scsi: lpfc: Prevent NDLP reference count underflow in dev_loss_tmo callback
authorJustin Tee <justin.tee@broadcom.com>
Thu, 31 Oct 2024 22:32:15 +0000 (15:32 -0700)
committerMartin K. Petersen <martin.petersen@oracle.com>
Sun, 3 Nov 2024 01:45:24 +0000 (21:45 -0400)
commit4281f44ea8bfedd25938a0031bebba1473ece9ad
treee66f7e4458cc0ad3c9ff31b083093e6642638394
parenteb038363d8e9ae0d9fa31a0600438d19b283dd41
scsi: lpfc: Prevent NDLP reference count underflow in dev_loss_tmo callback

Current dev_loss_tmo handling checks whether there has been a previous
call to unregister with SCSI transport.  If so, the NDLP kref count is
decremented a second time in dev_loss_tmo as the final kref release.
However, this can sometimes result in a reference count underflow if
there is also a race to unregister with NVMe transport as well.  Add a
check for NVMe transport registration before decrementing the final
kref.  If NVMe transport is still registered, then the NVMe transport
unregistration is designated as the final kref decrement.

Signed-off-by: Justin Tee <justin.tee@broadcom.com>
Link: https://lore.kernel.org/r/20241031223219.152342-8-justintee8345@gmail.com
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
drivers/scsi/lpfc/lpfc_hbadisc.c