Commit 6d16202b authored by Mike Snitzer's avatar Mike Snitzer
Browse files

dm thin: eliminate the no_free_space flag 



The pool's error_if_no_space flag can easily serve the same purpose that
no_free_space did, namely: control whether handle_unserviceable_bio()
will error a bio or requeue it.

This is cleaner since error_if_no_space is established when the pool's
features are processed during table load.  So it avoids managing the
no_free_space flag by taking the pool's spinlock.

Signed-off-by: default avatarMike Snitzer <snitzer@redhat.com>
parent 787a996c

drivers/md/dm-thin.c

+4 −22
Original line number Diff line number Diff line
@@ -165,7 +165,6 @@ struct pool { 


	struct pool_features pf;

	bool low_water_triggered:1;	/* A dm event has been sent */

	bool no_free_space:1;		/* bios will be requeued if set */



	struct dm_bio_prison *prison;

	struct dm_kcopyd_client *copier;
@@ -991,10 +990,10 @@ static void handle_unserviceable_bio(struct pool *pool, struct bio *bio) 
	 */

	WARN_ON_ONCE(get_pool_mode(pool) != PM_READ_ONLY);



	if (pool->no_free_space)

		retry_on_resume(bio);

	else

	if (pool->pf.error_if_no_space)

		bio_io_error(bio);

	else

		retry_on_resume(bio);

}



static void retry_bios_on_resume(struct pool *pool, struct dm_bio_prison_cell *cell)
@@ -1437,18 +1436,6 @@ static void set_pool_mode(struct pool *pool, enum pool_mode mode) 
	}

}



static void set_no_free_space(struct pool *pool)

{

	unsigned long flags;



	if (pool->pf.error_if_no_space)

		return;



	spin_lock_irqsave(&pool->lock, flags);

	pool->no_free_space = true;

	spin_unlock_irqrestore(&pool->lock, flags);

}



/*

 * Rather than calling set_pool_mode directly, use these which describe the

 * reason for mode degradation.
@@ -1457,7 +1444,6 @@ static void out_of_data_space(struct pool *pool) 
{

	DMERR_LIMIT("%s: no free data space available.",

		    dm_device_name(pool->pool_md));

	set_no_free_space(pool);

	set_pool_mode(pool, PM_READ_ONLY);

}
@@ -1470,11 +1456,9 @@ static void metadata_operation_failed(struct pool *pool, const char *op, int r) 


	if (r == -ENOSPC &&

	    !dm_pool_get_free_metadata_block_count(pool->pmd, &free_blocks) &&

	    !free_blocks) {

	    !free_blocks)

		DMERR_LIMIT("%s: no free metadata space available.",

			    dm_device_name(pool->pool_md));

		set_no_free_space(pool);

	}



	set_pool_mode(pool, PM_READ_ONLY);

}
@@ -1819,7 +1803,6 @@ static struct pool *pool_create(struct mapped_device *pool_md, 
	INIT_LIST_HEAD(&pool->prepared_mappings);

	INIT_LIST_HEAD(&pool->prepared_discards);

	pool->low_water_triggered = false;

	pool->no_free_space = false;

	bio_list_init(&pool->retry_on_resume_list);



	pool->shared_read_ds = dm_deferred_set_create();
@@ -2346,7 +2329,6 @@ static void pool_resume(struct dm_target *ti) 


	spin_lock_irqsave(&pool->lock, flags);

	pool->low_water_triggered = false;

	pool->no_free_space = false;

	__requeue_bios(pool);

	spin_unlock_irqrestore(&pool->lock, flags);

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