[PATCH] io_uring: Try to merge io requests only for regular files

[PATCH] io_uring: Try to merge io requests only for regular files

[Dmitry Monakhov]

Otherwise we may endup blocking on pipe or socket.

Fixes: 6d5d5ac ("io_uring: extend async work merge")
Testcase: https://github.com/dmonakhov/liburing/commit/16d171b6ef9d68e6db66650a83d98c5c721d01f6
Signed-off-by: Dmitry Monakhov <dmtrmonakhov@yandex-team.ru>
---
 fs/io_uring.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/fs/io_uring.c b/fs/io_uring.c
index 478df7e..848657c 100644
--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -2183,6 +2183,9 @@ static int __io_submit_sqe(struct io_ring_ctx *ctx, struct io_kiocb *req,
 static struct async_list *io_async_list_from_req(struct io_ring_ctx *ctx,
 						 struct io_kiocb *req)
 {
+	if (!(req->flags & REQ_F_ISREG))
+		return NULL;
+
 	switch (req->submit.opcode) {
 	case IORING_OP_READV:
 	case IORING_OP_READ_FIXED:
-- 
2.7.4

Re: [PATCH] io_uring: Try to merge io requests only for regular files

[Greg KH]

On Fri, Mar 19, 2021 at 05:28:59AM +0000, Dmitry Monakhov wrote:
> Otherwise we may endup blocking on pipe or socket.
> 
> Fixes: 6d5d5ac ("io_uring: extend async work merge")
> Testcase: https://github.com/dmonakhov/liburing/commit/16d171b6ef9d68e6db66650a83d98c5c721d01f6
> Signed-off-by: Dmitry Monakhov <dmtrmonakhov@yandex-team.ru>
> ---
>  fs/io_uring.c | 3 +++
>  1 file changed, 3 insertions(+)


<formletter>

This is not the correct way to submit patches for inclusion in the
stable kernel tree.  Please read:
    https://www.kernel.org/doc/html/latest/process/stable-kernel-rules.html
for how to do this properly.

</formletter>

Re: [PATCH] io_uring: Try to merge io requests only for regular files

[Pavel Begunkov]

On 19/03/2021 05:28, Dmitry Monakhov wrote:
> Otherwise we may endup blocking on pipe or socket.

CC: io-uring ml

> 
> Fixes: 6d5d5ac ("io_uring: extend async work merge")
> Testcase: https://github.com/dmonakhov/liburing/commit/16d171b6ef9d68e6db66650a83d98c5c721d01f6
> Signed-off-by: Dmitry Monakhov <dmtrmonakhov@yandex-team.ru>
> ---
>  fs/io_uring.c | 3 +++
>  1 file changed, 3 insertions(+)
> 
> diff --git a/fs/io_uring.c b/fs/io_uring.c
> index 478df7e..848657c 100644
> --- a/fs/io_uring.c
> +++ b/fs/io_uring.c
> @@ -2183,6 +2183,9 @@ static int __io_submit_sqe(struct io_ring_ctx *ctx, struct io_kiocb *req,
>  static struct async_list *io_async_list_from_req(struct io_ring_ctx *ctx,
>  						 struct io_kiocb *req)
>  {
> +	if (!(req->flags & REQ_F_ISREG))
> +		return NULL;
> +
>  	switch (req->submit.opcode) {
>  	case IORING_OP_READV:
>  	case IORING_OP_READ_FIXED:
> 

-- 
Pavel Begunkov

Re: [PATCH] io_uring: Try to merge io requests only for regular files

[Matthew Wilcox]

On Fri, Mar 19, 2021 at 05:28:59AM +0000, Dmitry Monakhov wrote:
> Otherwise we may endup blocking on pipe or socket.
> 
> Fixes: 6d5d5ac ("io_uring: extend async work merge")

7 bytes of sha1 isn't enough.  You can set core.abbrev to 12 or upgrade
to a version of git from this decade to get that automatically.

> 2.7.4

... is from 2016, so you're five years out of date.  Don't get cut
off when git switches from SHA1.