a question about block device driver

["Alex Huang" <alexjoy@sis.com.tw>]

 Hi
 Thank you very much for your help.
 In the linux kernel version 2.4.X,
 Does anybody mount a hard drive with MSDOS type file system ??

When I mount this hard drive using the command :
    mount -t msdos /dev/hda1 /mnt/hd -o blocksize=1024
 After mounting a hard disk, I read a file , and the system occours errors.
 After I check the msdos file system in "usr/src/linux/fs/fat/cvf.c"

 Iin the codes,
 struct cvf_format bigblock_cvf={
     :
     :
     :
    default_fat_bmap,
    NULL,
    default_fat_file_write,
     :
     :
 }


 I check the data struct , the NULL field is defined a file_read callback
 function. So , when I read a file , will cause the system error.

 In the kernel version 2.2.17, I can mount a MSDOS filesystem with the
option
 "-o blocksize=1024", and the driver can read/write two pages at the same
 time. But in the kernel version 2.4.X, it doesn't work.

  how two read/write two or more pages(blocks) at the same time in
 the kernel version 2.4.X ??

 Thanks