1 /* vi: set sw=4 ts=4: */
3 * ismounted.c --- Check to see if the filesystem was mounted
5 * Copyright (C) 1995,1996,1997,1998,1999,2000 Theodore Ts'o.
8 * This file may be redistributed under the terms of the GNU Public
21 #ifdef HAVE_LINUX_FD_H
27 #ifdef HAVE_GETMNTINFO
29 #include <sys/param.h>
30 #include <sys/mount.h>
31 #endif /* HAVE_GETMNTINFO */
40 * Helper function which checks a file in /etc/mtab format to see if a
41 * filesystem is mounted. Returns an error if the file doesn't exist
44 static errcode_t
check_mntent_file(const char *mtab_file
, const char *file
,
45 int *mount_flags
, char *mtpt
, int mtlen
)
50 dev_t file_dev
=0, file_rdev
=0;
56 if ((f
= setmntent (mtab_file
, "r")) == NULL
)
58 if (stat(file
, &st_buf
) == 0) {
59 if (S_ISBLK(st_buf
.st_mode
)) {
60 #ifndef __GNU__ /* The GNU hurd is broken with respect to stat devices */
61 file_rdev
= st_buf
.st_rdev
;
64 file_dev
= st_buf
.st_dev
;
65 file_ino
= st_buf
.st_ino
;
68 while ((mnt
= getmntent (f
)) != NULL
) {
69 if (strcmp(file
, mnt
->mnt_fsname
) == 0)
71 if (stat(mnt
->mnt_fsname
, &st_buf
) == 0) {
72 if (S_ISBLK(st_buf
.st_mode
)) {
74 if (file_rdev
&& (file_rdev
== st_buf
.st_rdev
))
78 if (file_dev
&& ((file_dev
== st_buf
.st_dev
) &&
79 (file_ino
== st_buf
.st_ino
)))
86 #ifndef __GNU__ /* The GNU hurd is broken with respect to stat devices */
88 * Do an extra check to see if this is the root device. We
89 * can't trust /etc/mtab, and /proc/mounts will only list
90 * /dev/root for the root filesystem. Argh. Instead we
91 * check if the given device has the same major/minor number
92 * as the device that the root directory is on.
94 if (file_rdev
&& stat("/", &st_buf
) == 0) {
95 if (st_buf
.st_dev
== file_rdev
) {
96 *mount_flags
= EXT2_MF_MOUNTED
;
98 strncpy(mtpt
, "/", mtlen
);
105 #ifndef __GNU__ /* The GNU hurd is deficient; what else is new? */
106 /* Validate the entry in case /etc/mtab is out of date */
108 * We need to be paranoid, because some broken distributions
109 * (read: Slackware) don't initialize /etc/mtab before checking
110 * all of the non-root filesystems on the disk.
112 if (stat(mnt
->mnt_dir
, &st_buf
) < 0) {
114 if (retval
== ENOENT
) {
116 printf("Bogus entry in %s! (%s does not exist)\n",
117 mtab_file
, mnt
->mnt_dir
);
123 if (file_rdev
&& (st_buf
.st_dev
!= file_rdev
)) {
125 printf("Bogus entry in %s! (%s not mounted on %s)\n",
126 mtab_file
, file
, mnt
->mnt_dir
);
131 *mount_flags
= EXT2_MF_MOUNTED
;
134 /* Check to see if the ro option is set */
135 if (hasmntopt(mnt
, MNTOPT_RO
))
136 *mount_flags
|= EXT2_MF_READONLY
;
140 strncpy(mtpt
, mnt
->mnt_dir
, mtlen
);
142 * Check to see if we're referring to the root filesystem.
143 * If so, do a manual check to see if we can open /etc/mtab
144 * read/write, since if the root is mounted read/only, the
145 * contents of /etc/mtab may not be accurate.
147 if (LONE_CHAR(mnt
->mnt_dir
, '/')) {
149 #define TEST_FILE "/.ismount-test-file"
150 *mount_flags
|= EXT2_MF_ISROOT
;
151 fd
= open(TEST_FILE
, O_RDWR
|O_CREAT
, 0777);
154 *mount_flags
|= EXT2_MF_READONLY
;
157 (void) unlink(TEST_FILE
);
165 static errcode_t
check_mntent(const char *file
, int *mount_flags
,
166 char *mtpt
, int mtlen
)
171 retval
= check_mntent_file("/tmp/mtab", file
, mount_flags
,
177 retval
= check_mntent_file("/proc/mounts", file
, mount_flags
,
180 #endif /* __linux__ */
181 #if defined(MOUNTED) || defined(_PATH_MOUNTED)
183 #define MOUNTED _PATH_MOUNTED
185 retval
= check_mntent_file(MOUNTED
, file
, mount_flags
, mtpt
, mtlen
);
190 #endif /* defined(MOUNTED) || defined(_PATH_MOUNTED) */
194 #if defined(HAVE_GETMNTINFO)
196 static errcode_t
check_getmntinfo(const char *file
, int *mount_flags
,
197 char *mtpt
, int mtlen
)
204 n
= getmntinfo(&mp
, MNT_NOWAIT
);
208 len
= sizeof(_PATH_DEV
) - 1;
210 if (strncmp(_PATH_DEV
, s1
, len
) == 0)
215 s2
= mp
->f_mntfromname
;
216 if (strncmp(_PATH_DEV
, s2
, len
) == 0) {
220 if (strcmp(s1
, s2
) == 0 || strcmp(s1
, &s2
[1]) == 0) {
221 *mount_flags
= EXT2_MF_MOUNTED
;
227 strncpy(mtpt
, mp
->f_mntonname
, mtlen
);
230 #endif /* HAVE_GETMNTINFO */
231 #endif /* HAVE_MNTENT_H */
234 * Check to see if we're dealing with the swap device.
236 static int is_swap_device(const char *file
)
245 #ifndef __GNU__ /* The GNU hurd is broken with respect to stat devices */
246 if ((stat(file
, &st_buf
) == 0) &&
247 S_ISBLK(st_buf
.st_mode
))
248 file_dev
= st_buf
.st_rdev
;
251 if (!(f
= fopen_for_read("/proc/swaps")))
253 /* Skip the first line */
254 fgets(buf
, sizeof(buf
), f
);
256 if (!fgets(buf
, sizeof(buf
), f
))
258 if ((cp
= strchr(buf
, ' ')) != NULL
)
260 if ((cp
= strchr(buf
, '\t')) != NULL
)
262 if (strcmp(buf
, file
) == 0) {
267 if (file_dev
&& (stat(buf
, &st_buf
) == 0) &&
268 S_ISBLK(st_buf
.st_mode
) &&
269 file_dev
== st_buf
.st_rdev
) {
281 * ext2fs_check_mount_point() returns 1 if the device is mounted, 0
282 * otherwise. If mtpt is non-NULL, the directory where the device is
283 * mounted is copied to where mtpt is pointing, up to mtlen
289 errcode_t
ext2fs_check_mount_point(const char *device
, int *mount_flags
,
290 char *mtpt
, int mtlen
)
292 if (is_swap_device(device
)) {
293 *mount_flags
= EXT2_MF_MOUNTED
| EXT2_MF_SWAP
;
294 strncpy(mtpt
, "<swap>", mtlen
);
298 return check_mntent(device
, mount_flags
, mtpt
, mtlen
);
300 #ifdef HAVE_GETMNTINFO
301 return check_getmntinfo(device
, mount_flags
, mtpt
, mtlen
);
304 #warning "Can't use getmntent or getmntinfo to check for mounted filesystems!"
308 #endif /* HAVE_GETMNTINFO */
309 #endif /* HAVE_MNTENT_H */
313 * ext2fs_check_if_mounted() sets the mount_flags EXT2_MF_MOUNTED,
314 * EXT2_MF_READONLY, and EXT2_MF_ROOT
317 errcode_t
ext2fs_check_if_mounted(const char *file
, int *mount_flags
)
319 return ext2fs_check_mount_point(file
, mount_flags
, NULL
, 0);
323 int main(int argc
, char **argv
)
325 int retval
, mount_flags
;
329 fprintf(stderr
, "Usage: %s device\n", argv
[0]);
334 retval
= ext2fs_check_mount_point(argv
[1], &mount_flags
,
335 mntpt
, sizeof(mntpt
));
337 com_err(argv
[0], retval
,
338 "while calling ext2fs_check_if_mounted");
341 printf("Device %s reports flags %02x\n", argv
[1], mount_flags
);
342 if (mount_flags
& EXT2_MF_BUSY
)
343 printf("\t%s is apparently in use.\n", argv
[1]);
344 if (mount_flags
& EXT2_MF_MOUNTED
)
345 printf("\t%s is mounted.\n", argv
[1]);
346 if (mount_flags
& EXT2_MF_SWAP
)
347 printf("\t%s is a swap device.\n", argv
[1]);
348 if (mount_flags
& EXT2_MF_READONLY
)
349 printf("\t%s is read-only.\n", argv
[1]);
350 if (mount_flags
& EXT2_MF_ISROOT
)
351 printf("\t%s is the root filesystem.\n", argv
[1]);
353 printf("\t%s is mounted on %s.\n", argv
[1], mntpt
);