* [PATCH 4/9 next] fs/io_uring Don't use the return value from import_iovec().
@ 2020-09-15 14:55 David Laight
2020-09-21 14:14 ` Christoph Hellwig
2020-11-07 1:14 ` Pavel Begunkov
0 siblings, 2 replies; 5+ messages in thread
From: David Laight @ 2020-09-15 14:55 UTC (permalink / raw)
To: linux-kernel, netdev, io-uring, Jens Axboe, David S. Miller,
Al Viro, linux-fsdevel
This is the only code that relies on import_iovec() returning
iter.count on success.
This allows a better interface to import_iovec().
Signed-off-by: David Laight <david.laight@aculab.com>
---
fs/io_uring.c | 8 ++++----
1 file changed, 4 insertions(+), 4 deletions(-)
diff --git a/fs/io_uring.c b/fs/io_uring.c
index 3790c7fe9fee..0df43882e4b3 100644
--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -2824,7 +2824,7 @@ static ssize_t __io_import_iovec(int rw, struct io_kiocb *req,
ret = import_single_range(rw, buf, sqe_len, *iovec, iter);
*iovec = NULL;
- return ret < 0 ? ret : sqe_len;
+ return ret;
}
if (req->flags & REQ_F_BUFFER_SELECT) {
@@ -2853,7 +2853,7 @@ static ssize_t io_import_iovec(int rw, struct io_kiocb *req,
if (!req->io)
return __io_import_iovec(rw, req, iovec, iter, needs_lock);
*iovec = NULL;
- return iov_iter_count(&req->io->rw.iter);
+ return 0;
}
static inline loff_t *io_kiocb_ppos(struct kiocb *kiocb)
@@ -3123,7 +3123,7 @@ static int io_read(struct io_kiocb *req, bool force_nonblock,
if (ret < 0)
return ret;
iov_count = iov_iter_count(iter);
- io_size = ret;
+ io_size = iov_count;
req->result = io_size;
ret = 0;
@@ -3246,7 +3246,7 @@ static int io_write(struct io_kiocb *req, bool force_nonblock,
if (ret < 0)
return ret;
iov_count = iov_iter_count(iter);
- io_size = ret;
+ io_size = iov_count;
req->result = io_size;
/* Ensure we clear previously set non-block flag */
--
2.25.1
-
Registered Address Lakeside, Bramley Road, Mount Farm, Milton Keynes, MK1 1PT, UK
Registration No: 1397386 (Wales)
^ permalink raw reply related [flat|nested] 5+ messages in thread
* Re: [PATCH 4/9 next] fs/io_uring Don't use the return value from import_iovec().
2020-09-15 14:55 [PATCH 4/9 next] fs/io_uring Don't use the return value from import_iovec() David Laight
@ 2020-09-21 14:14 ` Christoph Hellwig
2020-09-21 14:38 ` David Laight
2020-11-07 1:14 ` Pavel Begunkov
1 sibling, 1 reply; 5+ messages in thread
From: Christoph Hellwig @ 2020-09-21 14:14 UTC (permalink / raw)
To: David Laight
Cc: linux-kernel, netdev, io-uring, Jens Axboe, David S. Miller,
Al Viro, linux-fsdevel
On Tue, Sep 15, 2020 at 02:55:20PM +0000, David Laight wrote:
>
> This is the only code that relies on import_iovec() returning
> iter.count on success.
> This allows a better interface to import_iovec().
This looks generall sane, but a comment below:
> @@ -3123,7 +3123,7 @@ static int io_read(struct io_kiocb *req, bool force_nonblock,
> if (ret < 0)
> return ret;
> iov_count = iov_iter_count(iter);
> - io_size = ret;
> + io_size = iov_count;
> req->result = io_size;
> ret = 0;
>
> @@ -3246,7 +3246,7 @@ static int io_write(struct io_kiocb *req, bool force_nonblock,
> if (ret < 0)
> return ret;
> iov_count = iov_iter_count(iter);
> - io_size = ret;
> + io_size = iov_count;
> req->result = io_size;
I tink the local iov_count variable can go away in both functions,
as io_size only changes after the last use of iov_count (io_read) or
not at all (io_write).
^ permalink raw reply [flat|nested] 5+ messages in thread
* RE: [PATCH 4/9 next] fs/io_uring Don't use the return value from import_iovec().
2020-09-21 14:14 ` Christoph Hellwig
@ 2020-09-21 14:38 ` David Laight
2020-09-21 16:01 ` Pavel Begunkov
0 siblings, 1 reply; 5+ messages in thread
From: David Laight @ 2020-09-21 14:38 UTC (permalink / raw)
To: 'Christoph Hellwig'
Cc: linux-kernel, netdev, io-uring, Jens Axboe, David S. Miller,
Al Viro, linux-fsdevel
From: Christoph Hellwig
> Sent: 21 September 2020 15:15
>
> On Tue, Sep 15, 2020 at 02:55:20PM +0000, David Laight wrote:
> >
> > This is the only code that relies on import_iovec() returning
> > iter.count on success.
> > This allows a better interface to import_iovec().
>
> This looks generall sane, but a comment below:
>
> > @@ -3123,7 +3123,7 @@ static int io_read(struct io_kiocb *req, bool force_nonblock,
> > if (ret < 0)
> > return ret;
> > iov_count = iov_iter_count(iter);
> > - io_size = ret;
> > + io_size = iov_count;
> > req->result = io_size;
> > ret = 0;
> >
> > @@ -3246,7 +3246,7 @@ static int io_write(struct io_kiocb *req, bool force_nonblock,
> > if (ret < 0)
> > return ret;
> > iov_count = iov_iter_count(iter);
> > - io_size = ret;
> > + io_size = iov_count;
> > req->result = io_size;
>
> I tink the local iov_count variable can go away in both functions,
> as io_size only changes after the last use of iov_count (io_read) or
> not at all (io_write).
Yes, the compiler will probably make that optimisation.
I did a minimal change because my head hurts whenever I look at io_uring.c.
David
-
Registered Address Lakeside, Bramley Road, Mount Farm, Milton Keynes, MK1 1PT, UK
Registration No: 1397386 (Wales)
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [PATCH 4/9 next] fs/io_uring Don't use the return value from import_iovec().
2020-09-21 14:38 ` David Laight
@ 2020-09-21 16:01 ` Pavel Begunkov
0 siblings, 0 replies; 5+ messages in thread
From: Pavel Begunkov @ 2020-09-21 16:01 UTC (permalink / raw)
To: David Laight, 'Christoph Hellwig'
Cc: linux-kernel, netdev, io-uring, Jens Axboe, David S. Miller,
Al Viro, linux-fsdevel
On 21/09/2020 17:38, David Laight wrote:
> From: Christoph Hellwig
>> Sent: 21 September 2020 15:15
>>
>> On Tue, Sep 15, 2020 at 02:55:20PM +0000, David Laight wrote:
>>>
>>> This is the only code that relies on import_iovec() returning
>>> iter.count on success.
>>> This allows a better interface to import_iovec().
Reviewed-by: Pavel Begunkov <asml.silence@gmail.com>
>>
>> This looks generall sane, but a comment below:
>>
>>> @@ -3123,7 +3123,7 @@ static int io_read(struct io_kiocb *req, bool force_nonblock,
>>> if (ret < 0)
>>> return ret;
>>> iov_count = iov_iter_count(iter);
>>> - io_size = ret;
>>> + io_size = iov_count;
>>> req->result = io_size;
>>> ret = 0;
>>>
>>> @@ -3246,7 +3246,7 @@ static int io_write(struct io_kiocb *req, bool force_nonblock,
>>> if (ret < 0)
>>> return ret;
>>> iov_count = iov_iter_count(iter);
>>> - io_size = ret;
>>> + io_size = iov_count;
>>> req->result = io_size;
>>
>> I tink the local iov_count variable can go away in both functions,
>> as io_size only changes after the last use of iov_count (io_read) or
>> not at all (io_write).
Yes, iov_count should be killed, now or later.
>
> Yes, the compiler will probably make that optimisation.
> I did a minimal change because my head hurts whenever I look at io_uring.c.
>
> David
>
> -
> Registered Address Lakeside, Bramley Road, Mount Farm, Milton Keynes, MK1 1PT, UK
> Registration No: 1397386 (Wales)
>
--
Pavel Begunkov
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [PATCH 4/9 next] fs/io_uring Don't use the return value from import_iovec().
2020-09-15 14:55 [PATCH 4/9 next] fs/io_uring Don't use the return value from import_iovec() David Laight
2020-09-21 14:14 ` Christoph Hellwig
@ 2020-11-07 1:14 ` Pavel Begunkov
1 sibling, 0 replies; 5+ messages in thread
From: Pavel Begunkov @ 2020-11-07 1:14 UTC (permalink / raw)
To: David Laight, linux-kernel, netdev, io-uring, Jens Axboe,
David S. Miller, Al Viro, linux-fsdevel
On 15/09/2020 15:55, David Laight wrote:
>
> This is the only code that relies on import_iovec() returning
> iter.count on success.
> This allows a better interface to import_iovec().
Seems this got nowhere. I'll pick it and send with some other
patches to Jens.
> Signed-off-by: David Laight <david.laight@aculab.com>
> ---
> fs/io_uring.c | 8 ++++----
> 1 file changed, 4 insertions(+), 4 deletions(-)
>
> diff --git a/fs/io_uring.c b/fs/io_uring.c
> index 3790c7fe9fee..0df43882e4b3 100644
> --- a/fs/io_uring.c
> +++ b/fs/io_uring.c
> @@ -2824,7 +2824,7 @@ static ssize_t __io_import_iovec(int rw, struct io_kiocb *req,
>
> ret = import_single_range(rw, buf, sqe_len, *iovec, iter);
> *iovec = NULL;
> - return ret < 0 ? ret : sqe_len;
> + return ret;
> }
>
> if (req->flags & REQ_F_BUFFER_SELECT) {
> @@ -2853,7 +2853,7 @@ static ssize_t io_import_iovec(int rw, struct io_kiocb *req,
> if (!req->io)
> return __io_import_iovec(rw, req, iovec, iter, needs_lock);
> *iovec = NULL;
> - return iov_iter_count(&req->io->rw.iter);
> + return 0;
> }
>
> static inline loff_t *io_kiocb_ppos(struct kiocb *kiocb)
> @@ -3123,7 +3123,7 @@ static int io_read(struct io_kiocb *req, bool force_nonblock,
> if (ret < 0)
> return ret;
> iov_count = iov_iter_count(iter);
> - io_size = ret;
> + io_size = iov_count;
> req->result = io_size;
> ret = 0;
>
> @@ -3246,7 +3246,7 @@ static int io_write(struct io_kiocb *req, bool force_nonblock,
> if (ret < 0)
> return ret;
> iov_count = iov_iter_count(iter);
> - io_size = ret;
> + io_size = iov_count;
> req->result = io_size;
>
> /* Ensure we clear previously set non-block flag */
>
--
Pavel Begunkov
^ permalink raw reply [flat|nested] 5+ messages in thread
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2020-09-15 14:55 [PATCH 4/9 next] fs/io_uring Don't use the return value from import_iovec() David Laight
2020-09-21 14:14 ` Christoph Hellwig
2020-09-21 14:38 ` David Laight
2020-09-21 16:01 ` Pavel Begunkov
2020-11-07 1:14 ` Pavel Begunkov
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