[PATCH] f2fs: avoid the deadlock case when stopping discard thread
From: Jaegeuk Kim
Date: Tue Mar 19 2024 - 20:14:52 EST
f2fs_ioc_shutdown(F2FS_GOING_DOWN_NOSYNC) issue_discard_thread
- mnt_want_write_file()
- sb_start_write(SB_FREEZE_WRITE)
- sb_start_intwrite(SB_FREEZE_FS);
- f2fs_stop_checkpoint(sbi, false, : waiting
STOP_CP_REASON_SHUTDOWN);
- f2fs_stop_discard_thread(sbi);
- kthread_stop()
: waiting
- mnt_drop_write_file(filp);
Signed-off-by: Jaegeuk Kim <jaegeuk@xxxxxxxxxx>
---
fs/f2fs/segment.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/fs/f2fs/segment.c b/fs/f2fs/segment.c
index 4fd76e867e0a..088b8c48cffa 100644
--- a/fs/f2fs/segment.c
+++ b/fs/f2fs/segment.c
@@ -1923,7 +1923,9 @@ static int issue_discard_thread(void *data)
continue;
}
- sb_start_intwrite(sbi->sb);
+ /* Avoid the deadlock from F2FS_GOING_DOWN_NOSYNC. */
+ if (!sb_start_intwrite_trylock(sbi->sb))
+ continue;
issued = __issue_discard_cmd(sbi, &dpolicy);
if (issued > 0) {
--
2.44.0.291.gc1ea87d7ee-goog