@@ -815,14 +815,19 @@ static unsigned alua_stpg(struct scsi_device *sdev, struct alua_port_group *pg)
return SCSI_DH_RETRY;
}
-static bool alua_rtpg_select_sdev(struct alua_port_group *pg)
+/*
+ * The caller must call scsi_device_put() on the returned pointer if it is not
+ * NULL.
+ */
+static struct scsi_device * __must_check
+alua_rtpg_select_sdev(struct alua_port_group *pg)
{
struct alua_dh_data *h;
- struct scsi_device *sdev = NULL;
+ struct scsi_device *sdev = NULL, *prev_sdev;
lockdep_assert_held(&pg->lock);
if (WARN_ON(!pg->rtpg_sdev))
- return false;
+ return NULL;
/*
* RCU protection isn't necessary for dh_list here
@@ -849,22 +854,22 @@ static bool alua_rtpg_select_sdev(struct alua_port_group *pg)
pr_warn("%s: no device found for rtpg\n",
(pg->device_id_len ?
(char *)pg->device_id_str : "(nameless PG)"));
- return false;
+ return NULL;
}
sdev_printk(KERN_INFO, sdev, "rtpg retry on different device\n");
- scsi_device_put(pg->rtpg_sdev);
+ prev_sdev = pg->rtpg_sdev;
pg->rtpg_sdev = sdev;
- return true;
+ return prev_sdev;
}
static void alua_rtpg_work(struct work_struct *work)
{
struct alua_port_group *pg =
container_of(work, struct alua_port_group, rtpg_work.work);
- struct scsi_device *sdev;
+ struct scsi_device *sdev, *prev_sdev = NULL;
LIST_HEAD(qdata_list);
int err = SCSI_DH_OK;
struct alua_queue_data *qdata, *tmp;
@@ -905,7 +910,7 @@ static void alua_rtpg_work(struct work_struct *work)
/* If RTPG failed on the current device, try using another */
if (err == SCSI_DH_RES_TEMP_UNAVAIL &&
- alua_rtpg_select_sdev(pg))
+ (prev_sdev = alua_rtpg_select_sdev(pg)))
err = SCSI_DH_IMM_RETRY;
if (err == SCSI_DH_RETRY || err == SCSI_DH_IMM_RETRY ||
@@ -917,9 +922,7 @@ static void alua_rtpg_work(struct work_struct *work)
pg->interval = ALUA_RTPG_RETRY_DELAY;
pg->flags |= ALUA_PG_RUN_RTPG;
spin_unlock_irqrestore(&pg->lock, flags);
- queue_delayed_work(kaluad_wq, &pg->rtpg_work,
- pg->interval * HZ);
- return;
+ goto queue_rtpg;
}
if (err != SCSI_DH_OK)
pg->flags &= ~ALUA_PG_RUN_STPG;
@@ -934,9 +937,7 @@ static void alua_rtpg_work(struct work_struct *work)
pg->interval = 0;
pg->flags &= ~ALUA_PG_RUNNING;
spin_unlock_irqrestore(&pg->lock, flags);
- queue_delayed_work(kaluad_wq, &pg->rtpg_work,
- pg->interval * HZ);
- return;
+ goto queue_rtpg;
}
}
@@ -950,6 +951,9 @@ static void alua_rtpg_work(struct work_struct *work)
pg->rtpg_sdev = NULL;
spin_unlock_irqrestore(&pg->lock, flags);
+ if (prev_sdev)
+ scsi_device_put(prev_sdev);
+
list_for_each_entry_safe(qdata, tmp, &qdata_list, entry) {
list_del(&qdata->entry);
if (qdata->callback_fn)
@@ -961,6 +965,12 @@ static void alua_rtpg_work(struct work_struct *work)
spin_unlock_irqrestore(&pg->lock, flags);
scsi_device_put(sdev);
kref_put(&pg->kref, release_port_group);
+ return;
+
+queue_rtpg:
+ if (prev_sdev)
+ scsi_device_put(prev_sdev);
+ queue_delayed_work(kaluad_wq, &pg->rtpg_work, pg->interval * HZ);
}
/**
Move a scsi_device_put() call from alua_rtpg_select_sdev() to its callers. This patch fixes the following smatch complaint: drivers/scsi/device_handler/scsi_dh_alua.c:853 alua_rtpg_select_sdev() warn: sleeping in atomic context alua_rtpg_work() <- disables preempt -> alua_rtpg_select_sdev() -> scsi_device_put() Cc: Hannes Reinecke <hare@suse.de> Cc: Dan Carpenter <dan.carpenter@oracle.com> Reported-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: Bart Van Assche <bvanassche@acm.org> --- drivers/scsi/device_handler/scsi_dh_alua.c | 38 ++++++++++++++-------- 1 file changed, 24 insertions(+), 14 deletions(-)