[Devel] [RFC PATCH vz9 v6 21/62] dm-ploop: introduce per-md page locking

[Pavel Tikhomirov]

On 12/6/24 05:55, Alexander Atanasov wrote:
> @@ -411,7 +415,6 @@ static void ploop_apply_delta_mappings(struct ploop *ploop,
>   	if (!is_raw)
>   		d_md = ploop_md_first_entry(md_root);
>   
> -	write_lock_irq(&ploop->bat_rwlock);
>   	ploop_for_each_md_page(ploop, md, node) {
>   		bat_entries = md->kmpage;
>   		if (!is_raw)
> @@ -455,7 +458,6 @@ static void ploop_apply_delta_mappings(struct ploop *ploop,
>   		if (!is_raw)
>   			d_md = ploop_md_next_entry(d_md);
>   	}
> -	write_unlock_irq(&ploop->bat_rwlock);
>   }
>   
>   int ploop_check_delta_length(struct ploop *ploop, struct file *file, loff_t *file_size)

This is not possible to remove this lock, as ploop->bat_entries rbtree 
is protected by it. In other words ploop_for_each_md_page should be 
protected by critical section against concurrent ploop_add_md_pages.

-- 
Best regards, Tikhomirov Pavel
Senior Software Developer, Virtuozzo.