diff mbox series

[RFC,v2,for-6.8/block,11/18] erofs: use bdev api

Message ID 20231211140722.974745-1-yukuai1@huaweicloud.com (mailing list archive)
State Superseded
Headers show
Series block: don't access bd_inode directly from other modules | expand

Commit Message

Yu Kuai Dec. 11, 2023, 2:07 p.m. UTC 
From: Yu Kuai <yukuai3@huawei.com>

Avoid to access bd_inode directly, prepare to remove bd_inode from
block_devcie.

Signed-off-by: Yu Kuai <yukuai3@huawei.com>
---
 fs/erofs/data.c     | 18 ++++++++++++------
 fs/erofs/internal.h |  2 ++
 2 files changed, 14 insertions(+), 6 deletions(-)

Comments

Gao Xiang Dec. 12, 2023, 6:35 a.m. UTC | #1 
On 2023/12/11 22:07, Yu Kuai wrote:
> From: Yu Kuai <yukuai3@huawei.com>
> 
> Avoid to access bd_inode directly, prepare to remove bd_inode from
> block_devcie.
> 
> Signed-off-by: Yu Kuai <yukuai3@huawei.com>
> ---
>   fs/erofs/data.c     | 18 ++++++++++++------
>   fs/erofs/internal.h |  2 ++
>   2 files changed, 14 insertions(+), 6 deletions(-)
> 
> diff --git a/fs/erofs/data.c b/fs/erofs/data.c
> index c98aeda8abb2..8cf3618190ab 100644
> --- a/fs/erofs/data.c
> +++ b/fs/erofs/data.c
> @@ -32,8 +32,7 @@ void erofs_put_metabuf(struct erofs_buf *buf)
>   void *erofs_bread(struct erofs_buf *buf, erofs_blk_t blkaddr,
>   		  enum erofs_kmap_type type)
>   {
> -	struct inode *inode = buf->inode;
> -	erofs_off_t offset = (erofs_off_t)blkaddr << inode->i_blkbits;
> +	erofs_off_t offset = (erofs_off_t)blkaddr << buf->blkszbits;
I'd suggest that use `buf->blkszbits` only for bdev_read_folio() since
erofs_init_metabuf() is not always called before erofs_bread() is used.

For example, buf->inode can be one of directory inodes other than
initialized by erofs_init_metabuf().

Thanks,
Gao Xiang


>   	pgoff_t index = offset >> PAGE_SHIFT;
>   	struct page *page = buf->page;
>   	struct folio *folio;
> @@ -43,7 +42,9 @@ void *erofs_bread(struct erofs_buf *buf, erofs_blk_t blkaddr,
>   		erofs_put_metabuf(buf);
>   
>   		nofs_flag = memalloc_nofs_save();
> -		folio = read_cache_folio(inode->i_mapping, index, NULL, NULL);
> +		folio = buf->inode ?
> +			read_mapping_folio(buf->inode->i_mapping, index, NULL) :
> +			bdev_read_folio(buf->bdev, offset);
>   		memalloc_nofs_restore(nofs_flag);
>   		if (IS_ERR(folio))
>   			return folio;
> @@ -67,10 +68,15 @@ void *erofs_bread(struct erofs_buf *buf, erofs_blk_t blkaddr,
>   
>   void erofs_init_metabuf(struct erofs_buf *buf, struct super_block *sb)
>   {
> -	if (erofs_is_fscache_mode(sb))
> +	if (erofs_is_fscache_mode(sb)) {
>   		buf->inode = EROFS_SB(sb)->s_fscache->inode;
> -	else
> -		buf->inode = sb->s_bdev->bd_inode;
> +		buf->bdev = NULL;
> +		buf->blkszbits = buf->inode->i_blkbits;
> +	} else {
> +		buf->inode = NULL;
> +		buf->bdev = sb->s_bdev;
> +		buf->blkszbits = EROFS_SB(sb)->blkszbits;
> +	}
>   }
>   
>   void *erofs_read_metabuf(struct erofs_buf *buf, struct super_block *sb,
> diff --git a/fs/erofs/internal.h b/fs/erofs/internal.h
> index b0409badb017..c9206351b485 100644
> --- a/fs/erofs/internal.h
> +++ b/fs/erofs/internal.h
> @@ -224,8 +224,10 @@ enum erofs_kmap_type {
>   
>   struct erofs_buf {
>   	struct inode *inode;
> +	struct block_device *bdev;
>   	struct page *page;
>   	void *base;
> +	u8 blkszbits;
>   	enum erofs_kmap_type kmap_type;
>   };
>   #define __EROFS_BUF_INITIALIZER	((struct erofs_buf){ .page = NULL })
Yu Kuai Dec. 12, 2023, 6:49 a.m. UTC | #2 
Hi,

在 2023/12/12 14:35, Gao Xiang 写道:
> 
> 
> On 2023/12/11 22:07, Yu Kuai wrote:
>> From: Yu Kuai <yukuai3@huawei.com>
>>
>> Avoid to access bd_inode directly, prepare to remove bd_inode from
>> block_devcie.
>>
>> Signed-off-by: Yu Kuai <yukuai3@huawei.com>
>> ---
>>   fs/erofs/data.c     | 18 ++++++++++++------
>>   fs/erofs/internal.h |  2 ++
>>   2 files changed, 14 insertions(+), 6 deletions(-)
>>
>> diff --git a/fs/erofs/data.c b/fs/erofs/data.c
>> index c98aeda8abb2..8cf3618190ab 100644
>> --- a/fs/erofs/data.c
>> +++ b/fs/erofs/data.c
>> @@ -32,8 +32,7 @@ void erofs_put_metabuf(struct erofs_buf *buf)
>>   void *erofs_bread(struct erofs_buf *buf, erofs_blk_t blkaddr,
>>             enum erofs_kmap_type type)
>>   {
>> -    struct inode *inode = buf->inode;
>> -    erofs_off_t offset = (erofs_off_t)blkaddr << inode->i_blkbits;
>> +    erofs_off_t offset = (erofs_off_t)blkaddr << buf->blkszbits;
> I'd suggest that use `buf->blkszbits` only for bdev_read_folio() since
> erofs_init_metabuf() is not always called before erofs_bread() is used.
> 
> For example, buf->inode can be one of directory inodes other than
> initialized by erofs_init_metabuf().

Thanks for the notice, and you're right, I'll update code in v3:

u8 blkszbits = buf->inode ? inode->i_blkbits : buf->blkszbits;
erofs_off_t offset = (erofs_off_t)blkaddr << blkszbits;

Kuai
> 
> Thanks,
> Gao Xiang
> 
> 
>>       pgoff_t index = offset >> PAGE_SHIFT;
>>       struct page *page = buf->page;
>>       struct folio *folio;
>> @@ -43,7 +42,9 @@ void *erofs_bread(struct erofs_buf *buf, erofs_blk_t 
>> blkaddr,
>>           erofs_put_metabuf(buf);
>>           nofs_flag = memalloc_nofs_save();
>> -        folio = read_cache_folio(inode->i_mapping, index, NULL, NULL);
>> +        folio = buf->inode ?
>> +            read_mapping_folio(buf->inode->i_mapping, index, NULL) :
>> +            bdev_read_folio(buf->bdev, offset);
>>           memalloc_nofs_restore(nofs_flag);
>>           if (IS_ERR(folio))
>>               return folio;
>> @@ -67,10 +68,15 @@ void *erofs_bread(struct erofs_buf *buf, 
>> erofs_blk_t blkaddr,
>>   void erofs_init_metabuf(struct erofs_buf *buf, struct super_block *sb)
>>   {
>> -    if (erofs_is_fscache_mode(sb))
>> +    if (erofs_is_fscache_mode(sb)) {
>>           buf->inode = EROFS_SB(sb)->s_fscache->inode;
>> -    else
>> -        buf->inode = sb->s_bdev->bd_inode;
>> +        buf->bdev = NULL;
>> +        buf->blkszbits = buf->inode->i_blkbits;
>> +    } else {
>> +        buf->inode = NULL;
>> +        buf->bdev = sb->s_bdev;
>> +        buf->blkszbits = EROFS_SB(sb)->blkszbits;
>> +    }
>>   }
>>   void *erofs_read_metabuf(struct erofs_buf *buf, struct super_block *sb,
>> diff --git a/fs/erofs/internal.h b/fs/erofs/internal.h
>> index b0409badb017..c9206351b485 100644
>> --- a/fs/erofs/internal.h
>> +++ b/fs/erofs/internal.h
>> @@ -224,8 +224,10 @@ enum erofs_kmap_type {
>>   struct erofs_buf {
>>       struct inode *inode;
>> +    struct block_device *bdev;
>>       struct page *page;
>>       void *base;
>> +    u8 blkszbits;
>>       enum erofs_kmap_type kmap_type;
>>   };
>>   #define __EROFS_BUF_INITIALIZER    ((struct erofs_buf){ .page = NULL })
> .
>
diff mbox series

Patch

diff --git a/fs/erofs/data.c b/fs/erofs/data.c
index c98aeda8abb2..8cf3618190ab 100644
--- a/fs/erofs/data.c
+++ b/fs/erofs/data.c
@@ -32,8 +32,7 @@  void erofs_put_metabuf(struct erofs_buf *buf)
 void *erofs_bread(struct erofs_buf *buf, erofs_blk_t blkaddr,
 		  enum erofs_kmap_type type)
 {
-	struct inode *inode = buf->inode;
-	erofs_off_t offset = (erofs_off_t)blkaddr << inode->i_blkbits;
+	erofs_off_t offset = (erofs_off_t)blkaddr << buf->blkszbits;
 	pgoff_t index = offset >> PAGE_SHIFT;
 	struct page *page = buf->page;
 	struct folio *folio;
@@ -43,7 +42,9 @@  void *erofs_bread(struct erofs_buf *buf, erofs_blk_t blkaddr,
 		erofs_put_metabuf(buf);
 
 		nofs_flag = memalloc_nofs_save();
-		folio = read_cache_folio(inode->i_mapping, index, NULL, NULL);
+		folio = buf->inode ?
+			read_mapping_folio(buf->inode->i_mapping, index, NULL) :
+			bdev_read_folio(buf->bdev, offset);
 		memalloc_nofs_restore(nofs_flag);
 		if (IS_ERR(folio))
 			return folio;
@@ -67,10 +68,15 @@  void *erofs_bread(struct erofs_buf *buf, erofs_blk_t blkaddr,
 
 void erofs_init_metabuf(struct erofs_buf *buf, struct super_block *sb)
 {
-	if (erofs_is_fscache_mode(sb))
+	if (erofs_is_fscache_mode(sb)) {
 		buf->inode = EROFS_SB(sb)->s_fscache->inode;
-	else
-		buf->inode = sb->s_bdev->bd_inode;
+		buf->bdev = NULL;
+		buf->blkszbits = buf->inode->i_blkbits;
+	} else {
+		buf->inode = NULL;
+		buf->bdev = sb->s_bdev;
+		buf->blkszbits = EROFS_SB(sb)->blkszbits;
+	}
 }
 
 void *erofs_read_metabuf(struct erofs_buf *buf, struct super_block *sb,
diff --git a/fs/erofs/internal.h b/fs/erofs/internal.h
index b0409badb017..c9206351b485 100644
--- a/fs/erofs/internal.h
+++ b/fs/erofs/internal.h
@@ -224,8 +224,10 @@  enum erofs_kmap_type {
 
 struct erofs_buf {
 	struct inode *inode;
+	struct block_device *bdev;
 	struct page *page;
 	void *base;
+	u8 blkszbits;
 	enum erofs_kmap_type kmap_type;
 };
 #define __EROFS_BUF_INITIALIZER	((struct erofs_buf){ .page = NULL })