Linux kernel 2.6.20 and later supports per process I/O accounting. You can access every process/thread's I/O read/write values by using /proc filesystem. You can check if your kernel has built with I/O account by just simply checking /proc/self/io file. If it exists then you have I/O accounting built-in.
$ cat /proc/self/io
As you know, ever process is presented by it's pid number under /proc directory. You can access any process's I/O accounting values by just looking /proc/#pid/io file. There is a utility called iotop which collects these values and shows you in like top utility. You see your processes I/O activity with iotop utility.
rchar - bytes read
wchar - byres written
syscr - number of read syscalls
syscw - number of write syscalls
read_bytes - number of bytes caused by this process to read
from underlying storage
write_bytes - number of bytes caused by this process to written from