[PATCH 9/9] block: move the fail request code

[Christoph Hellwig <hch@lst.de>]

Keep all error injection in one place, and out of line for the main
I/O submission fast path.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 block/blk-core.c        | 37 ++-----------------------------------
 block/error-injection.c | 30 ++++++++++++++++++++++++++++++
 2 files changed, 32 insertions(+), 35 deletions(-)

diff --git a/block/blk-core.c b/block/blk-core.c
index 04a392849ab0..7465dd291272 100644
--- a/block/blk-core.c
+++ b/block/blk-core.c
@@ -29,7 +29,6 @@
 #include <linux/swap.h>
 #include <linux/writeback.h>
 #include <linux/task_io_accounting_ops.h>
-#include <linux/fault-inject.h>
 #include <linux/list_sort.h>
 #include <linux/delay.h>
 #include <linux/ratelimit.h>
@@ -534,32 +533,6 @@ bool blk_get_queue(struct request_queue *q)
 }
 EXPORT_SYMBOL(blk_get_queue);
 
-#ifdef CONFIG_FAIL_MAKE_REQUEST
-
-static DECLARE_FAULT_ATTR(fail_make_request);
-
-static int __init setup_fail_make_request(char *str)
-{
-	return setup_fault_attr(&fail_make_request, str);
-}
-__setup("fail_make_request=", setup_fail_make_request);
-
-bool should_fail_request(unsigned int bytes)
-{
-	return should_fail(&fail_make_request, bytes);
-}
-
-static int __init fail_make_request_debugfs(void)
-{
-	struct dentry *dir = fault_create_debugfs_attr("fail_make_request",
-						NULL, &fail_make_request);
-
-	return PTR_ERR_OR_ZERO(dir);
-}
-
-late_initcall(fail_make_request_debugfs);
-#endif /* CONFIG_FAIL_MAKE_REQUEST */
-
 static inline void bio_check_ro(struct bio *bio)
 {
 	if (op_is_write(bio_op(bio)) && bdev_read_only(bio->bi_bdev)) {
@@ -764,14 +737,8 @@ static void __submit_bio_noacct_mq(struct bio *bio)
 
 void submit_bio_noacct_nocheck(struct bio *bio, bool split)
 {
-	if (unlikely(may_fail_bio(bio))) {
-		if (blk_error_inject(bio))
-			return;
-		if (should_fail_request(bio->bi_iter.bi_size)) {
-			bio_io_error(bio);
-			return;
-		}
-	}
+	if (unlikely(may_fail_bio(bio)) && blk_error_inject(bio))
+		return;
 
 	blk_cgroup_bio_start(bio);
 
diff --git a/block/error-injection.c b/block/error-injection.c
index dc0420c4eb58..45f2454d0bca 100644
--- a/block/error-injection.c
+++ b/block/error-injection.c
@@ -4,6 +4,7 @@
  */
 #include <linux/debugfs.h>
 #include <linux/blkdev.h>
+#include <linux/fault-inject.h>
 #include <linux/parser.h>
 #include <linux/seq_file.h>
 #include "blk.h"
@@ -47,6 +48,13 @@ bool __blk_error_inject(struct bio *bio)
 		}
 	}
 	rcu_read_unlock();
+
+	/* legacy I/O error injection */
+	if (should_fail_request(bio->bi_iter.bi_size)) {
+		bio_io_error(bio);
+		return true;
+	}
+
 	return false;
 }
 
@@ -297,3 +305,25 @@ void blk_error_injection_exit(struct gendisk *disk)
 {
 	error_inject_removall(disk);
 }
+
+static DECLARE_FAULT_ATTR(fail_make_request);
+
+bool should_fail_request(unsigned int bytes)
+{
+	return should_fail(&fail_make_request, bytes);
+}
+
+static int __init setup_fail_make_request(char *str)
+{
+	return setup_fault_attr(&fail_make_request, str);
+}
+__setup("fail_make_request=", setup_fail_make_request);
+
+static int __init fail_make_request_debugfs(void)
+{
+	struct dentry *dir = fault_create_debugfs_attr("fail_make_request",
+						NULL, &fail_make_request);
+
+	return PTR_ERR_OR_ZERO(dir);
+}
+late_initcall(fail_make_request_debugfs);
-- 
2.53.0