scsi: scsi_dh_alua: Fix RCU annotations

This patch avoids that sparse complains about RCU pointer dereferences.

Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com>
Cc: Hannes Reinecke <hare@suse.de>
Cc: tang.junhui <tang.junhui@zte.com.cn>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

diff --git a/drivers/scsi/device_handler/scsi_dh_alua.c b/drivers/scsi/device_handler/scsi_dh_alua.c
index 241829e596680f8be89941fc43ce0db642e29b18..32e48cc4cf7115ded2beb4f789eca2d5a1d7ed7b 100644 (file)
--- a/drivers/scsi/device_handler/scsi_dh_alua.c
+++ b/drivers/scsi/device_handler/scsi_dh_alua.c
@@ -95,7 +95,7 @@ struct alua_port_group {
 
 struct alua_dh_data {
        struct list_head        node;
-       struct alua_port_group  *pg;
+       struct alua_port_group __rcu *pg;
        int                     group_id;
        spinlock_t              pg_lock;
        struct scsi_device      *sdev;
@@ -369,7 +369,7 @@ static int alua_check_vpd(struct scsi_device *sdev, struct alua_dh_data *h,
 
        /* Check for existing port group references */
        spin_lock(&h->pg_lock);
-       old_pg = h->pg;
+       old_pg = rcu_dereference_protected(h->pg, lockdep_is_held(&h->pg_lock));
        if (old_pg != pg) {
                /* port group has changed. Update to new port group */
                if (h->pg) {
@@ -388,7 +388,9 @@ static int alua_check_vpd(struct scsi_device *sdev, struct alua_dh_data *h,
                list_add_rcu(&h->node, &pg->dh_list);
        spin_unlock_irqrestore(&pg->lock, flags);
 
-       alua_rtpg_queue(h->pg, sdev, NULL, true);
+       alua_rtpg_queue(rcu_dereference_protected(h->pg,
+                                                 lockdep_is_held(&h->pg_lock)),
+                       sdev, NULL, true);
        spin_unlock(&h->pg_lock);
 
        if (old_pg)
@@ -937,7 +939,7 @@ static int alua_initialize(struct scsi_device *sdev, struct alua_dh_data *h)
 static int alua_set_params(struct scsi_device *sdev, const char *params)
 {
        struct alua_dh_data *h = sdev->handler_data;
-       struct alua_port_group __rcu *pg = NULL;
+       struct alua_port_group *pg = NULL;
        unsigned int optimize = 0, argc;
        const char *p = params;
        int result = SCSI_DH_OK;
@@ -984,7 +986,7 @@ static int alua_activate(struct scsi_device *sdev,
        struct alua_dh_data *h = sdev->handler_data;
        int err = SCSI_DH_OK;
        struct alua_queue_data *qdata;
-       struct alua_port_group __rcu *pg;
+       struct alua_port_group *pg;
 
        qdata = kzalloc(sizeof(*qdata), GFP_KERNEL);
        if (!qdata) {
@@ -1048,7 +1050,7 @@ static void alua_check(struct scsi_device *sdev, bool force)
 static int alua_prep_fn(struct scsi_device *sdev, struct request *req)
 {
        struct alua_dh_data *h = sdev->handler_data;
-       struct alua_port_group __rcu *pg;
+       struct alua_port_group *pg;
        unsigned char state = SCSI_ACCESS_STATE_OPTIMAL;
        int ret = BLKPREP_OK;
 
@@ -1118,7 +1120,7 @@ static void alua_bus_detach(struct scsi_device *sdev)
        struct alua_port_group *pg;
 
        spin_lock(&h->pg_lock);
-       pg = h->pg;
+       pg = rcu_dereference_protected(h->pg, lockdep_is_held(&h->pg_lock));
        rcu_assign_pointer(h->pg, NULL);
        h->sdev = NULL;
        spin_unlock(&h->pg_lock);