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-rw-r--r--lib/ext2fs/ismounted.c478
1 files changed, 478 insertions, 0 deletions
diff --git a/lib/ext2fs/ismounted.c b/lib/ext2fs/ismounted.c
new file mode 100644
index 0000000..a7db1a5
--- /dev/null
+++ b/lib/ext2fs/ismounted.c
@@ -0,0 +1,478 @@
+/*
+ * 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 Library
+ * General Public License, version 2.
+ * %End-Header%
+ */
+
+/* define BSD_SOURCE to make sure we get the major() macro */
+#ifndef _BSD_SOURCE
+#define _BSD_SOURCE
+#endif
+#ifndef _DEFAULT_SOURCE
+#define _DEFAULT_SOURCE /* since glibc 2.20 _SVID_SOURCE is deprecated */
+#endif
+
+#include "config.h"
+#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_LINUX_LOOP_H
+#include <linux/loop.h>
+#include <sys/ioctl.h>
+#ifdef HAVE_LINUX_MAJOR_H
+#include <linux/major.h>
+#endif /* HAVE_LINUX_MAJOR_H */
+#endif /* HAVE_LINUX_LOOP_H */
+#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>
+#if HAVE_SYS_TYPES_H
+#include <sys/types.h>
+#endif
+#ifdef HAVE_SYS_SYSMACROS_H
+#include <sys/sysmacros.h>
+#endif
+
+#include "ext2_fs.h"
+#include "ext2fs.h"
+#include "ext2fsP.h"
+
+#ifdef HAVE_SETMNTENT
+/*
+ * Check to see if a regular file is mounted.
+ * If /etc/mtab/ is a symlink of /proc/mounts, you will need the following check
+ * because the name in /proc/mounts is a loopback device not a regular file.
+ */
+static int check_loop_mounted(const char *mnt_fsname, dev_t mnt_rdev,
+ dev_t file_dev, ino_t file_ino)
+{
+#if defined(HAVE_LINUX_LOOP_H) && defined(HAVE_LINUX_MAJOR_H)
+ struct loop_info64 loopinfo = {0, };
+ int loop_fd, ret;
+
+ if (major(mnt_rdev) == LOOP_MAJOR) {
+ loop_fd = open(mnt_fsname, O_RDONLY);
+ if (loop_fd < 0)
+ return -1;
+
+ ret = ioctl(loop_fd, LOOP_GET_STATUS64, &loopinfo);
+ close(loop_fd);
+ if (ret < 0)
+ return -1;
+
+ if (file_dev == loopinfo.lo_device &&
+ file_ino == loopinfo.lo_inode)
+ return 1;
+ }
+#endif /* defined(HAVE_LINUX_LOOP_H) && defined(HAVE_LINUX_MAJOR_H) */
+ return 0;
+}
+
+/*
+ * 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, dir_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) {
+ if (errno == ENOENT) {
+ if (getenv("EXT2FS_NO_MTAB_OK"))
+ return 0;
+ else
+ return EXT2_ET_NO_MTAB_FILE;
+ }
+ return errno;
+ }
+ if (stat(file, &st_buf) == 0) {
+ if (ext2fsP_is_disk_device(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) {
+ if (stat(mnt->mnt_dir, &st_buf) != 0)
+ continue;
+ if (file_rdev && (file_rdev != st_buf.st_dev)) {
+#ifdef DEBUG
+ printf("Bogus entry in %s! "
+ "(%s is not mounted on %s)\n",
+ mtab_file, file, mnt->mnt_dir);
+#endif /* DEBUG */
+ continue;
+ }
+ break;
+ }
+ if (stat(mnt->mnt_fsname, &st_buf) == 0) {
+ if (ext2fsP_is_disk_device(st_buf.st_mode)) {
+#ifndef __GNU__
+ if (file_rdev &&
+ (file_rdev == st_buf.st_rdev)) {
+ if (stat(mnt->mnt_dir,
+ &dir_st_buf) != 0)
+ continue;
+ if (file_rdev == dir_st_buf.st_dev)
+ break;
+ }
+ if (check_loop_mounted(mnt->mnt_fsname,
+ st_buf.st_rdev, file_dev,
+ file_ino) == 1)
+ 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;
+ }
+ *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 (!strcmp(mnt->mnt_dir, "/")) {
+is_root:
+#define TEST_FILE "/.ismount-test-file"
+ *mount_flags |= EXT2_MF_ISROOT;
+ fd = open(TEST_FILE, O_RDWR|O_CREAT, 0600);
+ if (fd < 0) {
+ if (errno == EROFS)
+ *mount_flags |= EXT2_MF_READONLY;
+ } else
+ close(fd);
+ (void) unlink(TEST_FILE);
+ }
+
+ if (mnt && mnt->mnt_type &&
+ (!strcmp(mnt->mnt_type, "ext4") ||
+ !strcmp(mnt->mnt_type, "ext3") ||
+ !strcmp(mnt->mnt_type, "ext2")))
+ *mount_flags |= EXT2_MF_EXTFS;
+ 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)
+ 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_SETMNTENT */
+
+/*
+ * 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) &&
+ ext2fsP_is_disk_device(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) &&
+ ext2fsP_is_disk_device(st_buf.st_mode) &&
+ file_dev == st_buf.st_rdev) {
+ ret++;
+ break;
+ }
+#endif /* __GNU__ */
+ }
+
+leave:
+ fclose(f);
+ return ret;
+}
+
+
+/*
+ * ext2fs_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: EXT2_MF_MOUNTED, EXT2_MF_ISROOT,
+ * EXT2_MF_READONLY, EXT2_MF_SWAP, and EXT2_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
+errcode_t ext2fs_check_mount_point(const char *device, int *mount_flags,
+ char *mtpt, int mtlen)
+{
+ errcode_t retval = 0;
+ int busy = 0;
+
+ if (getenv("EXT2FS_PRETEND_RO_MOUNT")) {
+ *mount_flags = EXT2_MF_MOUNTED | EXT2_MF_READONLY;
+ if (getenv("EXT2FS_PRETEND_ROOTFS"))
+ *mount_flags = EXT2_MF_ISROOT;
+ return 0;
+ }
+ if (getenv("EXT2FS_PRETEND_RW_MOUNT")) {
+ *mount_flags = EXT2_MF_MOUNTED;
+ if (getenv("EXT2FS_PRETEND_ROOTFS"))
+ *mount_flags = EXT2_MF_ISROOT;
+ return 0;
+ }
+
+#ifdef __linux__ /* This only works on Linux 2.6+ systems */
+ {
+ struct stat st_buf;
+
+ if (stat(device, &st_buf) == 0 &&
+ ext2fsP_is_disk_device(st_buf.st_mode)) {
+ int fd = open(device, O_RDONLY | O_EXCL);
+
+ if (fd >= 0) {
+ /*
+ * The device is not busy so it's
+ * definitelly not mounted. No need to
+ * to perform any more checks.
+ */
+ close(fd);
+ *mount_flags = 0;
+ return 0;
+ } else if (errno == EBUSY) {
+ busy = 1;
+ }
+ }
+ }
+#endif
+
+ if (is_swap_device(device)) {
+ *mount_flags = EXT2_MF_MOUNTED | EXT2_MF_SWAP;
+ if (mtpt)
+ strncpy(mtpt, "<swap>", mtlen);
+ } else {
+#ifdef HAVE_SETMNTENT
+ retval = check_mntent(device, mount_flags, mtpt, mtlen);
+#else
+#ifdef HAVE_GETMNTINFO
+ retval = check_getmntinfo(device, mount_flags, mtpt, mtlen);
+#else
+#if defined(__GNUC__) && !defined(_WIN32)
+ #warning "Can't use getmntent or getmntinfo to check for mounted filesystems!"
+#endif
+ *mount_flags = 0;
+#endif /* HAVE_GETMNTINFO */
+#endif /* HAVE_SETMNTENT */
+ }
+ if (retval)
+ return retval;
+
+ if (busy)
+ *mount_flags |= EXT2_MF_BUSY;
+
+ return 0;
+}
+
+/*
+ * 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 DEBUG
+int 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);
+ }
+
+ add_error_table(&et_ext2_error_table);
+ 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 */
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