[PATCH 6.1 41/64] scsi: core: Move scsi_host_busy() out of host lock if it is for per-command

6.1-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Ming Lei <redacted>

[ Upstream commit 4e6c9011990726f4d175e2cdfebe5b0b8cce4839 ]

Commit 4373534a9850 ("scsi: core: Move scsi_host_busy() out of host lock
for waking up EH handler") intended to fix a hard lockup issue triggered by
EH. The core idea was to move scsi_host_busy() out of the host lock when
processing individual commands for EH. However, a suggested style change
inadvertently caused scsi_host_busy() to remain under the host lock. Fix
this by calling scsi_host_busy() outside the lock.

Fixes: 4373534a9850 ("scsi: core: Move scsi_host_busy() out of host lock for waking up EH handler")
Cc: Sathya Prakash Veerichetty <redacted>
Cc: Bart Van Assche <bvanassche@acm.org>
Cc: Ewan D. Milne <redacted>
Signed-off-by: Ming Lei <redacted>
Link: https://lore.kernel.org/r/20240203024521.2006455-1-ming.lei@redhat.com (local)
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Martin K. Petersen <redacted>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/scsi/scsi_error.c | 3 ++-
 drivers/scsi/scsi_lib.c   | 4 +++-
 2 files changed, 5 insertions(+), 2 deletions(-)

diff --git a/drivers/scsi/scsi_error.c b/drivers/scsi/scsi_error.c
index 66290961c47c..cfa6f0edff17 100644
--- a/drivers/scsi/scsi_error.c
+++ b/drivers/scsi/scsi_error.c

@@ -277,11 +277,12 @@ static void scsi_eh_inc_host_failed(struct rcu_head *head)
 {
 	struct scsi_cmnd *scmd = container_of(head, typeof(*scmd), rcu);
 	struct Scsi_Host *shost = scmd->device->host;
+	unsigned int busy = scsi_host_busy(shost);
 	unsigned long flags;
 
 	spin_lock_irqsave(shost->host_lock, flags);
 	shost->host_failed++;
-	scsi_eh_wakeup(shost, scsi_host_busy(shost));
+	scsi_eh_wakeup(shost, busy);
 	spin_unlock_irqrestore(shost->host_lock, flags);
 }
 

diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c
index 0e7e9f1e5a02..5c5954b78585 100644
--- a/drivers/scsi/scsi_lib.c
+++ b/drivers/scsi/scsi_lib.c

@@ -280,9 +280,11 @@ static void scsi_dec_host_busy(struct Scsi_Host *shost, struct scsi_cmnd *cmd)
 	rcu_read_lock();
 	__clear_bit(SCMD_STATE_INFLIGHT, &cmd->state);
 	if (unlikely(scsi_host_in_recovery(shost))) {
+		unsigned int busy = scsi_host_busy(shost);
+
 		spin_lock_irqsave(shost->host_lock, flags);
 		if (shost->host_failed || shost->host_eh_scheduled)
-			scsi_eh_wakeup(shost, scsi_host_busy(shost));
+			scsi_eh_wakeup(shost, busy);
 		spin_unlock_irqrestore(shost->host_lock, flags);
 	}
 	rcu_read_unlock();

-- 
2.43.0