thin-provisioning-tools/base/output_file_requirements.cc
2016-07-21 15:42:10 +01:00

55 lines
1.2 KiB
C++

#include "base/output_file_requirements.h"
#include <iostream>
#include <linux/fs.h>
#include <sstream>
#include <stdexcept>
#include <sys/ioctl.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <unistd.h>
using namespace base;
using namespace std;
//----------------------------------------------------------------
namespace {
void explain_output_file_requirements() {
ostringstream out;
out << "The output file should either be a block device,\n"
<< "or an existing file. The file needs to be large\n"
<< "enough to hold the metadata.";
throw runtime_error(out.str());
}
unsigned const MIN_SIZE = 32 * 1024;
}
void
base::check_output_file_requirements(string const &path)
{
struct stat info;
int r = ::stat(path.c_str(), &info);
if (r) {
cerr << "Output file does not exist.\n\n";
explain_output_file_requirements();
}
// We only really want these checks for regular files
if (S_ISREG(info.st_mode)) {
if (!info.st_size) {
cerr << "Zero size output file.\n\n";
explain_output_file_requirements();
}
if (info.st_size < MIN_SIZE) {
cerr << "Output file too small.\n\n";
explain_output_file_requirements();
}
}
}
//----------------------------------------------------------------