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ocfs2: fix a deadlock when commit trans 

commit 6f1b228529 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.

Link: https://lkml.kernel.org/r/20220121071205.100648-3-joseph.qi@linux.alibaba.com
Fixes: 6f1b228529 ("ocfs2: fix race between searching chunks and release journal_head from buffer_head")
Signed-off-by: Joseph Qi <joseph.qi@linux.alibaba.com>
Reported-by: Gautham Ananthakrishna <gautham.ananthakrishna@oracle.com>
Tested-by: Gautham Ananthakrishna <gautham.ananthakrishna@oracle.com>
Reported-by: Saeed Mirzamohammadi <saeed.mirzamohammadi@oracle.com>
Cc: "Theodore Ts'o" <tytso@mit.edu>
Cc: Andreas Dilger <adilger.kernel@dilger.ca>
Cc: Changwei Ge <gechangwei@live.cn>
Cc: Gang He <ghe@suse.com>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Jun Piao <piaojun@huawei.com>
Cc: Junxiao Bi <junxiao.bi@oracle.com>
Cc: Mark Fasheh <mark@fasheh.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Joseph Qi 2022-01-29 13:41:27 -08:00 committed by Linus Torvalds
parent 4cd1103d8c
commit ddf4b773aa
1 changed files with 11 additions and 14 deletions
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11
fs/ocfs2/suballoc.c
View File

@ -1251,17 +1251,15 @@ 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 ocfs2_group_desc *bg = (struct ocfs2_group_desc *) bg_bh->b_data;
struct journal_head *jh; struct journal_head *jh;
int ret = 1; int ret;
if (ocfs2_test_bit(nr, (unsigned long *)bg->bg_bitmap)) if (ocfs2_test_bit(nr, (unsigned long *)bg->bg_bitmap))
return 0; return 0;
if (!buffer_jbd(bg_bh)) jh = jbd2_journal_grab_journal_head(bg_bh);
if (!jh)
return 1; return 1;
jbd_lock_bh_journal_head(bg_bh);
if (buffer_jbd(bg_bh)) {
jh = bh2jh(bg_bh);
spin_lock(&jh->b_state_lock); spin_lock(&jh->b_state_lock);
bg = (struct ocfs2_group_desc *) jh->b_committed_data; bg = (struct ocfs2_group_desc *) jh->b_committed_data;
if (bg) if (bg)
@ -1269,8 +1267,7 @@ static int ocfs2_test_bg_bit_allocatable(struct buffer_head *bg_bh,
else else
ret = 1; ret = 1;
spin_unlock(&jh->b_state_lock); spin_unlock(&jh->b_state_lock);
} jbd2_journal_put_journal_head(jh);
jbd_unlock_bh_journal_head(bg_bh);
return ret; return ret;
} }