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ib_srpt: Fix a recently introduced RHEL 5 / CentOS 5 deadlock triggered by initiator logout

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git-svn-id: http://svn.code.sf.net/p/scst/svn/trunk@3545 d57e44dd-8a1f-0410-8b47-8ef2f437770f
This commit is contained in:
Bart Van Assche
2011-06-05 10:00:57 +00:00
parent ce81f59468
commit ab69b20fe2
2 changed files with 33 additions and 61 deletions
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92
srpt/src/ib_srpt.c
View File

@@ -152,6 +152,7 @@ static void srpt_unregister_procfs_entry(struct scst_tgt_template *tgt);
static void srpt_unmap_sg_to_ib_sge(struct srpt_rdma_ch *ch,
struct srpt_send_ioctx *ioctx);
static void srpt_release_channel(struct srpt_rdma_ch *ch);
static void srpt_free_ch(struct scst_session *sess);
static enum rdma_ch_state
srpt_set_ch_state(struct srpt_rdma_ch *ch, enum rdma_ch_state new_state)
@@ -1883,15 +1884,23 @@ static int srpt_compl_thread(void *arg)
/* Hibernation / freezing of the SRPT kernel thread is not supported. */
current->flags |= PF_NOFREEZE;
allow_signal(SIGTERM);
ch = arg;
BUG_ON(!ch);
while (!kthread_should_stop()) {
while (!kthread_should_stop() && !signal_pending(current)) {
set_current_state(TASK_INTERRUPTIBLE);
srpt_process_completion(ch->cq, ch, SCST_CONTEXT_THREAD,
SCST_CONTEXT_DIRECT);
schedule();
}
set_current_state(TASK_RUNNING);
disallow_signal(SIGTERM);
flush_signals(current);
scst_unregister_session(ch->scst_sess, false, srpt_free_ch);
return 0;
}
@@ -1955,17 +1964,6 @@ static int srpt_create_ch_ib(struct srpt_rdma_ch *ch)
if (ret)
goto err_destroy_qp;
TRACE_DBG("creating IB completion thread for session %s",
ch->sess_name);
ch->thread = kthread_run(srpt_compl_thread, ch, "ib_srpt_compl");
if (IS_ERR(ch->thread)) {
PRINT_ERROR("failed to create kernel thread %ld",
PTR_ERR(ch->thread));
ch->thread = NULL;
goto err_destroy_qp;
}
out:
kfree(qp_init);
return ret;
@@ -1981,11 +1979,6 @@ static void srpt_destroy_ch_ib(struct srpt_rdma_ch *ch)
{
TRACE_ENTRY();
if (ch->thread) {
kthread_stop(ch->thread);
ch->thread = NULL;
}
while (ib_poll_cq(ch->cq, ARRAY_SIZE(ch->wc), ch->wc) > 0)
;
@@ -2065,13 +2058,11 @@ static void srpt_drain_channel(struct ib_cm_id *cm_id)
{
struct srpt_rdma_ch *ch;
int ret;
bool do_reset;
WARN_ON_ONCE(irqs_disabled());
ch = cm_id->context;
do_reset = srpt_set_ch_state_to_draining(ch);
if (do_reset) {
if (srpt_set_ch_state_to_draining(ch)) {
ret = srpt_ch_qp_err(ch);
if (ret < 0)
PRINT_ERROR("Setting queue pair in error state"
@@ -2081,61 +2072,37 @@ static void srpt_drain_channel(struct ib_cm_id *cm_id)
/**
* srpt_release_channel() - Release channel resources.
*
* Schedules the actual release not only because invoking ib_destroy_cm_id()
* directly from inside an IB CM callback function would trigger a deadlock
* but also because scst_unregister_session() can sleep.
*/
static void srpt_release_channel(struct srpt_rdma_ch *ch)
{
TRACE_ENTRY();
WARN_ON(ch->state != CH_RELEASING);
schedule_work(&ch->release_work);
TRACE_EXIT();
kill_pid(task_pid(ch->thread), SIGTERM, 1);
}
#if LINUX_VERSION_CODE < KERNEL_VERSION(2, 6, 20) && !defined(BACKPORT_LINUX_WORKQUEUE_TO_2_6_19)
/* A vanilla 2.6.19 or older kernel without backported OFED kernel headers. */
static void srpt_release_channel_work(void *ctx)
#else
static void srpt_release_channel_work(struct work_struct *w)
#endif
static void srpt_free_ch(struct scst_session *sess)
{
struct srpt_rdma_ch *ch;
struct srpt_device *sdev;
TRACE_ENTRY();
#if LINUX_VERSION_CODE < KERNEL_VERSION(2, 6, 20) && !defined(BACKPORT_LINUX_WORKQUEUE_TO_2_6_19)
ch = ctx;
#else
ch = container_of(w, struct srpt_rdma_ch, release_work);
#endif
BUG_ON(!ch);
TRACE_DBG("ch = %p; ch->scst_sess = %p", ch, ch->scst_sess);
WARN_ON(ch->state != CH_RELEASING);
ch = scst_sess_get_tgt_priv(sess);
BUG_ON(ch->scst_sess != sess);
sdev = ch->sport->sdev;
BUG_ON(!sdev);
if (ch->thread) {
kthread_stop(ch->thread);
ch->thread = NULL;
}
BUG_ON(!ch->thread);
kthread_stop(ch->thread);
ch->thread = NULL;
/*
* Unregister the session and wait until processing of all commands
* associated with the session has finished.
*/
scst_unregister_session(ch->scst_sess, true, NULL);
ch->scst_sess = NULL;
srpt_destroy_ch_ib(ch);
srpt_free_ioctx_ring((struct srpt_ioctx **)ch->ioctx_ring,
ch->sport->sdev, ch->rq_size,
sdev, ch->rq_size,
srp_max_rsp_size, DMA_TO_DEVICE);
spin_lock_irq(&sdev->spinlock);
@@ -2325,11 +2292,6 @@ static int srpt_cm_req_recv(struct ib_cm_id *cm_id,
goto reject;
}
#if LINUX_VERSION_CODE < KERNEL_VERSION(2, 6, 20) && !defined(BACKPORT_LINUX_WORKQUEUE_TO_2_6_19)
INIT_WORK(&ch->release_work, srpt_release_channel_work, ch);
#else
INIT_WORK(&ch->release_work, srpt_release_channel_work);
#endif
memcpy(ch->i_port_id, req->initiator_port_id, 16);
memcpy(ch->t_port_id, req->target_port_id, 16);
ch->sport = &sdev->port[param->port - 1];
@@ -2365,13 +2327,21 @@ static int srpt_cm_req_recv(struct ib_cm_id *cm_id,
goto free_ring;
}
ch->thread = kthread_run(srpt_compl_thread, ch, "ib_srpt_compl");
if (IS_ERR(ch->thread)) {
PRINT_ERROR("failed to create kernel thread %ld",
PTR_ERR(ch->thread));
ch->thread = NULL;
goto destroy_ib;
}
ret = srpt_ch_qp_rtr(ch, ch->qp);
if (ret) {
rej->reason = __constant_cpu_to_be32(
SRP_LOGIN_REJ_INSUFFICIENT_RESOURCES);
PRINT_ERROR("rejected SRP_LOGIN_REQ because enabling"
" RTR failed (error code = %d)", ret);
goto destroy_ib;
goto stop_kthread;
}
if (use_port_guid_in_session_name) {
@@ -2451,9 +2421,13 @@ static int srpt_cm_req_recv(struct ib_cm_id *cm_id,
release_channel:
srpt_set_ch_state(ch, CH_DISCONNECTING);
scst_unregister_session(ch->scst_sess, 0, NULL);
scst_unregister_session(ch->scst_sess, false, NULL);
ch->scst_sess = NULL;
stop_kthread:
kthread_stop(ch->thread);
ch->thread = NULL;
destroy_ib:
srpt_destroy_ch_ib(ch);

2
srpt/src/ib_srpt.h
View File

@@ -291,7 +291,6 @@ enum rdma_ch_state {
* against concurrent modification by the cm_id spinlock.
* @scst_sess: SCST session information associated with this SRP channel.
* @sess_name: SCST session name.
* @release_work:
*/
struct srpt_rdma_ch {
struct task_struct *thread;
@@ -316,7 +315,6 @@ struct srpt_rdma_ch {
struct scst_session *scst_sess;
u8 sess_name[36];
struct work_struct release_work;
};
/**