2023-06-21 23:57:27

by Breno Leitao

[permalink] [raw]
Subject: [PATCH] io_uring: Add io_uring command support for sockets

Enable io_uring commands on network sockets. Create two new
SOCKET_URING_OP commands that will operate on sockets. Since these
commands are similar to ioctl, uses the _IO{R,W} helpers to embedded the
argument size and operation direction. Also allocates a unused ioctl
chunk for uring command usage.

In order to call ioctl on sockets, use the file_operations->uring_cmd
callbacks, and map it to a uring socket function, which handles the
SOCKET_URING_OP accordingly, and calls socket ioctls.

This patches was tested by creating a new test case in liburing.
Link: https://github.com/leitao/liburing/commit/3340908b742c6a26f662a0679c4ddf9df84ef431

Signed-off-by: Breno Leitao <[email protected]>
---
.../userspace-api/ioctl/ioctl-number.rst | 1 +
include/linux/io_uring.h | 6 +++++
include/uapi/linux/io_uring.h | 6 +++++
io_uring/uring_cmd.c | 27 +++++++++++++++++++
net/socket.c | 2 ++
5 files changed, 42 insertions(+)

diff --git a/Documentation/userspace-api/ioctl/ioctl-number.rst b/Documentation/userspace-api/ioctl/ioctl-number.rst
index 4f7b23faebb9..23348636f2ef 100644
--- a/Documentation/userspace-api/ioctl/ioctl-number.rst
+++ b/Documentation/userspace-api/ioctl/ioctl-number.rst
@@ -361,6 +361,7 @@ Code Seq# Include File Comments
0xCB 00-1F CBM serial IEC bus in development:
<mailto:[email protected]>
0xCC 00-0F drivers/misc/ibmvmc.h pseries VMC driver
+0xCC A0-BF uapi/linux/io_uring.h io_uring cmd subsystem
0xCD 01 linux/reiserfs_fs.h
0xCE 01-02 uapi/linux/cxl_mem.h Compute Express Link Memory Devices
0xCF 02 fs/smb/client/cifs_ioctl.h
diff --git a/include/linux/io_uring.h b/include/linux/io_uring.h
index 7fe31b2cd02f..d1b20e2a9fb0 100644
--- a/include/linux/io_uring.h
+++ b/include/linux/io_uring.h
@@ -71,6 +71,7 @@ static inline void io_uring_free(struct task_struct *tsk)
if (tsk->io_uring)
__io_uring_free(tsk);
}
+int uring_sock_cmd(struct io_uring_cmd *cmd, unsigned int issue_flags);
#else
static inline int io_uring_cmd_import_fixed(u64 ubuf, unsigned long len, int rw,
struct iov_iter *iter, void *ioucmd)
@@ -102,6 +103,11 @@ static inline const char *io_uring_get_opcode(u8 opcode)
{
return "";
}
+static inline int uring_sock_cmd(struct io_uring_cmd *cmd,
+ unsigned int issue_flags)
+{
+ return -EOPNOTSUPP;
+}
#endif

#endif
diff --git a/include/uapi/linux/io_uring.h b/include/uapi/linux/io_uring.h
index 0716cb17e436..e20ba410859d 100644
--- a/include/uapi/linux/io_uring.h
+++ b/include/uapi/linux/io_uring.h
@@ -703,6 +703,12 @@ struct io_uring_recvmsg_out {
__u32 flags;
};

+/*
+ * Argument for IORING_OP_URING_CMD when file is a socket
+ */
+#define SOCKET_URING_OP_SIOCINQ _IOR(0xcc, 0xa0, int)
+#define SOCKET_URING_OP_SIOCOUTQ _IOR(0xcc, 0xa1, int)
+
#ifdef __cplusplus
}
#endif
diff --git a/io_uring/uring_cmd.c b/io_uring/uring_cmd.c
index 5e32db48696d..dcbe6493b03f 100644
--- a/io_uring/uring_cmd.c
+++ b/io_uring/uring_cmd.c
@@ -7,6 +7,7 @@
#include <linux/nospec.h>

#include <uapi/linux/io_uring.h>
+#include <uapi/asm-generic/ioctls.h>

#include "io_uring.h"
#include "rsrc.h"
@@ -156,3 +157,29 @@ int io_uring_cmd_import_fixed(u64 ubuf, unsigned long len, int rw,
return io_import_fixed(rw, iter, req->imu, ubuf, len);
}
EXPORT_SYMBOL_GPL(io_uring_cmd_import_fixed);
+
+int uring_sock_cmd(struct io_uring_cmd *cmd, unsigned int issue_flags)
+{
+ struct socket *sock = cmd->file->private_data;
+ struct sock *sk = sock->sk;
+ int ret, arg = 0;
+
+ if (!sk->sk_prot || !sk->sk_prot->ioctl)
+ return -EOPNOTSUPP;
+
+ switch (cmd->sqe->cmd_op) {
+ case SOCKET_URING_OP_SIOCINQ:
+ ret = sk->sk_prot->ioctl(sk, SIOCINQ, &arg);
+ if (ret)
+ return ret;
+ return arg;
+ case SOCKET_URING_OP_SIOCOUTQ:
+ ret = sk->sk_prot->ioctl(sk, SIOCOUTQ, &arg);
+ if (ret)
+ return ret;
+ return arg;
+ default:
+ return -EOPNOTSUPP;
+ }
+}
+EXPORT_SYMBOL_GPL(uring_sock_cmd);
diff --git a/net/socket.c b/net/socket.c
index b778fc03c6e0..db11e94d2259 100644
--- a/net/socket.c
+++ b/net/socket.c
@@ -88,6 +88,7 @@
#include <linux/xattr.h>
#include <linux/nospec.h>
#include <linux/indirect_call_wrapper.h>
+#include <linux/io_uring.h>

#include <linux/uaccess.h>
#include <asm/unistd.h>
@@ -159,6 +160,7 @@ static const struct file_operations socket_file_ops = {
#ifdef CONFIG_COMPAT
.compat_ioctl = compat_sock_ioctl,
#endif
+ .uring_cmd = uring_sock_cmd,
.mmap = sock_mmap,
.release = sock_close,
.fasync = sock_fasync,
--
2.34.1



2023-06-22 05:50:06

by Greg Kroah-Hartman

[permalink] [raw]
Subject: Re: [PATCH] io_uring: Add io_uring command support for sockets

On Wed, Jun 21, 2023 at 04:21:26PM -0700, Breno Leitao wrote:
> Enable io_uring commands on network sockets. Create two new
> SOCKET_URING_OP commands that will operate on sockets. Since these
> commands are similar to ioctl, uses the _IO{R,W} helpers to embedded the
> argument size and operation direction. Also allocates a unused ioctl
> chunk for uring command usage.
>
> In order to call ioctl on sockets, use the file_operations->uring_cmd
> callbacks, and map it to a uring socket function, which handles the
> SOCKET_URING_OP accordingly, and calls socket ioctls.
>
> This patches was tested by creating a new test case in liburing.
> Link: https://github.com/leitao/liburing/commit/3340908b742c6a26f662a0679c4ddf9df84ef431
>
> Signed-off-by: Breno Leitao <[email protected]>
> ---

Isn't this a new version of an older patch?

> .../userspace-api/ioctl/ioctl-number.rst | 1 +
> include/linux/io_uring.h | 6 +++++
> include/uapi/linux/io_uring.h | 6 +++++
> io_uring/uring_cmd.c | 27 +++++++++++++++++++
> net/socket.c | 2 ++
> 5 files changed, 42 insertions(+)
>
> diff --git a/Documentation/userspace-api/ioctl/ioctl-number.rst b/Documentation/userspace-api/ioctl/ioctl-number.rst
> index 4f7b23faebb9..23348636f2ef 100644
> --- a/Documentation/userspace-api/ioctl/ioctl-number.rst
> +++ b/Documentation/userspace-api/ioctl/ioctl-number.rst
> @@ -361,6 +361,7 @@ Code Seq# Include File Comments
> 0xCB 00-1F CBM serial IEC bus in development:
> <mailto:[email protected]>
> 0xCC 00-0F drivers/misc/ibmvmc.h pseries VMC driver
> +0xCC A0-BF uapi/linux/io_uring.h io_uring cmd subsystem

This change is nice, but not totally related to this specific one,
shouldn't it be separate?


> 0xCD 01 linux/reiserfs_fs.h
> 0xCE 01-02 uapi/linux/cxl_mem.h Compute Express Link Memory Devices
> 0xCF 02 fs/smb/client/cifs_ioctl.h
> diff --git a/include/linux/io_uring.h b/include/linux/io_uring.h
> index 7fe31b2cd02f..d1b20e2a9fb0 100644
> --- a/include/linux/io_uring.h
> +++ b/include/linux/io_uring.h
> @@ -71,6 +71,7 @@ static inline void io_uring_free(struct task_struct *tsk)
> if (tsk->io_uring)
> __io_uring_free(tsk);
> }
> +int uring_sock_cmd(struct io_uring_cmd *cmd, unsigned int issue_flags);
> #else
> static inline int io_uring_cmd_import_fixed(u64 ubuf, unsigned long len, int rw,
> struct iov_iter *iter, void *ioucmd)
> @@ -102,6 +103,11 @@ static inline const char *io_uring_get_opcode(u8 opcode)
> {
> return "";
> }
> +static inline int uring_sock_cmd(struct io_uring_cmd *cmd,
> + unsigned int issue_flags)
> +{
> + return -EOPNOTSUPP;
> +}
> #endif
>
> #endif
> diff --git a/include/uapi/linux/io_uring.h b/include/uapi/linux/io_uring.h
> index 0716cb17e436..e20ba410859d 100644
> --- a/include/uapi/linux/io_uring.h
> +++ b/include/uapi/linux/io_uring.h
> @@ -703,6 +703,12 @@ struct io_uring_recvmsg_out {
> __u32 flags;
> };
>
> +/*
> + * Argument for IORING_OP_URING_CMD when file is a socket
> + */
> +#define SOCKET_URING_OP_SIOCINQ _IOR(0xcc, 0xa0, int)
> +#define SOCKET_URING_OP_SIOCOUTQ _IOR(0xcc, 0xa1, int)
> +
> #ifdef __cplusplus
> }
> #endif
> diff --git a/io_uring/uring_cmd.c b/io_uring/uring_cmd.c
> index 5e32db48696d..dcbe6493b03f 100644
> --- a/io_uring/uring_cmd.c
> +++ b/io_uring/uring_cmd.c
> @@ -7,6 +7,7 @@
> #include <linux/nospec.h>
>
> #include <uapi/linux/io_uring.h>
> +#include <uapi/asm-generic/ioctls.h>
>
> #include "io_uring.h"
> #include "rsrc.h"
> @@ -156,3 +157,29 @@ int io_uring_cmd_import_fixed(u64 ubuf, unsigned long len, int rw,
> return io_import_fixed(rw, iter, req->imu, ubuf, len);
> }
> EXPORT_SYMBOL_GPL(io_uring_cmd_import_fixed);
> +
> +int uring_sock_cmd(struct io_uring_cmd *cmd, unsigned int issue_flags)
> +{
> + struct socket *sock = cmd->file->private_data;
> + struct sock *sk = sock->sk;
> + int ret, arg = 0;
> +
> + if (!sk->sk_prot || !sk->sk_prot->ioctl)
> + return -EOPNOTSUPP;
> +
> + switch (cmd->sqe->cmd_op) {
> + case SOCKET_URING_OP_SIOCINQ:
> + ret = sk->sk_prot->ioctl(sk, SIOCINQ, &arg);
> + if (ret)
> + return ret;
> + return arg;
> + case SOCKET_URING_OP_SIOCOUTQ:
> + ret = sk->sk_prot->ioctl(sk, SIOCOUTQ, &arg);
> + if (ret)
> + return ret;
> + return arg;
> + default:
> + return -EOPNOTSUPP;
> + }
> +}
> +EXPORT_SYMBOL_GPL(uring_sock_cmd);

Did you forget the "io_" prefix?

thanks,

greg k-h

2023-06-22 15:21:27

by Breno Leitao

[permalink] [raw]
Subject: Re: [PATCH] io_uring: Add io_uring command support for sockets

On Thu, Jun 22, 2023 at 07:20:48AM +0200, Greg Kroah-Hartman wrote:
> On Wed, Jun 21, 2023 at 04:21:26PM -0700, Breno Leitao wrote:
> > Enable io_uring commands on network sockets. Create two new
> > SOCKET_URING_OP commands that will operate on sockets. Since these
> > commands are similar to ioctl, uses the _IO{R,W} helpers to embedded the
> > argument size and operation direction. Also allocates a unused ioctl
> > chunk for uring command usage.
> >
> > In order to call ioctl on sockets, use the file_operations->uring_cmd
> > callbacks, and map it to a uring socket function, which handles the
> > SOCKET_URING_OP accordingly, and calls socket ioctls.
> >
> > This patches was tested by creating a new test case in liburing.
> > Link: https://github.com/leitao/liburing/commit/3340908b742c6a26f662a0679c4ddf9df84ef431
> >
> > Signed-off-by: Breno Leitao <[email protected]>
> > ---
>
> Isn't this a new version of an older patch?

Yes, this should have tagged as V2.

[1] https://lore.kernel.org/lkml/[email protected]/#r

> > --- a/Documentation/userspace-api/ioctl/ioctl-number.rst
> > +++ b/Documentation/userspace-api/ioctl/ioctl-number.rst
> > @@ -361,6 +361,7 @@ Code Seq# Include File Comments
> > 0xCB 00-1F CBM serial IEC bus in development:
> > <mailto:[email protected]>
> > 0xCC 00-0F drivers/misc/ibmvmc.h pseries VMC driver
> > +0xCC A0-BF uapi/linux/io_uring.h io_uring cmd subsystem
>
> This change is nice, but not totally related to this specific one,
> shouldn't it be separate?

This is related to this patch, since I am using it below, in the
following part:

+#define SOCKET_URING_OP_SIOCINQ _IOR(0xcc, 0xa0, int)
+#define SOCKET_URING_OP_SIOCOUTQ _IOR(0xcc, 0xa1, int)

Should I have a different patch, even if they are related?

> > +EXPORT_SYMBOL_GPL(uring_sock_cmd);
>
> Did you forget the "io_" prefix?

Yes, I will rename the function.

Thanks for the review.

2023-06-22 16:17:00

by Greg Kroah-Hartman

[permalink] [raw]
Subject: Re: [PATCH] io_uring: Add io_uring command support for sockets

On Thu, Jun 22, 2023 at 08:02:37AM -0700, Breno Leitao wrote:
> On Thu, Jun 22, 2023 at 07:20:48AM +0200, Greg Kroah-Hartman wrote:
> > On Wed, Jun 21, 2023 at 04:21:26PM -0700, Breno Leitao wrote:
> > > Enable io_uring commands on network sockets. Create two new
> > > SOCKET_URING_OP commands that will operate on sockets. Since these
> > > commands are similar to ioctl, uses the _IO{R,W} helpers to embedded the
> > > argument size and operation direction. Also allocates a unused ioctl
> > > chunk for uring command usage.
> > >
> > > In order to call ioctl on sockets, use the file_operations->uring_cmd
> > > callbacks, and map it to a uring socket function, which handles the
> > > SOCKET_URING_OP accordingly, and calls socket ioctls.
> > >
> > > This patches was tested by creating a new test case in liburing.
> > > Link: https://github.com/leitao/liburing/commit/3340908b742c6a26f662a0679c4ddf9df84ef431
> > >
> > > Signed-off-by: Breno Leitao <[email protected]>
> > > ---
> >
> > Isn't this a new version of an older patch?
>
> Yes, this should have tagged as V2.
>
> [1] https://lore.kernel.org/lkml/[email protected]/#r

Great, also add what changed below the --- line please.

> > > --- a/Documentation/userspace-api/ioctl/ioctl-number.rst
> > > +++ b/Documentation/userspace-api/ioctl/ioctl-number.rst
> > > @@ -361,6 +361,7 @@ Code Seq# Include File Comments
> > > 0xCB 00-1F CBM serial IEC bus in development:
> > > <mailto:[email protected]>
> > > 0xCC 00-0F drivers/misc/ibmvmc.h pseries VMC driver
> > > +0xCC A0-BF uapi/linux/io_uring.h io_uring cmd subsystem
> >
> > This change is nice, but not totally related to this specific one,
> > shouldn't it be separate?
>
> This is related to this patch, since I am using it below, in the
> following part:
>
> +#define SOCKET_URING_OP_SIOCINQ _IOR(0xcc, 0xa0, int)
> +#define SOCKET_URING_OP_SIOCOUTQ _IOR(0xcc, 0xa1, int)
>
> Should I have a different patch, even if they are related?

Yes, as you are not using the 0xa2-0xbf range that you just carved out
here, right? Where did those numbers come from?

thanks,

greg k-h

2023-06-22 16:55:36

by Breno Leitao

[permalink] [raw]
Subject: Re: [PATCH] io_uring: Add io_uring command support for sockets

On Thu, Jun 22, 2023 at 06:10:00PM +0200, Greg Kroah-Hartman wrote:
> On Thu, Jun 22, 2023 at 08:02:37AM -0700, Breno Leitao wrote:
> > On Thu, Jun 22, 2023 at 07:20:48AM +0200, Greg Kroah-Hartman wrote:
> > > On Wed, Jun 21, 2023 at 04:21:26PM -0700, Breno Leitao wrote:
> > > > --- a/Documentation/userspace-api/ioctl/ioctl-number.rst
> > > > +++ b/Documentation/userspace-api/ioctl/ioctl-number.rst
> > > > @@ -361,6 +361,7 @@ Code Seq# Include File Comments
> > > > 0xCB 00-1F CBM serial IEC bus in development:
> > > > <mailto:[email protected]>
> > > > 0xCC 00-0F drivers/misc/ibmvmc.h pseries VMC driver
> > > > +0xCC A0-BF uapi/linux/io_uring.h io_uring cmd subsystem
> > >
> > > This change is nice, but not totally related to this specific one,
> > > shouldn't it be separate?
> >
> > This is related to this patch, since I am using it below, in the
> > following part:
> >
> > +#define SOCKET_URING_OP_SIOCINQ _IOR(0xcc, 0xa0, int)
> > +#define SOCKET_URING_OP_SIOCOUTQ _IOR(0xcc, 0xa1, int)
> >
> > Should I have a different patch, even if they are related?
>
> Yes, as you are not using the 0xa2-0xbf range that you just carved out
> here, right? Where did those numbers come from?

Correct. For now we are just using 0xa0 and 0xa1, and eventually we
might need more ioctls numbers.

I got these numbers finding a unused block and having some room for
expansion, as suggested by Documentation/userspace-api/ioctl/ioctl-number.rst,
that says:

If you are writing a driver for a new device and need a letter, pick an
unused block with enough room for expansion: 32 to 256 ioctl commands.

2023-06-22 17:21:09

by Greg Kroah-Hartman

[permalink] [raw]
Subject: Re: [PATCH] io_uring: Add io_uring command support for sockets

On Thu, Jun 22, 2023 at 09:38:15AM -0700, Breno Leitao wrote:
> On Thu, Jun 22, 2023 at 06:10:00PM +0200, Greg Kroah-Hartman wrote:
> > On Thu, Jun 22, 2023 at 08:02:37AM -0700, Breno Leitao wrote:
> > > On Thu, Jun 22, 2023 at 07:20:48AM +0200, Greg Kroah-Hartman wrote:
> > > > On Wed, Jun 21, 2023 at 04:21:26PM -0700, Breno Leitao wrote:
> > > > > --- a/Documentation/userspace-api/ioctl/ioctl-number.rst
> > > > > +++ b/Documentation/userspace-api/ioctl/ioctl-number.rst
> > > > > @@ -361,6 +361,7 @@ Code Seq# Include File Comments
> > > > > 0xCB 00-1F CBM serial IEC bus in development:
> > > > > <mailto:[email protected]>
> > > > > 0xCC 00-0F drivers/misc/ibmvmc.h pseries VMC driver
> > > > > +0xCC A0-BF uapi/linux/io_uring.h io_uring cmd subsystem
> > > >
> > > > This change is nice, but not totally related to this specific one,
> > > > shouldn't it be separate?
> > >
> > > This is related to this patch, since I am using it below, in the
> > > following part:
> > >
> > > +#define SOCKET_URING_OP_SIOCINQ _IOR(0xcc, 0xa0, int)
> > > +#define SOCKET_URING_OP_SIOCOUTQ _IOR(0xcc, 0xa1, int)
> > >
> > > Should I have a different patch, even if they are related?
> >
> > Yes, as you are not using the 0xa2-0xbf range that you just carved out
> > here, right? Where did those numbers come from?
>
> Correct. For now we are just using 0xa0 and 0xa1, and eventually we
> might need more ioctls numbers.
>
> I got these numbers finding a unused block and having some room for
> expansion, as suggested by Documentation/userspace-api/ioctl/ioctl-number.rst,
> that says:
>
> If you are writing a driver for a new device and need a letter, pick an
> unused block with enough room for expansion: 32 to 256 ioctl commands.

So is this the first io_uring ioctl? If so, why is this an ioctl and
not just a "normal" io_uring call?

thanks,

greg k-h

2023-06-22 18:19:14

by Jakub Kicinski

[permalink] [raw]
Subject: Re: [PATCH] io_uring: Add io_uring command support for sockets

On Thu, 22 Jun 2023 19:03:04 +0200 Greg Kroah-Hartman wrote:
> > Correct. For now we are just using 0xa0 and 0xa1, and eventually we
> > might need more ioctls numbers.
> >
> > I got these numbers finding a unused block and having some room for
> > expansion, as suggested by Documentation/userspace-api/ioctl/ioctl-number.rst,
> > that says:
> >
> > If you are writing a driver for a new device and need a letter, pick an
> > unused block with enough room for expansion: 32 to 256 ioctl commands.
>
> So is this the first io_uring ioctl? If so, why is this an ioctl and
> not just a "normal" io_uring call?

+1, the mixing with classic ioctl seems confusing and I'm not sure
if it buys us anything.
--
pw-bot: cr

2023-06-22 19:45:13

by Breno Leitao

[permalink] [raw]
Subject: Re: [PATCH] io_uring: Add io_uring command support for sockets

On Thu, Jun 22, 2023 at 10:39:48AM -0700, Jakub Kicinski wrote:
> On Thu, 22 Jun 2023 19:03:04 +0200 Greg Kroah-Hartman wrote:
> > > Correct. For now we are just using 0xa0 and 0xa1, and eventually we
> > > might need more ioctls numbers.
> > >
> > > I got these numbers finding a unused block and having some room for
> > > expansion, as suggested by Documentation/userspace-api/ioctl/ioctl-number.rst,
> > > that says:
> > >
> > > If you are writing a driver for a new device and need a letter, pick an
> > > unused block with enough room for expansion: 32 to 256 ioctl commands.
> >
> > So is this the first io_uring ioctl? If so, why is this an ioctl and
> > not just a "normal" io_uring call?
>
> +1, the mixing with classic ioctl seems confusing and I'm not sure
> if it buys us anything.

Sure, let me remove the dependency on ioctl()s then.

2023-06-22 19:55:29

by Breno Leitao

[permalink] [raw]
Subject: Re: [PATCH] io_uring: Add io_uring command support for sockets

On Thu, Jun 22, 2023 at 07:03:04PM +0200, Greg Kroah-Hartman wrote:
> On Thu, Jun 22, 2023 at 09:38:15AM -0700, Breno Leitao wrote:
> > On Thu, Jun 22, 2023 at 06:10:00PM +0200, Greg Kroah-Hartman wrote:
> > > On Thu, Jun 22, 2023 at 08:02:37AM -0700, Breno Leitao wrote:
> > > > On Thu, Jun 22, 2023 at 07:20:48AM +0200, Greg Kroah-Hartman wrote:
> > > > > On Wed, Jun 21, 2023 at 04:21:26PM -0700, Breno Leitao wrote:
> > > > > > --- a/Documentation/userspace-api/ioctl/ioctl-number.rst
> > > > > > +++ b/Documentation/userspace-api/ioctl/ioctl-number.rst
> > > > > > @@ -361,6 +361,7 @@ Code Seq# Include File Comments
> > > > > > 0xCB 00-1F CBM serial IEC bus in development:
> > > > > > <mailto:[email protected]>
> > > > > > 0xCC 00-0F drivers/misc/ibmvmc.h pseries VMC driver
> > > > > > +0xCC A0-BF uapi/linux/io_uring.h io_uring cmd subsystem
> > > > >
> > > > > This change is nice, but not totally related to this specific one,
> > > > > shouldn't it be separate?
> > > >
> > > > This is related to this patch, since I am using it below, in the
> > > > following part:
> > > >
> > > > +#define SOCKET_URING_OP_SIOCINQ _IOR(0xcc, 0xa0, int)
> > > > +#define SOCKET_URING_OP_SIOCOUTQ _IOR(0xcc, 0xa1, int)
> > > >
> > > > Should I have a different patch, even if they are related?
> > >
> > > Yes, as you are not using the 0xa2-0xbf range that you just carved out
> > > here, right? Where did those numbers come from?
> >
> > Correct. For now we are just using 0xa0 and 0xa1, and eventually we
> > might need more ioctls numbers.
> >
> > I got these numbers finding a unused block and having some room for
> > expansion, as suggested by Documentation/userspace-api/ioctl/ioctl-number.rst,
> > that says:
> >
> > If you are writing a driver for a new device and need a letter, pick an
> > unused block with enough room for expansion: 32 to 256 ioctl commands.
>
> So is this the first io_uring ioctl? If so, why is this an ioctl and
> not just a "normal" io_uring call?

This is a way to pass a generic command to file. This is not a ioctl per
se (not called through ioctl). I am leveraging the ioctl to embedded the
"direction" and "size" information in the command itself.

I can defintely do something as the following, if it is a better
implementation:

#define SOCKET_URING_OP_SIOCINQ 0
#define SOCKET_URING_OP_SIOCOUTQ 1