Commit 79bf31a3 authored by Shaohua Li's avatar Shaohua Li

md: fix a race condition for flush request handling

md_submit_flush_data calls pers->make_request, which missed the suspend check.
Fix it with the new md_handle_request API.
Reported-by: default avatarNate Dailey <>
Tested-by: default avatarNate Dailey <>
Fix: cc27b0c7(md: fix deadlock between mddev_suspend() and md_write_start())
Reviewed-by: default avatarNeilBrown <>
Signed-off-by: default avatarShaohua Li <>
parent 393debc2
......@@ -447,16 +447,22 @@ static void md_submit_flush_data(struct work_struct *ws)
struct mddev *mddev = container_of(ws, struct mddev, flush_work);
struct bio *bio = mddev->flush_bio;
* must reset flush_bio before calling into md_handle_request to avoid a
* deadlock, because other bios passed md_handle_request suspend check
* could wait for this and below md_handle_request could wait for those
* bios because of suspend check
mddev->flush_bio = NULL;
if (bio->bi_iter.bi_size == 0)
/* an empty barrier - all done */
else {
bio->bi_opf &= ~REQ_PREFLUSH;
mddev->pers->make_request(mddev, bio);
md_handle_request(mddev, bio);
mddev->flush_bio = NULL;
void md_flush_request(struct mddev *mddev, struct bio *bio)
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