diff mbox

[v4,3/3] fs: Add aio iopriority support for block_dev

Message ID 20180517203803.2664-4-adam.manzanares@wdc.com (mailing list archive)
State New, archived
Headers show

Commit Message

Adam Manzanares May 17, 2018, 8:38 p.m. UTC
From: Adam Manzanares <adam.manzanares@wdc.com>

This is the per-I/O equivalent of the ioprio_set system call.

When IOCB_FLAG_IOPRIO is set on the iocb aio_flags field, then we set the
newly added kiocb ki_ioprio field to the value in the iocb aio_reqprio field.

When a bio is created for an aio request by the block dev we set the priority
value of the bio to the user supplied value.

This patch depends on block: add ioprio_check_cap function

Signed-off-by: Adam Manzanares <adam.manzanares@wdc.com>
---
 fs/aio.c                     | 16 ++++++++++++++++
 fs/block_dev.c               |  2 ++
 include/linux/fs.h           |  2 ++
 include/uapi/linux/aio_abi.h |  1 +
 4 files changed, 21 insertions(+)

Comments

Jens Axboe May 18, 2018, 3:14 p.m. UTC | #1
On 5/17/18 2:38 PM, adam.manzanares@wdc.com wrote:
> From: Adam Manzanares <adam.manzanares@wdc.com>
> 
> This is the per-I/O equivalent of the ioprio_set system call.
> 
> When IOCB_FLAG_IOPRIO is set on the iocb aio_flags field, then we set the
> newly added kiocb ki_ioprio field to the value in the iocb aio_reqprio field.
> 
> When a bio is created for an aio request by the block dev we set the priority
> value of the bio to the user supplied value.
> 
> This patch depends on block: add ioprio_check_cap function

Actually, one comment on this one:

> diff --git a/fs/aio.c b/fs/aio.c
> index f3eae5d5771b..ff3107aa82d5 100644
> --- a/fs/aio.c
> +++ b/fs/aio.c
> @@ -1451,6 +1451,22 @@ static int aio_prep_rw(struct kiocb *req, struct iocb *iocb)
>  	if (iocb->aio_flags & IOCB_FLAG_RESFD)
>  		req->ki_flags |= IOCB_EVENTFD;
>  	req->ki_hint = file_write_hint(req->ki_filp);
> +	if (iocb->aio_flags & IOCB_FLAG_IOPRIO) {
> +		/*
> +		 * If the IOCB_FLAG_IOPRIO flag of aio_flags is set, then
> +		 * aio_reqprio is interpreted as an I/O scheduling
> +		 * class and priority.
> +		 */
> +		ret = ioprio_check_cap(iocb->aio_reqprio);
> +		if (ret) {
> +			pr_debug("aio ioprio check cap error\n");
> +			return -EINVAL;
> +		}
> +
> +		req->ki_ioprio = iocb->aio_reqprio;
> +		req->ki_flags |= IOCB_IOPRIO;
> +	}

Do we really need IOCB_IOPRIO? All zeroes is no priority set anyway,
so we should be able to get by with just setting ->ki_ioprio to either
the priority, or 0.

> diff --git a/fs/block_dev.c b/fs/block_dev.c
> index 7ec920e27065..970bef79caa6 100644
> --- a/fs/block_dev.c
> +++ b/fs/block_dev.c
> @@ -355,6 +355,8 @@ __blkdev_direct_IO(struct kiocb *iocb, struct iov_iter *iter, int nr_pages)
>  		bio->bi_write_hint = iocb->ki_hint;
>  		bio->bi_private = dio;
>  		bio->bi_end_io = blkdev_bio_end_io;
> +		if (iocb->ki_flags & IOCB_IOPRIO)
> +			bio->bi_ioprio = iocb->ki_ioprio;

And then this assignment can just happen unconditionally.
Adam Manzanares May 18, 2018, 3:29 p.m. UTC | #2
On 5/18/18 8:14 AM, Jens Axboe wrote:
> On 5/17/18 2:38 PM, adam.manzanares@wdc.com wrote:

>> From: Adam Manzanares <adam.manzanares@wdc.com>

>>

>> This is the per-I/O equivalent of the ioprio_set system call.

>>

>> When IOCB_FLAG_IOPRIO is set on the iocb aio_flags field, then we set the

>> newly added kiocb ki_ioprio field to the value in the iocb aio_reqprio field.

>>

>> When a bio is created for an aio request by the block dev we set the priority

>> value of the bio to the user supplied value.

>>

>> This patch depends on block: add ioprio_check_cap function

> 

> Actually, one comment on this one:

> 

>> diff --git a/fs/aio.c b/fs/aio.c

>> index f3eae5d5771b..ff3107aa82d5 100644

>> --- a/fs/aio.c

>> +++ b/fs/aio.c

>> @@ -1451,6 +1451,22 @@ static int aio_prep_rw(struct kiocb *req, struct iocb *iocb)

>>   	if (iocb->aio_flags & IOCB_FLAG_RESFD)

>>   		req->ki_flags |= IOCB_EVENTFD;

>>   	req->ki_hint = file_write_hint(req->ki_filp);

>> +	if (iocb->aio_flags & IOCB_FLAG_IOPRIO) {

>> +		/*

>> +		 * If the IOCB_FLAG_IOPRIO flag of aio_flags is set, then

>> +		 * aio_reqprio is interpreted as an I/O scheduling

>> +		 * class and priority.

>> +		 */

>> +		ret = ioprio_check_cap(iocb->aio_reqprio);

>> +		if (ret) {

>> +			pr_debug("aio ioprio check cap error\n");

>> +			return -EINVAL;

>> +		}

>> +

>> +		req->ki_ioprio = iocb->aio_reqprio;

>> +		req->ki_flags |= IOCB_IOPRIO;

>> +	}

> 

> Do we really need IOCB_IOPRIO? All zeroes is no priority set anyway,

> so we should be able to get by with just setting ->ki_ioprio to either

> the priority, or 0.

> 

>> diff --git a/fs/block_dev.c b/fs/block_dev.c

>> index 7ec920e27065..970bef79caa6 100644

>> --- a/fs/block_dev.c

>> +++ b/fs/block_dev.c

>> @@ -355,6 +355,8 @@ __blkdev_direct_IO(struct kiocb *iocb, struct iov_iter *iter, int nr_pages)

>>   		bio->bi_write_hint = iocb->ki_hint;

>>   		bio->bi_private = dio;

>>   		bio->bi_end_io = blkdev_bio_end_io;

>> +		if (iocb->ki_flags & IOCB_IOPRIO)

>> +			bio->bi_ioprio = iocb->ki_ioprio;

> 

> And then this assignment can just happen unconditionally.


That is a cleaner way of guaranteeing the ioprio set on the kiocb is 
only set when the user intends to use the ioprio from the iocb.

I'll resend the series.


>
Christoph Hellwig May 18, 2018, 4:06 p.m. UTC | #3
Looks fine, although I'd split it into a aio and block_dev patch.

Also please wire this up for the fs/iomap.c direct I/O code, it should
be essentially the same sniplet as in the block_dev.c code.
Adam Manzanares May 18, 2018, 7:54 p.m. UTC | #4
On 5/18/18 9:06 AM, Christoph Hellwig wrote:
> Looks fine, although I'd split it into a aio and block_dev patch.

> 

> Also please wire this up for the fs/iomap.c direct I/O code, it should

> be essentially the same sniplet as in the block_dev.c code.

> 


Will do.
kernel test robot May 18, 2018, 8:08 p.m. UTC | #5
Hi Adam,

Thank you for the patch! Yet something to improve:

[auto build test ERROR on next-20180516]
[cannot apply to linus/master block/for-next v4.17-rc5 v4.17-rc4 v4.17-rc3 v4.17-rc5]
[if your patch is applied to the wrong git tree, please drop us a note to help improve the system]

url:    https://github.com/0day-ci/linux/commits/adam-manzanares-wdc-com/AIO-add-per-command-iopriority/20180519-031848
config: x86_64-randconfig-x013-201819 (attached as .config)
compiler: gcc-7 (Debian 7.3.0-16) 7.3.0
reproduce:
        # save the attached .config to linux build tree
        make ARCH=x86_64 

All errors (new ones prefixed by >>):

   fs/aio.c: In function 'aio_prep_rw':
>> fs/aio.c:1460:9: error: implicit declaration of function 'ioprio_check_cap'; did you mean 'param_check_charp'? [-Werror=implicit-function-declaration]
      ret = ioprio_check_cap(iocb->aio_reqprio);
            ^~~~~~~~~~~~~~~~
            param_check_charp
   cc1: some warnings being treated as errors

vim +1460 fs/aio.c

  1440	
  1441	static int aio_prep_rw(struct kiocb *req, struct iocb *iocb)
  1442	{
  1443		int ret;
  1444	
  1445		req->ki_filp = fget(iocb->aio_fildes);
  1446		if (unlikely(!req->ki_filp))
  1447			return -EBADF;
  1448		req->ki_complete = aio_complete_rw;
  1449		req->ki_pos = iocb->aio_offset;
  1450		req->ki_flags = iocb_flags(req->ki_filp);
  1451		if (iocb->aio_flags & IOCB_FLAG_RESFD)
  1452			req->ki_flags |= IOCB_EVENTFD;
  1453		req->ki_hint = file_write_hint(req->ki_filp);
  1454		if (iocb->aio_flags & IOCB_FLAG_IOPRIO) {
  1455			/*
  1456			 * If the IOCB_FLAG_IOPRIO flag of aio_flags is set, then
  1457			 * aio_reqprio is interpreted as an I/O scheduling
  1458			 * class and priority.
  1459			 */
> 1460			ret = ioprio_check_cap(iocb->aio_reqprio);
  1461			if (ret) {
  1462				pr_debug("aio ioprio check cap error\n");
  1463				return -EINVAL;
  1464			}
  1465	
  1466			req->ki_ioprio = iocb->aio_reqprio;
  1467			req->ki_flags |= IOCB_IOPRIO;
  1468		}
  1469	
  1470		ret = kiocb_set_rw_flags(req, iocb->aio_rw_flags);
  1471		if (unlikely(ret))
  1472			fput(req->ki_filp);
  1473		return ret;
  1474	}
  1475	

---
0-DAY kernel test infrastructure                Open Source Technology Center
https://lists.01.org/pipermail/kbuild-all                   Intel Corporation
diff mbox

Patch

diff --git a/fs/aio.c b/fs/aio.c
index f3eae5d5771b..ff3107aa82d5 100644
--- a/fs/aio.c
+++ b/fs/aio.c
@@ -1451,6 +1451,22 @@  static int aio_prep_rw(struct kiocb *req, struct iocb *iocb)
 	if (iocb->aio_flags & IOCB_FLAG_RESFD)
 		req->ki_flags |= IOCB_EVENTFD;
 	req->ki_hint = file_write_hint(req->ki_filp);
+	if (iocb->aio_flags & IOCB_FLAG_IOPRIO) {
+		/*
+		 * If the IOCB_FLAG_IOPRIO flag of aio_flags is set, then
+		 * aio_reqprio is interpreted as an I/O scheduling
+		 * class and priority.
+		 */
+		ret = ioprio_check_cap(iocb->aio_reqprio);
+		if (ret) {
+			pr_debug("aio ioprio check cap error\n");
+			return -EINVAL;
+		}
+
+		req->ki_ioprio = iocb->aio_reqprio;
+		req->ki_flags |= IOCB_IOPRIO;
+	}
+
 	ret = kiocb_set_rw_flags(req, iocb->aio_rw_flags);
 	if (unlikely(ret))
 		fput(req->ki_filp);
diff --git a/fs/block_dev.c b/fs/block_dev.c
index 7ec920e27065..970bef79caa6 100644
--- a/fs/block_dev.c
+++ b/fs/block_dev.c
@@ -355,6 +355,8 @@  __blkdev_direct_IO(struct kiocb *iocb, struct iov_iter *iter, int nr_pages)
 		bio->bi_write_hint = iocb->ki_hint;
 		bio->bi_private = dio;
 		bio->bi_end_io = blkdev_bio_end_io;
+		if (iocb->ki_flags & IOCB_IOPRIO)
+			bio->bi_ioprio = iocb->ki_ioprio;
 
 		ret = bio_iov_iter_get_pages(bio, iter);
 		if (unlikely(ret)) {
diff --git a/include/linux/fs.h b/include/linux/fs.h
index 7a90ce387e00..3415e83f6350 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -294,6 +294,7 @@  enum rw_hint {
 #define IOCB_SYNC		(1 << 5)
 #define IOCB_WRITE		(1 << 6)
 #define IOCB_NOWAIT		(1 << 7)
+#define IOCB_IOPRIO		(1 << 8)
 
 struct kiocb {
 	struct file		*ki_filp;
@@ -302,6 +303,7 @@  struct kiocb {
 	void			*private;
 	int			ki_flags;
 	u16			ki_hint;
+	u16			ki_ioprio; /* See linux/ioprio.h */
 } __randomize_layout;
 
 static inline bool is_sync_kiocb(struct kiocb *kiocb)
diff --git a/include/uapi/linux/aio_abi.h b/include/uapi/linux/aio_abi.h
index 2c0a3415beee..d4e768d55d14 100644
--- a/include/uapi/linux/aio_abi.h
+++ b/include/uapi/linux/aio_abi.h
@@ -55,6 +55,7 @@  enum {
  *                   is valid.
  */
 #define IOCB_FLAG_RESFD		(1 << 0)
+#define IOCB_FLAG_IOPRIO	(1 << 1)
 
 /* read() from /dev/aio returns these structures. */
 struct io_event {