[PATCH 1/2] scsi: zfcp: Add __must_hold() attribute to zfcp_qdio_sbal_get()

Add __must_hold() attribute to zfcp_qdio_sbal_get() in order to let
clang's context analysis know that qdio->req_q_wq must be held on
function entry. This is also documented above the function. Without this
annotation this leads to a valid warning when context analysis is
enabled:

drivers/s390/scsi/zfcp_qdio.c:287:8: warning:
  expecting spinlock '->req_q_lock' to be held at start of each loop [-Wthread-safety-analysis]
  287 |         ret = wait_event_interruptible_lock_irq_timeout(qdio->req_q_wq,
      |               ^

Signed-off-by: Heiko Carstens <[email protected]>
---
 drivers/s390/scsi/zfcp_ext.h  | 3 ++-
 drivers/s390/scsi/zfcp_qdio.c | 1 +
 2 files changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/s390/scsi/zfcp_ext.h b/drivers/s390/scsi/zfcp_ext.h
index 40bd597fb4cd..0eb9bc9d03e4 100644
--- a/drivers/s390/scsi/zfcp_ext.h
+++ b/drivers/s390/scsi/zfcp_ext.h
@@ -154,7 +154,8 @@ extern ssize_t zfcp_fsf_scnprint_fc_security(char *buf, size_t size,
 /* zfcp_qdio.c */
 extern int zfcp_qdio_setup(struct zfcp_adapter *);
 extern void zfcp_qdio_destroy(struct zfcp_qdio *);
-extern int zfcp_qdio_sbal_get(struct zfcp_qdio *);
+extern int zfcp_qdio_sbal_get(struct zfcp_qdio *qdio)
+	__must_hold(qdio->req_q_lock);
 extern int zfcp_qdio_send(struct zfcp_qdio *, struct zfcp_qdio_req *);
 extern int zfcp_qdio_sbals_from_sg(struct zfcp_qdio *, struct zfcp_qdio_req *,
 				   struct scatterlist *);
diff --git a/drivers/s390/scsi/zfcp_qdio.c b/drivers/s390/scsi/zfcp_qdio.c
index ce1af72d9b61..bac8385e069f 100644
--- a/drivers/s390/scsi/zfcp_qdio.c
+++ b/drivers/s390/scsi/zfcp_qdio.c
@@ -281,6 +281,7 @@ static int zfcp_qdio_sbal_check(struct zfcp_qdio *qdio)
  * Returns: 0 on success, -EIO if there is no free sbal after waiting.
  */
 int zfcp_qdio_sbal_get(struct zfcp_qdio *qdio)
+	__must_hold(qdio->req_q_lock)
 {
 	long ret;
 
-- 
2.53.0