From: Joe Thornber <ejt@xxxxxxxxxx> Clarify what is expected during each cell release by introducing variants of __cell_release. Signed-off-by: Joe Thornber <ejt@xxxxxxxxxx> Acked-by: Mike Snitzer <snitzer@xxxxxxxxxx> --- drivers/md/dm-thin.c | 52 +++++++++++++++++++++++++++++++++---------------- 1 files changed, 35 insertions(+), 17 deletions(-) diff --git a/drivers/md/dm-thin.c b/drivers/md/dm-thin.c index 920304e..f796afb 100644 --- a/drivers/md/dm-thin.c +++ b/drivers/md/dm-thin.c @@ -306,22 +306,45 @@ static void cell_release(struct cell *cell, struct bio_list *bios) * bio may be in the cell. This function releases the cell, and also does * a sanity check. */ +static void __cell_release_singleton(struct cell *cell, struct bio *bio) +{ + hlist_del(&cell->list); + BUG_ON(cell->holder != bio); + BUG_ON(!bio_list_empty(&cell->bios)); +} + static void cell_release_singleton(struct cell *cell, struct bio *bio) { - struct bio_prison *prison = cell->prison; - struct bio_list bios; - struct bio *b; unsigned long flags; - - bio_list_init(&bios); + struct bio_prison *prison = cell->prison; spin_lock_irqsave(&prison->lock, flags); - __cell_release(cell, &bios); + __cell_release_singleton(cell, bio); spin_unlock_irqrestore(&prison->lock, flags); +} + +/* + * Sometimes we don't want the holder, just the additional bios. + */ +static void __cell_release_no_holder(struct cell *cell, struct bio_list *inmates) +{ + struct bio_prison *prison = cell->prison; - b = bio_list_pop(&bios); - BUG_ON(b != bio); - BUG_ON(!bio_list_empty(&bios)); + hlist_del(&cell->list); + if (inmates) + bio_list_merge(inmates, &cell->bios); + + mempool_free(cell, prison->cell_pool); +} + +static void cell_release_no_holder(struct cell *cell, struct bio_list *inmates) +{ + unsigned long flags; + struct bio_prison *prison = cell->prison; + + spin_lock_irqsave(&prison->lock, flags); + __cell_release_no_holder(cell, inmates); + spin_unlock_irqrestore(&prison->lock, flags); } static void cell_error(struct cell *cell) @@ -803,21 +826,16 @@ static void cell_defer(struct thin_c *tc, struct cell *cell, * Same as cell_defer above, except it omits one particular detainee, * a write bio that covers the block and has already been processed. */ -static void cell_defer_except(struct thin_c *tc, struct cell *cell, - struct bio *exception) +static void cell_defer_except(struct thin_c *tc, struct cell *cell) { struct bio_list bios; - struct bio *bio; struct pool *pool = tc->pool; unsigned long flags; bio_list_init(&bios); - cell_release(cell, &bios); spin_lock_irqsave(&pool->lock, flags); - while ((bio = bio_list_pop(&bios))) - if (bio != exception) - bio_list_add(&pool->deferred_bios, bio); + cell_release_no_holder(cell, &pool->deferred_bios); spin_unlock_irqrestore(&pool->lock, flags); wake_worker(pool); @@ -857,7 +875,7 @@ static void process_prepared_mapping(struct new_mapping *m) * the bios in the cell. */ if (bio) { - cell_defer_except(tc, m->cell, bio); + cell_defer_except(tc, m->cell); bio_endio(bio, 0); } else cell_defer(tc, m->cell, m->data_block); -- 1.7.1 -- dm-devel mailing list dm-devel@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/dm-devel