On 6/30/21 11:05 AM, J. Bruce Fields wrote:
On Wed, Jun 30, 2021 at 10:51:27AM -0700, dai.ngo@xxxxxxxxxx wrote:
On 6/28/21 1:23 PM, J. Bruce Fields wrote:
where ->fl_expire_lock is a new lock callback with second
argument "check"
where:
check = 1 means: just check whether this lock could be freed
Why do we need this, is there a use case for it? can we just always try
to expire the lock and return success/fail?
We can't expire the client while holding the flc_lock. And once we drop
that lock we need to restart the loop. Clearly we can't do that every
time.
(So, my code was wrong, it should have been:
if (fl->fl_lops->fl_expire_lock(fl, 1)) {
spin_unlock(&ct->flc_lock);
fl->fl_lops->fl_expire_locks(fl, 0);
goto retry;
}
)
This is what I currently have:
retry:
list_for_each_entry(fl, &ctx->flc_posix, fl_list) {
if (!posix_locks_conflict(request, fl))
continue;
if (fl->fl_lmops && fl->fl_lmops->lm_expire_lock) {
spin_unlock(&ctx->flc_lock);
ret = fl->fl_lmops->lm_expire_lock(fl, 0);
spin_lock(&ctx->flc_lock);
if (ret)
goto retry;
}
if (conflock)
locks_copy_conflock(conflock, fl);
But the 1 and 0 cases are starting to look pretty different; maybe they
should be two different callbacks.
why the case of 1 (test only) is needed, who would use this call?
-Dai
--b.
