mergerfs/src/fuse_mkdir.cpp

/*
  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 "fuse_mkdir.hpp"

#include "config.hpp"
#include "errno.hpp"
#include "error.hpp"
#include "fs_acl.hpp"
#include "fs_clonepath.hpp"
#include "fs_mkdir.hpp"
#include "fs_path.hpp"
#include "policy.hpp"
#include "ugid.hpp"

#include "fuse.h"

#include <string>


static
int
_mkdir_core(const fs::path &fullpath_,
            mode_t          mode_,
            const mode_t    umask_)
{
  if(!fs::acl::dir_has_defaults(fullpath_))
    mode_ &= ~umask_;

  return fs::mkdir(fullpath_,mode_);
}

static
int
_mkdir_loop_core(const fs::path &createpath_,
                 const fs::path &fusepath_,
                 const mode_t    mode_,
                 const mode_t    umask_)
{
  int rv;
  fs::path fullpath;

  fullpath = createpath_ / fusepath_;

  rv = ::_mkdir_core(fullpath,mode_,umask_);

  return rv;
}

static
int
_mkdir_loop(const Branch               *existingbranch_,
            const std::vector<Branch*> &createbranches_,
            const fs::path             &fusepath_,
            const fs::path             &fusedirpath_,
            const mode_t                mode_,
            const mode_t                umask_)
{
  int rv;
  Err err;

  for(const auto &createbranch : createbranches_)
    {
      rv = fs::clonepath_as_root(existingbranch_->path,
                                 createbranch->path,
                                 fusedirpath_);
      if(rv < 0)
        {
          err = rv;
          continue;
        }

      err = ::_mkdir_loop_core(createbranch->path,
                               fusepath_,
                               mode_,
                               umask_);
    }

  return err;
}

static
int
_mkdir(const Policy::Search &getattrPolicy_,
       const Policy::Create &mkdirPolicy_,
       const Branches       &branches_,
       const fs::path       &fusepath_,
       const mode_t          mode_,
       const mode_t          umask_)
{
  int rv;
  fs::path fusedirpath;
  std::vector<Branch*> createbranches;
  std::vector<Branch*> existingbranches;

  fusedirpath = fusepath_.parent_path();

  rv = getattrPolicy_(branches_,fusedirpath,existingbranches);
  if(rv < 0)
    return rv;

  rv = mkdirPolicy_(branches_,fusedirpath,createbranches);
  if(rv < 0)
    return rv;

  return ::_mkdir_loop(existingbranches[0],
                       createbranches,
                       fusepath_,
                       fusedirpath,
                       mode_,
                       umask_);
}

int
FUSE::mkdir(const fuse_req_ctx_t *ctx_,
            const char           *fusepath_,
            mode_t                mode_)
{
  int rv;
  const fs::path  fusepath{fusepath_};
  const ugid::Set ugid(ctx_);

  rv = ::_mkdir(cfg.func.getattr.policy,
                cfg.func.mkdir.policy,
                cfg.branches,
                fusepath,
                mode_,
                ctx_->umask);
  if(rv == -EROFS)
    {
      cfg.branches.find_and_set_mode_ro();
      rv = ::_mkdir(cfg.func.getattr.policy,
                    cfg.func.mkdir.policy,
                    cfg.branches,
                    fusepath,
                    mode_,
                    ctx_->umask);
    }

  return rv;
}