Merge tag 'for-5.8/block-2020-06-01' of git://git.kernel.dk/linux-block

[thirdparty/linux.git] / drivers / block / null_blk_main.c

diff --git a/drivers/block/null_blk_main.c b/drivers/block/null_blk_main.c
index ce9e33603a4d9540df90f2c7065332a0a4d112ae..87b31f9ca362ee17b6407811b223842cf28df88f 100644 (file)
--- a/drivers/block/null_blk_main.c
+++ b/drivers/block/null_blk_main.c
@@ -1250,8 +1250,34 @@ static inline blk_status_t null_handle_memory_backed(struct nullb_cmd *cmd,
        return errno_to_blk_status(err);
 }
 
+static void nullb_zero_read_cmd_buffer(struct nullb_cmd *cmd)
+{
+       struct nullb_device *dev = cmd->nq->dev;
+       struct bio *bio;
+
+       if (dev->memory_backed)
+               return;
+
+       if (dev->queue_mode == NULL_Q_BIO && bio_op(cmd->bio) == REQ_OP_READ) {
+               zero_fill_bio(cmd->bio);
+       } else if (req_op(cmd->rq) == REQ_OP_READ) {
+               __rq_for_each_bio(bio, cmd->rq)
+                       zero_fill_bio(bio);
+       }
+}
+
 static inline void nullb_complete_cmd(struct nullb_cmd *cmd)
 {
+       /*
+        * Since root privileges are required to configure the null_blk
+        * driver, it is fine that this driver does not initialize the
+        * data buffers of read commands. Zero-initialize these buffers
+        * anyway if KMSAN is enabled to prevent that KMSAN complains
+        * about null_blk not initializing read data buffers.
+        */
+       if (IS_ENABLED(CONFIG_KMSAN))
+               nullb_zero_read_cmd_buffer(cmd);
+
        /* Complete IO by inline, softirq or timer */
        switch (cmd->nq->dev->irqmode) {
        case NULL_IRQ_SOFTIRQ:
@@ -1397,7 +1423,7 @@ static bool should_requeue_request(struct request *rq)
 static enum blk_eh_timer_return null_timeout_rq(struct request *rq, bool res)
 {
        pr_info("rq %p timed out\n", rq);
-       blk_mq_complete_request(rq);
+       blk_mq_force_complete_rq(rq);
        return BLK_EH_DONE;
 }