Patch "md: Fix missing release of 'active_io' for flush" has been added to the 6.1-stable tree

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



This is a note to let you know that I've just added the patch titled

    md: Fix missing release of 'active_io' for flush

to the 6.1-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     md-fix-missing-release-of-active_io-for-flush.patch
and it can be found in the queue-6.1 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.


>From 855678ed8534518e2b428bcbcec695de9ba248e8 Mon Sep 17 00:00:00 2001
From: Yu Kuai <yukuai3@xxxxxxxxxx>
Date: Thu, 1 Feb 2024 17:25:51 +0800
Subject: md: Fix missing release of 'active_io' for flush

From: Yu Kuai <yukuai3@xxxxxxxxxx>

commit 855678ed8534518e2b428bcbcec695de9ba248e8 upstream.

submit_flushes
 atomic_set(&mddev->flush_pending, 1);
 rdev_for_each_rcu(rdev, mddev)
  atomic_inc(&mddev->flush_pending);
  bi->bi_end_io = md_end_flush
  submit_bio(bi);
                        /* flush io is done first */
                        md_end_flush
                         if (atomic_dec_and_test(&mddev->flush_pending))
                          percpu_ref_put(&mddev->active_io)
                          -> active_io is not released

 if (atomic_dec_and_test(&mddev->flush_pending))
  -> missing release of active_io

For consequence, mddev_suspend() will wait for 'active_io' to be zero
forever.

Fix this problem by releasing 'active_io' in submit_flushes() if
'flush_pending' is decreased to zero.

Fixes: fa2bbff7b0b4 ("md: synchronize flush io with array reconfiguration")
Cc: stable@xxxxxxxxxxxxxxx # v6.1+
Reported-by: Blazej Kucman <blazej.kucman@xxxxxxxxxxxxxxx>
Closes: https://lore.kernel.org/lkml/20240130172524.0000417b@xxxxxxxxxxxxxxx/
Signed-off-by: Yu Kuai <yukuai3@xxxxxxxxxx>
Signed-off-by: Song Liu <song@xxxxxxxxxx>
Link: https://lore.kernel.org/r/20240201092559.910982-7-yukuai1@xxxxxxxxxxxxxxx
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
 drivers/md/md.c |    6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

--- a/drivers/md/md.c
+++ b/drivers/md/md.c
@@ -564,8 +564,12 @@ static void submit_flushes(struct work_s
 			rcu_read_lock();
 		}
 	rcu_read_unlock();
-	if (atomic_dec_and_test(&mddev->flush_pending))
+	if (atomic_dec_and_test(&mddev->flush_pending)) {
+		/* The pair is percpu_ref_get() from md_flush_request() */
+		percpu_ref_put(&mddev->active_io);
+
 		queue_work(md_wq, &mddev->flush_work);
+	}
 }
 
 static void md_submit_flush_data(struct work_struct *ws)


Patches currently in stable-queue which might be from yukuai3@xxxxxxxxxx are

queue-6.1/md-fix-missing-release-of-active_io-for-flush.patch




[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
[Index of Archives]     [Linux USB Devel]     [Linux Audio Users]     [Yosemite News]     [Linux Kernel]     [Linux SCSI]

  Powered by Linux