mergerfs/src/policy_msplus.cpp
2020-08-18 19:28:36 -04:00

123 lines
3.2 KiB
C++

/*
Copyright (c) 2016, Antonio SJ Musumeci <trapexit@spawn.link>
Permission to use, copy, modify, and/or distribute this software for any
purpose with or without fee is hereby granted, provided that the above
copyright notice and this permission notice appear in all copies.
THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*/
#include "errno.hpp"
#include "fs_exists.hpp"
#include "fs_info.hpp"
#include "fs_path.hpp"
#include "fs_statvfs_cache.hpp"
#include "policy.hpp"
#include "policy_error.hpp"
#include "rwlock.hpp"
#include <limits>
#include <string>
#include <vector>
using std::string;
using std::vector;
namespace msplus
{
static
const
string*
create_1(const Branches &branches_,
const string &fusepath_,
const uint64_t minfreespace_,
int *err_)
{
int rv;
uint64_t lus;
string fusepath;
fs::info_t info;
const Branch *branch;
const string *basepath;
basepath = NULL;
lus = std::numeric_limits<uint64_t>::max();
for(size_t i = 0, ei = branches_.size(); i != ei; i++)
{
branch = &branches_[i];
if(!fs::exists(branch->path,fusepath))
error_and_continue(*err_,ENOENT);
if(branch->ro_or_nc())
error_and_continue(*err_,EROFS);
rv = fs::info(branch->path,&info);
if(rv == -1)
error_and_continue(*err_,ENOENT);
if(info.readonly)
error_and_continue(*err_,EROFS);
if(info.spaceavail < minfreespace_)
error_and_continue(*err_,ENOSPC);
if(info.spaceused >= lus)
continue;
lus = info.spaceused;;
basepath = &branch->path;
}
return basepath;
}
static
int
create(const Branches &branches_,
const char *fusepath_,
const uint64_t minfreespace_,
vector<string> *paths_)
{
int error;
string fusepath;
const string *basepath;
rwlock::ReadGuard guard(&branches_.lock);
error = ENOENT;
fusepath = fusepath_;
do
{
basepath = create_1(branches_,fusepath,minfreespace_,&error);
if(basepath)
break;
fusepath = fs::path::dirname(fusepath);
}
while(!fusepath.empty());
if(basepath == NULL)
return (errno=error,-1);
paths_->push_back(*basepath);
return 0;
}
}
int
Policy::Func::msplus(const Category type_,
const Branches &branches_,
const char *fusepath_,
const uint64_t minfreespace_,
vector<string> *paths_)
{
if(type_ == Category::CREATE)
return msplus::create(branches_,fusepath_,minfreespace_,paths_);
return Policy::Func::eplus(type_,branches_,fusepath_,minfreespace_,paths_);
}