diff mbox series

[11/30] lpfc: Coordinate adapter error handling with offline handling

Message ID 20190312233033.32670-12-jsmart2021@gmail.com (mailing list archive)
State Accepted
Headers show
Series lpfc updates for 12.2.0.1 | expand

Commit Message

James Smart March 12, 2019, 11:30 p.m. UTC 
The driver periodically checks for adapter error in a background
thread. If the thread detects an error, the adapter will be reset
including the deletion and reallocation of workqueues on the adapter.
Simultaneously, there may be a user-space request to offline the adapter
which may try to do many of the same steps, in parallel, on a different
thread. As memory was deallocated while unexpected, the parallel
offline request hit a bad pointer.

Add coordination between the two threads.  The error recovery thread
has precedence. So, when an error is detected, a flag is set on the
adapter to indicate the error thread is terminating the adapter. But,
before doing that work, it will look for a flag that is set by the
offline flow, and if set, will wait for it to complete before then
processing the error handling path.  Similarly, in the offline thread,
it first checks for whether the error thread is resetting the adapter,
and if so, will then wait for the error thread to finish. Only after it
has finished, will it set its flag and offline the adapter.

Signed-off-by: Dick Kennedy <dick.kennedy@broadcom.com>
Signed-off-by: James Smart <jsmart2021@gmail.com>
---
 drivers/scsi/lpfc/lpfc_attr.c | 19 +++++++++++++++++++
 drivers/scsi/lpfc/lpfc_init.c | 19 +++++++++++++++++++
 drivers/scsi/lpfc/lpfc_sli.c  |  6 +++---
 drivers/scsi/lpfc/lpfc_sli.h  |  4 ++++
 4 files changed, 45 insertions(+), 3 deletions(-)
diff mbox series

Patch

diff --git a/drivers/scsi/lpfc/lpfc_attr.c b/drivers/scsi/lpfc/lpfc_attr.c
index 5d6c874c44e7..61745f590916 100644
--- a/drivers/scsi/lpfc/lpfc_attr.c
+++ b/drivers/scsi/lpfc/lpfc_attr.c
@@ -1204,6 +1204,20 @@  lpfc_do_offline(struct lpfc_hba *phba, uint32_t type)
 
 	psli = &phba->sli;
 
+	/*
+	 * If freeing the queues have already started, don't access them.
+	 * Otherwise set FREE_WAIT to indicate that queues are being used
+	 * to hold the freeing process until we finish.
+	 */
+	spin_lock_irq(&phba->hbalock);
+	if (!(psli->sli_flag & LPFC_QUEUE_FREE_INIT)) {
+		psli->sli_flag |= LPFC_QUEUE_FREE_WAIT;
+	} else {
+		spin_unlock_irq(&phba->hbalock);
+		goto skip_wait;
+	}
+	spin_unlock_irq(&phba->hbalock);
+
 	/* Wait a little for things to settle down, but not
 	 * long enough for dev loss timeout to expire.
 	 */
@@ -1225,6 +1239,11 @@  lpfc_do_offline(struct lpfc_hba *phba, uint32_t type)
 		}
 	}
 out:
+	spin_lock_irq(&phba->hbalock);
+	psli->sli_flag &= ~LPFC_QUEUE_FREE_WAIT;
+	spin_unlock_irq(&phba->hbalock);
+
+skip_wait:
 	init_completion(&online_compl);
 	rc = lpfc_workq_post_event(phba, &status, &online_compl, type);
 	if (rc == 0)
diff --git a/drivers/scsi/lpfc/lpfc_init.c b/drivers/scsi/lpfc/lpfc_init.c
index 4a470f80f601..440b631c2155 100644
--- a/drivers/scsi/lpfc/lpfc_init.c
+++ b/drivers/scsi/lpfc/lpfc_init.c
@@ -9132,6 +9132,20 @@  lpfc_sli4_release_hdwq(struct lpfc_hba *phba)
 void
 lpfc_sli4_queue_destroy(struct lpfc_hba *phba)
 {
+	/*
+	 * Set FREE_INIT before beginning to free the queues.
+	 * Wait until the users of queues to acknowledge to
+	 * release queues by clearing FREE_WAIT.
+	 */
+	spin_lock_irq(&phba->hbalock);
+	phba->sli.sli_flag |= LPFC_QUEUE_FREE_INIT;
+	while (phba->sli.sli_flag & LPFC_QUEUE_FREE_WAIT) {
+		spin_unlock_irq(&phba->hbalock);
+		msleep(20);
+		spin_lock_irq(&phba->hbalock);
+	}
+	spin_unlock_irq(&phba->hbalock);
+
 	/* Release HBA eqs */
 	if (phba->sli4_hba.hdwq)
 		lpfc_sli4_release_hdwq(phba);
@@ -9170,6 +9184,11 @@  lpfc_sli4_queue_destroy(struct lpfc_hba *phba)
 
 	/* Everything on this list has been freed */
 	INIT_LIST_HEAD(&phba->sli4_hba.lpfc_wq_list);
+
+	/* Done with freeing the queues */
+	spin_lock_irq(&phba->hbalock);
+	phba->sli.sli_flag &= ~LPFC_QUEUE_FREE_INIT;
+	spin_unlock_irq(&phba->hbalock);
 }
 
 int
diff --git a/drivers/scsi/lpfc/lpfc_sli.c b/drivers/scsi/lpfc/lpfc_sli.c
index 9d7fc2d4f6d0..ea80f3e60699 100644
--- a/drivers/scsi/lpfc/lpfc_sli.c
+++ b/drivers/scsi/lpfc/lpfc_sli.c
@@ -14416,6 +14416,9 @@  lpfc_sli4_queue_free(struct lpfc_queue *queue)
 	if (!queue)
 		return;
 
+	if (!list_empty(&queue->wq_list))
+		list_del(&queue->wq_list);
+
 	while (!list_empty(&queue->page_list)) {
 		list_remove_head(&queue->page_list, dmabuf, struct lpfc_dmabuf,
 				 list);
@@ -14431,9 +14434,6 @@  lpfc_sli4_queue_free(struct lpfc_queue *queue)
 	if (!list_empty(&queue->cpu_list))
 		list_del(&queue->cpu_list);
 
-	if (!list_empty(&queue->wq_list))
-		list_del(&queue->wq_list);
-
 	kfree(queue);
 	return;
 }
diff --git a/drivers/scsi/lpfc/lpfc_sli.h b/drivers/scsi/lpfc/lpfc_sli.h
index 1153a6c91bde..467b8270f7fd 100644
--- a/drivers/scsi/lpfc/lpfc_sli.h
+++ b/drivers/scsi/lpfc/lpfc_sli.h
@@ -327,6 +327,10 @@  struct lpfc_sli {
 #define LPFC_SLI_ASYNC_MBX_BLK    0x2000 /* Async mailbox is blocked */
 #define LPFC_SLI_SUPPRESS_RSP     0x4000 /* Suppress RSP feature is supported */
 #define LPFC_SLI_USE_EQDR         0x8000 /* EQ Delay Register is supported */
+#define LPFC_QUEUE_FREE_INIT	  0x10000 /* Queue freeing is in progress */
+#define LPFC_QUEUE_FREE_WAIT	  0x20000 /* Hold Queue free as it is being
+					   * used outside worker thread
+					   */
 
 	struct lpfc_sli_ring *sli3_ring;