[tip:locking/core] block: Use DECLARE_COMPLETION_ONSTACK() in submit_bio_wait()

From: tip-bot for Christoph Hellwig
Date: Wed Oct 25 2017 - 07:14:21 EST


Commit-ID: 65e53aab6d54385dea799356defcbdcc456fb1a7
Gitweb: https://git.kernel.org/tip/65e53aab6d54385dea799356defcbdcc456fb1a7
Author: Christoph Hellwig <hch@xxxxxx>
AuthorDate: Wed, 25 Oct 2017 17:55:57 +0900
Committer: Ingo Molnar <mingo@xxxxxxxxxx>
CommitDate: Wed, 25 Oct 2017 12:18:59 +0200

block: Use DECLARE_COMPLETION_ONSTACK() in submit_bio_wait()

Simplify the code by getting rid of the submit_bio_ret structure.

(This also helps address a lockdep false positive.)

Signed-off-by: Christoph Hellwig <hch@xxxxxx>
Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: amir73il@xxxxxxxxx
Cc: axboe@xxxxxxxxx
Cc: darrick.wong@xxxxxxxxxx
Cc: david@xxxxxxxxxxxxx
Cc: hch@xxxxxxxxxxxxx
Cc: idryomov@xxxxxxxxx
Cc: johan@xxxxxxxxxx
Cc: johannes.berg@xxxxxxxxx
Cc: kernel-team@xxxxxxx
Cc: linux-block@xxxxxxxxxxxxxxx
Cc: linux-fsdevel@xxxxxxxxxxxxxxx
Cc: linux-mm@xxxxxxxxx
Cc: linux-xfs@xxxxxxxxxxxxxxx
Cc: oleg@xxxxxxxxxx
Cc: tj@xxxxxxxxxx
Link: http://lkml.kernel.org/r/1508921765-15396-2-git-send-email-byungchul.park@xxxxxxx
Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx>
---
block/bio.c | 19 +++++--------------
1 file changed, 5 insertions(+), 14 deletions(-)

diff --git a/block/bio.c b/block/bio.c
index 101c2a9..5e901bf 100644
--- a/block/bio.c
+++ b/block/bio.c
@@ -917,17 +917,9 @@ int bio_iov_iter_get_pages(struct bio *bio, struct iov_iter *iter)
}
EXPORT_SYMBOL_GPL(bio_iov_iter_get_pages);

-struct submit_bio_ret {
- struct completion event;
- int error;
-};
-
static void submit_bio_wait_endio(struct bio *bio)
{
- struct submit_bio_ret *ret = bio->bi_private;
-
- ret->error = blk_status_to_errno(bio->bi_status);
- complete(&ret->event);
+ complete(bio->bi_private);
}

/**
@@ -943,16 +935,15 @@ static void submit_bio_wait_endio(struct bio *bio)
*/
int submit_bio_wait(struct bio *bio)
{
- struct submit_bio_ret ret;
+ DECLARE_COMPLETION_ONSTACK(done);

- init_completion(&ret.event);
- bio->bi_private = &ret;
+ bio->bi_private = &done;
bio->bi_end_io = submit_bio_wait_endio;
bio->bi_opf |= REQ_SYNC;
submit_bio(bio);
- wait_for_completion_io(&ret.event);
+ wait_for_completion_io(&done);

- return ret.error;
+ return blk_status_to_errno(bio->bi_status);
}
EXPORT_SYMBOL(submit_bio_wait);