[PATCH v2 24/35] block: null_blk: fix opencoded find_and_set_bit() in get_tag()

Yury Norov
2023-12-03T19:37:19Z

get_tag() opencodes find_and_set_bit(). Switch the code to use the
dedicated function, and get rid of get_tag entirely.

Signed-off-by: Yury Norov <yury.norov@gmail.com>
---
drivers/block/null_blk/main.c | 41 +++++++++++------------------------
1 file changed, 13 insertions(+), 28 deletions(-)

diff --git a/drivers/block/null_blk/main.c b/drivers/block/null_blk/main.c
index 3021d58ca51c..671dbb9ab928 100644
--- a/drivers/block/null_blk/main.c
+++ b/drivers/block/null_blk/main.c
@@ -760,19 +760,6 @@ static void put_tag(struct nullb_queue *nq, unsigned int tag)
wake_up(&nq->wait);
}

-static unsigned int get_tag(struct nullb_queue *nq)
-{
- unsigned int tag;
-
- do {
- tag = find_first_zero_bit(nq->tag_map, nq->queue_depth);
- if (tag >= nq->queue_depth)
- return -1U;
- } while (test_and_set_bit_lock(tag, nq->tag_map));
-
- return tag;
-}
-
static void free_cmd(struct nullb_cmd *cmd)
{
put_tag(cmd->nq, cmd->tag);
@@ -782,24 +769,22 @@ static enum hrtimer_restart null_cmd_timer_expired(struct hrtimer *timer);

static struct nullb_cmd *__alloc_cmd(struct nullb_queue *nq)
{
+ unsigned int tag = find_and_set_bit_lock(nq->tag_map, nq->queue_depth);
struct nullb_cmd *cmd;
- unsigned int tag;
-
- tag = get_tag(nq);
- if (tag != -1U) {
- cmd = &nq->cmds[tag];
- cmd->tag = tag;
- cmd->error = BLK_STS_OK;
- cmd->nq = nq;
- if (nq->dev->irqmode == NULL_IRQ_TIMER) {
- hrtimer_init(&cmd->timer, CLOCK_MONOTONIC,
- HRTIMER_MODE_REL);
- cmd->timer.function = null_cmd_timer_expired;
- }
- return cmd;
+
+ if (tag >= nq->queue_depth)
+ return NULL;
+
+ cmd = &nq->cmds[tag];
+ cmd->tag = tag;
+ cmd->error = BLK_STS_OK;
+ cmd->nq = nq;
+ if (nq->dev->irqmode == NULL_IRQ_TIMER) {
+ hrtimer_init(&cmd->timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
+ cmd->timer.function = null_cmd_timer_expired;
}

- return NULL;
+ return cmd;
}

static struct nullb_cmd *alloc_cmd(struct nullb_queue *nq, struct bio *bio)
--
2.40.1