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authorMatias Bjorling <m@bjorling.me>2013-12-18 16:41:43 +0400
committerJens Axboe <axboe@kernel.dk>2013-12-19 19:09:42 +0400
commit2d263a7856cbaf26dd89b671e2161c4a49f8461b (patch)
tree967e3340dc9a90690b04a93bffdf4c12cf8ed4c8 /drivers/block/null_blk.c
parent12f8f4fc0314103d47f9b1cbc812597b8d893ce1 (diff)
downloadlinux-2d263a7856cbaf26dd89b671e2161c4a49f8461b.tar.xz
null_blk: refactor init and init errors code paths
Simplify the initialization logic of the three block-layers. - The queue initialization is split into two parts. This allows reuse of code when initializing the sq-, bio- and mq-based layers. - Set submit_queues default value to 0 and always set it at init time. - Simplify the init error code paths. Signed-off-by: Matias Bjorling <m@bjorling.me> Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'drivers/block/null_blk.c')
-rw-r--r--drivers/block/null_blk.c63
1 files changed, 38 insertions, 25 deletions
diff --git a/drivers/block/null_blk.c b/drivers/block/null_blk.c
index f370fc13aea5..f0aeb2a7a9ca 100644
--- a/drivers/block/null_blk.c
+++ b/drivers/block/null_blk.c
@@ -65,7 +65,7 @@ enum {
NULL_Q_MQ = 2,
};
-static int submit_queues = 1;
+static int submit_queues;
module_param(submit_queues, int, S_IRUGO);
MODULE_PARM_DESC(submit_queues, "Number of submission queues");
@@ -355,16 +355,24 @@ static void null_free_hctx(struct blk_mq_hw_ctx *hctx, unsigned int hctx_index)
kfree(hctx);
}
+static void null_init_queue(struct nullb *nullb, struct nullb_queue *nq)
+{
+ BUG_ON(!nullb);
+ BUG_ON(!nq);
+
+ init_waitqueue_head(&nq->wait);
+ nq->queue_depth = nullb->queue_depth;
+}
+
static int null_init_hctx(struct blk_mq_hw_ctx *hctx, void *data,
unsigned int index)
{
struct nullb *nullb = data;
struct nullb_queue *nq = &nullb->queues[index];
- init_waitqueue_head(&nq->wait);
- nq->queue_depth = nullb->queue_depth;
- nullb->nr_queues++;
hctx->driver_data = nq;
+ null_init_queue(nullb, nq);
+ nullb->nr_queues++;
return 0;
}
@@ -417,13 +425,13 @@ static int setup_commands(struct nullb_queue *nq)
nq->cmds = kzalloc(nq->queue_depth * sizeof(*cmd), GFP_KERNEL);
if (!nq->cmds)
- return 1;
+ return -ENOMEM;
tag_size = ALIGN(nq->queue_depth, BITS_PER_LONG) / BITS_PER_LONG;
nq->tag_map = kzalloc(tag_size * sizeof(unsigned long), GFP_KERNEL);
if (!nq->tag_map) {
kfree(nq->cmds);
- return 1;
+ return -ENOMEM;
}
for (i = 0; i < nq->queue_depth; i++) {
@@ -454,33 +462,37 @@ static void cleanup_queues(struct nullb *nullb)
static int setup_queues(struct nullb *nullb)
{
- struct nullb_queue *nq;
- int i;
-
- nullb->queues = kzalloc(submit_queues * sizeof(*nq), GFP_KERNEL);
+ nullb->queues = kzalloc(submit_queues * sizeof(struct nullb_queue),
+ GFP_KERNEL);
if (!nullb->queues)
- return 1;
+ return -ENOMEM;
nullb->nr_queues = 0;
nullb->queue_depth = hw_queue_depth;
- if (queue_mode == NULL_Q_MQ)
- return 0;
+ return 0;
+}
+
+static int init_driver_queues(struct nullb *nullb)
+{
+ struct nullb_queue *nq;
+ int i, ret = 0;
for (i = 0; i < submit_queues; i++) {
nq = &nullb->queues[i];
- init_waitqueue_head(&nq->wait);
- nq->queue_depth = hw_queue_depth;
- if (setup_commands(nq))
- break;
+
+ null_init_queue(nullb, nq);
+
+ ret = setup_commands(nq);
+ if (ret)
+ goto err_queue;
nullb->nr_queues++;
}
- if (i == submit_queues)
- return 0;
-
+ return 0;
+err_queue:
cleanup_queues(nullb);
- return 1;
+ return ret;
}
static int null_add_dev(void)
@@ -495,9 +507,6 @@ static int null_add_dev(void)
spin_lock_init(&nullb->lock);
- if (queue_mode == NULL_Q_MQ && use_per_node_hctx)
- submit_queues = nr_online_nodes;
-
if (setup_queues(nullb))
goto err;
@@ -518,11 +527,13 @@ static int null_add_dev(void)
} else if (queue_mode == NULL_Q_BIO) {
nullb->q = blk_alloc_queue_node(GFP_KERNEL, home_node);
blk_queue_make_request(nullb->q, null_queue_bio);
+ init_driver_queues(nullb);
} else {
nullb->q = blk_init_queue_node(null_request_fn, &nullb->lock, home_node);
blk_queue_prep_rq(nullb->q, null_rq_prep_fn);
if (nullb->q)
blk_queue_softirq_done(nullb->q, null_softirq_done_fn);
+ init_driver_queues(nullb);
}
if (!nullb->q)
@@ -579,7 +590,9 @@ static int __init null_init(void)
}
#endif
- if (submit_queues > nr_cpu_ids)
+ if (queue_mode == NULL_Q_MQ && use_per_node_hctx)
+ submit_queues = nr_online_nodes;
+ else if (submit_queues > nr_cpu_ids)
submit_queues = nr_cpu_ids;
else if (!submit_queues)
submit_queues = 1;