From d1e063beb43e595680c65e3804d1f8ddff53373b Mon Sep 17 00:00:00 2001 From: Guido Guenther Date: Sat, 18 Nov 2006 23:48:07 +0100 Subject: Imported Debian version 0.3.8.8 --- e2fslib/ismounted.c | 261 ++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 261 insertions(+) create mode 100644 e2fslib/ismounted.c (limited to 'e2fslib/ismounted.c') diff --git a/e2fslib/ismounted.c b/e2fslib/ismounted.c new file mode 100644 index 0000000..1b145c6 --- /dev/null +++ b/e2fslib/ismounted.c @@ -0,0 +1,261 @@ +/* + * 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 +#if HAVE_UNISTD_H +#include +#endif +#if HAVE_ERRNO_H +#include +#endif +#include +#ifdef HAVE_LINUX_FD_H +#include +#endif +#ifdef HAVE_MNTENT_H +#include +#endif +#ifdef HAVE_GETMNTINFO +#include +#include +#include +#endif /* HAVE_GETMNTINFO */ +#include +#include + +#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_mntpnt, st_file; + errcode_t retval = 0; + FILE *f; + int fd; + + *mount_flags = 0; + if ((f = setmntent (mtab_file, "r")) == NULL) + return errno; + while ((mnt = getmntent (f)) != NULL) + if (strcmp(file, mnt->mnt_fsname) == 0) + 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 (stat("/", &st_mntpnt) == 0 && stat(file, &st_file) == 0) { + if (st_mntpnt.st_dev == st_file.st_rdev) { + *mount_flags = EXT2_MF_MOUNTED; + if (mtpt) + strncpy(mtpt, "/", mtlen); + goto is_root; + } + } +#endif + goto exit; + } +#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 */ + /* Validate the entry in case /etc/mtab is out of date */ + /* + * We need to be paranoid, because some broken distributions + * (read: Slackware) don't initialize /etc/mtab before checking + * all of the non-root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_mntpnt) < 0) { + retval = errno; + if (retval == ENOENT) { +#ifdef DEBUG + printf("Bogus entry in %s! (%s does not exist)\n", + mtab_file, mnt->mnt_dir); +#endif + retval = 0; + } + goto exit; + } + if (stat(file, &st_file) == 0) { + if (st_mntpnt.st_dev != st_file.st_rdev) { +#ifdef DEBUG + printf("Bogus entry in %s! (%s not mounted on %s)\n", + mtab_file, file, mnt->mnt_dir); +#endif + goto exit; + } + } +#endif + *mount_flags = EXT2_MF_MOUNTED; + + /* Check to see if the ro option is set */ + if (hasmntopt(mnt, MNTOPT_RO)) + *mount_flags |= EXT2_MF_READONLY; + + 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; +exit: + 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 +#ifdef __linux__ + retval = check_mntent_file("/proc/mounts", file, mount_flags, + mtpt, mtlen); + if (retval == 0) + return 0; +#endif + retval = check_mntent_file(MOUNTED, file, mount_flags, mtpt, mtlen); + return retval; +} + +#elif 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 */ + +/* + * 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) +{ +#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 +#warning "Can't use getmntent or getmntinfo to check for mounted filesystems!" + *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; + + if (argc < 2) { + fprintf(stderr, "Usage: %s device\n", argv[0]); + exit(1); + } + + retval = ext2fs_check_if_mounted(argv[1], &mount_flags); + 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_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]); + + exit(0); +} +#endif -- cgit v1.2.3