umount_fs.c

早期freebsd实现

/*
 * Copyright (c) 1990 Jan-Simon Pendry
 * Copyright (c) 1990 Imperial College of Science, Technology & Medicine
 * Copyright (c) 1990, 1993
 *	The Regents of the University of California.  All rights reserved.
 *
 * This code is derived from software contributed to Berkeley by
 * Jan-Simon Pendry at Imperial College, London.
 *
 * 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. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *	This product includes software developed by the University of
 *	California, Berkeley and its contributors.
 * 4. 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.
 *
 *	@(#)umount_fs.c	8.1 (Berkeley) 6/6/93
 *
 * $Id: umount_fs.c,v 5.2.2.1 1992/02/09 15:09:10 jsp beta $
 *
 */

#include "am.h"

#ifdef NEED_UMOUNT_BSD

int umount_fs P((char *fs_name));
int umount_fs(fs_name)
char *fs_name;
{
	int error;

eintr:
	error = unmount(fs_name, 0);
	if (error < 0)
		error = errno;

	switch (error) {
	case EINVAL:
	case ENOTBLK:
	case ENOENT:
		plog(XLOG_WARNING, "unmount: %s is not mounted", fs_name);
		error = 0;	/* Not really an error */
		break;

	case EINTR:
#ifdef DEBUG
		/* not sure why this happens, but it does.  ask kirk one day... */
		dlog("%s: unmount: %m", fs_name);
#endif /* DEBUG */
		goto eintr;

#ifdef DEBUG
	default:
		dlog("%s: unmount: %m", fs_name);
		break;
#endif /* DEBUG */
	}

	return error;
}

#endif /* NEED_UMOUNT_BSD */

#ifdef NEED_UMOUNT_OSF

#include <sys/mount.h>		/* For MNT_NOFORCE */

int umount_fs(fs_name)
char *fs_name;
{
	int error;

eintr:
	error = umount(fs_name, MNT_NOFORCE);
	if (error < 0)
		error = errno;

	switch (error) {
	case EINVAL:
	case ENOTBLK:
		plog(XLOG_WARNING, "unmount: %s is not mounted", fs_name);
		error = 0;	/* Not really an error */
		break;

	case ENOENT:
		plog(XLOG_ERROR, "mount point %s: %m", fs_name);
		break;

	case EINTR:
#ifdef DEBUG
		/* not sure why this happens, but it does.  ask kirk one day... */
		dlog("%s: unmount: %m", fs_name);
#endif /* DEBUG */
		goto eintr;

#ifdef DEBUG
	default:
		dlog("%s: unmount: %m", fs_name);
		break;
#endif /* DEBUG */
	}

	return error;
}

#endif /* NEED_UMOUNT_OSF */

#ifdef NEED_UMOUNT_FS

int umount_fs(fs_name)
char *fs_name;
{
	mntlist *mlist, *mp, *mp_save = 0;
	int error = 0;

	mp = mlist = read_mtab(fs_name);

	/*
	 * Search the mount table looking for
	 * the correct (ie last) matching entry
	 */
	while (mp) {
		if (strcmp(mp->mnt->mnt_fsname, fs_name) == 0 ||
				strcmp(mp->mnt->mnt_dir, fs_name) == 0)
			mp_save = mp;
		mp = mp->mnext;
	}

	if (mp_save) {
#ifdef DEBUG
		dlog("Trying unmount(%s)", mp_save->mnt->mnt_dir);
#endif /* DEBUG */
		/*
		 * This unmount may hang leaving this
		 * process with an exlusive lock on
		 * /etc/mtab. Therefore it is necessary
		 * to unlock mtab, do the unmount, then
		 * lock mtab (again) and reread it and
		 * finally update it.
		 */
		unlock_mntlist();
		if (UNMOUNT_TRAP(mp_save->mnt) < 0) {
			switch (error = errno) {
			case EINVAL:
			case ENOTBLK:
				plog(XLOG_WARNING, "unmount: %s is not mounted", mp_save->mnt->mnt_dir);
				error = 0;	/* Not really an error */
				break;

			case ENOENT:
				plog(XLOG_ERROR, "mount point %s: %m", mp_save->mnt->mnt_dir);
				break;

			default:
#ifdef DEBUG
				dlog("%s: unmount: %m", mp_save->mnt->mnt_dir);
#endif /* DEBUG */
				break;
			}
		}
#ifdef DEBUG
		dlog("Finished unmount(%s)", mp_save->mnt->mnt_dir);
#endif


#ifdef UPDATE_MTAB
		if (!error) {
		        free_mntlist(mlist);
			mp = mlist = read_mtab(fs_name);
			
			/*
			 * Search the mount table looking for
			 * the correct (ie last) matching entry
			 */
			mp_save = 0;
			while (mp) {
				if (strcmp(mp->mnt->mnt_fsname, fs_name) == 0 ||
						strcmp(mp->mnt->mnt_dir, fs_name) == 0)
					mp_save = mp;
				mp = mp->mnext;
			}
			
			if (mp_save) {
				mnt_free(mp_save->mnt);
				mp_save->mnt = 0;
				rewrite_mtab(mlist);
			}
		}
#endif /* UPDATE_MTAB */
	} else {
		plog(XLOG_ERROR, "Couldn't find how to unmount %s", fs_name);
		/*
		 * Assume it is already unmounted
		 */
		error = 0;
	}

	free_mntlist(mlist);

	return error;
}

#endif /* NEED_UMOUNT_FS */