* [PATCH] blk-mq: don't clear RQF_MQ_INFLIGHT in blk_mq_rq_ctx_init()
@ 2018-01-13 17:49 Ming Lei
2018-01-14 17:38 ` Jens Axboe
0 siblings, 1 reply; 4+ messages in thread
From: Ming Lei @ 2018-01-13 17:49 UTC (permalink / raw)
To: Jens Axboe, linux-block, Christoph Hellwig
Cc: Ming Lei, Laurence Oberman, Mike Snitzer
In case of no IO scheduler, RQF_MQ_INFLIGHT is set in blk_mq_rq_ctx_init(),
but 7c3fb70f0341 clears it mistakenly, so fix it.
This patch fixes systemd-udevd hang when starting multipathd service:
[ 914.409660] systemd-journald[213]: Successfully sent stream file descriptor to service manager.
[ 984.028104] INFO: task systemd-udevd:1518 blocked for more than 120 seconds.
[ 984.030916] Not tainted 4.15.0-rc6+ #62
[ 984.032709] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
[ 984.035818] systemd-udevd D 0 1518 232 0x80000006
[ 984.035826] Call Trace:
[ 984.035846] ? __schedule+0x626/0x759
[ 984.035855] schedule+0x88/0x9b
[ 984.035861] io_schedule+0x12/0x33
[ 984.035867] __lock_page+0xef/0x127
[ 984.035874] ? add_to_page_cache_lru+0xd4/0xd4
[ 984.035889] truncate_inode_pages_range+0x533/0x62f
[ 984.035929] ? cpumask_next+0x17/0x18
[ 984.035937] ? cpumask_next+0x17/0x18
[ 984.035943] ? smp_call_function_many+0x1e4/0x218
[ 984.035949] ? __find_get_block+0x2ba/0x2ba
[ 984.035961] ? __find_get_block+0x216/0x2ba
[ 984.035977] ? on_each_cpu_cond+0xbf/0x143
[ 984.035992] __blkdev_put+0x69/0x1a5
[ 984.036009] blkdev_close+0x21/0x24
[ 984.036025] __fput+0xdb/0x18a
[ 984.036039] task_work_run+0x6f/0x80
[ 984.036048] do_exit+0x452/0x96b
[ 984.036055] ? preempt_count_add+0x7a/0x8c
[ 984.036061] do_group_exit+0x3c/0x98
[ 984.036067] get_signal+0x47c/0x4fd
[ 984.036076] do_signal+0x36/0x51f
[ 984.036090] exit_to_usermode_loop+0x3a/0x73
[ 984.036096] syscall_return_slowpath+0x97/0xcf
[ 984.036103] entry_SYSCALL_64_fastpath+0x7b/0x7d
[ 984.036109] RIP: 0033:0x7f2ffce94540
[ 984.036112] RSP: 002b:00007ffffd1cb888 EFLAGS: 00000246 ORIG_RAX: 0000000000000000
[ 984.036117] RAX: fffffffffffffffc RBX: 000055d9840e72d0 RCX: 00007f2ffce94540
[ 984.036120] RDX: 0000000000000018 RSI: 000055d9840e72f8 RDI: 0000000000000007
[ 984.036122] RBP: 000055d984111860 R08: 000055d9840e72d0 R09: 0000000000000092
[ 984.036125] R10: 00007f2ffce7ebb8 R11: 0000000000000246 R12: 0000000000000018
[ 984.036127] R13: 000000020014e200 R14: 000055d9841118b0 R15: 000055d9840e72e8
[ 1034.410125] systemd-journald[213]: Sent WATCHDOG=1 notification.
Cc: Laurence Oberman <loberman@redhat.com>
Cc: Mike Snitzer <snitzer@redhat.com>
Fixes: 7c3fb70f0341 ("block: rearrange a few request fields for better cache layout")
Signed-off-by: Ming Lei <ming.lei@redhat.com>
---
block/blk-mq.c | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)
diff --git a/block/blk-mq.c b/block/blk-mq.c
index ef9beca2d117..c1c74d891ce7 100644
--- a/block/blk-mq.c
+++ b/block/blk-mq.c
@@ -269,13 +269,14 @@ static struct request *blk_mq_rq_ctx_init(struct blk_mq_alloc_data *data,
{
struct blk_mq_tags *tags = blk_mq_tags_from_data(data);
struct request *rq = tags->static_rqs[tag];
+ bool inflight = false;
if (data->flags & BLK_MQ_REQ_INTERNAL) {
rq->tag = -1;
rq->internal_tag = tag;
} else {
if (blk_mq_tag_busy(data->hctx)) {
- rq->rq_flags = RQF_MQ_INFLIGHT;
+ inflight = true;
atomic_inc(&data->hctx->nr_active);
}
rq->tag = tag;
@@ -286,7 +287,7 @@ static struct request *blk_mq_rq_ctx_init(struct blk_mq_alloc_data *data,
/* csd/requeue_work/fifo_time is initialized before use */
rq->q = data->q;
rq->mq_ctx = data->ctx;
- rq->rq_flags = 0;
+ rq->rq_flags = inflight ? RQF_MQ_INFLIGHT : 0;
rq->cpu = -1;
rq->cmd_flags = op;
if (data->flags & BLK_MQ_REQ_PREEMPT)
--
2.9.5
^ permalink raw reply related [flat|nested] 4+ messages in thread
* Re: [PATCH] blk-mq: don't clear RQF_MQ_INFLIGHT in blk_mq_rq_ctx_init()
2018-01-13 17:49 [PATCH] blk-mq: don't clear RQF_MQ_INFLIGHT in blk_mq_rq_ctx_init() Ming Lei
@ 2018-01-14 17:38 ` Jens Axboe
2018-01-14 17:43 ` Mike Snitzer
0 siblings, 1 reply; 4+ messages in thread
From: Jens Axboe @ 2018-01-14 17:38 UTC (permalink / raw)
To: Ming Lei, linux-block, Christoph Hellwig; +Cc: Laurence Oberman, Mike Snitzer
On 1/13/18 10:49 AM, Ming Lei wrote:
> In case of no IO scheduler, RQF_MQ_INFLIGHT is set in blk_mq_rq_ctx_init(),
> but 7c3fb70f0341 clears it mistakenly, so fix it.
Oops yeah, that's my bad. However, I think the below fix is cleaner
and avoids a conditional.
diff --git a/block/blk-mq.c b/block/blk-mq.c
index b3b2003b7429..c8f62e6be6b6 100644
--- a/block/blk-mq.c
+++ b/block/blk-mq.c
@@ -269,13 +269,14 @@ static struct request *blk_mq_rq_ctx_init(struct blk_mq_alloc_data *data,
{
struct blk_mq_tags *tags = blk_mq_tags_from_data(data);
struct request *rq = tags->static_rqs[tag];
+ req_flags_t rq_flags = 0;
if (data->flags & BLK_MQ_REQ_INTERNAL) {
rq->tag = -1;
rq->internal_tag = tag;
} else {
if (blk_mq_tag_busy(data->hctx)) {
- rq->rq_flags = RQF_MQ_INFLIGHT;
+ rq_flags = RQF_MQ_INFLIGHT;
atomic_inc(&data->hctx->nr_active);
}
rq->tag = tag;
@@ -286,7 +287,7 @@ static struct request *blk_mq_rq_ctx_init(struct blk_mq_alloc_data *data,
/* csd/requeue_work/fifo_time is initialized before use */
rq->q = data->q;
rq->mq_ctx = data->ctx;
- rq->rq_flags = 0;
+ rq->rq_flags = rq_flags;
rq->cpu = -1;
rq->cmd_flags = op;
if (data->flags & BLK_MQ_REQ_PREEMPT)
--
Jens Axboe
--
Jens Axboe
^ permalink raw reply related [flat|nested] 4+ messages in thread
* Re: blk-mq: don't clear RQF_MQ_INFLIGHT in blk_mq_rq_ctx_init()
2018-01-14 17:38 ` Jens Axboe
@ 2018-01-14 17:43 ` Mike Snitzer
2018-01-14 17:47 ` Jens Axboe
0 siblings, 1 reply; 4+ messages in thread
From: Mike Snitzer @ 2018-01-14 17:43 UTC (permalink / raw)
To: Jens Axboe; +Cc: Ming Lei, linux-block, Christoph Hellwig, Laurence Oberman
On Sun, Jan 14 2018 at 12:38pm -0500,
Jens Axboe <axboe@kernel.dk> wrote:
> On 1/13/18 10:49 AM, Ming Lei wrote:
> > In case of no IO scheduler, RQF_MQ_INFLIGHT is set in blk_mq_rq_ctx_init(),
> > but 7c3fb70f0341 clears it mistakenly, so fix it.
>
> Oops yeah, that's my bad. However, I think the below fix is cleaner
> and avoids a conditional.
>
>
> diff --git a/block/blk-mq.c b/block/blk-mq.c
> index b3b2003b7429..c8f62e6be6b6 100644
> --- a/block/blk-mq.c
> +++ b/block/blk-mq.c
> @@ -269,13 +269,14 @@ static struct request *blk_mq_rq_ctx_init(struct blk_mq_alloc_data *data,
> {
> struct blk_mq_tags *tags = blk_mq_tags_from_data(data);
> struct request *rq = tags->static_rqs[tag];
> + req_flags_t rq_flags = 0;
>
> if (data->flags & BLK_MQ_REQ_INTERNAL) {
> rq->tag = -1;
> rq->internal_tag = tag;
> } else {
> if (blk_mq_tag_busy(data->hctx)) {
> - rq->rq_flags = RQF_MQ_INFLIGHT;
> + rq_flags = RQF_MQ_INFLIGHT;
> atomic_inc(&data->hctx->nr_active);
> }
> rq->tag = tag;
> @@ -286,7 +287,7 @@ static struct request *blk_mq_rq_ctx_init(struct blk_mq_alloc_data *data,
> /* csd/requeue_work/fifo_time is initialized before use */
> rq->q = data->q;
> rq->mq_ctx = data->ctx;
> - rq->rq_flags = 0;
> + rq->rq_flags = rq_flags;
> rq->cpu = -1;
> rq->cmd_flags = op;
> if (data->flags & BLK_MQ_REQ_PREEMPT)
Yeap, looks good.
Reviewed-by: Mike Snitzer <snitzer@redhat.com>
Defintely need this fix, without it all my dm-mpath testing hangs
Thanks,
Mike
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: blk-mq: don't clear RQF_MQ_INFLIGHT in blk_mq_rq_ctx_init()
2018-01-14 17:43 ` Mike Snitzer
@ 2018-01-14 17:47 ` Jens Axboe
0 siblings, 0 replies; 4+ messages in thread
From: Jens Axboe @ 2018-01-14 17:47 UTC (permalink / raw)
To: Mike Snitzer; +Cc: Ming Lei, linux-block, Christoph Hellwig, Laurence Oberman
On 1/14/18 10:43 AM, Mike Snitzer wrote:
> On Sun, Jan 14 2018 at 12:38pm -0500,
> Jens Axboe <axboe@kernel.dk> wrote:
>
>> On 1/13/18 10:49 AM, Ming Lei wrote:
>>> In case of no IO scheduler, RQF_MQ_INFLIGHT is set in blk_mq_rq_ctx_init(),
>>> but 7c3fb70f0341 clears it mistakenly, so fix it.
>>
>> Oops yeah, that's my bad. However, I think the below fix is cleaner
>> and avoids a conditional.
>>
>>
>> diff --git a/block/blk-mq.c b/block/blk-mq.c
>> index b3b2003b7429..c8f62e6be6b6 100644
>> --- a/block/blk-mq.c
>> +++ b/block/blk-mq.c
>> @@ -269,13 +269,14 @@ static struct request *blk_mq_rq_ctx_init(struct blk_mq_alloc_data *data,
>> {
>> struct blk_mq_tags *tags = blk_mq_tags_from_data(data);
>> struct request *rq = tags->static_rqs[tag];
>> + req_flags_t rq_flags = 0;
>>
>> if (data->flags & BLK_MQ_REQ_INTERNAL) {
>> rq->tag = -1;
>> rq->internal_tag = tag;
>> } else {
>> if (blk_mq_tag_busy(data->hctx)) {
>> - rq->rq_flags = RQF_MQ_INFLIGHT;
>> + rq_flags = RQF_MQ_INFLIGHT;
>> atomic_inc(&data->hctx->nr_active);
>> }
>> rq->tag = tag;
>> @@ -286,7 +287,7 @@ static struct request *blk_mq_rq_ctx_init(struct blk_mq_alloc_data *data,
>> /* csd/requeue_work/fifo_time is initialized before use */
>> rq->q = data->q;
>> rq->mq_ctx = data->ctx;
>> - rq->rq_flags = 0;
>> + rq->rq_flags = rq_flags;
>> rq->cpu = -1;
>> rq->cmd_flags = op;
>> if (data->flags & BLK_MQ_REQ_PREEMPT)
>
> Yeap, looks good.
>
> Reviewed-by: Mike Snitzer <snitzer@redhat.com>
>
> Defintely need this fix, without it all my dm-mpath testing hangs
Yeah, pretty unfortunate... I've applied it and pushed it out.
--
Jens Axboe
^ permalink raw reply [flat|nested] 4+ messages in thread
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2018-01-13 17:49 [PATCH] blk-mq: don't clear RQF_MQ_INFLIGHT in blk_mq_rq_ctx_init() Ming Lei
2018-01-14 17:38 ` Jens Axboe
2018-01-14 17:43 ` Mike Snitzer
2018-01-14 17:47 ` Jens Axboe
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