Re: [PATCH v5 04/12] f2fs: cache: introduce writeback thread

[Wenjie Qi]

Hi Chao,

> if (flags & SB_RDONLY) {
> 	if (sbi->cache_thread.cache_wb_task) {
> 		f2fs_stop_cache_wb_thread(sbi);
> 		need_restart_wb = true;
> 	}
> }

and later:

> err = f2fs_sync_fs(sb, 1);
> if (err)
> 	goto restore_gc;

The writeback rollback begins at:

> restore_wb:

and the GC rollback begins later at:

> restore_gc:

The common option rollback then contains:

> restore_opts:
> 	sbi->mount_opt = org_mount_opt;
> 	sb->s_flags = old_sb_flags;

The RW-to-RO path stops `cache_wb_task` and sets `need_restart_wb`, but
the sync error jumps directly to `restore_gc`.  Since `restore_wb` precedes
`restore_gc`, this edge does not execute the writeback-thread rollback before
the old mount options and flags are restored.