Re: use counts for /proc modules
Bill Hawes (whawes@star.net)
Thu, 02 Oct 1997 23:36:33 -0400
Philip Gladstone wrote:
> I approached the problem in a different (and yet murky) way. I have
> a _fill_inode function that is pointed to by the proc_dir_entry
> structure. This gets called when someone cd's into the directory. I
> increment the i_count counter in the inode and also do the
> MOD_INC_USE_COUNT
> (first time only).
>
> This takes care of processes going into the directory.
>
> On a regular basis (every 30 seconds), I check to see if the i_count is
> back to 1. (which means that nobody is in the directory). If so, then I
> do the MOD_DEC_USE_COUNT, and do an iput on the inode to release it.
Hi Philip,
The fill_inode call looks like just the right hook for this function.
How about if I add a second argument to fill_inode, 1 or 0, non-zero
means increment your module count. I'll call the function again with
second argument == 0 when the inode is going out of use, so you can
decrement the module count. This will give you a much cleaner
interface.
I don't see any problem with overloading fill_inode to have both a
first-use and last-use call, and this will save having to add a new
function pointer to the dir_entry structure.
If you're willing to use your module as a guinea pig, I can send a patch
tomorrow.
Regards,
Bill