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* [PATCH RFC] io_uring: support ioctl
@ 2020-11-02  7:44 Hao Xu
  2020-11-02 11:07 ` Pavel Begunkov
  0 siblings, 1 reply; 3+ messages in thread
From: Hao Xu @ 2020-11-02  7:44 UTC (permalink / raw)
  To: Jens Axboe, io-uring; +Cc: Alexander Viro, linux-fsdevel, Joseph Qi

Async ioctl is necessary for some scenarios like nonblocking
single-threaded model

Signed-off-by: Hao Xu <haoxu@linux.alibaba.com>
---
I've written corresponding liburing tests for this feature. Currently
just a simple test for BLKGETSIZE operation. I'll release it later soon
when it gets better.

 fs/io_uring.c                 | 56 +++++++++++++++++++++++++++++++++++++++++++
 fs/ioctl.c                    |  4 ++--
 include/linux/fs.h            |  3 ++-
 include/uapi/linux/io_uring.h |  1 +
 4 files changed, 61 insertions(+), 3 deletions(-)

diff --git a/fs/io_uring.c b/fs/io_uring.c
index b42dfa0243bf..c8ab6b6d2d70 100644
--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -539,6 +539,13 @@ struct io_statx {
 	struct statx __user		*buffer;
 };
 
+struct io_ioctl {
+	struct file			*file;
+	unsigned int                    fd;
+	unsigned int                    cmd;
+	unsigned long                   arg;
+};
+
 struct io_completion {
 	struct file			*file;
 	struct list_head		list;
@@ -665,6 +672,7 @@ struct io_kiocb {
 		struct io_splice	splice;
 		struct io_provide_buf	pbuf;
 		struct io_statx		statx;
+		struct io_ioctl         ioctl;
 		/* use only after cleaning per-op data, see io_clean_op() */
 		struct io_completion	compl;
 	};
@@ -932,6 +940,10 @@ struct io_op_def {
 		.hash_reg_file		= 1,
 		.unbound_nonreg_file	= 1,
 	},
+	[IORING_OP_IOCTL] = {
+		.needs_file             = 1,
+		.work_flags             = IO_WQ_WORK_MM | IO_WQ_WORK_FILES
+	},
 };
 
 enum io_mem_account {
@@ -4819,6 +4831,45 @@ static int io_connect(struct io_kiocb *req, bool force_nonblock,
 }
 #endif /* CONFIG_NET */
 
+static int io_ioctl_prep(struct io_kiocb *req,
+			 const struct io_uring_sqe *sqe)
+{
+	if (sqe->ioprio || sqe->buf_index || sqe->rw_flags)
+		return -EINVAL;
+	if (unlikely(req->ctx->flags & IORING_SETUP_IOPOLL))
+		return -EINVAL;
+
+	req->ioctl.fd = READ_ONCE(sqe->fd);
+	req->ioctl.cmd = READ_ONCE(sqe->len);
+	req->ioctl.arg = READ_ONCE(sqe->addr);
+	return 0;
+}
+
+static int io_ioctl(struct io_kiocb *req, bool force_nonblock)
+{
+	int ret;
+
+	if (force_nonblock)
+		return -EAGAIN;
+
+	if (!req->file)
+		return -EBADF;
+
+	ret = security_file_ioctl(req->file, req->ioctl.cmd, req->ioctl.arg);
+	if (ret)
+		goto out;
+
+	ret = do_vfs_ioctl(req->file, req->ioctl.fd, req->ioctl.cmd, req->ioctl.arg);
+	if (ret == -ENOIOCTLCMD)
+		ret = vfs_ioctl(req->file, req->ioctl.cmd, req->ioctl.arg);
+
+out:
+	if (ret)
+		req_set_fail_links(req);
+	io_req_complete(req, ret);
+	return 0;
+}
+
 struct io_poll_table {
 	struct poll_table_struct pt;
 	struct io_kiocb *req;
@@ -5742,6 +5793,8 @@ static int io_req_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
 		return io_remove_buffers_prep(req, sqe);
 	case IORING_OP_TEE:
 		return io_tee_prep(req, sqe);
+	case IORING_OP_IOCTL:
+		return io_ioctl_prep(req, sqe);
 	}
 
 	printk_once(KERN_WARNING "io_uring: unhandled opcode %d\n",
@@ -5985,6 +6038,9 @@ static int io_issue_sqe(struct io_kiocb *req, bool force_nonblock,
 	case IORING_OP_TEE:
 		ret = io_tee(req, force_nonblock);
 		break;
+	case IORING_OP_IOCTL:
+		ret = io_ioctl(req, force_nonblock);
+		break;
 	default:
 		ret = -EINVAL;
 		break;
diff --git a/fs/ioctl.c b/fs/ioctl.c
index 4e6cc0a7d69c..4ff2eb0d8ee0 100644
--- a/fs/ioctl.c
+++ b/fs/ioctl.c
@@ -664,8 +664,8 @@ static int ioctl_file_dedupe_range(struct file *file,
  * When you add any new common ioctls to the switches above and below,
  * please ensure they have compatible arguments in compat mode.
  */
-static int do_vfs_ioctl(struct file *filp, unsigned int fd,
-			unsigned int cmd, unsigned long arg)
+int do_vfs_ioctl(struct file *filp, unsigned int fd,
+		unsigned int cmd, unsigned long arg)
 {
 	void __user *argp = (void __user *)arg;
 	struct inode *inode = file_inode(filp);
diff --git a/include/linux/fs.h b/include/linux/fs.h
index 0bd126418bb6..ad62aa6f6136 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -1732,7 +1732,8 @@ int vfs_mkobj(struct dentry *, umode_t,
 int vfs_utimes(const struct path *path, struct timespec64 *times);
 
 extern long vfs_ioctl(struct file *file, unsigned int cmd, unsigned long arg);
-
+extern int do_vfs_ioctl(struct file *filp, unsigned int fd,
+			unsigned int cmd, unsigned long arg);
 #ifdef CONFIG_COMPAT
 extern long compat_ptr_ioctl(struct file *file, unsigned int cmd,
 					unsigned long arg);
diff --git a/include/uapi/linux/io_uring.h b/include/uapi/linux/io_uring.h
index 98d8e06dea22..4919b4e94c12 100644
--- a/include/uapi/linux/io_uring.h
+++ b/include/uapi/linux/io_uring.h
@@ -132,6 +132,7 @@ enum {
 	IORING_OP_PROVIDE_BUFFERS,
 	IORING_OP_REMOVE_BUFFERS,
 	IORING_OP_TEE,
+	IORING_OP_IOCTL,
 
 	/* this goes last, obviously */
 	IORING_OP_LAST,
-- 
1.8.3.1


^ permalink raw reply related	[flat|nested] 3+ messages in thread
* Re: [PATCH RFC] io_uring: support ioctl
  2020-11-02  7:44 [PATCH RFC] io_uring: support ioctl Hao Xu
@ 2020-11-02 11:07 ` Pavel Begunkov
  2020-11-03  3:02   ` Hao Xu
  0 siblings, 1 reply; 3+ messages in thread
From: Pavel Begunkov @ 2020-11-02 11:07 UTC (permalink / raw)
  To: Hao Xu, Jens Axboe, io-uring; +Cc: Alexander Viro, linux-fsdevel, Joseph Qi

On 02/11/2020 07:44, Hao Xu wrote:
> Async ioctl is necessary for some scenarios like nonblocking
> single-threaded model

Once I fell for it myself, see Jann explained why that's a bad idea.
https://lore.kernel.org/io-uring/CAG48ez0N_b+kjbddhHe+BUvSnOSvpm1vdfQ9cv+cgTLuCMXqug@mail.gmail.com/

> 
> Signed-off-by: Hao Xu <haoxu@linux.alibaba.com>
> ---
> I've written corresponding liburing tests for this feature. Currently
> just a simple test for BLKGETSIZE operation. I'll release it later soon
> when it gets better.
> 
>  fs/io_uring.c                 | 56 +++++++++++++++++++++++++++++++++++++++++++
>  fs/ioctl.c                    |  4 ++--
>  include/linux/fs.h            |  3 ++-
>  include/uapi/linux/io_uring.h |  1 +
>  4 files changed, 61 insertions(+), 3 deletions(-)
> 
> diff --git a/fs/io_uring.c b/fs/io_uring.c
> index b42dfa0243bf..c8ab6b6d2d70 100644
> --- a/fs/io_uring.c
> +++ b/fs/io_uring.c
> @@ -539,6 +539,13 @@ struct io_statx {
>  	struct statx __user		*buffer;
>  };
>  
> +struct io_ioctl {
> +	struct file			*file;
> +	unsigned int                    fd;
> +	unsigned int                    cmd;
> +	unsigned long                   arg;
> +};
> +
>  struct io_completion {
>  	struct file			*file;
>  	struct list_head		list;
> @@ -665,6 +672,7 @@ struct io_kiocb {
>  		struct io_splice	splice;
>  		struct io_provide_buf	pbuf;
>  		struct io_statx		statx;
> +		struct io_ioctl         ioctl;
>  		/* use only after cleaning per-op data, see io_clean_op() */
>  		struct io_completion	compl;
>  	};
> @@ -932,6 +940,10 @@ struct io_op_def {
>  		.hash_reg_file		= 1,
>  		.unbound_nonreg_file	= 1,
>  	},
> +	[IORING_OP_IOCTL] = {
> +		.needs_file             = 1,
> +		.work_flags             = IO_WQ_WORK_MM | IO_WQ_WORK_FILES
> +	},
>  };
>  
>  enum io_mem_account {
> @@ -4819,6 +4831,45 @@ static int io_connect(struct io_kiocb *req, bool force_nonblock,
>  }
>  #endif /* CONFIG_NET */
>  
> +static int io_ioctl_prep(struct io_kiocb *req,
> +			 const struct io_uring_sqe *sqe)
> +{
> +	if (sqe->ioprio || sqe->buf_index || sqe->rw_flags)
> +		return -EINVAL;
> +	if (unlikely(req->ctx->flags & IORING_SETUP_IOPOLL))
> +		return -EINVAL;
> +
> +	req->ioctl.fd = READ_ONCE(sqe->fd);
> +	req->ioctl.cmd = READ_ONCE(sqe->len);
> +	req->ioctl.arg = READ_ONCE(sqe->addr);
> +	return 0;
> +}
> +
> +static int io_ioctl(struct io_kiocb *req, bool force_nonblock)
> +{
> +	int ret;
> +
> +	if (force_nonblock)
> +		return -EAGAIN;
> +
> +	if (!req->file)
> +		return -EBADF;
> +
> +	ret = security_file_ioctl(req->file, req->ioctl.cmd, req->ioctl.arg);
> +	if (ret)
> +		goto out;
> +
> +	ret = do_vfs_ioctl(req->file, req->ioctl.fd, req->ioctl.cmd, req->ioctl.arg);
> +	if (ret == -ENOIOCTLCMD)
> +		ret = vfs_ioctl(req->file, req->ioctl.cmd, req->ioctl.arg);
> +
> +out:
> +	if (ret)
> +		req_set_fail_links(req);
> +	io_req_complete(req, ret);
> +	return 0;
> +}
> +
>  struct io_poll_table {
>  	struct poll_table_struct pt;
>  	struct io_kiocb *req;
> @@ -5742,6 +5793,8 @@ static int io_req_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
>  		return io_remove_buffers_prep(req, sqe);
>  	case IORING_OP_TEE:
>  		return io_tee_prep(req, sqe);
> +	case IORING_OP_IOCTL:
> +		return io_ioctl_prep(req, sqe);
>  	}
>  
>  	printk_once(KERN_WARNING "io_uring: unhandled opcode %d\n",
> @@ -5985,6 +6038,9 @@ static int io_issue_sqe(struct io_kiocb *req, bool force_nonblock,
>  	case IORING_OP_TEE:
>  		ret = io_tee(req, force_nonblock);
>  		break;
> +	case IORING_OP_IOCTL:
> +		ret = io_ioctl(req, force_nonblock);
> +		break;
>  	default:
>  		ret = -EINVAL;
>  		break;
> diff --git a/fs/ioctl.c b/fs/ioctl.c
> index 4e6cc0a7d69c..4ff2eb0d8ee0 100644
> --- a/fs/ioctl.c
> +++ b/fs/ioctl.c
> @@ -664,8 +664,8 @@ static int ioctl_file_dedupe_range(struct file *file,
>   * When you add any new common ioctls to the switches above and below,
>   * please ensure they have compatible arguments in compat mode.
>   */
> -static int do_vfs_ioctl(struct file *filp, unsigned int fd,
> -			unsigned int cmd, unsigned long arg)
> +int do_vfs_ioctl(struct file *filp, unsigned int fd,
> +		unsigned int cmd, unsigned long arg)
>  {
>  	void __user *argp = (void __user *)arg;
>  	struct inode *inode = file_inode(filp);
> diff --git a/include/linux/fs.h b/include/linux/fs.h
> index 0bd126418bb6..ad62aa6f6136 100644
> --- a/include/linux/fs.h
> +++ b/include/linux/fs.h
> @@ -1732,7 +1732,8 @@ int vfs_mkobj(struct dentry *, umode_t,
>  int vfs_utimes(const struct path *path, struct timespec64 *times);
>  
>  extern long vfs_ioctl(struct file *file, unsigned int cmd, unsigned long arg);
> -
> +extern int do_vfs_ioctl(struct file *filp, unsigned int fd,
> +			unsigned int cmd, unsigned long arg);
>  #ifdef CONFIG_COMPAT
>  extern long compat_ptr_ioctl(struct file *file, unsigned int cmd,
>  					unsigned long arg);
> diff --git a/include/uapi/linux/io_uring.h b/include/uapi/linux/io_uring.h
> index 98d8e06dea22..4919b4e94c12 100644
> --- a/include/uapi/linux/io_uring.h
> +++ b/include/uapi/linux/io_uring.h
> @@ -132,6 +132,7 @@ enum {
>  	IORING_OP_PROVIDE_BUFFERS,
>  	IORING_OP_REMOVE_BUFFERS,
>  	IORING_OP_TEE,
> +	IORING_OP_IOCTL,
>  
>  	/* this goes last, obviously */
>  	IORING_OP_LAST,
> 

-- 
Pavel Begunkov

^ permalink raw reply	[flat|nested] 3+ messages in thread
* Re: [PATCH RFC] io_uring: support ioctl
  2020-11-02 11:07 ` Pavel Begunkov
@ 2020-11-03  3:02   ` Hao Xu
  0 siblings, 0 replies; 3+ messages in thread
From: Hao Xu @ 2020-11-03  3:02 UTC (permalink / raw)
  To: Pavel Begunkov, Jens Axboe, io-uring
  Cc: Alexander Viro, linux-fsdevel, Joseph Qi

在 2020/11/2 下午7:07, Pavel Begunkov 写道:
> On 02/11/2020 07:44, Hao Xu wrote:
>> Async ioctl is necessary for some scenarios like nonblocking
>> single-threaded model
> 
> Once I fell for it myself, see Jann explained why that's a bad idea.
Thanks, Pavel. The information is helpful and make sense to me.
It seems I have to rethink it. Btw, your version is more robust.
> https://lore.kernel.org/io-uring/CAG48ez0N_b+kjbddhHe+BUvSnOSvpm1vdfQ9cv+cgTLuCMXqug@mail.gmail.com/
> 
>>
>> Signed-off-by: Hao Xu <haoxu@linux.alibaba.com>
>> ---
>> I've written corresponding liburing tests for this feature. Currently
>> just a simple test for BLKGETSIZE operation. I'll release it later soon
>> when it gets better.
>>
>>   fs/io_uring.c                 | 56 +++++++++++++++++++++++++++++++++++++++++++
>>   fs/ioctl.c                    |  4 ++--
>>   include/linux/fs.h            |  3 ++-
>>   include/uapi/linux/io_uring.h |  1 +
>>   4 files changed, 61 insertions(+), 3 deletions(-)
>>
>> diff --git a/fs/io_uring.c b/fs/io_uring.c
>> index b42dfa0243bf..c8ab6b6d2d70 100644
>> --- a/fs/io_uring.c
>> +++ b/fs/io_uring.c
>> @@ -539,6 +539,13 @@ struct io_statx {
>>   	struct statx __user		*buffer;
>>   };
>>   
>> +struct io_ioctl {
>> +	struct file			*file;
>> +	unsigned int                    fd;
>> +	unsigned int                    cmd;
>> +	unsigned long                   arg;
>> +};
>> +
>>   struct io_completion {
>>   	struct file			*file;
>>   	struct list_head		list;
>> @@ -665,6 +672,7 @@ struct io_kiocb {
>>   		struct io_splice	splice;
>>   		struct io_provide_buf	pbuf;
>>   		struct io_statx		statx;
>> +		struct io_ioctl         ioctl;
>>   		/* use only after cleaning per-op data, see io_clean_op() */
>>   		struct io_completion	compl;
>>   	};
>> @@ -932,6 +940,10 @@ struct io_op_def {
>>   		.hash_reg_file		= 1,
>>   		.unbound_nonreg_file	= 1,
>>   	},
>> +	[IORING_OP_IOCTL] = {
>> +		.needs_file             = 1,
>> +		.work_flags             = IO_WQ_WORK_MM | IO_WQ_WORK_FILES
>> +	},
>>   };
>>   
>>   enum io_mem_account {
>> @@ -4819,6 +4831,45 @@ static int io_connect(struct io_kiocb *req, bool force_nonblock,
>>   }
>>   #endif /* CONFIG_NET */
>>   
>> +static int io_ioctl_prep(struct io_kiocb *req,
>> +			 const struct io_uring_sqe *sqe)
>> +{
>> +	if (sqe->ioprio || sqe->buf_index || sqe->rw_flags)
>> +		return -EINVAL;
>> +	if (unlikely(req->ctx->flags & IORING_SETUP_IOPOLL))
>> +		return -EINVAL;
>> +
>> +	req->ioctl.fd = READ_ONCE(sqe->fd);
>> +	req->ioctl.cmd = READ_ONCE(sqe->len);
>> +	req->ioctl.arg = READ_ONCE(sqe->addr);
>> +	return 0;
>> +}
>> +
>> +static int io_ioctl(struct io_kiocb *req, bool force_nonblock)
>> +{
>> +	int ret;
>> +
>> +	if (force_nonblock)
>> +		return -EAGAIN;
>> +
>> +	if (!req->file)
>> +		return -EBADF;
>> +
>> +	ret = security_file_ioctl(req->file, req->ioctl.cmd, req->ioctl.arg);
>> +	if (ret)
>> +		goto out;
>> +
>> +	ret = do_vfs_ioctl(req->file, req->ioctl.fd, req->ioctl.cmd, req->ioctl.arg);
>> +	if (ret == -ENOIOCTLCMD)
>> +		ret = vfs_ioctl(req->file, req->ioctl.cmd, req->ioctl.arg);
>> +
>> +out:
>> +	if (ret)
>> +		req_set_fail_links(req);
>> +	io_req_complete(req, ret);
>> +	return 0;
>> +}
>> +
>>   struct io_poll_table {
>>   	struct poll_table_struct pt;
>>   	struct io_kiocb *req;
>> @@ -5742,6 +5793,8 @@ static int io_req_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
>>   		return io_remove_buffers_prep(req, sqe);
>>   	case IORING_OP_TEE:
>>   		return io_tee_prep(req, sqe);
>> +	case IORING_OP_IOCTL:
>> +		return io_ioctl_prep(req, sqe);
>>   	}
>>   
>>   	printk_once(KERN_WARNING "io_uring: unhandled opcode %d\n",
>> @@ -5985,6 +6038,9 @@ static int io_issue_sqe(struct io_kiocb *req, bool force_nonblock,
>>   	case IORING_OP_TEE:
>>   		ret = io_tee(req, force_nonblock);
>>   		break;
>> +	case IORING_OP_IOCTL:
>> +		ret = io_ioctl(req, force_nonblock);
>> +		break;
>>   	default:
>>   		ret = -EINVAL;
>>   		break;
>> diff --git a/fs/ioctl.c b/fs/ioctl.c
>> index 4e6cc0a7d69c..4ff2eb0d8ee0 100644
>> --- a/fs/ioctl.c
>> +++ b/fs/ioctl.c
>> @@ -664,8 +664,8 @@ static int ioctl_file_dedupe_range(struct file *file,
>>    * When you add any new common ioctls to the switches above and below,
>>    * please ensure they have compatible arguments in compat mode.
>>    */
>> -static int do_vfs_ioctl(struct file *filp, unsigned int fd,
>> -			unsigned int cmd, unsigned long arg)
>> +int do_vfs_ioctl(struct file *filp, unsigned int fd,
>> +		unsigned int cmd, unsigned long arg)
>>   {
>>   	void __user *argp = (void __user *)arg;
>>   	struct inode *inode = file_inode(filp);
>> diff --git a/include/linux/fs.h b/include/linux/fs.h
>> index 0bd126418bb6..ad62aa6f6136 100644
>> --- a/include/linux/fs.h
>> +++ b/include/linux/fs.h
>> @@ -1732,7 +1732,8 @@ int vfs_mkobj(struct dentry *, umode_t,
>>   int vfs_utimes(const struct path *path, struct timespec64 *times);
>>   
>>   extern long vfs_ioctl(struct file *file, unsigned int cmd, unsigned long arg);
>> -
>> +extern int do_vfs_ioctl(struct file *filp, unsigned int fd,
>> +			unsigned int cmd, unsigned long arg);
>>   #ifdef CONFIG_COMPAT
>>   extern long compat_ptr_ioctl(struct file *file, unsigned int cmd,
>>   					unsigned long arg);
>> diff --git a/include/uapi/linux/io_uring.h b/include/uapi/linux/io_uring.h
>> index 98d8e06dea22..4919b4e94c12 100644
>> --- a/include/uapi/linux/io_uring.h
>> +++ b/include/uapi/linux/io_uring.h
>> @@ -132,6 +132,7 @@ enum {
>>   	IORING_OP_PROVIDE_BUFFERS,
>>   	IORING_OP_REMOVE_BUFFERS,
>>   	IORING_OP_TEE,
>> +	IORING_OP_IOCTL,
>>   
>>   	/* this goes last, obviously */
>>   	IORING_OP_LAST,
>>
> 


^ permalink raw reply	[flat|nested] 3+ messages in thread
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