From: NeilBrown <neilb@suse.de>

Subject: kabi for for md: improve handling of bio with REQ_PREFLUSH in md_flush_request()

Patch-mainline: never, kabi

References: git-fixes

1/ Don't mark 'make_request' method as '__must_check'

2/ Instead of changing return value of md_flush_request(),

  create a new md_flush_request2(), and leave md_flush_request()

  with the old (slughtly buggy) behaviour.

Signed-off-by: NeilBrown <neilb@suse.de>

---

 drivers/md/md-linear.c    |    2 +-

 drivers/md/md-multipath.c |    2 +-

 drivers/md/md.c           |    9 ++++++++-

 drivers/md/md.h           |    5 +++--

 drivers/md/raid0.c        |    2 +-

 drivers/md/raid1.c        |    2 +-

 drivers/md/raid10.c       |    2 +-

 drivers/md/raid5.c        |    2 +-

 8 files changed, 17 insertions(+), 9 deletions(-)

--- a/drivers/md/md-linear.c

+++ b/drivers/md/md-linear.c

@@ -253,7 +253,7 @@ static bool linear_make_request(struct m

 	sector_t bio_sector = bio->bi_iter.bi_sector;

 	if (unlikely(bio->bi_opf & REQ_PREFLUSH)

-	    && md_flush_request(mddev, bio))

+	    && md_flush_request2(mddev, bio))

 		return true;

 	tmp_dev = which_dev(mddev, bio_sector);

--- a/drivers/md/md-multipath.c

+++ b/drivers/md/md-multipath.c

@@ -113,7 +113,7 @@ static bool multipath_make_request(struc

 	struct multipath_info *multipath;

 	if (unlikely(bio->bi_opf & REQ_PREFLUSH)

-	    && md_flush_request(mddev, bio))

+	    && md_flush_request2(mddev, bio))

 		return true;

 	mp_bh = mempool_alloc(conf->pool, GFP_NOIO);

--- a/drivers/md/md.c

+++ b/drivers/md/md.c

@@ -494,7 +494,7 @@ static void md_submit_flush_data(struct

  * being finished in another context.  Returns false if the flushing is

  * complete but still needs the I/O portion of the bio to be processed.

  */

-bool md_flush_request(struct mddev *mddev, struct bio *bio)

+bool md_flush_request2(struct mddev *mddev, struct bio *bio)

 {

 	ktime_t start = ktime_get_boottime();

 	spin_lock_irq(&mddev->lock);

@@ -524,6 +524,13 @@ bool md_flush_request(struct mddev *mdde

 	}

 	return true;

 }

+EXPORT_SYMBOL(md_flush_request2);

+

+void md_flush_request(struct mddev *mddev, struct bio *bio)

+{

+	if (!md_flush_request2(mddev, bio))

+		mddev->pers->make_request(mddev, bio);

+}

 EXPORT_SYMBOL(md_flush_request);

 static inline struct mddev *mddev_get(struct mddev *mddev)

--- a/drivers/md/md.h

+++ b/drivers/md/md.h

@@ -566,7 +566,7 @@ struct md_personality

 	int level;

 	struct list_head list;

 	struct module *owner;

-	bool __must_check (*make_request)(struct mddev *mddev, struct bio *bio);

+	bool (*make_request)(struct mddev *mddev, struct bio *bio);

 	/*

 	 * start up works that do NOT require md_thread. tasks that

 	 * requires md_thread should go into start()

@@ -682,7 +682,8 @@ extern void md_error(struct mddev *mddev

 extern void md_finish_reshape(struct mddev *mddev);

 extern int mddev_congested(struct mddev *mddev, int bits);

-extern bool __must_check md_flush_request(struct mddev *mddev, struct bio *bio);

+extern void md_flush_request(struct mddev *mddev, struct bio *bio);

+extern bool __must_check md_flush_request2(struct mddev *mddev, struct bio *bio);

 extern void md_super_write(struct mddev *mddev, struct md_rdev *rdev,

 			   sector_t sector, int size, struct page *page);

 extern int md_super_wait(struct mddev *mddev);

--- a/drivers/md/raid0.c

+++ b/drivers/md/raid0.c

@@ -578,7 +578,7 @@ static bool raid0_make_request(struct md

 	unsigned sectors;

 	if (unlikely(bio->bi_opf & REQ_PREFLUSH)

-	    && md_flush_request(mddev, bio))

+	    && md_flush_request2(mddev, bio))

 		return true;

 	if (unlikely((bio_op(bio) == REQ_OP_DISCARD))) {

--- a/drivers/md/raid1.c

+++ b/drivers/md/raid1.c

@@ -1539,7 +1539,7 @@ static bool raid1_make_request(struct md

 	sector_t sectors;

 	if (unlikely(bio->bi_opf & REQ_PREFLUSH)

-	    && md_flush_request(mddev, bio))

+	    && md_flush_request2(mddev, bio))

 		return true;

 	/*

--- a/drivers/md/raid10.c

+++ b/drivers/md/raid10.c

@@ -1575,7 +1575,7 @@ static bool raid10_make_request(struct m

 	int sectors = bio_sectors(bio);

 	if (unlikely(bio->bi_opf & REQ_PREFLUSH)

-	    && md_flush_request(mddev, bio))

+	    && md_flush_request2(mddev, bio))

 		return true;

 	if (!md_write_start(mddev, bio))

--- a/drivers/md/raid5.c

+++ b/drivers/md/raid5.c

@@ -5584,7 +5584,7 @@ static bool raid5_make_request(struct md

 		if (ret == 0)

 			return true;

 		if (ret == -ENODEV) {

-			if (md_flush_request(mddev, bi))

+			if (md_flush_request2(mddev, bi))

 				return true;

 		}

 		/* ret == -EAGAIN, fallback */