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

2023-12-11 Thread Yu Kuai

Hi,

在 2023/12/12 14:35, Gao Xiang 写道:



On 2023/12/11 22:07, Yu Kuai wrote:

From: Yu Kuai 

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

Signed-off-by: Yu Kuai 
---
  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 })

.






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

2023-12-11 Thread Gao Xiang




On 2023/12/11 22:07, Yu Kuai wrote:

From: Yu Kuai 

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

Signed-off-by: Yu Kuai 
---
  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 })




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

2023-12-11 Thread Yu Kuai
From: Yu Kuai 

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

Signed-off-by: Yu Kuai 
---
 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;
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 })
-- 
2.39.2