I'm now studying proc file system. I now know that read_proc_t function is called when the proofs file is read, and so for write_proc_t function when the proofs file is written to. But I also find the file_operaitons* field in the definition of proc_dir_entry, and this example code (http://linux.die.net/lkmpg/x810.html). 

So I'm confused that what happened if I provide both read_proc_t function, and the read function in file_operations structure?  Thanks very much.

Best,

Siyuan