2022-10-05 03:20:58

by Chaitanya Kulkarni

Subject: [PATCH 4/6] null_blk: initialize cmd->bio in __alloc_cmd()

The function __alloc_cmd() is responsible to allocate tag and
initializae the different members of the null_cmd structure e.g.
cmd->tag, cmd->error, and cmd->nq, Move only member bio that is initialized
from alloc_cmd() into __alloc_cmd().

Signed-off-by: Chaitanya Kulkarni <[email protected]>
---
drivers/block/null_blk/main.c | 9 ++++-----
1 file changed, 4 insertions(+), 5 deletions(-)

diff --git a/drivers/block/null_blk/main.c b/drivers/block/null_blk/main.c
index b82c2ffeb086..765c1ca0edf5 100644
--- a/drivers/block/null_blk/main.c
+++ b/drivers/block/null_blk/main.c
@@ -743,7 +743,7 @@ static void free_cmd(struct nullb_cmd *cmd)

static enum hrtimer_restart null_cmd_timer_expired(struct hrtimer *timer);

-static struct nullb_cmd *__alloc_cmd(struct nullb_queue *nq)
+static struct nullb_cmd *__alloc_cmd(struct nullb_queue *nq, struct bio *bio)
{
struct nullb_cmd *cmd;
unsigned int tag;
@@ -754,6 +754,7 @@ static struct nullb_cmd *__alloc_cmd(struct nullb_queue *nq)
cmd->tag = tag;
cmd->error = BLK_STS_OK;
cmd->nq = nq;
+ cmd->bio = bio;
if (nq->dev->irqmode == NULL_IRQ_TIMER) {
hrtimer_init(&cmd->timer, CLOCK_MONOTONIC,
HRTIMER_MODE_REL);
@@ -775,11 +776,9 @@ static struct nullb_cmd *alloc_cmd(struct nullb_queue *nq, struct bio *bio)
* This avoids multiple return statements, multiple calls to
* __alloc_cmd() and a fast path call to prepare_to_wait().
*/
- cmd = __alloc_cmd(nq);
- if (cmd) {
- cmd->bio = bio;
+ cmd = __alloc_cmd(nq, bio);
+ if (cmd)
return cmd;
- }
prepare_to_wait(&nq->wait, &wait, TASK_UNINTERRUPTIBLE);
io_schedule();
finish_wait(&nq->wait, &wait);
--
2.29.0

2022-10-05 05:09:54

by Damien Le Moal

Subject: Re: [PATCH 4/6] null_blk: initialize cmd->bio in __alloc_cmd()

On 10/5/22 12:16, Chaitanya Kulkarni wrote:
> The function __alloc_cmd() is responsible to allocate tag and
> initializae the different members of the null_cmd structure e.g.
> cmd->tag, cmd->error, and cmd->nq, Move only member bio that is initialized
> from alloc_cmd() into __alloc_cmd().
>
> Signed-off-by: Chaitanya Kulkarni <[email protected]>

Reviewed-by: Damien Le Moal <[email protected]>

> ---
> drivers/block/null_blk/main.c | 9 ++++-----
> 1 file changed, 4 insertions(+), 5 deletions(-)
>
> diff --git a/drivers/block/null_blk/main.c b/drivers/block/null_blk/main.c
> index b82c2ffeb086..765c1ca0edf5 100644
> --- a/drivers/block/null_blk/main.c
> +++ b/drivers/block/null_blk/main.c
> @@ -743,7 +743,7 @@ static void free_cmd(struct nullb_cmd *cmd)
>
> static enum hrtimer_restart null_cmd_timer_expired(struct hrtimer *timer);
>
> -static struct nullb_cmd *__alloc_cmd(struct nullb_queue *nq)
> +static struct nullb_cmd *__alloc_cmd(struct nullb_queue *nq, struct bio *bio)
> {
> struct nullb_cmd *cmd;
> unsigned int tag;
> @@ -754,6 +754,7 @@ static struct nullb_cmd *__alloc_cmd(struct nullb_queue *nq)
> cmd->tag = tag;
> cmd->error = BLK_STS_OK;
> cmd->nq = nq;
> + cmd->bio = bio;
> if (nq->dev->irqmode == NULL_IRQ_TIMER) {
> hrtimer_init(&cmd->timer, CLOCK_MONOTONIC,
> HRTIMER_MODE_REL);
> @@ -775,11 +776,9 @@ static struct nullb_cmd *alloc_cmd(struct nullb_queue *nq, struct bio *bio)
> * This avoids multiple return statements, multiple calls to
> * __alloc_cmd() and a fast path call to prepare_to_wait().
> */
> - cmd = __alloc_cmd(nq);
> - if (cmd) {
> - cmd->bio = bio;
> + cmd = __alloc_cmd(nq, bio);
> + if (cmd)
> return cmd;
> - }
> prepare_to_wait(&nq->wait, &wait, TASK_UNINTERRUPTIBLE);
> io_schedule();
> finish_wait(&nq->wait, &wait);

--
Damien Le Moal
Western Digital Research