Alright, looking through some git blame -w, I think this broke and then was restored in 2912fad98e. Jim had a diff in 2014 (823625c5da) to make the code compile, but crucially the buffer code no longer had a “max len” just a length.
I think this broke the “clever” reuse of the input buffdesc as the argument to GetFH (which has been there since 2012 from 878f45493e).
The input when mapped is a 16-byte thingy (sizeof nfs23_map_handle_t), and GetFH needs to expand the 16-byte mapped handle into an FH4. I assume the code when written had a FH4_SIZE as it’s max length, rather than the fh_desc buffer appearing to be trimmed to 16-bytes (that is, I think there was a length separate from max length at the time or something).
Digging into this a little more, I think the following commit actually originally broke things:
3016c4cee45635afa9c25b21c2f5b014d80d1b6d
In that commit, the "netbuf" data type used as an argument for HandleMap_GetFH is replaced with the "gsh_buffdesc" data type. As far as I can tell, "gsh_buffdesc" never had a "maxlen" member, so the following code in that function would not have compiled after that:
==
...
if(rc == HASHTABLE_SUCCESS)
{
handle_pool_entry_t *h = (handle_pool_entry_t *)buffval.pdata;
if(h->fh_len < p_out_fsal_handle->maxlen)
{
p_out_fsal_handle->len = h->fh_len;
memcpy(p_out_fsal_handle->buf, h->fh_data, h->fh_len);
memcpy(p_out_fsal_handle->addr, h->fh_data, h->fh_len);
rc = HANDLEMAP_SUCCESS;
}
...
==
After that change, there are various iterations of renaming the "p_out_fsal_handle" parameter to other things, up until the commit that you mentioned that fixed the compile issues (823625c5da2373606dd4f75dce46a92be143507c), which resulted in the code having "p_out_fsal_handle" renamed to the value actually being passed in, and the "maxlen" member replaced with "len".