[PATCH 1/2] md: change the return value type of md_write_start to void

From: linan666
Date: Sat May 25 2024 - 07:00:16 EST


From: Li Nan <linan122@xxxxxxxxxx>

Commit cc27b0c78c79 ("md: fix deadlock between mddev_suspend() and
md_write_start()") aborted md_write_start() with false when mddev is
suspended, which fixed a deadlock if calling mddev_suspend() with
holding reconfig_mutex(). Since mddev_suspend() now includes
lockdep_assert_not_held(), it no longer holds the reconfig_mutex. This
makes previous abort unnecessary. Now, remove unnecessary abort and
change function return value to void.

Signed-off-by: Li Nan <linan122@xxxxxxxxxx>
---
drivers/md/md.h | 2 +-
drivers/md/md.c | 14 ++++----------
drivers/md/raid1.c | 3 +--
drivers/md/raid10.c | 3 +--
drivers/md/raid5.c | 3 +--
5 files changed, 8 insertions(+), 17 deletions(-)

diff --git a/drivers/md/md.h b/drivers/md/md.h
index ca085ecad504..487582058f74 100644
--- a/drivers/md/md.h
+++ b/drivers/md/md.h
@@ -785,7 +785,7 @@ extern void md_unregister_thread(struct mddev *mddev, struct md_thread __rcu **t
extern void md_wakeup_thread(struct md_thread __rcu *thread);
extern void md_check_recovery(struct mddev *mddev);
extern void md_reap_sync_thread(struct mddev *mddev);
-extern bool md_write_start(struct mddev *mddev, struct bio *bi);
+extern void md_write_start(struct mddev *mddev, struct bio *bi);
extern void md_write_inc(struct mddev *mddev, struct bio *bi);
extern void md_write_end(struct mddev *mddev);
extern void md_done_sync(struct mddev *mddev, int blocks, int ok);
diff --git a/drivers/md/md.c b/drivers/md/md.c
index 509e5638cea1..14d6e615bcbb 100644
--- a/drivers/md/md.c
+++ b/drivers/md/md.c
@@ -8638,12 +8638,12 @@ EXPORT_SYMBOL(md_done_sync);
* A return value of 'false' means that the write wasn't recorded
* and cannot proceed as the array is being suspend.
*/
-bool md_write_start(struct mddev *mddev, struct bio *bi)
+void md_write_start(struct mddev *mddev, struct bio *bi)
{
int did_change = 0;

if (bio_data_dir(bi) != WRITE)
- return true;
+ return;

BUG_ON(mddev->ro == MD_RDONLY);
if (mddev->ro == MD_AUTO_READ) {
@@ -8676,15 +8676,9 @@ bool md_write_start(struct mddev *mddev, struct bio *bi)
if (did_change)
sysfs_notify_dirent_safe(mddev->sysfs_state);
if (!mddev->has_superblocks)
- return true;
+ return;
wait_event(mddev->sb_wait,
- !test_bit(MD_SB_CHANGE_PENDING, &mddev->sb_flags) ||
- is_md_suspended(mddev));
- if (test_bit(MD_SB_CHANGE_PENDING, &mddev->sb_flags)) {
- percpu_ref_put(&mddev->writes_pending);
- return false;
- }
- return true;
+ !test_bit(MD_SB_CHANGE_PENDING, &mddev->sb_flags));
}
EXPORT_SYMBOL(md_write_start);

diff --git a/drivers/md/raid1.c b/drivers/md/raid1.c
index 7b8a71ca66dd..0d80ff471c73 100644
--- a/drivers/md/raid1.c
+++ b/drivers/md/raid1.c
@@ -1687,8 +1687,7 @@ static bool raid1_make_request(struct mddev *mddev, struct bio *bio)
if (bio_data_dir(bio) == READ)
raid1_read_request(mddev, bio, sectors, NULL);
else {
- if (!md_write_start(mddev,bio))
- return false;
+ md_write_start(mddev,bio);
raid1_write_request(mddev, bio, sectors);
}
return true;
diff --git a/drivers/md/raid10.c b/drivers/md/raid10.c
index a4556d2e46bf..f8d7c02c6ed5 100644
--- a/drivers/md/raid10.c
+++ b/drivers/md/raid10.c
@@ -1836,8 +1836,7 @@ static bool raid10_make_request(struct mddev *mddev, struct bio *bio)
&& md_flush_request(mddev, bio))
return true;

- if (!md_write_start(mddev, bio))
- return false;
+ md_write_start(mddev, bio);

if (unlikely(bio_op(bio) == REQ_OP_DISCARD))
if (!raid10_handle_discard(mddev, bio))
diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c
index 2bd1ce9b3922..a84389311dd1 100644
--- a/drivers/md/raid5.c
+++ b/drivers/md/raid5.c
@@ -6078,8 +6078,7 @@ static bool raid5_make_request(struct mddev *mddev, struct bio * bi)
ctx.do_flush = bi->bi_opf & REQ_PREFLUSH;
}

- if (!md_write_start(mddev, bi))
- return false;
+ md_write_start(mddev, bi);
/*
* If array is degraded, better not do chunk aligned read because
* later we might have to read it again in order to reconstruct
--
2.39.2