From: Jaegeuk Kim jaegeuk@kernel.org
commit 4f99484d27961cb194cebcd917176fa038a5025f upstream.
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 chao@kernel.org Signed-off-by: Jaegeuk Kim jaegeuk@kernel.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- fs/f2fs/super.c | 6 ++++++ 1 file changed, 6 insertions(+)
--- a/fs/f2fs/super.c +++ b/fs/f2fs/super.c @@ -2181,6 +2181,9 @@ static void f2fs_enable_checkpoint(struc 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) @@ -2346,6 +2349,9 @@ static int f2fs_remount(struct super_blo 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,