From 4f99484d27961cb194cebcd917176fa038a5025f Mon Sep 17 00:00:00 2001 From: Jaegeuk Kim Date: Thu, 18 Aug 2022 22:40:09 -0700 Subject: [PATCH] f2fs: complete checkpoints during remount Otherwise, pending checkpoints can contribute a race condition to give a quota warning. - Thread - checkpoint thread add checkpoints to the list do_remount() down_write(&sb->s_umount); f2fs_remount() block_operations() down_read_trylock(&sb->s_umount) = 0 up_write(&sb->s_umount); f2fs_quota_sync() dquot_writeback_dquots() WARN_ON_ONCE(!rwsem_is_locked(&sb->s_umount)); Or, do_remount() down_write(&sb->s_umount); f2fs_remount() create a ckpt thread f2fs_enable_checkpoint() adds checkpoints wait for f2fs_sync_fs() trigger another pending checkpoint block_operations() down_read_trylock(&sb->s_umount) = 0 up_write(&sb->s_umount); f2fs_quota_sync() dquot_writeback_dquots() WARN_ON_ONCE(!rwsem_is_locked(&sb->s_umount)); Cc: stable@vger.kernel.org Reviewed-by: Chao Yu Signed-off-by: Jaegeuk Kim --- fs/f2fs/super.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c index 4f2ff50b247c..0f29c759a898 100644 --- a/fs/f2fs/super.c +++ b/fs/f2fs/super.c @@ -2185,6 +2185,9 @@ static void f2fs_enable_checkpoint(struct f2fs_sb_info *sbi) f2fs_up_write(&sbi->gc_lock); f2fs_sync_fs(sbi->sb, 1); + + /* Let's ensure there's no pending checkpoint anymore */ + f2fs_flush_ckpt_thread(sbi); } static int f2fs_remount(struct super_block *sb, int *flags, char *data) @@ -2350,6 +2353,9 @@ static int f2fs_remount(struct super_block *sb, int *flags, char *data) f2fs_stop_ckpt_thread(sbi); need_restart_ckpt = true; } else { + /* Flush if the prevous checkpoint, if exists. */ + f2fs_flush_ckpt_thread(sbi); + err = f2fs_start_ckpt_thread(sbi); if (err) { f2fs_err(sbi,