mirror of https://github.com/trapexit/mergerfs.git
You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
137 lines
3.0 KiB
137 lines
3.0 KiB
/*
|
|
ISC License
|
|
|
|
Copyright (c) 2018, 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_clonefile.hpp"
|
|
#include "fs_close.hpp"
|
|
#include "fs_lstat.hpp"
|
|
#include "fs_mktemp.hpp"
|
|
#include "fs_open.hpp"
|
|
#include "fs_rename.hpp"
|
|
#include "fs_unlink.hpp"
|
|
|
|
#include <string>
|
|
|
|
#include <fcntl.h>
|
|
#include <sys/stat.h>
|
|
#include <sys/types.h>
|
|
#include <unistd.h>
|
|
|
|
using std::string;
|
|
|
|
namespace l
|
|
{
|
|
static
|
|
int
|
|
cleanup_on_error(const int src_fd_,
|
|
const int dst_fd_ = -1,
|
|
const string &dst_fullpath_ = string())
|
|
{
|
|
int error = errno;
|
|
|
|
if(src_fd_ >= 0)
|
|
fs::close(src_fd_);
|
|
if(dst_fd_ >= 0)
|
|
fs::close(dst_fd_);
|
|
if(!dst_fullpath_.empty())
|
|
fs::unlink(dst_fullpath_);
|
|
|
|
errno = error;
|
|
|
|
return -1;
|
|
}
|
|
}
|
|
|
|
namespace fs
|
|
{
|
|
namespace cow
|
|
{
|
|
bool
|
|
is_eligible(const int flags_)
|
|
{
|
|
int accmode;
|
|
|
|
accmode = (flags_ & O_ACCMODE);
|
|
|
|
return ((accmode == O_RDWR) ||
|
|
(accmode == O_WRONLY));
|
|
}
|
|
|
|
bool
|
|
is_eligible(const struct stat &st_)
|
|
{
|
|
return ((S_ISREG(st_.st_mode)) && (st_.st_nlink > 1));
|
|
}
|
|
|
|
bool
|
|
is_eligible(const int flags_,
|
|
const struct stat &st_)
|
|
{
|
|
return (is_eligible(flags_) && is_eligible(st_));
|
|
}
|
|
|
|
bool
|
|
is_eligible(const char *fullpath_,
|
|
const int flags_)
|
|
{
|
|
int rv;
|
|
struct stat st;
|
|
|
|
if(!fs::cow::is_eligible(flags_))
|
|
return false;
|
|
|
|
rv = fs::lstat(fullpath_,&st);
|
|
if(rv == -1)
|
|
return false;
|
|
|
|
return fs::cow::is_eligible(st);
|
|
}
|
|
|
|
int
|
|
break_link(const char *src_fullpath_)
|
|
{
|
|
int rv;
|
|
int src_fd;
|
|
int dst_fd;
|
|
string dst_fullpath;
|
|
|
|
src_fd = fs::open(src_fullpath_,O_RDONLY|O_NOFOLLOW);
|
|
if(src_fd == -1)
|
|
return -1;
|
|
|
|
dst_fullpath = src_fullpath_;
|
|
|
|
dst_fd = fs::mktemp(&dst_fullpath,O_WRONLY);
|
|
if(dst_fd == -1)
|
|
return l::cleanup_on_error(src_fd);
|
|
|
|
rv = fs::clonefile(src_fd,dst_fd);
|
|
if(rv == -1)
|
|
return l::cleanup_on_error(src_fd,dst_fd,dst_fullpath);
|
|
|
|
rv = fs::rename(dst_fullpath,src_fullpath_);
|
|
if(rv == -1)
|
|
return l::cleanup_on_error(src_fd,dst_fd,dst_fullpath);
|
|
|
|
fs::close(src_fd);
|
|
fs::close(dst_fd);
|
|
|
|
return 0;
|
|
}
|
|
}
|
|
}
|