Re: [PATCH 07/19] staging: lustre: simplify l_wait_event when intr handler but no timeout.

James Simmons
2018-01-17T15:31:40Z

> If l_wait_event() is given a function to be called on a signal,
> but no timeout or timeout handler, then the intr function is simply
> called at the end if the wait was aborted by a signal.
> So a simpler way to write the code (in the one place this case is
> used) it to open-code the body of the function after the
> wait_event, if -ERESTARTSYS was returned.

Reviewed-by: James Simmons <jsimmons@infradead.org>

> Signed-off-by: NeilBrown <neilb@suse.com>
> ---
> drivers/staging/lustre/lustre/ldlm/ldlm_flock.c | 30 +++++------------------
> 1 file changed, 7 insertions(+), 23 deletions(-)
>
> diff --git a/drivers/staging/lustre/lustre/ldlm/ldlm_flock.c b/drivers/staging/lustre/lustre/ldlm/ldlm_flock.c
> index 657ab95091a0..411b540b96d9 100644
> --- a/drivers/staging/lustre/lustre/ldlm/ldlm_flock.c
> +++ b/drivers/staging/lustre/lustre/ldlm/ldlm_flock.c
> @@ -310,24 +310,6 @@ static int ldlm_process_flock_lock(struct ldlm_lock *req)
> return LDLM_ITER_CONTINUE;
> }
>
> -struct ldlm_flock_wait_data {
> - struct ldlm_lock *fwd_lock;
> -};
> -
> -static void
> -ldlm_flock_interrupted_wait(void *data)
> -{
> - struct ldlm_lock *lock;
> -
> - lock = ((struct ldlm_flock_wait_data *)data)->fwd_lock;
> -
> - lock_res_and_lock(lock);
> -
> - /* client side - set flag to prevent lock from being put on LRU list */
> - ldlm_set_cbpending(lock);
> - unlock_res_and_lock(lock);
> -}
> -
> /**
> * Flock completion callback function.
> *
> @@ -342,8 +324,6 @@ int
> ldlm_flock_completion_ast(struct ldlm_lock *lock, __u64 flags, void *data)
> {
> struct file_lock *getlk = lock->l_ast_data;
> - struct ldlm_flock_wait_data fwd;
> - struct l_wait_info lwi;
> int rc = 0;
>
> OBD_FAIL_TIMEOUT(OBD_FAIL_LDLM_CP_CB_WAIT2, 4);
> @@ -372,13 +352,17 @@ ldlm_flock_completion_ast(struct ldlm_lock *lock, __u64 flags, void *data)
>
> LDLM_DEBUG(lock,
> "client-side enqueue returned a blocked lock, sleeping");
> - fwd.fwd_lock = lock;
> - lwi = LWI_TIMEOUT_INTR(0, NULL, ldlm_flock_interrupted_wait, &fwd);
>
> /* Go to sleep until the lock is granted. */
> - rc = l_wait_event(lock->l_waitq, is_granted_or_cancelled(lock), &lwi);
> + rc = l_wait_event_abortable(lock->l_waitq, is_granted_or_cancelled(lock));
>
> if (rc) {
> + lock_res_and_lock(lock);
> +
> + /* client side - set flag to prevent lock from being put on LRU list */
> + ldlm_set_cbpending(lock);
> + unlock_res_and_lock(lock);
> +
> LDLM_DEBUG(lock, "client-side enqueue waking up: failed (%d)",
> rc);
> return rc;
>
>
>