[thirdparty/util-linux.git] / lib / ismounted.c

/*
 * ismounted.c --- Check to see if the filesystem was mounted
 *
 * Copyright (C) 1995,1996,1997,1998,1999,2000,2008 Theodore Ts'o.
 *
 * This file may be redistributed under the terms of the GNU Public
 * License.
 */
#include <stdio.h>
#include <unistd.h>
#include <stdlib.h>
#include <errno.h>
#include <fcntl.h>
#ifdef HAVE_MNTENT_H
#include <mntent.h>
#endif
#include <string.h>
#include <sys/stat.h>
#include <ctype.h>
#include <sys/param.h>

#ifndef __linux__
# ifdef HAVE_SYS_UCRED_H
#  include <sys/ucred.h>
# endif
# ifdef HAVE_SYS_MOUNT_H
#  include <sys/mount.h>
# endif
#endif

#include "pathnames.h"
#include "strutils.h"
#include "ismounted.h"
#include "c.h"
#ifdef __linux__
# include "loopdev.h"
#endif


#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 int check_mntent_file(const char *mtab_file, const char *file,
				   int *mount_flags, char *mtpt, int mtlen)
{
	struct mntent	*mnt;
	struct stat	st_buf;
	int		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 (mnt->mnt_fsname[0] != '/')
			continue;
		if (strcmp(file, mnt->mnt_fsname) == 0)
			break;
		if (stat(mnt->mnt_fsname, &st_buf) != 0)
			continue;

		if (S_ISBLK(st_buf.st_mode)) {
#ifndef __GNU__
			if (file_rdev && file_rdev == st_buf.st_rdev)
				break;
#ifdef __linux__
			/* maybe the file is loopdev backing file */
			if (file_dev
			    && major(st_buf.st_rdev) == LOOPDEV_MAJOR
			    && loopdev_is_used(mnt->mnt_fsname, file, 0, 0, 0))
				break;
#endif /* __linux__ */
#endif	/* __GNU__ */
		} else {
			if (file_dev && ((file_dev == st_buf.st_dev) &&
					 (file_ino == st_buf.st_ino)))
				break;
		}
	}

	if (mnt == NULL) {
#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 &&
		    st_buf.st_dev == file_rdev) {
			*mount_flags = MF_MOUNTED;
			if (mtpt)
				xstrncpy(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 = MF_MOUNTED;

#ifdef MNTOPT_RO
	/* Check to see if the ro option is set */
	if (hasmntopt(mnt, MNTOPT_RO))
		*mount_flags |= MF_READONLY;
#endif

	if (mtpt)
		xstrncpy(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 (!strcmp(mnt->mnt_dir, "/")) {
is_root:
#define TEST_FILE "/.ismount-test-file"
		*mount_flags |= MF_ISROOT;
		fd = open(TEST_FILE, O_RDWR|O_CREAT|O_CLOEXEC, 0600);
		if (fd < 0) {
			if (errno == EROFS)
				*mount_flags |= MF_READONLY;
		} else
			close(fd);
		(void) unlink(TEST_FILE);
	}
	retval = 0;
errout:
	endmntent (f);
	return retval;
}

static int check_mntent(const char *file, int *mount_flags,
			      char *mtpt, int mtlen)
{
	int	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;
	if (access("/proc/mounts", R_OK) == 0) {
		*mount_flags = 0;
		return retval;
	}
#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 int 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 = MF_MOUNTED;
			break;
		}
                ++mp;
	}
	if (mtpt)
		xstrncpy(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" UL_CLOEXECSTR)))
		return 0;
	/* Skip the first line */
	if (!fgets(buf, sizeof(buf), f))
		goto leave;
	if (*buf && strncmp(buf, "Filename\t", 9) != 0)
		/* Linux <=2.6.19 contained a bug in the /proc/swaps
		 * code where the header would not be displayed
		 */
		goto valid_first_line;

	while (fgets(buf, sizeof(buf), f)) {
valid_first_line:
		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__ */
	}

leave:
	fclose(f);
	return ret;
}


/*
 * check_mount_point() fills determines if the device is mounted or otherwise
 * busy, and fills in mount_flags with one or more of the following flags:
 * MF_MOUNTED, MF_ISROOT, MF_READONLY, MF_SWAP, and MF_BUSY.  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
#endif
int check_mount_point(const char *device, int *mount_flags,
				  char *mtpt, int mtlen)
{
	int	retval = 0;

	if (is_swap_device(device)) {
		*mount_flags = MF_MOUNTED | MF_SWAP;
		if (mtpt && mtlen)
			xstrncpy(mtpt, "[SWAP]", mtlen);
	} else {
#ifdef HAVE_MNTENT_H
		retval = check_mntent(device, mount_flags, mtpt, mtlen);
#else
#ifdef HAVE_GETMNTINFO
		retval = 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;
#endif /* HAVE_GETMNTINFO */
#endif /* HAVE_MNTENT_H */
	}
	if (retval)
		return retval;

#ifdef __linux__ /* This only works on Linux 2.6+ systems */
	{
		struct stat st_buf;
		int fd;
		if ((stat(device, &st_buf) != 0) ||
		    !S_ISBLK(st_buf.st_mode))
			return 0;
		fd = open(device, O_RDONLY|O_EXCL|O_CLOEXEC);
		if (fd < 0) {
			if (errno == EBUSY)
				*mount_flags |= MF_BUSY;
		} else
			close(fd);
	}
#endif

	return 0;
}

int is_mounted(const char *file)
{
	int	retval;
	int	mount_flags = 0;

	retval = check_mount_point(file, &mount_flags, NULL, 0);
	if (retval)
		return 0;
	return mount_flags & MF_MOUNTED;
}

#ifdef TEST_PROGRAM_ISMOUNTED
int main(int argc, char **argv)
{
	int flags = 0;
	char devname[PATH_MAX];

	if (argc < 2) {
		fprintf(stderr, "Usage: %s device\n", argv[0]);
		return EXIT_FAILURE;
	}

	if (check_mount_point(argv[1], &flags, devname, sizeof(devname)) == 0 &&
	    (flags & MF_MOUNTED)) {
		if (flags & MF_SWAP)
			printf("used swap device\n");
		else
			printf("mounted on %s\n", devname);
		return EXIT_SUCCESS;
	}

	printf("not mounted\n");
	return EXIT_FAILURE;
}
#endif /* DEBUG */
Commit	Line	Data
607c2a72 KZ	1	/*
	2	* ismounted.c --- Check to see if the filesystem was mounted
	3	*
	4	* Copyright (C) 1995,1996,1997,1998,1999,2000,2008 Theodore Ts'o.
	5	*
	6	* This file may be redistributed under the terms of the GNU Public
	7	* License.
	8	*/
	9	#include <stdio.h>
	10	#include <unistd.h>
	11	#include <stdlib.h>
	12	#include <errno.h>
	13	#include <fcntl.h>
fbc333fe	14	#ifdef HAVE_MNTENT_H
607c2a72	15	#include <mntent.h>
9779651e	16	#endif
607c2a72 KZ	17	#include <string.h>
	18	#include <sys/stat.h>
	19	#include <ctype.h>
acf6ab6f	20	#include <sys/param.h>
ac1c53e4 RM	21
	22	#ifndef __linux__
	23	# ifdef HAVE_SYS_UCRED_H
	24	# include <sys/ucred.h>
	25	# endif
	26	# ifdef HAVE_SYS_MOUNT_H
	27	# include <sys/mount.h>
	28	# endif
9779651e	29	#endif
607c2a72	30
fb429f22	31	#include "pathnames.h"
8ecc6ba8	32	#include "strutils.h"
607c2a72	33	#include "ismounted.h"
4951f9b3	34	#include "c.h"
ca4f6229 KZ	35	#ifdef __linux__
	36	# include "loopdev.h"
	37	#endif
	38
	39
607c2a72	40
acf6ab6f	41	#ifdef HAVE_MNTENT_H
607c2a72 KZ	42	/*
	43	* Helper function which checks a file in /etc/mtab format to see if a
	44	* filesystem is mounted. Returns an error if the file doesn't exist
	45	* or can't be opened.
	46	*/
	47	static int check_mntent_file(const char mtab_file, const char file,
acf6ab6f	48	int mount_flags, char mtpt, int mtlen)
607c2a72	49	{
acf6ab6f	50	struct mntent *mnt;
607c2a72 KZ	51	struct stat st_buf;
607c2a72 KZ	52	int retval = 0;
45ddc110	53	dev_t file_dev=0, file_rdev=0;
607c2a72	54	ino_t file_ino=0;
fb429f22	55	FILE *f;
acf6ab6f	56	int fd;
607c2a72 KZ	57
607c2a72 KZ	58	*mount_flags = 0;
607c2a72 KZ	59	if ((f = setmntent (mtab_file, "r")) == NULL)
607c2a72 KZ	60	return errno;
ca4f6229	61
607c2a72 KZ	62	if (stat(file, &st_buf) == 0) {
	63	if (S_ISBLK(st_buf.st_mode)) {
	64	#ifndef __GNU__ /* The GNU hurd is broken with respect to stat devices */
	65	file_rdev = st_buf.st_rdev;
	66	#endif /* __GNU__ */
	67	} else {
	68	file_dev = st_buf.st_dev;
	69	file_ino = st_buf.st_ino;
	70	}
	71	}
ca4f6229	72
acf6ab6f KZ	73	while ((mnt = getmntent (f)) != NULL) {
acf6ab6f KZ	74	if (mnt->mnt_fsname[0] != '/')
607c2a72	75	continue;
acf6ab6f	76	if (strcmp(file, mnt->mnt_fsname) == 0)
607c2a72	77	break;
ca4f6229 KZ	78	if (stat(mnt->mnt_fsname, &st_buf) != 0)
	79	continue;
	80
	81	if (S_ISBLK(st_buf.st_mode)) {
607c2a72	82	#ifndef __GNU__
45ddc110 KZ	83	if (file_rdev && file_rdev == st_buf.st_rdev)
	84	break;
	85	#ifdef __linux__
	86	/* maybe the file is loopdev backing file */
	87	if (file_dev
	88	&& major(st_buf.st_rdev) == LOOPDEV_MAJOR
74a4705a	89	&& loopdev_is_used(mnt->mnt_fsname, file, 0, 0, 0))
ca4f6229	90	break;
45ddc110	91	#endif /* __linux__ */
ca4f6229 KZ	92	#endif /* __GNU__ */
	93	} else {
	94	if (file_dev && ((file_dev == st_buf.st_dev) &&
	95	(file_ino == st_buf.st_ino)))
	96	break;
607c2a72 KZ	97	}
	98	}
	99
f8bd089b	100	if (mnt == NULL) {
607c2a72 KZ	101	#ifndef __GNU__ /* The GNU hurd is broken with respect to stat devices */
	102	/*
	103	* Do an extra check to see if this is the root device. We
	104	* can't trust /etc/mtab, and /proc/mounts will only list
	105	* /dev/root for the root filesystem. Argh. Instead we
	106	* check if the given device has the same major/minor number
	107	* as the device that the root directory is on.
	108	*/
acf6ab6f KZ	109	if (file_rdev && stat("/", &st_buf) == 0 &&
acf6ab6f KZ	110	st_buf.st_dev == file_rdev) {
607c2a72	111	*mount_flags = MF_MOUNTED;
acf6ab6f	112	if (mtpt)
8ecc6ba8	113	xstrncpy(mtpt, "/", mtlen);
acf6ab6f KZ	114	goto is_root;
acf6ab6f KZ	115	}
607c2a72 KZ	116	#endif /* __GNU__ */
	117	goto errout;
	118	}
	119	#ifndef __GNU__ /* The GNU hurd is deficient; what else is new? */
	120	/* Validate the entry in case /etc/mtab is out of date */
	121	/*
	122	* We need to be paranoid, because some broken distributions
	123	* (read: Slackware) don't initialize /etc/mtab before checking
	124	* all of the non-root filesystems on the disk.
	125	*/
acf6ab6f	126	if (stat(mnt->mnt_dir, &st_buf) < 0) {
607c2a72 KZ	127	retval = errno;
	128	if (retval == ENOENT) {
	129	#ifdef DEBUG
	130	printf("Bogus entry in %s! (%s does not exist)\n",
acf6ab6f	131	mtab_file, mnt->mnt_dir);
607c2a72 KZ	132	#endif /* DEBUG */
	133	retval = 0;
	134	}
	135	goto errout;
	136	}
	137	if (file_rdev && (st_buf.st_dev != file_rdev)) {
	138	#ifdef DEBUG
	139	printf("Bogus entry in %s! (%s not mounted on %s)\n",
acf6ab6f	140	mtab_file, file, mnt->mnt_dir);
607c2a72 KZ	141	#endif /* DEBUG */
	142	goto errout;
	143	}
	144	#endif /* __GNU__ */
	145	*mount_flags = MF_MOUNTED;
	146
acf6ab6f KZ	147	#ifdef MNTOPT_RO
	148	/* Check to see if the ro option is set */
	149	if (hasmntopt(mnt, MNTOPT_RO))
	150	*mount_flags \|= MF_READONLY;
	151	#endif
	152
	153	if (mtpt)
8ecc6ba8	154	xstrncpy(mtpt, mnt->mnt_dir, mtlen);
acf6ab6f KZ	155	/*
	156	* Check to see if we're referring to the root filesystem.
	157	* If so, do a manual check to see if we can open /etc/mtab
	158	* read/write, since if the root is mounted read/only, the
	159	* contents of /etc/mtab may not be accurate.
	160	*/
	161	if (!strcmp(mnt->mnt_dir, "/")) {
	162	is_root:
	163	#define TEST_FILE "/.ismount-test-file"
	164	*mount_flags \|= MF_ISROOT;
b1fa3e22	165	fd = open(TEST_FILE, O_RDWR\|O_CREAT\|O_CLOEXEC, 0600);
acf6ab6f KZ	166	if (fd < 0) {
	167	if (errno == EROFS)
	168	*mount_flags \|= MF_READONLY;
	169	} else
	170	close(fd);
	171	(void) unlink(TEST_FILE);
	172	}
607c2a72 KZ	173	retval = 0;
	174	errout:
	175	endmntent (f);
	176	return retval;
	177	}
	178
acf6ab6f KZ	179	static int check_mntent(const char file, int mount_flags,
acf6ab6f KZ	180	char *mtpt, int mtlen)
607c2a72 KZ	181	{
607c2a72 KZ	182	int retval;
607c2a72	183
acf6ab6f KZ	184	#ifdef DEBUG
	185	retval = check_mntent_file("/tmp/mtab", file, mount_flags,
	186	mtpt, mtlen);
	187	if (retval == 0)
	188	return 0;
	189	#endif /* DEBUG */
607c2a72	190	#ifdef __linux__
acf6ab6f KZ	191	retval = check_mntent_file("/proc/mounts", file, mount_flags,
	192	mtpt, mtlen);
	193	if (retval == 0 && (*mount_flags != 0))
607c2a72	194	return 0;
8c9e72ce KZ	195	if (access("/proc/mounts", R_OK) == 0) {
	196	*mount_flags = 0;
	197	return retval;
	198	}
607c2a72	199	#endif /* __linux__ */
acf6ab6f KZ	200	#if defined(MOUNTED) \|\| defined(_PATH_MOUNTED)
	201	#ifndef MOUNTED
	202	#define MOUNTED _PATH_MOUNTED
	203	#endif /* MOUNTED */
	204	retval = check_mntent_file(MOUNTED, file, mount_flags, mtpt, mtlen);
	205	return retval;
	206	#else
	207	*mount_flags = 0;
	208	return 0;
	209	#endif /* defined(MOUNTED) \|\| defined(_PATH_MOUNTED) */
	210	}
	211
	212	#else
	213	#if defined(HAVE_GETMNTINFO)
	214
	215	static int check_getmntinfo(const char file, int mount_flags,
	216	char *mtpt, int mtlen)
	217	{
	218	struct statfs *mp;
	219	int len, n;
	220	const char *s1;
	221	char *s2;
	222
	223	n = getmntinfo(&mp, MNT_NOWAIT);
	224	if (n == 0)
	225	return errno;
	226
	227	len = sizeof(_PATH_DEV) - 1;
	228	s1 = file;
	229	if (strncmp(_PATH_DEV, s1, len) == 0)
	230	s1 += len;
	231
	232	*mount_flags = 0;
	233	while (--n >= 0) {
	234	s2 = mp->f_mntfromname;
	235	if (strncmp(_PATH_DEV, s2, len) == 0) {
	236	s2 += len - 1;
	237	*s2 = 'r';
	238	}
	239	if (strcmp(s1, s2) == 0 \|\| strcmp(s1, &s2[1]) == 0) {
	240	*mount_flags = MF_MOUNTED;
	241	break;
	242	}
	243	++mp;
	244	}
	245	if (mtpt)
8ecc6ba8	246	xstrncpy(mtpt, mp->f_mntonname, mtlen);
acf6ab6f KZ	247	return 0;
	248	}
	249	#endif /* HAVE_GETMNTINFO */
	250	#endif /* HAVE_MNTENT_H */
	251
	252	/*
	253	* Check to see if we're dealing with the swap device.
	254	*/
	255	static int is_swap_device(const char *file)
	256	{
	257	FILE *f;
	258	char buf[1024], *cp;
	259	dev_t file_dev;
	260	struct stat st_buf;
	261	int ret = 0;
	262
	263	file_dev = 0;
	264	#ifndef __GNU__ /* The GNU hurd is broken with respect to stat devices */
	265	if ((stat(file, &st_buf) == 0) &&
	266	S_ISBLK(st_buf.st_mode))
	267	file_dev = st_buf.st_rdev;
	268	#endif /* __GNU__ */
	269
b1fa3e22	270	if (!(f = fopen("/proc/swaps", "r" UL_CLOEXECSTR)))
acf6ab6f KZ	271	return 0;
	272	/* Skip the first line */
	273	if (!fgets(buf, sizeof(buf), f))
	274	goto leave;
ad296391	275	if (*buf && strncmp(buf, "Filename\t", 9) != 0)
acf6ab6f KZ	276	/* Linux <=2.6.19 contained a bug in the /proc/swaps
	277	* code where the header would not be displayed
	278	*/
	279	goto valid_first_line;
	280
	281	while (fgets(buf, sizeof(buf), f)) {
	282	valid_first_line:
	283	if ((cp = strchr(buf, ' ')) != NULL)
	284	*cp = 0;
	285	if ((cp = strchr(buf, '\t')) != NULL)
	286	*cp = 0;
	287	if (strcmp(buf, file) == 0) {
	288	ret++;
	289	break;
	290	}
	291	#ifndef __GNU__
	292	if (file_dev && (stat(buf, &st_buf) == 0) &&
	293	S_ISBLK(st_buf.st_mode) &&
	294	file_dev == st_buf.st_rdev) {
	295	ret++;
	296	break;
	297	}
	298	#endif /* __GNU__ */
	299	}
	300
	301	leave:
	302	fclose(f);
	303	return ret;
	304	}
	305
	306
	307	/*
	308	* check_mount_point() fills determines if the device is mounted or otherwise
	309	* busy, and fills in mount_flags with one or more of the following flags:
	310	* MF_MOUNTED, MF_ISROOT, MF_READONLY, MF_SWAP, and MF_BUSY. If mtpt is
	311	* non-NULL, the directory where the device is mounted is copied to where mtpt
	312	* is pointing, up to mtlen characters.
	313	*/
	314	#ifdef __TURBOC__
	315	#pragma argsused
	316	#endif
	317	int check_mount_point(const char device, int mount_flags,
	318	char *mtpt, int mtlen)
	319	{
acf6ab6f	320	int retval = 0;
acf6ab6f KZ	321
	322	if (is_swap_device(device)) {
	323	*mount_flags = MF_MOUNTED \| MF_SWAP;
f3135f93	324	if (mtpt && mtlen)
8ecc6ba8	325	xstrncpy(mtpt, "[SWAP]", mtlen);
acf6ab6f KZ	326	} else {
	327	#ifdef HAVE_MNTENT_H
	328	retval = check_mntent(device, mount_flags, mtpt, mtlen);
	329	#else
	330	#ifdef HAVE_GETMNTINFO
	331	retval = check_getmntinfo(device, mount_flags, mtpt, mtlen);
	332	#else
	333	#ifdef __GNUC__
	334	#warning "Can't use getmntent or getmntinfo to check for mounted filesystems!"
	335	#endif
	336	*mount_flags = 0;
	337	#endif /* HAVE_GETMNTINFO */
	338	#endif /* HAVE_MNTENT_H */
	339	}
	340	if (retval)
	341	return retval;
	342
	343	#ifdef __linux__ /* This only works on Linux 2.6+ systems */
8b9cf26a RM	344	{
	345	struct stat st_buf;
	346	int fd;
	347	if ((stat(device, &st_buf) != 0) \|\|
	348	!S_ISBLK(st_buf.st_mode))
	349	return 0;
	350	fd = open(device, O_RDONLY\|O_EXCL\|O_CLOEXEC);
	351	if (fd < 0) {
	352	if (errno == EBUSY)
	353	*mount_flags \|= MF_BUSY;
	354	} else
	355	close(fd);
	356	}
acf6ab6f KZ	357	#endif
	358
	359	return 0;
	360	}
	361
	362	int is_mounted(const char *file)
	363	{
	364	int retval;
	365	int mount_flags = 0;
	366
	367	retval = check_mount_point(file, &mount_flags, NULL, 0);
607c2a72 KZ	368	if (retval)
607c2a72 KZ	369	return 0;
acf6ab6f	370	return mount_flags & MF_MOUNTED;
607c2a72 KZ	371	}
607c2a72 KZ	372
e8f7acb0	373	#ifdef TEST_PROGRAM_ISMOUNTED
607c2a72 KZ	374	int main(int argc, char **argv)
607c2a72 KZ	375	{
acf6ab6f KZ	376	int flags = 0;
	377	char devname[PATH_MAX];
	378
607c2a72 KZ	379	if (argc < 2) {
607c2a72 KZ	380	fprintf(stderr, "Usage: %s device\n", argv[0]);
355eceba	381	return EXIT_FAILURE;
607c2a72 KZ	382	}
607c2a72 KZ	383
acf6ab6f KZ	384	if (check_mount_point(argv[1], &flags, devname, sizeof(devname)) == 0 &&
	385	(flags & MF_MOUNTED)) {
	386	if (flags & MF_SWAP)
	387	printf("used swap device\n");
	388	else
	389	printf("mounted on %s\n", devname);
355eceba KZ	390	return EXIT_SUCCESS;
355eceba KZ	391	}
acf6ab6f	392
355eceba KZ	393	printf("not mounted\n");
355eceba KZ	394	return EXIT_FAILURE;
607c2a72 KZ	395	}
607c2a72 KZ	396	#endif /* DEBUG */