-
Yury Umanets authoredr=panda,shadow - fixes race in ptlrpcd which leads to busy import and obd; - cleanups and debugs in llcd code.
Yury Umanets authoredr=panda,shadow - fixes race in ptlrpcd which leads to busy import and obd; - cleanups and debugs in llcd code.
ptlrpcd.c 10.58 KiB
/* -*- mode: c; c-basic-offset: 8; indent-tabs-mode: nil; -*-
* vim:expandtab:shiftwidth=8:tabstop=8:
*
* GPL HEADER START
*
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 only,
* as published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License version 2 for more details (a copy is included
* in the LICENSE file that accompanied this code).
*
* You should have received a copy of the GNU General Public License
* version 2 along with this program; If not, see
* http://www.sun.com/software/products/lustre/docs/GPLv2.pdf
*
* Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
* CA 95054 USA or visit www.sun.com if you need additional information or
* have any questions.
*
* GPL HEADER END
*/
/*
* Copyright 2008 Sun Microsystems, Inc. All rights reserved
* Use is subject to license terms.
*/
/*
* This file is part of Lustre, http://www.lustre.org/
* Lustre is a trademark of Sun Microsystems, Inc.
*
* lustre/ptlrpc/ptlrpcd.c
*/
#define DEBUG_SUBSYSTEM S_RPC
#ifdef __KERNEL__
# include <libcfs/libcfs.h>
#else /* __KERNEL__ */
# include <liblustre.h>
# include <ctype.h>
#endif
#include <libcfs/kp30.h>
#include <lustre_net.h>
# include <lustre_lib.h>
#include <lustre_ha.h>
#include <obd_class.h> /* for obd_zombie */
#include <obd_support.h> /* for OBD_FAIL_CHECK */
#include <lprocfs_status.h>
static struct ptlrpcd_ctl ptlrpcd_pc;
static struct ptlrpcd_ctl ptlrpcd_recovery_pc;
struct semaphore ptlrpcd_sem;
static int ptlrpcd_users = 0;
void ptlrpcd_wake(struct ptlrpc_request *req)
{
struct ptlrpc_request_set *rq_set = req->rq_set;
LASSERT(rq_set != NULL);
cfs_waitq_signal(&rq_set->set_waitq);
}
/*
* Requests that are added to the ptlrpcd queue are sent via
* ptlrpcd_check->ptlrpc_check_set().
*/
void ptlrpcd_add_req(struct ptlrpc_request *req)
{
struct ptlrpcd_ctl *pc;
int rc;
if (req->rq_send_state == LUSTRE_IMP_FULL)
pc = &ptlrpcd_pc;
else
pc = &ptlrpcd_recovery_pc;
rc = ptlrpc_set_add_new_req(pc, req);
if (rc) {
int (*interpreter)(struct ptlrpc_request *,
void *, int);
interpreter = req->rq_interpret_reply;
/*
* Thread is probably in stop now so we need to
* kill this rpc as it was not added. Let's call
* interpret for it to let know we're killing it
* so that higher levels might free assosiated
* resources.
*/
req->rq_status = -EBADR;
interpreter(req, &req->rq_async_args,
req->rq_status);
req->rq_set = NULL;
ptlrpc_req_finished(req);
}
}
static int ptlrpcd_check(struct ptlrpcd_ctl *pc)
{
struct list_head *tmp, *pos;
struct ptlrpc_request *req;
int rc = 0;
ENTRY;
spin_lock(&pc->pc_set->set_new_req_lock);
list_for_each_safe(pos, tmp, &pc->pc_set->set_new_requests) {
req = list_entry(pos, struct ptlrpc_request, rq_set_chain);
list_del_init(&req->rq_set_chain);
ptlrpc_set_add_req(pc->pc_set, req);
/*
* Need to calculate its timeout.
*/
rc = 1;
}
spin_unlock(&pc->pc_set->set_new_req_lock);
if (pc->pc_set->set_remaining) {
rc = rc | ptlrpc_check_set(pc->pc_set);
/*
* XXX: our set never completes, so we prune the completed
* reqs after each iteration. boy could this be smarter.
*/
list_for_each_safe(pos, tmp, &pc->pc_set->set_requests) {
req = list_entry(pos, struct ptlrpc_request,
rq_set_chain);
if (req->rq_phase != RQ_PHASE_COMPLETE)
continue;
list_del_init(&req->rq_set_chain); req->rq_set = NULL;
ptlrpc_req_finished (req);
}
}
if (rc == 0) {
/*
* If new requests have been added, make sure to wake up.
*/
spin_lock(&pc->pc_set->set_new_req_lock);
rc = !list_empty(&pc->pc_set->set_new_requests);
spin_unlock(&pc->pc_set->set_new_req_lock);
}
RETURN(rc);
}
#ifdef __KERNEL__
/*
* ptlrpc's code paths like to execute in process context, so we have this
* thread which spins on a set which contains the io rpcs. llite specifies
* ptlrpcd's set when it pushes pages down into the oscs.
*/
static int ptlrpcd(void *arg)
{
struct ptlrpcd_ctl *pc = arg;
int rc, exit = 0;
ENTRY;
if ((rc = cfs_daemonize_ctxt(pc->pc_name))) {
complete(&pc->pc_starting);
goto out;
}
complete(&pc->pc_starting);
/*
* This mainloop strongly resembles ptlrpc_set_wait() except that our
* set never completes. ptlrpcd_check() calls ptlrpc_check_set() when
* there are requests in the set. New requests come in on the set's
* new_req_list and ptlrpcd_check() moves them into the set.
*/
do {
struct l_wait_info lwi;
int timeout;
timeout = ptlrpc_set_next_timeout(pc->pc_set);
lwi = LWI_TIMEOUT(cfs_time_seconds(timeout ? timeout : 1),
ptlrpc_expired_set, pc->pc_set);
l_wait_event(pc->pc_set->set_waitq, ptlrpcd_check(pc), &lwi);
/*
* Abort inflight rpcs for forced stop case.
*/
if (test_bit(LIOD_STOP, &pc->pc_flags)) {
if (test_bit(LIOD_FORCE, &pc->pc_flags))
ptlrpc_abort_set(pc->pc_set);
exit++;
}
/*
* Let's make one more loop to make sure that ptlrpcd_check()
* copied all raced new rpcs into the set so we can kill them.
*/
} while (exit < 2);
/*
* Wait for inflight requests to drain.
*/ if (!list_empty(&pc->pc_set->set_requests))
ptlrpc_set_wait(pc->pc_set);
complete(&pc->pc_finishing);
out:
clear_bit(LIOD_START, &pc->pc_flags);
clear_bit(LIOD_STOP, &pc->pc_flags);
clear_bit(LIOD_FORCE, &pc->pc_flags);
return 0;
}
#else
int ptlrpcd_check_async_rpcs(void *arg)
{
struct ptlrpcd_ctl *pc = arg;
int rc = 0;
/*
* Single threaded!!
*/
pc->pc_recurred++;
if (pc->pc_recurred == 1) {
rc = ptlrpcd_check(pc);
if (!rc)
ptlrpc_expired_set(pc->pc_set);
/*
* XXX: send replay requests.
*/
if (pc == &ptlrpcd_recovery_pc)
rc = ptlrpcd_check(pc);
}
pc->pc_recurred--;
return rc;
}
int ptlrpcd_idle(void *arg)
{
struct ptlrpcd_ctl *pc = arg;
return (list_empty(&pc->pc_set->set_new_requests) &&
pc->pc_set->set_remaining == 0);
}
#endif
int ptlrpcd_start(char *name, struct ptlrpcd_ctl *pc)
{
int rc = 0;
ENTRY;
/*
* Do not allow start second thread for one pc.
*/
if (test_bit(LIOD_START, &pc->pc_flags)) {
CERROR("Starting second thread (%s) for same pc %p\n",
name, pc);
RETURN(-EALREADY);
}
set_bit(LIOD_START, &pc->pc_flags);
init_completion(&pc->pc_starting);
init_completion(&pc->pc_finishing);
spin_lock_init(&pc->pc_lock);
snprintf (pc->pc_name, sizeof (pc->pc_name), name);
pc->pc_set = ptlrpc_prep_set();
if (pc->pc_set == NULL) GOTO(out, rc = -ENOMEM);
#ifdef __KERNEL__
rc = cfs_kernel_thread(ptlrpcd, pc, 0);
if (rc < 0) {
ptlrpc_set_destroy(pc->pc_set);
GOTO(out, rc);
}
rc = 0;
wait_for_completion(&pc->pc_starting);
#else
pc->pc_wait_callback =
liblustre_register_wait_callback("ptlrpcd_check_async_rpcs",
&ptlrpcd_check_async_rpcs, pc);
pc->pc_idle_callback =
liblustre_register_idle_callback("ptlrpcd_check_idle_rpcs",
&ptlrpcd_idle, pc);
#endif
out:
if (rc)
clear_bit(LIOD_START, &pc->pc_flags);
RETURN(rc);
}
void ptlrpcd_stop(struct ptlrpcd_ctl *pc, int force)
{
if (!test_bit(LIOD_START, &pc->pc_flags)) {
CERROR("Thread for pc %p was not started\n", pc);
return;
}
set_bit(LIOD_STOP, &pc->pc_flags);
if (force)
set_bit(LIOD_FORCE, &pc->pc_flags);
cfs_waitq_signal(&pc->pc_set->set_waitq);
#ifdef __KERNEL__
wait_for_completion(&pc->pc_finishing);
#else
liblustre_deregister_wait_callback(pc->pc_wait_callback);
liblustre_deregister_idle_callback(pc->pc_idle_callback);
#endif
ptlrpc_set_destroy(pc->pc_set);
}
int ptlrpcd_addref(void)
{
int rc = 0;
ENTRY;
mutex_down(&ptlrpcd_sem);
if (++ptlrpcd_users != 1)
GOTO(out, rc);
rc = ptlrpcd_start("ptlrpcd", &ptlrpcd_pc);
if (rc) {
--ptlrpcd_users;
GOTO(out, rc);
}
rc = ptlrpcd_start("ptlrpcd-recov", &ptlrpcd_recovery_pc);
if (rc) {
ptlrpcd_stop(&ptlrpcd_pc, 0);
--ptlrpcd_users;
GOTO(out, rc);
}
out:
mutex_up(&ptlrpcd_sem);
RETURN(rc);
}
void ptlrpcd_decref(void)
{
mutex_down(&ptlrpcd_sem);
if (--ptlrpcd_users == 0) {
ptlrpcd_stop(&ptlrpcd_pc, 0);
ptlrpcd_stop(&ptlrpcd_recovery_pc, 0);
}
mutex_up(&ptlrpcd_sem);
}