[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Message-Id: <20250403190745.2677620-17-sashal@kernel.org>
Date: Thu, 3 Apr 2025 15:07:36 -0400
From: Sasha Levin <sashal@...nel.org>
To: linux-kernel@...r.kernel.org,
stable@...r.kernel.org
Cc: Ojaswin Mujoo <ojaswin@...ux.ibm.com>,
Jan Kara <jack@...e.cz>,
Baokun Li <libaokun1@...wei.com>,
Theodore Ts'o <tytso@....edu>,
Sasha Levin <sashal@...nel.org>,
adilger.kernel@...ger.ca,
linux-ext4@...r.kernel.org
Subject: [PATCH AUTOSEL 6.6 17/26] ext4: protect ext4_release_dquot against freezing
From: Ojaswin Mujoo <ojaswin@...ux.ibm.com>
[ Upstream commit 530fea29ef82e169cd7fe048c2b7baaeb85a0028 ]
Protect ext4_release_dquot against freezing so that we
don't try to start a transaction when FS is frozen, leading
to warnings.
Further, avoid taking the freeze protection if a transaction
is already running so that we don't need end up in a deadlock
as described in
46e294efc355 ext4: fix deadlock with fs freezing and EA inodes
Suggested-by: Jan Kara <jack@...e.cz>
Signed-off-by: Ojaswin Mujoo <ojaswin@...ux.ibm.com>
Reviewed-by: Baokun Li <libaokun1@...wei.com>
Reviewed-by: Jan Kara <jack@...e.cz>
Link: https://patch.msgid.link/20241121123855.645335-3-ojaswin@linux.ibm.com
Signed-off-by: Theodore Ts'o <tytso@....edu>
Signed-off-by: Sasha Levin <sashal@...nel.org>
---
fs/ext4/super.c | 17 +++++++++++++++++
1 file changed, 17 insertions(+)
diff --git a/fs/ext4/super.c b/fs/ext4/super.c
index f019ce64eba48..26d693813a80f 100644
--- a/fs/ext4/super.c
+++ b/fs/ext4/super.c
@@ -6926,12 +6926,25 @@ static int ext4_release_dquot(struct dquot *dquot)
{
int ret, err;
handle_t *handle;
+ bool freeze_protected = false;
+
+ /*
+ * Trying to sb_start_intwrite() in a running transaction
+ * can result in a deadlock. Further, running transactions
+ * are already protected from freezing.
+ */
+ if (!ext4_journal_current_handle()) {
+ sb_start_intwrite(dquot->dq_sb);
+ freeze_protected = true;
+ }
handle = ext4_journal_start(dquot_to_inode(dquot), EXT4_HT_QUOTA,
EXT4_QUOTA_DEL_BLOCKS(dquot->dq_sb));
if (IS_ERR(handle)) {
/* Release dquot anyway to avoid endless cycle in dqput() */
dquot_release(dquot);
+ if (freeze_protected)
+ sb_end_intwrite(dquot->dq_sb);
return PTR_ERR(handle);
}
ret = dquot_release(dquot);
@@ -6942,6 +6955,10 @@ static int ext4_release_dquot(struct dquot *dquot)
err = ext4_journal_stop(handle);
if (!ret)
ret = err;
+
+ if (freeze_protected)
+ sb_end_intwrite(dquot->dq_sb);
+
return ret;
}
--
2.39.5
Powered by blists - more mailing lists