104 lines
2.3 KiB
C
104 lines
2.3 KiB
C
/*
|
|
* realpath.c - realpath() aware of device mapper
|
|
* Originated from the util-linux project.
|
|
*/
|
|
|
|
#ifdef HAVE_CONFIG_H
|
|
#include "config.h"
|
|
#endif
|
|
|
|
#include <stdlib.h>
|
|
#include <stdio.h>
|
|
#include <string.h>
|
|
|
|
#ifdef HAVE_LIMITS_H
|
|
#include <limits.h>
|
|
#endif
|
|
#ifdef HAVE_CTYPE_H
|
|
#include <ctype.h>
|
|
#endif
|
|
|
|
#include "param.h"
|
|
#include "realpath.h"
|
|
|
|
/* If there is no realpath() on the system, provide a dummy one. */
|
|
#ifndef HAVE_REALPATH
|
|
char *ntfs_realpath(const char *path, char *resolved_path)
|
|
{
|
|
strncpy(resolved_path, path, PATH_MAX);
|
|
resolved_path[PATH_MAX] = '\0';
|
|
return resolved_path;
|
|
}
|
|
#endif
|
|
|
|
|
|
#ifdef linux
|
|
|
|
/*
|
|
* Converts private "dm-N" names to "/dev/mapper/<name>"
|
|
*
|
|
* Since 2.6.29 (patch 784aae735d9b0bba3f8b9faef4c8b30df3bf0128) kernel sysfs
|
|
* provides the real DM device names in /sys/block/<ptname>/dm/name
|
|
*/
|
|
static char *
|
|
canonicalize_dm_name(const char *ptname, char *canonical)
|
|
{
|
|
FILE *f;
|
|
size_t sz;
|
|
char path[MAPPERNAMELTH + 24];
|
|
char name[MAPPERNAMELTH + 16];
|
|
char *res = NULL;
|
|
|
|
snprintf(path, sizeof(path), "/sys/block/%s/dm/name", ptname);
|
|
if (!(f = fopen(path, "r")))
|
|
return NULL;
|
|
|
|
/* read "<name>\n" from sysfs */
|
|
if (fgets(name, sizeof(name), f) && (sz = strlen(name)) > 1) {
|
|
name[sz - 1] = '\0';
|
|
snprintf(path, sizeof(path), "/dev/mapper/%s", name);
|
|
res = strcpy(canonical, path);
|
|
}
|
|
fclose(f);
|
|
return res;
|
|
}
|
|
|
|
/*
|
|
* Canonicalize a device path
|
|
*
|
|
* Workaround from "basinilya" for fixing device mapper paths.
|
|
*
|
|
* Background (Phillip Susi, 2011-04-09)
|
|
* - ntfs-3g canonicalizes the device name so that if you mount with
|
|
* /dev/mapper/foo, the device name listed in mtab is /dev/dm-n,
|
|
* so you can not umount /dev/mapper/foo
|
|
* - umount won't even recognize and translate /dev/dm-n to the mount
|
|
* point, apparently because of the '-' involved. Editing mtab and
|
|
* removing the '-' allows you to umount /dev/dmn successfully.
|
|
*
|
|
* This code restores the devmapper name after canonicalization,
|
|
* until a proper fix is implemented.
|
|
*/
|
|
|
|
char *ntfs_realpath_canonicalize(const char *path, char *canonical)
|
|
{
|
|
char *p;
|
|
|
|
if (path == NULL)
|
|
return NULL;
|
|
|
|
if (!ntfs_realpath(path, canonical))
|
|
return NULL;
|
|
|
|
p = strrchr(canonical, '/');
|
|
if (p && strncmp(p, "/dm-", 4) == 0 && isdigit(*(p + 4))) {
|
|
p = canonicalize_dm_name(p+1, canonical);
|
|
if (p)
|
|
return p;
|
|
}
|
|
|
|
return canonical;
|
|
}
|
|
|
|
#endif
|