LCOV - code coverage report
Current view: top level - src/client - open_file_map.cpp (source / functions) Hit Total Coverage
Test: coverage.info Lines: 87 104 83.7 %
Date: 2024-04-30 13:21:35 Functions: 18 19 94.7 %
Legend: Lines: hit not hit

          Line data    Source code
       1             : /*
       2             :   Copyright 2018-2024, Barcelona Supercomputing Center (BSC), Spain
       3             :   Copyright 2015-2024, Johannes Gutenberg Universitaet Mainz, Germany
       4             : 
       5             :   This software was partially supported by the
       6             :   EC H2020 funded project NEXTGenIO (Project ID: 671951, www.nextgenio.eu).
       7             : 
       8             :   This software was partially supported by the
       9             :   ADA-FS project under the SPPEXA project funded by the DFG.
      10             : 
      11             :   This file is part of GekkoFS' POSIX interface.
      12             : 
      13             :   GekkoFS' POSIX interface is free software: you can redistribute it and/or
      14             :   modify it under the terms of the GNU Lesser General Public License as
      15             :   published by the Free Software Foundation, either version 3 of the License,
      16             :   or (at your option) any later version.
      17             : 
      18             :   GekkoFS' POSIX interface is distributed in the hope that it will be useful,
      19             :   but WITHOUT ANY WARRANTY; without even the implied warranty of
      20             :   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
      21             :   GNU Lesser General Public License for more details.
      22             : 
      23             :   You should have received a copy of the GNU Lesser General Public License
      24             :   along with GekkoFS' POSIX interface.  If not, see
      25             :   <https://www.gnu.org/licenses/>.
      26             : 
      27             :   SPDX-License-Identifier: LGPL-3.0-or-later
      28             : */
      29             : 
      30             : #include <client/open_file_map.hpp>
      31             : #include <client/open_dir.hpp>
      32             : #include <client/preload.hpp>
      33             : #include <client/preload_util.hpp>
      34             : #include <client/logging.hpp>
      35             : 
      36             : extern "C" {
      37             : #include <fcntl.h>
      38             : }
      39             : 
      40             : using namespace std;
      41             : 
      42             : namespace gkfs::filemap {
      43             : 
      44        1143 : OpenFile::OpenFile(const string& path, const int flags, FileType type)
      45        1143 :     : type_(type), path_(path) {
      46             :     // set flags to OpenFile
      47        1143 :     if(flags & O_CREAT)
      48        1039 :         flags_[gkfs::utils::to_underlying(OpenFile_flags::creat)] = true;
      49        1143 :     if(flags & O_APPEND)
      50           4 :         flags_[gkfs::utils::to_underlying(OpenFile_flags::append)] = true;
      51        1143 :     if(flags & O_TRUNC)
      52        1005 :         flags_[gkfs::utils::to_underlying(OpenFile_flags::trunc)] = true;
      53        1143 :     if(flags & O_RDONLY)
      54             :         flags_[gkfs::utils::to_underlying(OpenFile_flags::rdonly)] = true;
      55        1143 :     if(flags & O_WRONLY)
      56        1073 :         flags_[gkfs::utils::to_underlying(OpenFile_flags::wronly)] = true;
      57        1143 :     if(flags & O_RDWR)
      58           2 :         flags_[gkfs::utils::to_underlying(OpenFile_flags::rdwr)] = true;
      59             : 
      60        1143 :     pos_ = 0; // If O_APPEND flag is used, it will be used before each write.
      61        1143 : }
      62             : 
      63         248 : OpenFileMap::OpenFileMap() : fd_idx(10000), fd_validation_needed(false) {}
      64             : 
      65             : string
      66        1120 : OpenFile::path() const {
      67        1120 :     return path_;
      68             : }
      69             : 
      70             : void
      71           0 : OpenFile::path(const string& path) {
      72           0 :     OpenFile::path_ = path;
      73           0 : }
      74             : 
      75             : unsigned long
      76          97 : OpenFile::pos() {
      77          97 :     lock_guard<mutex> lock(pos_mutex_);
      78          97 :     return pos_;
      79             : }
      80             : 
      81             : void
      82          67 : OpenFile::pos(unsigned long pos) {
      83          67 :     lock_guard<mutex> lock(pos_mutex_);
      84          67 :     OpenFile::pos_ = pos;
      85          67 : }
      86             : 
      87             : bool
      88          45 : OpenFile::get_flag(OpenFile_flags flag) {
      89          45 :     lock_guard<mutex> lock(pos_mutex_);
      90          45 :     return flags_[gkfs::utils::to_underlying(flag)];
      91             : }
      92             : 
      93             : void
      94           2 : OpenFile::set_flag(OpenFile_flags flag, bool value) {
      95           2 :     lock_guard<mutex> lock(flag_mutex_);
      96           2 :     flags_[gkfs::utils::to_underlying(flag)] = value;
      97           2 : }
      98             : 
      99             : FileType
     100         105 : OpenFile::type() const {
     101         105 :     return type_;
     102             : }
     103             : 
     104             : // OpenFileMap starts here
     105             : 
     106             : shared_ptr<OpenFile>
     107         142 : OpenFileMap::get(int fd) {
     108         142 :     lock_guard<recursive_mutex> lock(files_mutex_);
     109         142 :     auto f = files_.find(fd);
     110         142 :     if(f == files_.end()) {
     111           0 :         return nullptr;
     112             :     } else {
     113         284 :         return f->second;
     114             :     }
     115             : }
     116             : 
     117             : shared_ptr<OpenDir>
     118          32 : OpenFileMap::get_dir(int dirfd) {
     119          64 :     auto f = get(dirfd);
     120          32 :     if(f == nullptr || f->type() != FileType::directory) {
     121           1 :         return nullptr;
     122             :     }
     123          95 :     return static_pointer_cast<OpenDir>(f);
     124             : }
     125             : 
     126             : bool
     127      370968 : OpenFileMap::exist(const int fd) {
     128      370968 :     lock_guard<recursive_mutex> lock(files_mutex_);
     129      370968 :     auto f = files_.find(fd);
     130      370968 :     return !(f == files_.end());
     131             : }
     132             : 
     133             : int
     134        1143 : OpenFileMap::safe_generate_fd_idx_() {
     135        1143 :     auto fd = generate_fd_idx();
     136             :     /*
     137             :      * Check if fd is still in use and generate another if yes
     138             :      * Note that this can only happen once the all fd indices within the int has
     139             :      * been used to the int::max Once this limit is exceeded, we set fd_idx back
     140             :      * to 3 and begin anew. Only then, if a file was open for a long time will
     141             :      * we have to generate another index.
     142             :      *
     143             :      * This situation can only occur when all fd indices have been given away
     144             :      * once and we start again, in which case the fd_validation_needed flag is
     145             :      * set. fd_validation is set to false, if
     146             :      */
     147        1143 :     if(fd_validation_needed) {
     148           0 :         while(exist(fd)) {
     149           0 :             fd = generate_fd_idx();
     150             :         }
     151             :     }
     152        1143 :     return fd;
     153             : }
     154             : 
     155             : int
     156        1140 : OpenFileMap::add(std::shared_ptr<OpenFile> open_file) {
     157        1140 :     auto fd = safe_generate_fd_idx_();
     158        1140 :     lock_guard<recursive_mutex> lock(files_mutex_);
     159        2280 :     files_.insert(make_pair(fd, open_file));
     160        2280 :     return fd;
     161             : }
     162             : 
     163             : bool
     164        1006 : OpenFileMap::remove(const int fd) {
     165        1006 :     lock_guard<recursive_mutex> lock(files_mutex_);
     166        1006 :     auto f = files_.find(fd);
     167        1006 :     if(f == files_.end()) {
     168             :         return false;
     169             :     }
     170        1006 :     files_.erase(fd);
     171        1006 :     if(fd_validation_needed && files_.empty()) {
     172           0 :         fd_validation_needed = false;
     173           0 :         LOG(DEBUG, "fd_validation flag reset");
     174             :     }
     175             :     return true;
     176             : }
     177             : 
     178             : int
     179           3 : OpenFileMap::dup(const int oldfd) {
     180           6 :     lock_guard<recursive_mutex> lock(files_mutex_);
     181           6 :     auto open_file = get(oldfd);
     182           3 :     if(open_file == nullptr) {
     183           0 :         errno = EBADF;
     184           0 :         return -1;
     185             :     }
     186           3 :     auto newfd = safe_generate_fd_idx_();
     187           6 :     files_.insert(make_pair(newfd, open_file));
     188           3 :     return newfd;
     189             : }
     190             : 
     191             : int
     192           1 : OpenFileMap::dup2(const int oldfd, const int newfd) {
     193           2 :     lock_guard<recursive_mutex> lock(files_mutex_);
     194           2 :     auto open_file = get(oldfd);
     195           1 :     if(open_file == nullptr) {
     196           0 :         errno = EBADF;
     197           0 :         return -1;
     198             :     }
     199           1 :     if(oldfd == newfd)
     200             :         return newfd;
     201             :     // remove newfd if exists in filemap silently
     202           1 :     if(exist(newfd)) {
     203           1 :         remove(newfd);
     204             :     }
     205             :     // to prevent duplicate fd idx in the future. First three fd are reservered
     206             :     // by os streams that we do not overwrite
     207           1 :     if(get_fd_idx() < newfd && newfd != 0 && newfd != 1 && newfd != 2)
     208           0 :         fd_validation_needed = true;
     209           2 :     files_.insert(make_pair(newfd, open_file));
     210           1 :     return newfd;
     211             : }
     212             : 
     213             : /**
     214             :  * Generate new file descriptor index to be used as an fd within one process
     215             :  * @return fd_idx
     216             :  */
     217             : int
     218        1143 : OpenFileMap::generate_fd_idx() {
     219             :     // We need a mutex here for thread safety
     220        1143 :     std::lock_guard<std::mutex> inode_lock(fd_idx_mutex);
     221        1143 :     if(fd_idx == std::numeric_limits<int>::max()) {
     222           0 :         LOG(WARNING,
     223           0 :             "File descriptor index exceeded ints max value. Setting it back to 100000");
     224             :         /*
     225             :          * Setting fd_idx back to 3 could have the effect that fd are given
     226             :          * twice for different path. This must not happen. Instead a flag is set
     227             :          * which tells can tell the OpenFileMap that it should check if this fd
     228             :          * is really safe to use.
     229             :          */
     230           0 :         fd_idx = 100000;
     231           0 :         fd_validation_needed = true;
     232             :     }
     233        2286 :     return fd_idx++;
     234             : }
     235             : 
     236             : int
     237           1 : OpenFileMap::get_fd_idx() {
     238           1 :     std::lock_guard<std::mutex> inode_lock(fd_idx_mutex);
     239           1 :     return fd_idx;
     240             : }
     241             : 
     242             : } // namespace gkfs::filemap

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