diff mbox series

[5/7] add llseek_nowait support for xfs

Message ID 20230726102603.155522-6-hao.xu@linux.dev (mailing list archive)
State Deferred, archived
Headers show
Series io_uring lseek | expand

Commit Message

Hao Xu July 26, 2023, 10:26 a.m. UTC 
From: Hao Xu <howeyxu@tencent.com>

Add llseek_nowait() operation for xfs, it acts just like llseek(). The
thing different is it delivers nowait parameter to iomap layer.

Signed-off-by: Hao Xu <howeyxu@tencent.com>
---
 fs/xfs/xfs_file.c | 29 +++++++++++++++++++++++++++--
 1 file changed, 27 insertions(+), 2 deletions(-)

Comments

Dave Chinner July 26, 2023, 10:14 p.m. UTC | #1 
On Wed, Jul 26, 2023 at 06:26:01PM +0800, Hao Xu wrote:
> From: Hao Xu <howeyxu@tencent.com>
> 
> Add llseek_nowait() operation for xfs, it acts just like llseek(). The
> thing different is it delivers nowait parameter to iomap layer.
> 
> Signed-off-by: Hao Xu <howeyxu@tencent.com>
> ---
>  fs/xfs/xfs_file.c | 29 +++++++++++++++++++++++++++--
>  1 file changed, 27 insertions(+), 2 deletions(-)
> 
> diff --git a/fs/xfs/xfs_file.c b/fs/xfs/xfs_file.c
> index 73adc0aee2ff..cba82264221d 100644
> --- a/fs/xfs/xfs_file.c
> +++ b/fs/xfs/xfs_file.c
> @@ -1257,10 +1257,11 @@ xfs_file_readdir(
>  }
>  
>  STATIC loff_t
> -xfs_file_llseek(
> +__xfs_file_llseek(
>  	struct file	*file,
>  	loff_t		offset,
> -	int		whence)
> +	int		whence,
> +	bool		nowait)
>  {
>  	struct inode		*inode = file->f_mapping->host;
>  
> @@ -1282,6 +1283,28 @@ xfs_file_llseek(
>  	return vfs_setpos(file, offset, inode->i_sb->s_maxbytes);
>  }
>  
> +STATIC loff_t
> +xfs_file_llseek(
> +	struct file	*file,
> +	loff_t		offset,
> +	int		whence)
> +{
> +	return __xfs_file_llseek(file, offset, whence, false);
> +}
> +
> +STATIC loff_t
> +xfs_file_llseek_nowait(
> +	struct file	*file,
> +	loff_t		offset,
> +	int		whence,
> +	bool		nowait)
> +{
> +	if (file->f_op == &xfs_file_operations)
> +		return __xfs_file_llseek(file, offset, whence, nowait);
> +	else
> +		return generic_file_llseek(file, offset, whence);
> +}
> +
>  #ifdef CONFIG_FS_DAX
>  static inline vm_fault_t
>  xfs_dax_fault(
> @@ -1442,6 +1465,7 @@ xfs_file_mmap(
>  
>  const struct file_operations xfs_file_operations = {
>  	.llseek		= xfs_file_llseek,
> +	.llseek_nowait	= xfs_file_llseek_nowait,
>  	.read_iter	= xfs_file_read_iter,
>  	.write_iter	= xfs_file_write_iter,
>  	.splice_read	= xfs_file_splice_read,
> @@ -1467,6 +1491,7 @@ const struct file_operations xfs_dir_file_operations = {
>  	.read		= generic_read_dir,
>  	.iterate_shared	= xfs_file_readdir,
>  	.llseek		= generic_file_llseek,
> +	.llseek_nowait	= xfs_file_llseek_nowait,
>  	.unlocked_ioctl	= xfs_file_ioctl,
>  #ifdef CONFIG_COMPAT
>  	.compat_ioctl	= xfs_file_compat_ioctl,

This is pretty nasty. It would be far better just to change the
.llseek method than to inflict this on every filesystem for the
forseeable future.

Not that I'm a fan of passing "nowait" booleans all through the file
operations methods - that way lies madness. We use a control
structure for the IO path operations (kiocb) to hold per-call
context information, perhaps we need something similar for these
other methods that people are wanting to hook up to io_uring (e.g.
readdir) so taht we don't have to play whack-a-mole with every new
io_uring method that people want and then end up with a different
nowait solution for every method.

-Dave.
Hao Xu July 27, 2023, 12:26 p.m. UTC | #2 
On 7/27/23 06:14, Dave Chinner wrote:
> On Wed, Jul 26, 2023 at 06:26:01PM +0800, Hao Xu wrote:
>> From: Hao Xu <howeyxu@tencent.com>
>>
>> Add llseek_nowait() operation for xfs, it acts just like llseek(). The
>> thing different is it delivers nowait parameter to iomap layer.
>>
>> Signed-off-by: Hao Xu <howeyxu@tencent.com>
>> ---
>>   fs/xfs/xfs_file.c | 29 +++++++++++++++++++++++++++--
>>   1 file changed, 27 insertions(+), 2 deletions(-)
>>
>> diff --git a/fs/xfs/xfs_file.c b/fs/xfs/xfs_file.c
>> index 73adc0aee2ff..cba82264221d 100644
>> --- a/fs/xfs/xfs_file.c
>> +++ b/fs/xfs/xfs_file.c
>> @@ -1257,10 +1257,11 @@ xfs_file_readdir(
>>   }
>>   
>>   STATIC loff_t
>> -xfs_file_llseek(
>> +__xfs_file_llseek(
>>   	struct file	*file,
>>   	loff_t		offset,
>> -	int		whence)
>> +	int		whence,
>> +	bool		nowait)
>>   {
>>   	struct inode		*inode = file->f_mapping->host;
>>   
>> @@ -1282,6 +1283,28 @@ xfs_file_llseek(
>>   	return vfs_setpos(file, offset, inode->i_sb->s_maxbytes);
>>   }
>>   
>> +STATIC loff_t
>> +xfs_file_llseek(
>> +	struct file	*file,
>> +	loff_t		offset,
>> +	int		whence)
>> +{
>> +	return __xfs_file_llseek(file, offset, whence, false);
>> +}
>> +
>> +STATIC loff_t
>> +xfs_file_llseek_nowait(
>> +	struct file	*file,
>> +	loff_t		offset,
>> +	int		whence,
>> +	bool		nowait)
>> +{
>> +	if (file->f_op == &xfs_file_operations)
>> +		return __xfs_file_llseek(file, offset, whence, nowait);
>> +	else
>> +		return generic_file_llseek(file, offset, whence);
>> +}
>> +
>>   #ifdef CONFIG_FS_DAX
>>   static inline vm_fault_t
>>   xfs_dax_fault(
>> @@ -1442,6 +1465,7 @@ xfs_file_mmap(
>>   
>>   const struct file_operations xfs_file_operations = {
>>   	.llseek		= xfs_file_llseek,
>> +	.llseek_nowait	= xfs_file_llseek_nowait,
>>   	.read_iter	= xfs_file_read_iter,
>>   	.write_iter	= xfs_file_write_iter,
>>   	.splice_read	= xfs_file_splice_read,
>> @@ -1467,6 +1491,7 @@ const struct file_operations xfs_dir_file_operations = {
>>   	.read		= generic_read_dir,
>>   	.iterate_shared	= xfs_file_readdir,
>>   	.llseek		= generic_file_llseek,
>> +	.llseek_nowait	= xfs_file_llseek_nowait,
>>   	.unlocked_ioctl	= xfs_file_ioctl,
>>   #ifdef CONFIG_COMPAT
>>   	.compat_ioctl	= xfs_file_compat_ioctl,
> 
> This is pretty nasty. It would be far better just to change the
> .llseek method than to inflict this on every filesystem for the
> forseeable future.
> 
> Not that I'm a fan of passing "nowait" booleans all through the file
> operations methods - that way lies madness. We use a control
> structure for the IO path operations (kiocb) to hold per-call
> context information, perhaps we need something similar for these
> other methods that people are wanting to hook up to io_uring (e.g.
> readdir) so taht we don't have to play whack-a-mole with every new
> io_uring method that people want and then end up with a different
> nowait solution for every method.
> 
> -Dave.

whack-a-mole is exactly what I thought when I tried to find a place to
hold that...I'll think about it in next version, a generic structure for
io_uring is good I believe. I'll update this patchset after the getdents
stuff are merged.

Thanks,
Hao
diff mbox series

Patch

diff --git a/fs/xfs/xfs_file.c b/fs/xfs/xfs_file.c
index 73adc0aee2ff..cba82264221d 100644
--- a/fs/xfs/xfs_file.c
+++ b/fs/xfs/xfs_file.c
@@ -1257,10 +1257,11 @@  xfs_file_readdir(
 }
 
 STATIC loff_t
-xfs_file_llseek(
+__xfs_file_llseek(
 	struct file	*file,
 	loff_t		offset,
-	int		whence)
+	int		whence,
+	bool		nowait)
 {
 	struct inode		*inode = file->f_mapping->host;
 
@@ -1282,6 +1283,28 @@  xfs_file_llseek(
 	return vfs_setpos(file, offset, inode->i_sb->s_maxbytes);
 }
 
+STATIC loff_t
+xfs_file_llseek(
+	struct file	*file,
+	loff_t		offset,
+	int		whence)
+{
+	return __xfs_file_llseek(file, offset, whence, false);
+}
+
+STATIC loff_t
+xfs_file_llseek_nowait(
+	struct file	*file,
+	loff_t		offset,
+	int		whence,
+	bool		nowait)
+{
+	if (file->f_op == &xfs_file_operations)
+		return __xfs_file_llseek(file, offset, whence, nowait);
+	else
+		return generic_file_llseek(file, offset, whence);
+}
+
 #ifdef CONFIG_FS_DAX
 static inline vm_fault_t
 xfs_dax_fault(
@@ -1442,6 +1465,7 @@  xfs_file_mmap(
 
 const struct file_operations xfs_file_operations = {
 	.llseek		= xfs_file_llseek,
+	.llseek_nowait	= xfs_file_llseek_nowait,
 	.read_iter	= xfs_file_read_iter,
 	.write_iter	= xfs_file_write_iter,
 	.splice_read	= xfs_file_splice_read,
@@ -1467,6 +1491,7 @@  const struct file_operations xfs_dir_file_operations = {
 	.read		= generic_read_dir,
 	.iterate_shared	= xfs_file_readdir,
 	.llseek		= generic_file_llseek,
+	.llseek_nowait	= xfs_file_llseek_nowait,
 	.unlocked_ioctl	= xfs_file_ioctl,
 #ifdef CONFIG_COMPAT
 	.compat_ioctl	= xfs_file_compat_ioctl,