fis-gtm/sr_port/get_fs_block_size.c

51 lines
1.7 KiB
C

/****************************************************************
* *
* Copyright 2010 Fidelity Information Services, Inc *
* *
* This source code contains the intellectual property *
* of its copyright holder(s), and is made available *
* under a license. If you do not know the terms of *
* the license, please stop and do not read further. *
* *
****************************************************************/
#include "mdef.h"
#include "get_fs_block_size.h"
#ifndef VMS
#include "gtm_statvfs.h"
#endif
uint4 get_fs_block_size(int fd)
{
# ifndef VMS
struct statvfs bufvfs;
int status;
# endif
uint4 gtm_fs_block_size;
unsigned long sys_fs_block_size;
# if defined(__vms)
sys_fs_block_size = DISK_BLOCK_SIZE;
# else
FSTATVFS(fd, &bufvfs, status);
assert(-1 != status);
assert(SIZEOF(sys_fs_block_size) == SIZEOF(bufvfs.f_frsize));
/* If fstatvfs call fails, we dont know what the underlying filesystem size is.
* Instead of erroring out at this point, we assume a safe value and continue as much as we can.
* The higher the value, the more safe it is since it is more likely a multiple of the underlying
* filesystem size. We therefore pick 4K.
*/
sys_fs_block_size = (-1 == status) ? 4096 : bufvfs.f_frsize;
# endif
/* Fit file system block size in a 4-byte unsigned integer as that is the size in jnl_buffer.
* Assert that we never get a block size > what can be held in a 4-byte unsigned integer.
*/
gtm_fs_block_size = (uint4)sys_fs_block_size;
assert(gtm_fs_block_size == sys_fs_block_size);
assert(MAX_IO_BLOCK_SIZE >= gtm_fs_block_size);
assert(MAX_IO_BLOCK_SIZE % gtm_fs_block_size == 0);
return gtm_fs_block_size;
}