Sure, will do it in v2.
So could this patch resolve your issue?
Thanks,
Joseph
On 1/23/22 1:31 PM, Gautham Ananthakrishna wrote:
> Hi,
> This deadlock was originally reported by saeed.mirzamohammadi@xxxxxxxxxx Could you please add Saeed as the reportedby.
>
> Thanks,
> Gautham.
>
> -----Original Message-----
> From: Joseph Qi <joseph.qi@xxxxxxxxxxxxxxxxx>
> Sent: Friday, January 21, 2022 12:42 PM
> To: akpm@xxxxxxxxxxxxxxxxxxxx; tytso@xxxxxxx; adilger.kernel@xxxxxxxxx
> Cc: Gautham Ananthakrishna <gautham.ananthakrishna@xxxxxxxxxx>; ocfs2-devel@xxxxxxxxxxxxxx; linux-ext4@xxxxxxxxxxxxxxx
> Subject: [PATCH 2/2] ocfs2: fix a deadlock when commit trans
>
> commit 6f1b228529ae introduces a regression which can deadlock as
> follows:
>
> Task1: Task2:
> jbd2_journal_commit_transaction ocfs2_test_bg_bit_allocatable
> spin_lock(&jh->b_state_lock) jbd_lock_bh_journal_head
> __jbd2_journal_remove_checkpoint spin_lock(&jh->b_state_lock)
> jbd2_journal_put_journal_head
> jbd_lock_bh_journal_head
>
> Task1 and Task2 lock bh->b_state and jh->b_state_lock in different order, which finally result in a deadlock.
>
> So use jbd2_journal_[grab|put]_journal_head instead in
> ocfs2_test_bg_bit_allocatable() to fix it.
>
> Reported-by: Gautham Ananthakrishna <gautham.ananthakrishna@xxxxxxxxxx>
> Fixes: 6f1b228529ae ("ocfs2: fix race between searching chunks and release journal_head from buffer_head")
> Cc: <stable@xxxxxxxxxxxxxxx>
> Signed-off-by: Joseph Qi <joseph.qi@xxxxxxxxxxxxxxxxx>
> ---
> fs/ocfs2/suballoc.c | 25 +++++++++++--------------
> 1 file changed, 11 insertions(+), 14 deletions(-)
>
> diff --git a/fs/ocfs2/suballoc.c b/fs/ocfs2/suballoc.c index 481017e1dac5..166c8918c825 100644
> --- a/fs/ocfs2/suballoc.c
> +++ b/fs/ocfs2/suballoc.c
> @@ -1251,26 +1251,23 @@ static int ocfs2_test_bg_bit_allocatable(struct buffer_head *bg_bh, {
> struct ocfs2_group_desc *bg = (struct ocfs2_group_desc *) bg_bh->b_data;
> struct journal_head *jh;
> - int ret = 1;
> + int ret;
>
> if (ocfs2_test_bit(nr, (unsigned long *)bg->bg_bitmap))
> return 0;
>
> - if (!buffer_jbd(bg_bh))
> + jh = jbd2_journal_grab_journal_head(bg_bh);
> + if (!jh)
> return 1;
>
> - jbd_lock_bh_journal_head(bg_bh);
> - if (buffer_jbd(bg_bh)) {
> - jh = bh2jh(bg_bh);
> - spin_lock(&jh->b_state_lock);
> - bg = (struct ocfs2_group_desc *) jh->b_committed_data;
> - if (bg)
> - ret = !ocfs2_test_bit(nr, (unsigned long *)bg->bg_bitmap);
> - else
> - ret = 1;
> - spin_unlock(&jh->b_state_lock);
> - }
> - jbd_unlock_bh_journal_head(bg_bh);
> + spin_lock(&jh->b_state_lock);
> + bg = (struct ocfs2_group_desc *) jh->b_committed_data;
> + if (bg)
> + ret = !ocfs2_test_bit(nr, (unsigned long *)bg->bg_bitmap);
> + else
> + ret = 1;
> + spin_unlock(&jh->b_state_lock);
> + jbd2_journal_put_journal_head(jh);
>
> return ret;
> }
> --
> 2.19.1.6.gb485710b
