1 files changed, 358 insertions, 0 deletions

diff --git a/e2fsprogs/ext2fs/ismounted.c b/e2fsprogs/ext2fs/ismounted.c
new file mode 100644
index 000000000..3f2241d23
--- /dev/null
+++ b/e2fsprogs/ext2fs/ismounted.c
@@ -0,0 +1,358 @@
+/*
+ * 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 (!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);
+                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
+#endif
+errcode_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 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);
+        }
+
+        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_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 */