systemd/udev-remove.c

/*
 * udev-remove.c
 *
 * Userspace devfs
 *
 * Copyright (C) 2003 Greg Kroah-Hartman <greg@kroah.com>
 *
 *
 *	This program is free software; you can redistribute it and/or modify it
 *	under the terms of the GNU General Public License as published by the
 *	Free Software Foundation version 2 of the License.
 * 
 *	This program is distributed in the hope that it will be useful, but
 *	WITHOUT ANY WARRANTY; without even the implied warranty of
 *	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 *	General Public License for more details.
 * 
 *	You should have received a copy of the GNU General Public License along
 *	with this program; if not, write to the Free Software Foundation, Inc.,
 *	675 Mass Ave, Cambridge, MA 02139, USA.
 *
 */

#include <stdlib.h>
#include <string.h>
#include <stdio.h>
#include <fcntl.h>
#include <unistd.h>
#include <errno.h>

#include "udev.h"
#include "udev_lib.h"
#include "udev_version.h"
#include "logging.h"
#include "namedev.h"
#include "udevdb.h"

static int delete_path(char *path)
{
	char *pos;
	int retval;

	pos = strrchr(path, '/');
	while (1) {
		*pos = '\0';
		pos = strrchr(path, '/');

		/* don't remove the last one */
		if ((pos == path) || (pos == NULL))
			break;

		/* remove if empty */
		retval = rmdir(path);
		if (errno == ENOENT)
			retval = 0;
		if (retval) {
			if (errno == ENOTEMPTY)
				return 0;
			dbg("rmdir(%s) failed with error '%s'",
			    path, strerror(errno));
			break;
		}
		dbg("removed '%s'", path);
	}
	return 0;
}

static int delete_node(struct udevice *dev)
{
	char filename[NAME_SIZE];
	char linkname[NAME_SIZE];
	char partitionname[NAME_SIZE];
	int retval;
	int i;
	char *pos;
	int len;

	strfieldcpy(filename, udev_root);
	strfieldcat(filename, dev->name);

	info("removing device node '%s'", filename);
	retval = unlink(filename);
	if (errno == ENOENT)
		retval = 0;
	if (retval) {
		dbg("unlink(%s) failed with error '%s'",
			filename, strerror(errno));
		return retval;
	}

	/* remove partition nodes */
	if (dev->partitions > 0) {
		info("removing partitions '%s[1-%i]'", filename, dev->partitions);
		for (i = 1; i <= dev->partitions; i++) {
			strfieldcpy(partitionname, filename);
			strintcat(partitionname, i);
			unlink(partitionname);
		}
	}

	/* remove subdirectories */
	if (strchr(dev->name, '/'))
		delete_path(filename);

	foreach_strpart(dev->symlink, " ", pos, len) {
		strfieldcpymax(linkname, pos, len+1);
		strfieldcpy(filename, udev_root);
		strfieldcat(filename, linkname);

		dbg("unlinking symlink '%s'", filename);
		retval = unlink(filename);
		if (errno == ENOENT)
			retval = 0;
		if (retval) {
			dbg("unlink(%s) failed with error '%s'",
				filename, strerror(errno));
			return retval;
		}
		if (strchr(dev->symlink, '/')) {
			delete_path(filename);
		}
	}

	return retval;
}

/*
 * Look up the sysfs path in the database to see if we have named this device
 * something different from the kernel name.  If we have, us it.  If not, use
 * the default kernel name for lack of anything else to know to do.
 */
int udev_remove_device(char *path, char *subsystem)
{
	struct udevice dev;
	char *temp;
	int retval;

	memset(&dev, 0x00, sizeof(dev));

	dev.type = get_device_type(path, subsystem);

	switch (dev.type) {
	case 'b':
	case 'c':
		retval = udevdb_get_dev(path, &dev);
		if (retval) {
			dbg("'%s' not found in database, falling back on default name", path);
			temp = strrchr(path, '/');
			if (temp == NULL)
				return -ENODEV;
			strfieldcpy(dev.name, &temp[1]);
		}

		dbg("name='%s'", dev.name);
		udevdb_delete_dev(path);

		dev_d_send(&dev, subsystem);

		retval = delete_node(&dev);
		break;

	case 'n':
		retval = 0;
		break;

	default:
		dbg("unknown device type '%c'", dev.type);
		retval = -EINVAL;
	}

	return retval;
}