[PATCH 1/2] scsi: mpi3mr: Fix locking in an error path

[Bart Van Assche <bvanassche@acm.org>]

Make all error paths unlock rioc->bsg_cmds.mutex.

This patch fixes the following Clang -Wthread-safety errors:

drivers/scsi/mpi3mr/mpi3mr_app.c:2835:1: error: mutex 'mrioc->bsg_cmds.mutex' is not held on every path through here [-Werror,-Wthread-safety-analysis]
 2835 | }
      | ^
drivers/scsi/mpi3mr/mpi3mr_app.c:2332:6: note: mutex acquired here
 2332 |         if (mutex_lock_interruptible(&mrioc->bsg_cmds.mutex))
      |             ^
./include/linux/mutex.h:172:40: note: expanded from macro 'mutex_lock_interruptible'
  172 | #define mutex_lock_interruptible(lock) mutex_lock_interruptible_nested(lock, 0)
      |                                        ^

Cc: Sathya Prakash <sathya.prakash@broadcom.com>
Fixes: fb231d7deffb ("scsi: mpi3mr: Support for preallocation of SGL BSG data buffers part-2")
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
---
 drivers/scsi/mpi3mr/mpi3mr_app.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/scsi/mpi3mr/mpi3mr_app.c b/drivers/scsi/mpi3mr/mpi3mr_app.c
index 26582776749f..c6bd5c8c0ea5 100644
--- a/drivers/scsi/mpi3mr/mpi3mr_app.c
+++ b/drivers/scsi/mpi3mr/mpi3mr_app.c
@@ -2425,6 +2425,7 @@ static long mpi3mr_bsg_process_mpt_cmds(struct bsg_job *job)
 	}
 
 	if (!mrioc->ioctl_sges_allocated) {
+		mutex_unlock(&mrioc->bsg_cmds.mutex);
 		dprint_bsg_err(mrioc, "%s: DMA memory was not allocated\n",
 			       __func__);
 		return -ENOMEM;