[PATCH 31/34] qla2xxx: Complain loudly about reference count underflow

[Bart Van Assche]

A reference count underflow is a severe bug. Hence complain loudly if a
reference count underflow happens.

Cc: Himanshu Madhani <hmadh...@marvell.com>
Cc: Giridhar Malavali <gmalav...@marvell.com>
Signed-off-by: Bart Van Assche <bvanass...@acm.org>
---
 drivers/scsi/qla2xxx/qla_nvme.c | 15 +++++----------
 drivers/scsi/qla2xxx/qla_os.c   | 16 ++--------------
 2 files changed, 7 insertions(+), 24 deletions(-)

diff --git a/drivers/scsi/qla2xxx/qla_nvme.c b/drivers/scsi/qla2xxx/qla_nvme.c
index 4c1112107e88..22e3fba28e51 100644
--- a/drivers/scsi/qla2xxx/qla_nvme.c
+++ b/drivers/scsi/qla2xxx/qla_nvme.c
@@ -131,11 +131,8 @@ static void qla_nvme_sp_ls_done(void *ptr, int res)
        struct nvmefc_ls_req   *fd;
        struct nvme_private *priv;
 
-       if (atomic_read(&sp->ref_count) == 0) {
-               ql_log(ql_log_warn, sp->fcport->vha, 0x2123,
-                   "SP reference-count to ZERO on LS_done -- sp=%p.\n", sp);
+       if (WARN_ON_ONCE(atomic_read(&sp->ref_count) == 0))
                return;
-       }
 
        atomic_dec(&sp->ref_count);
 
@@ -160,6 +157,9 @@ static void qla_nvme_sp_done(void *ptr, int res)
        nvme = &sp->u.iocb_cmd;
        fd = nvme->u.nvme.desc;
 
+       if (WARN_ON_ONCE(atomic_read(&sp->ref_count) == 0))
+               return;
+
        atomic_dec(&sp->ref_count);
 
        if (res == QLA_SUCCESS) {
@@ -199,13 +199,8 @@ static void qla_nvme_abort_work(struct work_struct *work)
                return;
        }
 
-       if (atomic_read(&sp->ref_count) == 0) {
-               WARN_ON(1);
-               ql_log(ql_log_info, fcport->vha, 0xffff,
-                       "%s: command already aborted on sp: %p\n",
-                       __func__, sp);
+       if (WARN_ON_ONCE(atomic_read(&sp->ref_count) == 0))
                return;
-       }
 
        rval = ha->isp_ops->abort_command(sp);
 
diff --git a/drivers/scsi/qla2xxx/qla_os.c b/drivers/scsi/qla2xxx/qla_os.c
index 73ddd02d1a39..e1c82a0a9745 100644
--- a/drivers/scsi/qla2xxx/qla_os.c
+++ b/drivers/scsi/qla2xxx/qla_os.c
@@ -716,14 +716,8 @@ qla2x00_sp_compl(void *ptr, int res)
        struct scsi_cmnd *cmd = GET_CMD_SP(sp);
        struct completion *comp = sp->comp;
 
-       if (atomic_read(&sp->ref_count) == 0) {
-               ql_dbg(ql_dbg_io, sp->vha, 0x3015,
-                   "SP reference-count to ZERO -- sp=%p cmd=%p.\n",
-                   sp, GET_CMD_SP(sp));
-               if (ql2xextended_error_logging & ql_dbg_io)
-                       WARN_ON(atomic_read(&sp->ref_count) == 0);
+       if (WARN_ON_ONCE(atomic_read(&sp->ref_count) == 0))
                return;
-       }
 
        atomic_dec(&sp->ref_count);
 
@@ -827,14 +821,8 @@ qla2xxx_qpair_sp_compl(void *ptr, int res)
        struct scsi_cmnd *cmd = GET_CMD_SP(sp);
        struct completion *comp = sp->comp;
 
-       if (atomic_read(&sp->ref_count) == 0) {
-               ql_dbg(ql_dbg_io, sp->fcport->vha, 0x3079,
-                   "SP reference-count to ZERO -- sp=%p cmd=%p.\n",
-                   sp, GET_CMD_SP(sp));
-               if (ql2xextended_error_logging & ql_dbg_io)
-                       WARN_ON(atomic_read(&sp->ref_count) == 0);
+       if (WARN_ON_ONCE(atomic_read(&sp->ref_count) == 0))
                return;
-       }
 
        atomic_dec(&sp->ref_count);
 
-- 
2.21.0.196.g041f5ea1cf98