[PATCH AUTOSEL 6.8 10/24] f2fs: don't set RO when shutting down f2fs

Sasha Levin
2024-06-05T11:51:22Z

From: Jaegeuk Kim <jaegeuk@kernel.org>

[ Upstream commit 3bdb7f161697e2d5123b89fe1778ef17a44858e7 ]

Shutdown does not check the error of thaw_super due to readonly, which
causes a deadlock like below.

f2fs_ioc_shutdown(F2FS_GOING_DOWN_FULLSYNC) issue_discard_thread
- bdev_freeze
- freeze_super
- f2fs_stop_checkpoint()
- f2fs_handle_critical_error - sb_start_write
- set RO - waiting
- bdev_thaw
- thaw_super_locked
- return -EINVAL, if sb_rdonly()
- f2fs_stop_discard_thread
-> wait for kthread_stop(discard_thread);

Reported-by: "Light Hsieh (謝明燈)" <Light.Hsieh@mediatek.com>
Reviewed-by: Daeho Jeong <daehojeong@google.com>
Reviewed-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
fs/f2fs/super.c | 10 ++++++++--
1 file changed, 8 insertions(+), 2 deletions(-)

diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c
index 67bedd5b69cc1..e1e2f0a067b99 100644
--- a/fs/f2fs/super.c
+++ b/fs/f2fs/super.c
@@ -4194,9 +4194,15 @@ void f2fs_handle_critical_error(struct f2fs_sb_info *sbi, unsigned char reason,
if (shutdown)
set_sbi_flag(sbi, SBI_IS_SHUTDOWN);

- /* continue filesystem operators if errors=continue */
- if (continue_fs || f2fs_readonly(sb))
+ /*
+ * Continue filesystem operators if errors=continue. Should not set
+ * RO by shutdown, since RO bypasses thaw_super which can hang the
+ * system.
+ */
+ if (continue_fs || f2fs_readonly(sb) || shutdown) {
+ f2fs_warn(sbi, "Stopped filesystem due to reason: %d", reason);
return;
+ }

f2fs_warn(sbi, "Remounting filesystem read-only");
/*
--
2.43.0