/* vi: set sw=4 ts=4: *//* * ismounted.c --- Check to see if the filesystem was mounted * * Copyright (C) 1995,1996,1997,1998,1999,2000 Theodore Ts'o. * * %Begin-Header% * This file may be redistributed under the terms of the GNU Public * License. * %End-Header% */#include <stdio.h>#if HAVE_UNISTD_H#include <unistd.h>#endif#if HAVE_ERRNO_H#include <errno.h>#endif#include <fcntl.h>#ifdef HAVE_LINUX_FD_H#include <linux/fd.h>#endif#ifdef HAVE_MNTENT_H#include <mntent.h>#endif#ifdef HAVE_GETMNTINFO#include <paths.h>#include <sys/param.h>#include <sys/mount.h>#endif /* HAVE_GETMNTINFO */#include <string.h>#include <sys/stat.h>#include "ext2_fs.h"#include "ext2fs.h"#ifdef HAVE_MNTENT_H/* * Helper function which checks a file in /etc/mtab format to see if a * filesystem is mounted.  Returns an error if the file doesn't exist * or can't be opened. */static errcode_t check_mntent_file(const char *mtab_file, const char *file,				   int *mount_flags, char *mtpt, int mtlen){	struct mntent	*mnt;	struct stat	st_buf;	errcode_t	retval = 0;	dev_t		file_dev=0, file_rdev=0;	ino_t		file_ino=0;	FILE		*f;	int		fd;	*mount_flags = 0;	if ((f = setmntent (mtab_file, "r")) == NULL)		return errno;	if (stat(file, &st_buf) == 0) {		if (S_ISBLK(st_buf.st_mode)) {#ifndef __GNU__ /* The GNU hurd is broken with respect to stat devices */			file_rdev = st_buf.st_rdev;#endif	/* __GNU__ */		} else {			file_dev = st_buf.st_dev;			file_ino = st_buf.st_ino;		}	}	while ((mnt = getmntent (f)) != NULL) {		if (strcmp(file, mnt->mnt_fsname) == 0)			break;		if (stat(mnt->mnt_fsname, &st_buf) == 0) {			if (S_ISBLK(st_buf.st_mode)) {#ifndef __GNU__				if (file_rdev && (file_rdev == st_buf.st_rdev))					break;#endif	/* __GNU__ */			} else {				if (file_dev && ((file_dev == st_buf.st_dev) &&						 (file_ino == st_buf.st_ino)))					break;			}		}	}	if (mnt == 0) {#ifndef __GNU__ /* The GNU hurd is broken with respect to stat devices */		/*		 * Do an extra check to see if this is the root device.  We		 * can't trust /etc/mtab, and /proc/mounts will only list		 * /dev/root for the root filesystem.  Argh.  Instead we		 * check if the given device has the same major/minor number		 * as the device that the root directory is on.		 */		if (file_rdev && stat("/", &st_buf) == 0) {			if (st_buf.st_dev == file_rdev) {				*mount_flags = EXT2_MF_MOUNTED;				if (mtpt)					strncpy(mtpt, "/", mtlen);				goto is_root;			}		}#endif	/* __GNU__ */		goto errout;	}#ifndef __GNU__ /* The GNU hurd is deficient; what else is new? */	/* Validate the entry in case /etc/mtab is out of date */	/*	 * We need to be paranoid, because some broken distributions	 * (read: Slackware) don't initialize /etc/mtab before checking	 * all of the non-root filesystems on the disk.	 */	if (stat(mnt->mnt_dir, &st_buf) < 0) {		retval = errno;		if (retval == ENOENT) {#ifdef DEBUG			printf("Bogus entry in %s!  (%s does not exist)\n",			       mtab_file, mnt->mnt_dir);#endif /* DEBUG */			retval = 0;		}		goto errout;	}	if (file_rdev && (st_buf.st_dev != file_rdev)) {#ifdef DEBUG		printf("Bogus entry in %s!  (%s not mounted on %s)\n",		       mtab_file, file, mnt->mnt_dir);#endif /* DEBUG */		goto errout;	}#endif /* __GNU__ */	*mount_flags = EXT2_MF_MOUNTED;#ifdef MNTOPT_RO	/* Check to see if the ro option is set */	if (hasmntopt(mnt, MNTOPT_RO))		*mount_flags |= EXT2_MF_READONLY;#endif	if (mtpt)		strncpy(mtpt, mnt->mnt_dir, mtlen);	/*	 * Check to see if we're referring to the root filesystem.	 * If so, do a manual check to see if we can open /etc/mtab	 * read/write, since if the root is mounted read/only, the	 * contents of /etc/mtab may not be accurate.	 */	if (LONE_CHAR(mnt->mnt_dir, '/')) {is_root:#define TEST_FILE "/.ismount-test-file"		*mount_flags |= EXT2_MF_ISROOT;		fd = open(TEST_FILE, O_RDWR|O_CREAT);		if (fd < 0) {			if (errno == EROFS)				*mount_flags |= EXT2_MF_READONLY;		} else			close(fd);		(void) unlink(TEST_FILE);	}	retval = 0;errout:	endmntent (f);	return retval;}static errcode_t check_mntent(const char *file, int *mount_flags,			      char *mtpt, int mtlen){	errcode_t	retval;#ifdef DEBUG	retval = check_mntent_file("/tmp/mtab", file, mount_flags,				   mtpt, mtlen);	if (retval == 0)		return 0;#endif /* DEBUG */#ifdef __linux__	retval = check_mntent_file("/proc/mounts", file, mount_flags,				   mtpt, mtlen);	if (retval == 0 && (*mount_flags != 0))		return 0;#endif /* __linux__ */#if defined(MOUNTED) || defined(_PATH_MOUNTED)#ifndef MOUNTED#define MOUNTED _PATH_MOUNTED#endif /* MOUNTED */	retval = check_mntent_file(MOUNTED, file, mount_flags, mtpt, mtlen);	return retval;#else	*mount_flags = 0;	return 0;#endif /* defined(MOUNTED) || defined(_PATH_MOUNTED) */}#else#if defined(HAVE_GETMNTINFO)static errcode_t check_getmntinfo(const char *file, int *mount_flags,				  char *mtpt, int mtlen){	struct statfs *mp;	int    len, n;	const  char   *s1;	char	*s2;	n = getmntinfo(&mp, MNT_NOWAIT);	if (n == 0)		return errno;	len = sizeof(_PATH_DEV) - 1;	s1 = file;	if (strncmp(_PATH_DEV, s1, len) == 0)		s1 += len;	*mount_flags = 0;	while (--n >= 0) {		s2 = mp->f_mntfromname;		if (strncmp(_PATH_DEV, s2, len) == 0) {			s2 += len - 1;			*s2 = 'r';		}		if (strcmp(s1, s2) == 0 || strcmp(s1, &s2[1]) == 0) {			*mount_flags = EXT2_MF_MOUNTED;			break;		}		++mp;	}	if (mtpt)		strncpy(mtpt, mp->f_mntonname, mtlen);	return 0;}#endif /* HAVE_GETMNTINFO */#endif /* HAVE_MNTENT_H *//* * Check to see if we're dealing with the swap device. */static int is_swap_device(const char *file){	FILE		*f;	char		buf[1024], *cp;	dev_t		file_dev;	struct stat	st_buf;	int		ret = 0;	file_dev = 0;#ifndef __GNU__ /* The GNU hurd is broken with respect to stat devices */	if ((stat(file, &st_buf) == 0) &&	    S_ISBLK(st_buf.st_mode))		file_dev = st_buf.st_rdev;#endif	/* __GNU__ */	if (!(f = fopen("/proc/swaps", "r")))		return 0;	/* Skip the first line */	fgets(buf, sizeof(buf), f);	while (!feof(f)) {		if (!fgets(buf, sizeof(buf), f))			break;		if ((cp = strchr(buf, ' ')) != NULL)			*cp = 0;		if ((cp = strchr(buf, '\t')) != NULL)			*cp = 0;		if (strcmp(buf, file) == 0) {			ret++;			break;		}#ifndef __GNU__		if (file_dev && (stat(buf, &st_buf) == 0) &&		    S_ISBLK(st_buf.st_mode) &&		    file_dev == st_buf.st_rdev) {			ret++;			break;		}#endif	/* __GNU__ */	}	fclose(f);	return ret;}/* * ext2fs_check_mount_point() returns 1 if the device is mounted, 0 * otherwise.  If mtpt is non-NULL, the directory where the device is * mounted is copied to where mtpt is pointing, up to mtlen * characters. */#ifdef __TURBOC__# pragma argsused#endiferrcode_t ext2fs_check_mount_point(const char *device, int *mount_flags,				  char *mtpt, int mtlen){	if (is_swap_device(device)) {		*mount_flags = EXT2_MF_MOUNTED | EXT2_MF_SWAP;		strncpy(mtpt, "<swap>", mtlen);		return 0;	}#ifdef HAVE_MNTENT_H	return check_mntent(device, mount_flags, mtpt, mtlen);#else#ifdef HAVE_GETMNTINFO	return check_getmntinfo(device, mount_flags, mtpt, mtlen);#else#ifdef __GNUC__ #warning "Can't use getmntent or getmntinfo to check for mounted filesystems!"#endif	*mount_flags = 0;	return 0;#endif /* HAVE_GETMNTINFO */#endif /* HAVE_MNTENT_H */}/* * ext2fs_check_if_mounted() sets the mount_flags EXT2_MF_MOUNTED, * EXT2_MF_READONLY, and EXT2_MF_ROOT * */errcode_t ext2fs_check_if_mounted(const char *file, int *mount_flags){	return ext2fs_check_mount_point(file, mount_flags, NULL, 0);}#ifdef DEBUGint main(int argc, char **argv){	int	retval, mount_flags;	char	mntpt[80];	if (argc < 2) {		fprintf(stderr, "Usage: %s device\n", argv[0]);		exit(1);	}	mntpt[0] = 0;	retval = ext2fs_check_mount_point(argv[1], &mount_flags,					  mntpt, sizeof(mntpt));	if (retval) {		com_err(argv[0], retval,			"while calling ext2fs_check_if_mounted");		exit(1);	}	printf("Device %s reports flags %02x\n", argv[1], mount_flags);	if (mount_flags & EXT2_MF_BUSY)		printf("\t%s is apparently in use.\n", argv[1]);	if (mount_flags & EXT2_MF_MOUNTED)		printf("\t%s is mounted.\n", argv[1]);	if (mount_flags & EXT2_MF_SWAP)		printf("\t%s is a swap device.\n", argv[1]);	if (mount_flags & EXT2_MF_READONLY)		printf("\t%s is read-only.\n", argv[1]);	if (mount_flags & EXT2_MF_ISROOT)		printf("\t%s is the root filesystem.\n", argv[1]);	if (mntpt[0])		printf("\t%s is mounted on %s.\n", argv[1], mntpt);	exit(0);}#endif /* DEBUG */