void *)eopnotsupp, /* vfs_fhtovp */ (void *)eopnotsupp, /* vfs_vptofh */ fdesc_init, NULL, fdesc_done, NULL, /* vfs_mountroot */ (int (*)(struct mount *, struct vnode *, struct timespec *)) eopnotsupp, vfs_stdextattrctl, (void *)eopnotsupp, /* vfs_suspendctl */ genfs_renamelock_enter, genfs_renamelock_exit, (void *)eopnotsupp, fdesc_vnodeopv_descs, 0, { NULL, NULL}, }; static int fdesc_modcmd(modcmd_t cmd, void *arg) { int error; switch (cmd) { case MODULE_CMD_INIT: error = vfs_attach(&fdesc_vfsops); if (error != 0) break; sysctl_createv(&fdesc_sysctl_log, 0, NULL, NULL, CTLFLAG_PERMANENT, CTLTYPE_NODE, "vfs", NULL, NULL, 0, NULL, 0, CTL_VFS, CTL_EOL); sysctl_createv(&fdesc_sysctl_log, 0, NULL, NULL, CTLFLAG_PERMANENT, CTLTYPE_NODE, "fdesc", SYSCTL_DESCR("File-descriptor file system"), NULL, 0, NULL, 0, CTL_VFS, 7, CTL_EOL); /* * XXX the "7" above could be dynamic, thereby eliminating one * more instance of the "number to vfs" mapping problem, but * "7" is the order as taken from sys/mount.h */ break; case MODULE_CMD_FINI: error = vfs_detach(&fdesc_vfsops); if (error != 0) break; sysctl_teardown(&fdesc_sysctl_log); break; default: error = ENOTTY; break; } return (error); }