#include <string.h>
#include <sys/stat.h>
#include <ctype.h>
+#include <sys/param.h>
#include "pathnames.h"
#include "ismounted.h"
-/*
- * ext2fs_check_if_mounted flags
- */
-#define MF_MOUNTED 1
-
-static char *skip_over_blank(char *cp)
-{
- while (*cp && isspace(*cp))
- cp++;
- return cp;
-}
-
-static char *skip_over_word(char *cp)
-{
- while (*cp && !isspace(*cp))
- cp++;
- return cp;
-}
-
-static char *parse_word(char **buf)
-{
- char *word, *next;
-
- word = *buf;
- if (*word == 0)
- return 0;
-
- word = skip_over_blank(word);
- next = skip_over_word(word);
- if (*next)
- *next++ = 0;
- *buf = next;
- return word;
-}
-
+#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)
+ 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;
- char buf[1024], *device = 0, *mnt_dir = 0, *cp;
+ int fd;
*mount_flags = 0;
if ((f = setmntent (mtab_file, "r")) == NULL)
file_ino = st_buf.st_ino;
}
}
- while (1) {
- if (!fgets(buf, sizeof(buf), f)) {
- device = mnt_dir = 0;
- break;
- }
- buf[sizeof(buf)-1] = 0;
-
- cp = buf;
- device = parse_word(&cp);
- if (!device || *device == '#')
- return 0; /* Ignore blank lines and comments */
- mnt_dir = parse_word(&cp);
-
- if (device[0] != '/')
+ while ((mnt = getmntent (f)) != NULL) {
+ if (mnt->mnt_fsname[0] != '/')
continue;
-
- if (strcmp(file, device) == 0)
+ if (strcmp(file, mnt->mnt_fsname) == 0)
break;
- if (stat(device, &st_buf) == 0) {
+ 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))
}
}
- if (mnt_dir == 0) {
+ 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
* 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))
+ if (file_rdev && stat("/", &st_buf) == 0 &&
+ st_buf.st_dev == file_rdev) {
*mount_flags = MF_MOUNTED;
+ if (mtpt)
+ strncpy(mtpt, "/", mtlen);
+ goto is_root;
+ }
#endif /* __GNU__ */
goto errout;
}
* (read: Slackware) don't initialize /etc/mtab before checking
* all of the non-root filesystems on the disk.
*/
- if (stat(mnt_dir, &st_buf) < 0) {
+ 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_dir);
+ mtab_file, mnt->mnt_dir);
#endif /* DEBUG */
retval = 0;
}
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_dir);
+ 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)
+ 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 (!strcmp(mnt->mnt_dir, "/")) {
+is_root:
+#define TEST_FILE "/.ismount-test-file"
+ *mount_flags |= MF_ISROOT;
+ fd = open(TEST_FILE, O_RDWR|O_CREAT, 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;
}
-int is_mounted(const char *file)
+static int check_mntent(const char *file, int *mount_flags,
+ char *mtpt, int mtlen)
{
int retval;
- int mount_flags = 0;
+#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(_PATH_PROC_MOUNTS, file, &mount_flags);
- if (retval)
+ retval = check_mntent_file("/proc/mounts", file, mount_flags,
+ mtpt, mtlen);
+ if (retval == 0 && (*mount_flags != 0))
return 0;
- if (mount_flags)
- return 1;
#endif /* __linux__ */
- retval = check_mntent_file(_PATH_MOUNTED, file, &mount_flags);
+#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)
+ 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 */
+ if (!fgets(buf, sizeof(buf), f))
+ goto leave;
+ if (*buf && strncmp(buf, "Filename\t", 9))
+ /* 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)
+{
+ struct stat st_buf;
+ int retval = 0;
+ int fd;
+
+ if (is_swap_device(device)) {
+ *mount_flags = MF_MOUNTED | MF_SWAP;
+ strncpy(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 */
+ if ((stat(device, &st_buf) != 0) ||
+ !S_ISBLK(st_buf.st_mode))
+ return 0;
+ fd = open(device, O_RDONLY | O_EXCL);
+ 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;
+ return mount_flags & MF_MOUNTED;
}
#ifdef TEST_PROGRAM
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 (is_mounted(argv[1])) {
- printf("mounted\n");
+ 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;
}
projects / util-linux / commitdiff