Commit fa82ebd2 authored by unknown's avatar unknown
Browse files

BUG#24566 - Incorrect key file for table ( the size of table is more than 2G) 

Accessing a file that is bigger than 2G may report that read/write operation
failed. This may affect anything that uses my_pread/my_pwrite functions, e.g.
MyISAM, ARCHIVE, binary log.

For MyISAM INSERT may report that table is crashed when writing to a table
that is bigger than 2G.

This is fixed by using proper offset type in my_pread/my_pwrite functions on
systems that do not have native pread/pwrite calls.

Affects systems that do not have native pread/pwrite calls, e.g. Windows.

No test case for this fix, since it requires huge table.


mysys/my_pread.c:
  Use proper offset type for restoring position on systems that do not have native
  pread/pwrite calls.
parent 99c5c28c

mysys/my_pread.c

+4 −4
Original line number Diff line number Diff line
@@ -37,7 +37,7 @@ uint my_pread(File Filedes, byte *Buffer, uint Count, my_off_t offset, 
    errno=0;					/* Linux doesn't reset this */

#endif

#ifndef HAVE_PREAD

    off_t old_offset;

    os_off_t old_offset;



    pthread_mutex_lock(&my_file_info[Filedes].mutex);

    /*
@@ -45,7 +45,7 @@ uint my_pread(File Filedes, byte *Buffer, uint Count, my_off_t offset, 
      before seeking to the given offset

    */



    error= (old_offset= (off_t)lseek(Filedes, 0L, MY_SEEK_CUR)) == -1L ||

    error= (old_offset= lseek(Filedes, 0L, MY_SEEK_CUR)) == -1L ||

           lseek(Filedes, offset, MY_SEEK_SET) == -1L;



    if (!error)                                 /* Seek was successful */
@@ -116,7 +116,7 @@ uint my_pwrite(int Filedes, const byte *Buffer, uint Count, my_off_t offset, 
  {

#ifndef HAVE_PREAD

    int error= 0;

    off_t old_offset;

    os_off_t old_offset;

    writenbytes= (uint) -1;

    pthread_mutex_lock(&my_file_info[Filedes].mutex);
@@ -124,7 +124,7 @@ uint my_pwrite(int Filedes, const byte *Buffer, uint Count, my_off_t offset, 
      As we cannot change the file pointer, we save the old position,

      before seeking to the given offset

    */

    error= ((old_offset= (off_t)lseek(Filedes, 0L, MY_SEEK_CUR)) == -1L ||

    error= ((old_offset= lseek(Filedes, 0L, MY_SEEK_CUR)) == -1L ||

            lseek(Filedes, offset, MY_SEEK_SET) == -1L);



    if (!error)                                 /* Seek was successful */