* [PATCHSET 0/3] Fixups/improvements for iopoll passthrough
@ 2022-09-02 23:00 Jens Axboe
2022-09-02 23:00 ` [PATCH 1/3] io_uring: cleanly separate request types for iopoll Jens Axboe
` (2 more replies)
0 siblings, 3 replies; 6+ messages in thread
From: Jens Axboe @ 2022-09-02 23:00 UTC (permalink / raw)
To: io-uring; +Cc: joshi.k
Hi,
A mix of cleanups and fixes for the passthrough iopoll support.
1) Cleanup the io_uring iopoll checking, making sure we never mix
types.
2) Use a separate handler for the uring_cmd completion. This fixes
a hang with iopoll passthrough and no poll queues.
3) Let's not add an ->uring_cmd_iopoll() handler with a type we know
we have to change, once we support batching. And more importantly,
pass in the poll flags.
--
Jens Axboe
^ permalink raw reply [flat|nested] 6+ messages in thread
* [PATCH 1/3] io_uring: cleanly separate request types for iopoll
2022-09-02 23:00 [PATCHSET 0/3] Fixups/improvements for iopoll passthrough Jens Axboe
@ 2022-09-02 23:00 ` Jens Axboe
2022-09-02 23:00 ` [PATCH 2/3] nvme: use separate end IO handler for IOPOLL Jens Axboe
2022-09-02 23:00 ` [PATCH 3/3] fs: add batch and poll flags to the uring_cmd_iopoll() handler Jens Axboe
2 siblings, 0 replies; 6+ messages in thread
From: Jens Axboe @ 2022-09-02 23:00 UTC (permalink / raw)
To: io-uring; +Cc: joshi.k, Jens Axboe
After the addition of iopoll support for passthrough, there's a bit of
a mixup here. Clean it up and get rid of the casting for the passthrough
command type.
Signed-off-by: Jens Axboe <[email protected]>
---
io_uring/rw.c | 15 +++++++++------
1 file changed, 9 insertions(+), 6 deletions(-)
diff --git a/io_uring/rw.c b/io_uring/rw.c
index 9698a789b3d5..3f03b6d2a5a3 100644
--- a/io_uring/rw.c
+++ b/io_uring/rw.c
@@ -994,7 +994,7 @@ int io_do_iopoll(struct io_ring_ctx *ctx, bool force_nonspin)
wq_list_for_each(pos, start, &ctx->iopoll_list) {
struct io_kiocb *req = container_of(pos, struct io_kiocb, comp_list);
- struct io_rw *rw = io_kiocb_to_cmd(req, struct io_rw);
+ struct file *file = req->file;
int ret;
/*
@@ -1006,12 +1006,15 @@ int io_do_iopoll(struct io_ring_ctx *ctx, bool force_nonspin)
break;
if (req->opcode == IORING_OP_URING_CMD) {
- struct io_uring_cmd *ioucmd = (struct io_uring_cmd *)rw;
+ struct io_uring_cmd *ioucmd;
- ret = req->file->f_op->uring_cmd_iopoll(ioucmd);
- } else
- ret = rw->kiocb.ki_filp->f_op->iopoll(&rw->kiocb, &iob,
- poll_flags);
+ ioucmd = io_kiocb_to_cmd(req, struct io_uring_cmd);
+ ret = file->f_op->uring_cmd_iopoll(ioucmd, poll_flags);
+ } else {
+ struct io_rw *rw = io_kiocb_to_cmd(req, struct io_rw);
+
+ ret = file->f_op->iopoll(&rw->kiocb, &iob, poll_flags);
+ }
if (unlikely(ret < 0))
return ret;
else if (ret)
--
2.35.1
^ permalink raw reply related [flat|nested] 6+ messages in thread
* [PATCH 2/3] nvme: use separate end IO handler for IOPOLL
2022-09-02 23:00 [PATCHSET 0/3] Fixups/improvements for iopoll passthrough Jens Axboe
2022-09-02 23:00 ` [PATCH 1/3] io_uring: cleanly separate request types for iopoll Jens Axboe
@ 2022-09-02 23:00 ` Jens Axboe
2022-09-03 9:56 ` Kanchan Joshi
2022-09-02 23:00 ` [PATCH 3/3] fs: add batch and poll flags to the uring_cmd_iopoll() handler Jens Axboe
2 siblings, 1 reply; 6+ messages in thread
From: Jens Axboe @ 2022-09-02 23:00 UTC (permalink / raw)
To: io-uring; +Cc: joshi.k, Jens Axboe
Don't need to rely on the cookie or request type, set the right handler
based on how we're handling the IO.
Signed-off-by: Jens Axboe <[email protected]>
---
drivers/nvme/host/ioctl.c | 30 ++++++++++++++++++++++--------
1 file changed, 22 insertions(+), 8 deletions(-)
diff --git a/drivers/nvme/host/ioctl.c b/drivers/nvme/host/ioctl.c
index 7756b439a688..f34abe95821e 100644
--- a/drivers/nvme/host/ioctl.c
+++ b/drivers/nvme/host/ioctl.c
@@ -385,25 +385,36 @@ static void nvme_uring_task_cb(struct io_uring_cmd *ioucmd)
io_uring_cmd_done(ioucmd, status, result);
}
-static void nvme_uring_cmd_end_io(struct request *req, blk_status_t err)
+static void nvme_uring_iopoll_cmd_end_io(struct request *req, blk_status_t err)
{
struct io_uring_cmd *ioucmd = req->end_io_data;
struct nvme_uring_cmd_pdu *pdu = nvme_uring_cmd_pdu(ioucmd);
/* extract bio before reusing the same field for request */
struct bio *bio = pdu->bio;
- void *cookie = READ_ONCE(ioucmd->cookie);
pdu->req = req;
req->bio = bio;
/*
* For iopoll, complete it directly.
- * Otherwise, move the completion to task work.
*/
- if (cookie != NULL && blk_rq_is_poll(req))
- nvme_uring_task_cb(ioucmd);
- else
- io_uring_cmd_complete_in_task(ioucmd, nvme_uring_task_cb);
+ nvme_uring_task_cb(ioucmd);
+}
+
+static void nvme_uring_cmd_end_io(struct request *req, blk_status_t err)
+{
+ struct io_uring_cmd *ioucmd = req->end_io_data;
+ struct nvme_uring_cmd_pdu *pdu = nvme_uring_cmd_pdu(ioucmd);
+ /* extract bio before reusing the same field for request */
+ struct bio *bio = pdu->bio;
+
+ pdu->req = req;
+ req->bio = bio;
+
+ /*
+ * Move the completion to task work.
+ */
+ io_uring_cmd_complete_in_task(ioucmd, nvme_uring_task_cb);
}
static int nvme_uring_cmd_io(struct nvme_ctrl *ctrl, struct nvme_ns *ns,
@@ -464,7 +475,10 @@ static int nvme_uring_cmd_io(struct nvme_ctrl *ctrl, struct nvme_ns *ns,
blk_flags);
if (IS_ERR(req))
return PTR_ERR(req);
- req->end_io = nvme_uring_cmd_end_io;
+ if (issue_flags & IO_URING_F_IOPOLL)
+ req->end_io = nvme_uring_iopoll_cmd_end_io;
+ else
+ req->end_io = nvme_uring_cmd_end_io;
req->end_io_data = ioucmd;
if (issue_flags & IO_URING_F_IOPOLL && rq_flags & REQ_POLLED) {
--
2.35.1
^ permalink raw reply related [flat|nested] 6+ messages in thread
* [PATCH 3/3] fs: add batch and poll flags to the uring_cmd_iopoll() handler
2022-09-02 23:00 [PATCHSET 0/3] Fixups/improvements for iopoll passthrough Jens Axboe
2022-09-02 23:00 ` [PATCH 1/3] io_uring: cleanly separate request types for iopoll Jens Axboe
2022-09-02 23:00 ` [PATCH 2/3] nvme: use separate end IO handler for IOPOLL Jens Axboe
@ 2022-09-02 23:00 ` Jens Axboe
2 siblings, 0 replies; 6+ messages in thread
From: Jens Axboe @ 2022-09-02 23:00 UTC (permalink / raw)
To: io-uring; +Cc: joshi.k, Jens Axboe
We need the poll_flags to know how to poll for the IO, and we should
have the batch structure in preparation for supporting batched
completions with iopoll.
Signed-off-by: Jens Axboe <[email protected]>
---
drivers/nvme/host/ioctl.c | 12 ++++++++----
drivers/nvme/host/nvme.h | 6 ++++--
include/linux/fs.h | 3 ++-
io_uring/rw.c | 3 ++-
4 files changed, 16 insertions(+), 8 deletions(-)
diff --git a/drivers/nvme/host/ioctl.c b/drivers/nvme/host/ioctl.c
index f34abe95821e..7a0b12ef49ae 100644
--- a/drivers/nvme/host/ioctl.c
+++ b/drivers/nvme/host/ioctl.c
@@ -637,7 +637,9 @@ int nvme_ns_chr_uring_cmd(struct io_uring_cmd *ioucmd, unsigned int issue_flags)
return nvme_ns_uring_cmd(ns, ioucmd, issue_flags);
}
-int nvme_ns_chr_uring_cmd_iopoll(struct io_uring_cmd *ioucmd)
+int nvme_ns_chr_uring_cmd_iopoll(struct io_uring_cmd *ioucmd,
+ struct io_comp_batch *iob,
+ unsigned int poll_flags)
{
struct bio *bio;
int ret = 0;
@@ -650,7 +652,7 @@ int nvme_ns_chr_uring_cmd_iopoll(struct io_uring_cmd *ioucmd)
struct nvme_ns, cdev);
q = ns->queue;
if (test_bit(QUEUE_FLAG_POLL, &q->queue_flags) && bio && bio->bi_bdev)
- ret = bio_poll(bio, NULL, 0);
+ ret = bio_poll(bio, iob, poll_flags);
rcu_read_unlock();
return ret;
}
@@ -736,7 +738,9 @@ int nvme_ns_head_chr_uring_cmd(struct io_uring_cmd *ioucmd,
return ret;
}
-int nvme_ns_head_chr_uring_cmd_iopoll(struct io_uring_cmd *ioucmd)
+int nvme_ns_head_chr_uring_cmd_iopoll(struct io_uring_cmd *ioucmd,
+ struct io_comp_batch *iob,
+ unsigned int poll_flags)
{
struct cdev *cdev = file_inode(ioucmd->file)->i_cdev;
struct nvme_ns_head *head = container_of(cdev, struct nvme_ns_head, cdev);
@@ -752,7 +756,7 @@ int nvme_ns_head_chr_uring_cmd_iopoll(struct io_uring_cmd *ioucmd)
q = ns->queue;
if (test_bit(QUEUE_FLAG_POLL, &q->queue_flags) && bio
&& bio->bi_bdev)
- ret = bio_poll(bio, NULL, 0);
+ ret = bio_poll(bio, iob, poll_flags);
rcu_read_unlock();
}
srcu_read_unlock(&head->srcu, srcu_idx);
diff --git a/drivers/nvme/host/nvme.h b/drivers/nvme/host/nvme.h
index fdcbc93dea21..216acbe953b3 100644
--- a/drivers/nvme/host/nvme.h
+++ b/drivers/nvme/host/nvme.h
@@ -821,8 +821,10 @@ long nvme_ns_head_chr_ioctl(struct file *file, unsigned int cmd,
unsigned long arg);
long nvme_dev_ioctl(struct file *file, unsigned int cmd,
unsigned long arg);
-int nvme_ns_chr_uring_cmd_iopoll(struct io_uring_cmd *ioucmd);
-int nvme_ns_head_chr_uring_cmd_iopoll(struct io_uring_cmd *ioucmd);
+int nvme_ns_chr_uring_cmd_iopoll(struct io_uring_cmd *ioucmd,
+ struct io_comp_batch *iob, unsigned int poll_flags);
+int nvme_ns_head_chr_uring_cmd_iopoll(struct io_uring_cmd *ioucmd,
+ struct io_comp_batch *iob, unsigned int poll_flags);
int nvme_ns_chr_uring_cmd(struct io_uring_cmd *ioucmd,
unsigned int issue_flags);
int nvme_ns_head_chr_uring_cmd(struct io_uring_cmd *ioucmd,
diff --git a/include/linux/fs.h b/include/linux/fs.h
index d6badd19784f..01681d061a6a 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -2132,7 +2132,8 @@ struct file_operations {
loff_t len, unsigned int remap_flags);
int (*fadvise)(struct file *, loff_t, loff_t, int);
int (*uring_cmd)(struct io_uring_cmd *ioucmd, unsigned int issue_flags);
- int (*uring_cmd_iopoll)(struct io_uring_cmd *ioucmd);
+ int (*uring_cmd_iopoll)(struct io_uring_cmd *, struct io_comp_batch *,
+ unsigned int poll_flags);
} __randomize_layout;
struct inode_operations {
diff --git a/io_uring/rw.c b/io_uring/rw.c
index 3f03b6d2a5a3..4a061326c664 100644
--- a/io_uring/rw.c
+++ b/io_uring/rw.c
@@ -1009,7 +1009,8 @@ int io_do_iopoll(struct io_ring_ctx *ctx, bool force_nonspin)
struct io_uring_cmd *ioucmd;
ioucmd = io_kiocb_to_cmd(req, struct io_uring_cmd);
- ret = file->f_op->uring_cmd_iopoll(ioucmd, poll_flags);
+ ret = file->f_op->uring_cmd_iopoll(ioucmd, &iob,
+ poll_flags);
} else {
struct io_rw *rw = io_kiocb_to_cmd(req, struct io_rw);
--
2.35.1
^ permalink raw reply related [flat|nested] 6+ messages in thread
* Re: [PATCH 2/3] nvme: use separate end IO handler for IOPOLL
2022-09-02 23:00 ` [PATCH 2/3] nvme: use separate end IO handler for IOPOLL Jens Axboe
@ 2022-09-03 9:56 ` Kanchan Joshi
2022-09-03 15:23 ` Jens Axboe
0 siblings, 1 reply; 6+ messages in thread
From: Kanchan Joshi @ 2022-09-03 9:56 UTC (permalink / raw)
To: Jens Axboe; +Cc: io-uring
[-- Attachment #1: Type: text/plain, Size: 2941 bytes --]
On Fri, Sep 02, 2022 at 05:00:51PM -0600, Jens Axboe wrote:
>Don't need to rely on the cookie or request type, set the right handler
>based on how we're handling the IO.
>
>Signed-off-by: Jens Axboe <[email protected]>
>---
> drivers/nvme/host/ioctl.c | 30 ++++++++++++++++++++++--------
> 1 file changed, 22 insertions(+), 8 deletions(-)
>
>diff --git a/drivers/nvme/host/ioctl.c b/drivers/nvme/host/ioctl.c
>index 7756b439a688..f34abe95821e 100644
>--- a/drivers/nvme/host/ioctl.c
>+++ b/drivers/nvme/host/ioctl.c
>@@ -385,25 +385,36 @@ static void nvme_uring_task_cb(struct io_uring_cmd *ioucmd)
> io_uring_cmd_done(ioucmd, status, result);
> }
>
>-static void nvme_uring_cmd_end_io(struct request *req, blk_status_t err)
>+static void nvme_uring_iopoll_cmd_end_io(struct request *req, blk_status_t err)
> {
> struct io_uring_cmd *ioucmd = req->end_io_data;
> struct nvme_uring_cmd_pdu *pdu = nvme_uring_cmd_pdu(ioucmd);
> /* extract bio before reusing the same field for request */
> struct bio *bio = pdu->bio;
>- void *cookie = READ_ONCE(ioucmd->cookie);
>
> pdu->req = req;
> req->bio = bio;
>
> /*
> * For iopoll, complete it directly.
>- * Otherwise, move the completion to task work.
> */
>- if (cookie != NULL && blk_rq_is_poll(req))
>- nvme_uring_task_cb(ioucmd);
>- else
>- io_uring_cmd_complete_in_task(ioucmd, nvme_uring_task_cb);
>+ nvme_uring_task_cb(ioucmd);
>+}
>+
>+static void nvme_uring_cmd_end_io(struct request *req, blk_status_t err)
>+{
>+ struct io_uring_cmd *ioucmd = req->end_io_data;
>+ struct nvme_uring_cmd_pdu *pdu = nvme_uring_cmd_pdu(ioucmd);
>+ /* extract bio before reusing the same field for request */
>+ struct bio *bio = pdu->bio;
>+
>+ pdu->req = req;
>+ req->bio = bio;
>+
>+ /*
>+ * Move the completion to task work.
>+ */
>+ io_uring_cmd_complete_in_task(ioucmd, nvme_uring_task_cb);
> }
>
> static int nvme_uring_cmd_io(struct nvme_ctrl *ctrl, struct nvme_ns *ns,
>@@ -464,7 +475,10 @@ static int nvme_uring_cmd_io(struct nvme_ctrl *ctrl, struct nvme_ns *ns,
> blk_flags);
> if (IS_ERR(req))
> return PTR_ERR(req);
>- req->end_io = nvme_uring_cmd_end_io;
>+ if (issue_flags & IO_URING_F_IOPOLL)
>+ req->end_io = nvme_uring_iopoll_cmd_end_io;
>+ else
>+ req->end_io = nvme_uring_cmd_end_io;
The polled handler (nvme_uring_iopoll_cmd_end_io) may get called in irq
context (some swapper/kworker etc.) too. And in that case will it be
safe to call nvme_uring_task_cb directly.
We don't touch the user-fields in cmd (thanks to Big CQE) so that part is
sorted. But there is blk_rq_unmap_user call - can that or anything else
inside io_req_complete_post() cause trouble.
* A matching blk_rq_unmap_user() must be issued at the end of I/O, while
* still in process context.
*/
int blk_rq_map_user_iov(struct request_queue *q, struct request *rq,
struct rq_map_data *map_data,
const struct iov_iter *iter, gfp_t gfp_mask)
[-- Attachment #2: Type: text/plain, Size: 0 bytes --]
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH 2/3] nvme: use separate end IO handler for IOPOLL
2022-09-03 9:56 ` Kanchan Joshi
@ 2022-09-03 15:23 ` Jens Axboe
0 siblings, 0 replies; 6+ messages in thread
From: Jens Axboe @ 2022-09-03 15:23 UTC (permalink / raw)
To: Kanchan Joshi; +Cc: io-uring
On 9/3/22 3:56 AM, Kanchan Joshi wrote:
> On Fri, Sep 02, 2022 at 05:00:51PM -0600, Jens Axboe wrote:
>> Don't need to rely on the cookie or request type, set the right handler
>> based on how we're handling the IO.
>>
>> Signed-off-by: Jens Axboe <[email protected]>
>> ---
>> drivers/nvme/host/ioctl.c | 30 ++++++++++++++++++++++--------
>> 1 file changed, 22 insertions(+), 8 deletions(-)
>>
>> diff --git a/drivers/nvme/host/ioctl.c b/drivers/nvme/host/ioctl.c
>> index 7756b439a688..f34abe95821e 100644
>> --- a/drivers/nvme/host/ioctl.c
>> +++ b/drivers/nvme/host/ioctl.c
>> @@ -385,25 +385,36 @@ static void nvme_uring_task_cb(struct io_uring_cmd *ioucmd)
>> ????io_uring_cmd_done(ioucmd, status, result);
>> }
>>
>> -static void nvme_uring_cmd_end_io(struct request *req, blk_status_t err)
>> +static void nvme_uring_iopoll_cmd_end_io(struct request *req, blk_status_t err)
>> {
>> ????struct io_uring_cmd *ioucmd = req->end_io_data;
>> ????struct nvme_uring_cmd_pdu *pdu = nvme_uring_cmd_pdu(ioucmd);
>> ????/* extract bio before reusing the same field for request */
>> ????struct bio *bio = pdu->bio;
>> -??? void *cookie = READ_ONCE(ioucmd->cookie);
>>
>> ????pdu->req = req;
>> ????req->bio = bio;
>>
>> ????/*
>> ???? * For iopoll, complete it directly.
>> -???? * Otherwise, move the completion to task work.
>> ???? */
>> -??? if (cookie != NULL && blk_rq_is_poll(req))
>> -??????? nvme_uring_task_cb(ioucmd);
>> -??? else
>> -??????? io_uring_cmd_complete_in_task(ioucmd, nvme_uring_task_cb);
>> +??? nvme_uring_task_cb(ioucmd);
>> +}
>> +
>> +static void nvme_uring_cmd_end_io(struct request *req, blk_status_t err)
>> +{
>> +??? struct io_uring_cmd *ioucmd = req->end_io_data;
>> +??? struct nvme_uring_cmd_pdu *pdu = nvme_uring_cmd_pdu(ioucmd);
>> +??? /* extract bio before reusing the same field for request */
>> +??? struct bio *bio = pdu->bio;
>> +
>> +??? pdu->req = req;
>> +??? req->bio = bio;
>> +
>> +??? /*
>> +???? * Move the completion to task work.
>> +???? */
>> +??? io_uring_cmd_complete_in_task(ioucmd, nvme_uring_task_cb);
>> }
>>
>> static int nvme_uring_cmd_io(struct nvme_ctrl *ctrl, struct nvme_ns *ns,
>> @@ -464,7 +475,10 @@ static int nvme_uring_cmd_io(struct nvme_ctrl *ctrl, struct nvme_ns *ns,
>> ??????????? blk_flags);
>> ????if (IS_ERR(req))
>> ??????? return PTR_ERR(req);
>> -??? req->end_io = nvme_uring_cmd_end_io;
>> +??? if (issue_flags & IO_URING_F_IOPOLL)
>> +??????? req->end_io = nvme_uring_iopoll_cmd_end_io;
>> +??? else
>> +??????? req->end_io = nvme_uring_cmd_end_io;
>
> The polled handler (nvme_uring_iopoll_cmd_end_io) may get called in
> irq context (some swapper/kworker etc.) too. And in that case will it
> be safe to call nvme_uring_task_cb directly. We don't touch the
> user-fields in cmd (thanks to Big CQE) so that part is sorted. But
> there is blk_rq_unmap_user call - can that or anything else inside
> io_req_complete_post() cause trouble.
The unmap might be problematic if the data wasn't mapped. That's a slow
path and unexpected, however. Might be better to just leave the unified
completion path and ensure that nvme_uring_task_cb() checks for polled
as well. I'll give it a quick spin.
--
Jens Axboe
^ permalink raw reply [flat|nested] 6+ messages in thread
end of thread, other threads:[~2022-09-03 15:23 UTC | newest]
Thread overview: 6+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2022-09-02 23:00 [PATCHSET 0/3] Fixups/improvements for iopoll passthrough Jens Axboe
2022-09-02 23:00 ` [PATCH 1/3] io_uring: cleanly separate request types for iopoll Jens Axboe
2022-09-02 23:00 ` [PATCH 2/3] nvme: use separate end IO handler for IOPOLL Jens Axboe
2022-09-03 9:56 ` Kanchan Joshi
2022-09-03 15:23 ` Jens Axboe
2022-09-02 23:00 ` [PATCH 3/3] fs: add batch and poll flags to the uring_cmd_iopoll() handler Jens Axboe
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