[PATCH v2 01/14] ublk: use vmalloc for ublk_device's __queues

[Caleb Sander Mateos <csander@purestorage.com>]

struct ublk_device's __queues points to an allocation with up to
UBLK_MAX_NR_QUEUES (4096) queues, each of which have:
- struct ublk_queue (48 bytes)
- Tail array of up to UBLK_MAX_QUEUE_DEPTH (4096) struct ublk_io's,
  32 bytes each
This means the full allocation can exceed 512 MB, which may well be
impossible to service with contiguous physical pages. Switch to
kvcalloc() and kvfree(), since there is no need for physically
contiguous memory.

Signed-off-by: Caleb Sander Mateos <csander@purestorage.com>
Fixes: 71f28f3136af ("ublk_drv: add io_uring based userspace block driver")
---
 drivers/block/ublk_drv.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/block/ublk_drv.c b/drivers/block/ublk_drv.c
index d36f44f5ee80..467769fc388f 100644
--- a/drivers/block/ublk_drv.c
+++ b/drivers/block/ublk_drv.c
@@ -2486,22 +2486,22 @@ static void ublk_deinit_queues(struct ublk_device *ub)
 	if (!ub->__queues)
 		return;
 
 	for (i = 0; i < nr_queues; i++)
 		ublk_deinit_queue(ub, i);
-	kfree(ub->__queues);
+	kvfree(ub->__queues);
 }
 
 static int ublk_init_queues(struct ublk_device *ub)
 {
 	int nr_queues = ub->dev_info.nr_hw_queues;
 	int depth = ub->dev_info.queue_depth;
 	int ubq_size = sizeof(struct ublk_queue) + depth * sizeof(struct ublk_io);
 	int i, ret = -ENOMEM;
 
 	ub->queue_size = ubq_size;
-	ub->__queues = kcalloc(nr_queues, ubq_size, GFP_KERNEL);
+	ub->__queues = kvcalloc(nr_queues, ubq_size, GFP_KERNEL);
 	if (!ub->__queues)
 		return ret;
 
 	for (i = 0; i < nr_queues; i++) {
 		if (ublk_init_queue(ub, i))
-- 
2.45.2