[PATCH v16 04/10] erofs: add erofs_inode_set_aops helper to set the aops.

Hongbo Li posted 10 patches 2 weeks, 4 days ago
There is a newer version of this series
[PATCH v16 04/10] erofs: add erofs_inode_set_aops helper to set the aops.
Posted by Hongbo Li 2 weeks, 4 days ago
Add erofs_inode_set_aops helper to set the inode->i_mapping->a_ops,
and using IS_ENABLED to make it cleaner.

Signed-off-by: Hongbo Li <lihongbo22@huawei.com>
---
 fs/erofs/inode.c    | 23 +----------------------
 fs/erofs/internal.h | 23 +++++++++++++++++++++++
 2 files changed, 24 insertions(+), 22 deletions(-)

diff --git a/fs/erofs/inode.c b/fs/erofs/inode.c
index bce98c845a18..389632bb46c4 100644
--- a/fs/erofs/inode.c
+++ b/fs/erofs/inode.c
@@ -235,28 +235,7 @@ static int erofs_fill_inode(struct inode *inode)
 	}
 
 	mapping_set_large_folios(inode->i_mapping);
-	if (erofs_inode_is_data_compressed(vi->datalayout)) {
-#ifdef CONFIG_EROFS_FS_ZIP
-		DO_ONCE_LITE_IF(inode->i_blkbits != PAGE_SHIFT,
-			  erofs_info, inode->i_sb,
-			  "EXPERIMENTAL EROFS subpage compressed block support in use. Use at your own risk!");
-		inode->i_mapping->a_ops = &z_erofs_aops;
-#else
-		err = -EOPNOTSUPP;
-#endif
-	} else {
-		inode->i_mapping->a_ops = &erofs_aops;
-#ifdef CONFIG_EROFS_FS_ONDEMAND
-		if (erofs_is_fscache_mode(inode->i_sb))
-			inode->i_mapping->a_ops = &erofs_fscache_access_aops;
-#endif
-#ifdef CONFIG_EROFS_FS_BACKED_BY_FILE
-		if (erofs_is_fileio_mode(EROFS_SB(inode->i_sb)))
-			inode->i_mapping->a_ops = &erofs_fileio_aops;
-#endif
-	}
-
-	return err;
+	return erofs_inode_set_aops(inode, inode, false);
 }
 
 /*
diff --git a/fs/erofs/internal.h b/fs/erofs/internal.h
index ec79e8b44d3b..8e28c2fa8735 100644
--- a/fs/erofs/internal.h
+++ b/fs/erofs/internal.h
@@ -455,6 +455,29 @@ static inline void *erofs_vm_map_ram(struct page **pages, unsigned int count)
 	return NULL;
 }
 
+static inline int erofs_inode_set_aops(struct inode *inode,
+				       struct inode *realinode, bool no_fscache)
+{
+	if (erofs_inode_is_data_compressed(EROFS_I(realinode)->datalayout)) {
+		if (!IS_ENABLED(CONFIG_EROFS_FS_ZIP))
+			return -EOPNOTSUPP;
+		DO_ONCE_LITE_IF(realinode->i_blkbits != PAGE_SHIFT,
+			  erofs_info, realinode->i_sb,
+			  "EXPERIMENTAL EROFS subpage compressed block support in use. Use at your own risk!");
+		inode->i_mapping->a_ops = &z_erofs_aops;
+		return 0;
+	}
+	inode->i_mapping->a_ops = &erofs_aops;
+	if (IS_ENABLED(CONFIG_EROFS_FS_ONDEMAND)) {
+		if (!no_fscache && erofs_is_fscache_mode(realinode->i_sb))
+			inode->i_mapping->a_ops = &erofs_fscache_access_aops;
+	} else {
+		if (erofs_is_fileio_mode(EROFS_SB(realinode->i_sb)))
+			inode->i_mapping->a_ops = &erofs_fileio_aops;
+	}
+	return 0;
+}
+
 int erofs_register_sysfs(struct super_block *sb);
 void erofs_unregister_sysfs(struct super_block *sb);
 int __init erofs_init_sysfs(void);
-- 
2.22.0
Re: [PATCH v16 04/10] erofs: add erofs_inode_set_aops helper to set the aops.
Posted by Gao Xiang 2 weeks, 4 days ago

On 2026/1/22 21:37, Hongbo Li wrote:
> Add erofs_inode_set_aops helper to set the inode->i_mapping->a_ops,
> and using IS_ENABLED to make it cleaner.
> 
> Signed-off-by: Hongbo Li <lihongbo22@huawei.com>
> ---
>   fs/erofs/inode.c    | 23 +----------------------
>   fs/erofs/internal.h | 23 +++++++++++++++++++++++
>   2 files changed, 24 insertions(+), 22 deletions(-)
> 
> diff --git a/fs/erofs/inode.c b/fs/erofs/inode.c
> index bce98c845a18..389632bb46c4 100644
> --- a/fs/erofs/inode.c
> +++ b/fs/erofs/inode.c
> @@ -235,28 +235,7 @@ static int erofs_fill_inode(struct inode *inode)
>   	}
>   
>   	mapping_set_large_folios(inode->i_mapping);
> -	if (erofs_inode_is_data_compressed(vi->datalayout)) {
> -#ifdef CONFIG_EROFS_FS_ZIP
> -		DO_ONCE_LITE_IF(inode->i_blkbits != PAGE_SHIFT,
> -			  erofs_info, inode->i_sb,
> -			  "EXPERIMENTAL EROFS subpage compressed block support in use. Use at your own risk!");
> -		inode->i_mapping->a_ops = &z_erofs_aops;
> -#else
> -		err = -EOPNOTSUPP;
> -#endif
> -	} else {
> -		inode->i_mapping->a_ops = &erofs_aops;
> -#ifdef CONFIG_EROFS_FS_ONDEMAND
> -		if (erofs_is_fscache_mode(inode->i_sb))
> -			inode->i_mapping->a_ops = &erofs_fscache_access_aops;
> -#endif
> -#ifdef CONFIG_EROFS_FS_BACKED_BY_FILE
> -		if (erofs_is_fileio_mode(EROFS_SB(inode->i_sb)))
> -			inode->i_mapping->a_ops = &erofs_fileio_aops;
> -#endif
> -	}
> -
> -	return err;
> +	return erofs_inode_set_aops(inode, inode, false);
>   }
>   
>   /*
> diff --git a/fs/erofs/internal.h b/fs/erofs/internal.h
> index ec79e8b44d3b..8e28c2fa8735 100644
> --- a/fs/erofs/internal.h
> +++ b/fs/erofs/internal.h
> @@ -455,6 +455,29 @@ static inline void *erofs_vm_map_ram(struct page **pages, unsigned int count)
>   	return NULL;
>   }
>   
> +static inline int erofs_inode_set_aops(struct inode *inode,
> +				       struct inode *realinode, bool no_fscache)
> +{
> +	if (erofs_inode_is_data_compressed(EROFS_I(realinode)->datalayout)) {
> +		if (!IS_ENABLED(CONFIG_EROFS_FS_ZIP))
> +			return -EOPNOTSUPP;
> +		DO_ONCE_LITE_IF(realinode->i_blkbits != PAGE_SHIFT,
> +			  erofs_info, realinode->i_sb,
> +			  "EXPERIMENTAL EROFS subpage compressed block support in use. Use at your own risk!");
> +		inode->i_mapping->a_ops = &z_erofs_aops;

Is that available if CONFIG_EROFS_FS_ZIP is undefined?

> +		return 0;
> +	}
> +	inode->i_mapping->a_ops = &erofs_aops;
> +	if (IS_ENABLED(CONFIG_EROFS_FS_ONDEMAND)) {
> +		if (!no_fscache && erofs_is_fscache_mode(realinode->i_sb))
> +			inode->i_mapping->a_ops = &erofs_fscache_access_aops;
> +	} else {

I really don't think they are equal, could you just move
the code without any change?

Thanks,
Gao Xiang
> +		if (erofs_is_fileio_mode(EROFS_SB(realinode->i_sb)))
> +			inode->i_mapping->a_ops = &erofs_fileio_aops;
> +	}
> +	return 0;
> +}
> +
>   int erofs_register_sysfs(struct super_block *sb);
>   void erofs_unregister_sysfs(struct super_block *sb);
>   int __init erofs_init_sysfs(void);
Re: [PATCH v16 04/10] erofs: add erofs_inode_set_aops helper to set the aops.
Posted by Christoph Hellwig 2 weeks, 3 days ago
On Thu, Jan 22, 2026 at 09:54:15PM +0800, Gao Xiang wrote:
>> @@ -455,6 +455,29 @@ static inline void *erofs_vm_map_ram(struct page **pages, unsigned int count)
>>   	return NULL;
>>   }
>>   +static inline int erofs_inode_set_aops(struct inode *inode,
>> +				       struct inode *realinode, bool no_fscache)
>> +{
>> +	if (erofs_inode_is_data_compressed(EROFS_I(realinode)->datalayout)) {
>> +		if (!IS_ENABLED(CONFIG_EROFS_FS_ZIP))
>> +			return -EOPNOTSUPP;
>> +		DO_ONCE_LITE_IF(realinode->i_blkbits != PAGE_SHIFT,
>> +			  erofs_info, realinode->i_sb,
>> +			  "EXPERIMENTAL EROFS subpage compressed block support in use. Use at your own risk!");
>> +		inode->i_mapping->a_ops = &z_erofs_aops;
>
> Is that available if CONFIG_EROFS_FS_ZIP is undefined?

z_erofs_aops is declared unconditionally, and the IS_ENABLED above
ensures the compiler will never generate a reference to it.

So this is fine, and a very usualy trick to make the code more
readable.
Re: [PATCH v16 04/10] erofs: add erofs_inode_set_aops helper to set the aops.
Posted by Gao Xiang 2 weeks, 3 days ago

On 2026/1/23 14:18, Christoph Hellwig wrote:
> On Thu, Jan 22, 2026 at 09:54:15PM +0800, Gao Xiang wrote:
>>> @@ -455,6 +455,29 @@ static inline void *erofs_vm_map_ram(struct page **pages, unsigned int count)
>>>    	return NULL;
>>>    }
>>>    +static inline int erofs_inode_set_aops(struct inode *inode,
>>> +				       struct inode *realinode, bool no_fscache)
>>> +{
>>> +	if (erofs_inode_is_data_compressed(EROFS_I(realinode)->datalayout)) {
>>> +		if (!IS_ENABLED(CONFIG_EROFS_FS_ZIP))
>>> +			return -EOPNOTSUPP;
>>> +		DO_ONCE_LITE_IF(realinode->i_blkbits != PAGE_SHIFT,
>>> +			  erofs_info, realinode->i_sb,
>>> +			  "EXPERIMENTAL EROFS subpage compressed block support in use. Use at your own risk!");
>>> +		inode->i_mapping->a_ops = &z_erofs_aops;
>>
>> Is that available if CONFIG_EROFS_FS_ZIP is undefined?
> 
> z_erofs_aops is declared unconditionally, and the IS_ENABLED above
> ensures the compiler will never generate a reference to it.
> 
> So this is fine, and a very usualy trick to make the code more
> readable.

Yeah, I get your point, that is really helpful and I haven't
used that trick.

The other problem was the else part is incorrect, Hongbo,
how about applying the following code and resend the next
version, I will apply all patches later:

static inline int erofs_inode_set_aops(struct inode *inode,
                                        struct inode *realinode, bool no_fscache)
{
         if (erofs_inode_is_data_compressed(EROFS_I(realinode)->datalayout)) {
                 if (!IS_ENABLED(CONFIG_EROFS_FS_ZIP))
                         return -EOPNOTSUPP;
                 DO_ONCE_LITE_IF(realinode->i_blkbits != PAGE_SHIFT,
                           erofs_info, realinode->i_sb,
                           "EXPERIMENTAL EROFS subpage compressed block support in use. Use at your own risk!");
                 inode->i_mapping->a_ops = &z_erofs_aops;
                 return 0;
         }
         inode->i_mapping->a_ops = &erofs_aops;
         if (IS_ENABLED(CONFIG_EROFS_FS_ONDEMAND) && !no_fscache &&
             erofs_is_fscache_mode(realinode->i_sb))
                 inode->i_mapping->a_ops = &erofs_fscache_access_aops;
         if (IS_ENABLED(CONFIG_EROFS_FS_BACKED_BY_FILE) &&
             erofs_is_fileio_mode(EROFS_SB(realinode->i_sb)))
                 inode->i_mapping->a_ops = &erofs_fileio_aops;
         return 0;
}

Thanks,
Gao Xiang
Re: [PATCH v16 04/10] erofs: add erofs_inode_set_aops helper to set the aops.
Posted by Hongbo Li 2 weeks, 3 days ago
Hi Xiang and Christoph,

On 2026/1/23 15:42, Gao Xiang wrote:
> 
> 
> On 2026/1/23 14:18, Christoph Hellwig wrote:
>> On Thu, Jan 22, 2026 at 09:54:15PM +0800, Gao Xiang wrote:
>>>> @@ -455,6 +455,29 @@ static inline void *erofs_vm_map_ram(struct 
>>>> page **pages, unsigned int count)
>>>>        return NULL;
>>>>    }
>>>>    +static inline int erofs_inode_set_aops(struct inode *inode,
>>>> +                       struct inode *realinode, bool no_fscache)
>>>> +{
>>>> +    if 
>>>> (erofs_inode_is_data_compressed(EROFS_I(realinode)->datalayout)) {
>>>> +        if (!IS_ENABLED(CONFIG_EROFS_FS_ZIP))
>>>> +            return -EOPNOTSUPP;
>>>> +        DO_ONCE_LITE_IF(realinode->i_blkbits != PAGE_SHIFT,
>>>> +              erofs_info, realinode->i_sb,
>>>> +              "EXPERIMENTAL EROFS subpage compressed block support 
>>>> in use. Use at your own risk!");
>>>> +        inode->i_mapping->a_ops = &z_erofs_aops;
>>>
>>> Is that available if CONFIG_EROFS_FS_ZIP is undefined?
>>
>> z_erofs_aops is declared unconditionally, and the IS_ENABLED above
>> ensures the compiler will never generate a reference to it.
>>
>> So this is fine, and a very usualy trick to make the code more
>> readable.
> 
> Yeah, I get your point, that is really helpful and I haven't
> used that trick.
> 
> The other problem was the else part is incorrect, Hongbo,
> how about applying the following code and resend the next
> version, I will apply all patches later:
> 

Thanks you very much for your careful review and help. It was indeed my 
own mistake (I have been making errors too easily lately which taught me 
a lot...).
I have updated the new version in:

https://lore.kernel.org/all/20260123075239.664330-1-lihongbo22@huawei.com/

Thanks,
Hongbo

> static inline int erofs_inode_set_aops(struct inode *inode,
>                                         struct inode *realinode, bool 
> no_fscache)
> {
>          if 
> (erofs_inode_is_data_compressed(EROFS_I(realinode)->datalayout)) {
>                  if (!IS_ENABLED(CONFIG_EROFS_FS_ZIP))
>                          return -EOPNOTSUPP;
>                  DO_ONCE_LITE_IF(realinode->i_blkbits != PAGE_SHIFT,
>                            erofs_info, realinode->i_sb,
>                            "EXPERIMENTAL EROFS subpage compressed block 
> support in use. Use at your own risk!");
>                  inode->i_mapping->a_ops = &z_erofs_aops;
>                  return 0;
>          }
>          inode->i_mapping->a_ops = &erofs_aops;
>          if (IS_ENABLED(CONFIG_EROFS_FS_ONDEMAND) && !no_fscache &&
>              erofs_is_fscache_mode(realinode->i_sb))
>                  inode->i_mapping->a_ops = &erofs_fscache_access_aops;
>          if (IS_ENABLED(CONFIG_EROFS_FS_BACKED_BY_FILE) &&
>              erofs_is_fileio_mode(EROFS_SB(realinode->i_sb)))
>                  inode->i_mapping->a_ops = &erofs_fileio_aops;
>          return 0;
> }
> 
> Thanks,
> Gao Xiang