why crc16_t10dif() may make mistakes but crc16_t10dif_copy() running OK in file storage test ?

[joehou89]

Problem description
in our distributed file storage， we use isa-l crc as data validation in file storage io . to be sure, we use the API as follows:
crc16_t10dif()
however, in our test，the API return error, and some partial stack information is as follows:

(gdb) bt
#0 0x00000000004404f4  in crc16_t10dif_by16_10() 
#1 0x00007fdef2d86377 in hcrc_calc_csum16_inner (...)
...

The calling relationship of functions is: hcrc_calc_csum16_inner -- > crc16_t10dif -- > crc16_t10dif_by16_10

and，there is crc bug happens when performing file write operations.
But when we switch crc16_t10dif to crc16_t10dif_copy(), the program is OK
What a strange thing ???
now， we have 2 ideas as follows:
(1). the function crc16_t10dif has mistakes itself when using it, but we have no idea how it happens, e.g compile optimization;
(2). running error in crc16_t10dif maybe has relationship with our file storage business or something , however， we can't catch it.

So, we want to know， if somebody has meet the same questions ? thanks a lot.