1  /* File identity for the dynamic linker.  Generic POSIX.1 version.
       2     Copyright (C) 2015-2023 Free Software Foundation, Inc.
       3     This file is part of the GNU C Library.
       4  
       5     The GNU C Library is free software; you can redistribute it and/or
       6     modify it under the terms of the GNU Lesser General Public
       7     License as published by the Free Software Foundation; either
       8     version 2.1 of the License, or (at your option) any later version.
       9  
      10     The GNU C Library is distributed in the hope that it will be useful,
      11     but WITHOUT ANY WARRANTY; without even the implied warranty of
      12     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
      13     Lesser General Public License for more details.
      14  
      15     You should have received a copy of the GNU Lesser General Public
      16     License along with the GNU C Library; if not, see
      17     <https://www.gnu.org/licenses/>.  */
      18  
      19  #include <stdbool.h>
      20  #include <sys/stat.h>
      21  
      22  /* For POSIX.1 systems, the pair of st_dev and st_ino constitute
      23     a unique identifier for a file.  */
      24  struct r_file_id
      25    {
      26      dev_t dev;
      27      ino64_t ino;
      28    };
      29  
      30  /* Sample FD to fill in *ID.  Returns true on success.
      31     On error, returns false, with errno set.  */
      32  static inline bool
      33  _dl_get_file_id (int fd, struct r_file_id *id)
      34  {
      35    struct __stat64_t64 st;
      36  
      37    if (__glibc_unlikely (__fstat64_time64 (fd, &st) < 0))
      38      return false;
      39  
      40    id->dev = st.st_dev;
      41    id->ino = st.st_ino;
      42    return true;
      43  }
      44  
      45  /* Compare two results from _dl_get_file_id for equality.  */
      46  static inline bool
      47  _dl_file_id_match_p (const struct r_file_id *a, const struct r_file_id *b)
      48  {
      49    return a->dev == b->dev && a->ino == b->ino;
      50  }