From 4cd1103d8c66b2cdb7e64385c274edb0ac5e8887 Mon Sep 17 00:00:00 2001
From: Joseph Qi <joseph.qi@linux.alibaba.com>
Date: Sat, 29 Jan 2022 13:41:23 -0800
Subject: [PATCH] jbd2: export jbd2_journal_[grab|put]_journal_head
Git-commit: 4cd1103d8c66b2cdb7e64385c274edb0ac5e8887
Patch-mainline: v5.17-rc2
References: bsc#1202775

Patch series "ocfs2: fix a deadlock case".

This fixes a deadlock case in ocfs2.  We firstly export jbd2 symbols
jbd2_journal_[grab|put]_journal_head as preparation and later use them
in ocfs2 insread of jbd_[lock|unlock]_bh_journal_head to fix the
deadlock.

This patch (of 2):

This exports symbols jbd2_journal_[grab|put]_journal_head, which will be
used outside modules, e.g.  ocfs2.

Link: https://lkml.kernel.org/r/20220121071205.100648-2-joseph.qi@linux.alibaba.com
Signed-off-by: Joseph Qi <joseph.qi@linux.alibaba.com>
Cc: Mark Fasheh <mark@fasheh.com>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Junxiao Bi <junxiao.bi@oracle.com>
Cc: Changwei Ge <gechangwei@live.cn>
Cc: Gang He <ghe@suse.com>
Cc: Jun Piao <piaojun@huawei.com>
Cc: Andreas Dilger <adilger.kernel@dilger.ca>
Cc: Gautham Ananthakrishna <gautham.ananthakrishna@oracle.com>
Cc: Saeed Mirzamohammadi <saeed.mirzamohammadi@oracle.com>
Cc: "Theodore Ts'o" <tytso@mit.edu>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Acked-by: Jan Kara <jack@suse.cz>

---
 fs/jbd2/journal.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/fs/jbd2/journal.c b/fs/jbd2/journal.c
index f13d548e4a7f..bf108d4493d2 100644
--- a/fs/jbd2/journal.c
+++ b/fs/jbd2/journal.c
@@ -2972,6 +2972,7 @@ struct journal_head *jbd2_journal_grab_journal_head(struct buffer_head *bh)
 	jbd_unlock_bh_journal_head(bh);
 	return jh;
 }
+EXPORT_SYMBOL(jbd2_journal_grab_journal_head);
 
 static void __journal_remove_journal_head(struct buffer_head *bh)
 {
@@ -3024,6 +3025,7 @@ void jbd2_journal_put_journal_head(struct journal_head *jh)
 		jbd_unlock_bh_journal_head(bh);
 	}
 }
+EXPORT_SYMBOL(jbd2_journal_put_journal_head);
 
 /*
  * Initialize jbd inode head
-- 
2.35.3