commit 596444e7570587867924c3ab025183b1a8726897
author Bart Van Assche <bvanassche@acm.org> Mon Mar 09 21:26:23 2020 -0700
committer Jens Axboe <axboe@kernel.dk> Tue Mar 10 07:09:59 2020 -0600
tree ef51b84af05c982be1f4b8349f4a87a18ef9086d
parent 9b03b713082a31a5b90e0a893c72aa620e255c26

null_blk: Add support for init_hctx() fault injection

This makes it possible to test the error path in blk_mq_realloc_hw_ctxs()
and also several error paths in null_blk.

Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Cc: Johannes Thumshirn <jth@kernel.org>
Cc: Hannes Reinecke <hare@suse.com>
Cc: Ming Lei <ming.lei@redhat.com>
Cc: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

drivers/block/null_blk_main.c

diff --git a/drivers/block/null_blk_main.c b/drivers/block/null_blk_main.c
index d21c82c886..89bb16a 100644
--- a/drivers/block/null_blk_main.c
+++ b/drivers/block/null_blk_main.c
@@ -23,6 +23,7 @@
 #ifdef CONFIG_BLK_DEV_NULL_BLK_FAULT_INJECTION
 static DECLARE_FAULT_ATTR(null_timeout_attr);
 static DECLARE_FAULT_ATTR(null_requeue_attr);
+static DECLARE_FAULT_ATTR(null_init_hctx_attr);
 #endif
 
 static inline u64 mb_per_tick(int mbps)
@@ -101,6 +102,9 @@
 
 static char g_requeue_str[80];
 module_param_string(requeue, g_requeue_str, sizeof(g_requeue_str), 0444);
+
+static char g_init_hctx_str[80];
+module_param_string(init_hctx, g_init_hctx_str, sizeof(g_init_hctx_str), 0444);
 #endif
 
 static int g_queue_mode = NULL_Q_MQ;
@@ -1451,6 +1455,11 @@
 	struct nullb *nullb = hctx->queue->queuedata;
 	struct nullb_queue *nq;
 
+#ifdef CONFIG_BLK_DEV_NULL_BLK_FAULT_INJECTION
+	if (g_init_hctx_str[0] && should_fail(&null_init_hctx_attr, 1))
+		return -EFAULT;
+#endif
+
 	nq = &nullb->queues[hctx_idx];
 	hctx->driver_data = nq;
 	null_init_queue(nullb, nq);
@@ -1683,6 +1692,8 @@
 		return false;
 	if (!__null_setup_fault(&null_requeue_attr, g_requeue_str))
 		return false;
+	if (!__null_setup_fault(&null_init_hctx_attr, g_init_hctx_str))
+		return false;
 #endif
 	return true;
 }