This is a note to let you know that I've just added the patch titled
Revert "Revert "md/raid5: Wait for MD_SB_CHANGE_PENDING in raid5d""
to the 6.6-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:
revert-revert-md-raid5-wait-for-md_sb_change_pending-in-raid5d.patch
and it can be found in the queue-6.6 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From song@xxxxxxxxxx Thu Jan 25 13:56:36 2024
From: Song Liu <song@xxxxxxxxxx>
Date: Thu, 25 Jan 2024 00:21:31 -0800
Subject: Revert "Revert "md/raid5: Wait for MD_SB_CHANGE_PENDING in raid5d""
To: linux-raid@xxxxxxxxxxxxxxx
Cc: yukuai1@xxxxxxxxxxxxxxx, Song Liu <song@xxxxxxxxxx>, Dan Moulding <dan@xxxxxxxx>, stable@xxxxxxxxxxxxxxx, Junxiao Bi <junxiao.bi@xxxxxxxxxx>, Yu Kuai <yukuai3@xxxxxxxxxx>
Message-ID: <20240125082131.788600-1-song@xxxxxxxxxx>
From: Song Liu <song@xxxxxxxxxx>
This reverts commit bed9e27baf52a09b7ba2a3714f1e24e17ced386d.
The original set [1][2] was expected to undo a suboptimal fix in [2], and
replace it with a better fix [1]. However, as reported by Dan Moulding [2]
causes an issue with raid5 with journal device.
Revert [2] for now to close the issue. We will follow up on another issue
reported by Juxiao Bi, as [2] is expected to fix it. We believe this is a
good trade-off, because the latter issue happens less freqently.
In the meanwhile, we will NOT revert [1], as it contains the right logic.
[1] commit d6e035aad6c0 ("md: bypass block throttle for superblock update")
[2] commit bed9e27baf52 ("Revert "md/raid5: Wait for MD_SB_CHANGE_PENDING in raid5d"")
Reported-by: Dan Moulding <dan@xxxxxxxx>
Closes: https://lore.kernel.org/linux-raid/20240123005700.9302-1-dan@xxxxxxxx/
Fixes: bed9e27baf52 ("Revert "md/raid5: Wait for MD_SB_CHANGE_PENDING in raid5d"")
Cc: stable@xxxxxxxxxxxxxxx # v5.19+
Cc: Junxiao Bi <junxiao.bi@xxxxxxxxxx>
Cc: Yu Kuai <yukuai3@xxxxxxxxxx>
Signed-off-by: Song Liu <song@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/md/raid5.c | 12 ++++++++++++
1 file changed, 12 insertions(+)
--- a/drivers/md/raid5.c
+++ b/drivers/md/raid5.c
@@ -36,6 +36,7 @@
*/
#include <linux/blkdev.h>
+#include <linux/delay.h>
#include <linux/kthread.h>
#include <linux/raid/pq.h>
#include <linux/async_tx.h>
@@ -6842,7 +6843,18 @@ static void raid5d(struct md_thread *thr
spin_unlock_irq(&conf->device_lock);
md_check_recovery(mddev);
spin_lock_irq(&conf->device_lock);
+
+ /*
+ * Waiting on MD_SB_CHANGE_PENDING below may deadlock
+ * seeing md_check_recovery() is needed to clear
+ * the flag when using mdmon.
+ */
+ continue;
}
+
+ wait_event_lock_irq(mddev->sb_wait,
+ !test_bit(MD_SB_CHANGE_PENDING, &mddev->sb_flags),
+ conf->device_lock);
}
pr_debug("%d stripes handled\n", handled);
Patches currently in stable-queue which might be from song@xxxxxxxxxx are
queue-6.6/perf-env-avoid-recursively-taking-env-bpf_progs.lock.patch
queue-6.6/md-synchronize-flush-io-with-array-reconfiguration.patch
queue-6.6/bpf-fix-re-attachment-branch-in-bpf_tracing_prog_attach.patch
queue-6.6/md-raid1-use-blk_opf_t-for-read-and-write-operations.patch
queue-6.6/revert-revert-md-raid5-wait-for-md_sb_change_pending-in-raid5d.patch
