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/*
* Copyright (C) 2014 John Crispin <blogic@openwrt.org>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU Lesser General Public License version 2.1
* as published by the Free Software Foundation
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*/
#include <errno.h>
#include <stdio.h>
#include <string.h>
#include <sys/stat.h>
#include <sys/sysmacros.h>
#include "libfstools.h"
int
find_overlay_mount(char *overlay)
{
FILE *fp = fopen("/proc/mounts", "r");
size_t len = strlen(overlay);
static char line[256];
int ret = -1;
if(!fp)
return ret;
while (ret && fgets(line, sizeof(line), fp))
if (len < sizeof(line) && !strncmp(line, overlay, len) && line[len] == ' ')
ret = 0;
fclose(fp);
return ret;
}
/*
* Find path of a device mounted to the given point.
*/
char*
find_mount(char *mp)
{
FILE *fp = fopen("/proc/mounts", "r");
static char line[256];
if(!fp)
return NULL;
while (fgets(line, sizeof(line), fp)) {
char *s, *t = strstr(line, " ");
if (!t) {
fclose(fp);
return NULL;
}
*t = '\0';
t++;
s = strstr(t, " ");
if (!s) {
fclose(fp);
return NULL;
}
*s = '\0';
if (!strcmp(t, mp)) {
fclose(fp);
return line;
}
}
fclose(fp);
return NULL;
}
/*
* Match filesystem type against a bunch of valid types
*
* jffs2reset may ask if the filesystem type is actually ready for use
* with overlayfs before wiping it...
*/
static int fs_rootfs_only(char *fstype)
{
if (strncmp(fstype, "ext4", 4) &&
strncmp(fstype, "f2fs", 4) &&
strncmp(fstype, "jffs2", 5) &&
strncmp(fstype, "ubifs", 5)) {
ULOG_ERR("block is mounted with wrong fs\n");
return 1;
}
return 0;
}
/*
* Check if a given device is mounted and return its mountpoint
*/
char*
find_mount_point(char *block, int root_only)
{
FILE *fp = fopen("/proc/self/mountinfo", "r");
static char line[256];
char *point = NULL, *pos, *tmp, *cpoint, *devname, *fstype;
struct stat s;
int rstat;
unsigned int minor, major;
if (!block)
return NULL;
if (!fp)
return NULL;
rstat = stat(block, &s);
while (fgets(line, sizeof(line), fp)) {
/* skip first two columns */
pos = strchr(line, ' ');
if (!pos)
continue;
pos = strchr(pos + 1, ' ');
if (!pos)
continue;
/* extract block device major:minor */
tmp = ++pos;
pos = strchr(pos, ':');
if (!pos)
continue;
*pos = '\0';
major = atoi(tmp);
tmp = ++pos;
pos = strchr(pos, ' ');
if (!pos)
continue;
*pos = '\0';
minor = atoi(tmp);
/* skip another column */
pos = strchr(pos + 1, ' ');
if (!pos)
continue;
/* get mountpoint */
tmp = ++pos;
pos = strchr(pos, ' ');
if (!pos)
continue;
*pos = '\0';
cpoint = tmp;
/* skip another two columns */
pos = strchr(pos + 1, ' ');
if (!pos)
continue;
pos = strchr(pos + 1, ' ');
if (!pos)
continue;
/* get fstype */
tmp = ++pos;
pos = strchr(pos, ' ');
if (!pos)
continue;
*pos = '\0';
fstype = tmp;
/* get device name */
tmp = ++pos;
pos = strchr(pos, ' ');
if (!pos)
continue;
*pos = '\0';
devname = tmp;
/* if device name matches */
if (!strcmp(block, devname)) {
if (root_only && fs_rootfs_only(fstype))
break;
/* found, return mountpoint */
point = strdup(cpoint);
break;
}
/* last chance: check if major:minor of block device match */
if (rstat)
continue;
if (!S_ISBLK(s.st_mode))
continue;
if (major == major(s.st_rdev) &&
minor == minor(s.st_rdev)) {
if (root_only && fs_rootfs_only(fstype))
break;
/* found, return mountpoint */
point = strdup(cpoint);
break;
}
}
fclose(fp);
return point;
}
int
find_filesystem(char *fs)
{
FILE *fp = fopen("/proc/filesystems", "r");
static char line[256];
int ret = -1;
if (!fp) {
ULOG_ERR("opening /proc/filesystems failed: %m\n");
goto out;
}
while (ret && fgets(line, sizeof(line), fp))
if (strstr(line, fs))
ret = 0;
fclose(fp);
out:
return ret;
}
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