[PATCH] iomap: iomap_read_inline_data cleanup

[PATCH] iomap: iomap_read_inline_data cleanup

[Andreas Gruenbacher]

Change iomap_read_inline_data to return 0 or an error code; this
simplifies the callers.  Add a description.

Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
---
 fs/iomap/buffered-io.c | 30 ++++++++++++++----------------
 1 file changed, 14 insertions(+), 16 deletions(-)

diff --git a/fs/iomap/buffered-io.c b/fs/iomap/buffered-io.c
index fe10d8a30f6b..f1bc9a35184d 100644
--- a/fs/iomap/buffered-io.c
+++ b/fs/iomap/buffered-io.c
@@ -205,7 +205,15 @@ struct iomap_readpage_ctx {
 	struct readahead_control *rac;
 };
 
-static loff_t iomap_read_inline_data(const struct iomap_iter *iter,
+/**
+ * iomap_read_inline_data - copy inline data into the page cache
+ * @iter: iteration structure
+ * @page: page to copy to
+ *
+ * Copy the inline data in @iter into @page and zero out the rest of the page.
+ * Only a single IOMAP_INLINE extent is allowed at the end of each file.
+ */
+static int iomap_read_inline_data(const struct iomap_iter *iter,
 		struct page *page)
 {
 	const struct iomap *iomap = iomap_iter_srcmap(iter);
@@ -214,7 +222,7 @@ static loff_t iomap_read_inline_data(const struct iomap_iter *iter,
 	void *addr;
 
 	if (PageUptodate(page))
-		return PAGE_SIZE - poff;
+		return 0;
 
 	if (WARN_ON_ONCE(size > PAGE_SIZE - poff))
 		return -EIO;
@@ -231,7 +239,7 @@ static loff_t iomap_read_inline_data(const struct iomap_iter *iter,
 	memset(addr + size, 0, PAGE_SIZE - poff - size);
 	kunmap_local(addr);
 	iomap_set_range_uptodate(page, poff, PAGE_SIZE - poff);
-	return PAGE_SIZE - poff;
+	return 0;
 }
 
 static inline bool iomap_block_needs_zeroing(const struct iomap_iter *iter,
@@ -256,13 +264,8 @@ static loff_t iomap_readpage_iter(const struct iomap_iter *iter,
 	unsigned poff, plen;
 	sector_t sector;
 
-	if (iomap->type == IOMAP_INLINE) {
-		loff_t ret = iomap_read_inline_data(iter, page);
-
-		if (ret < 0)
-			return ret;
-		return 0;
-	}
+	if (iomap->type == IOMAP_INLINE)
+		return iomap_read_inline_data(iter, page);
 
 	/* zero post-eof blocks as the page may be mapped */
 	iop = iomap_page_create(iter->inode, page);
@@ -587,15 +590,10 @@ static int __iomap_write_begin(const struct iomap_iter *iter, loff_t pos,
 static int iomap_write_begin_inline(const struct iomap_iter *iter,
 		struct page *page)
 {
-	int ret;
-
 	/* needs more work for the tailpacking case; disable for now */
 	if (WARN_ON_ONCE(iomap_iter_srcmap(iter)->offset != 0))
 		return -EIO;
-	ret = iomap_read_inline_data(iter, page);
-	if (ret < 0)
-		return ret;
-	return 0;
+	return iomap_read_inline_data(iter, page);
 }
 
 static int iomap_write_begin(const struct iomap_iter *iter, loff_t pos,
-- 
2.31.1

Re: [PATCH] iomap: iomap_read_inline_data cleanup

[Christoph Hellwig]

On Wed, Nov 17, 2021 at 11:32:02AM +0100, Andreas Gruenbacher wrote:
> Change iomap_read_inline_data to return 0 or an error code; this
> simplifies the callers.  Add a description.

Looks good,

Reviewed-by: Christoph Hellwig <hch@lst.de>

Re: [PATCH] iomap: iomap_read_inline_data cleanup

[Darrick J. Wong]

On Wed, Nov 17, 2021 at 11:32:02AM +0100, Andreas Gruenbacher wrote:
> Change iomap_read_inline_data to return 0 or an error code; this
> simplifies the callers.  Add a description.
> 
> Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>

Looks good, thank you for cleaning this up for me!
Reviewed-by: Darrick J. Wong <djwong@kernel.org>

--D

> ---
>  fs/iomap/buffered-io.c | 30 ++++++++++++++----------------
>  1 file changed, 14 insertions(+), 16 deletions(-)
> 
> diff --git a/fs/iomap/buffered-io.c b/fs/iomap/buffered-io.c
> index fe10d8a30f6b..f1bc9a35184d 100644
> --- a/fs/iomap/buffered-io.c
> +++ b/fs/iomap/buffered-io.c
> @@ -205,7 +205,15 @@ struct iomap_readpage_ctx {
>  	struct readahead_control *rac;
>  };
>  
> -static loff_t iomap_read_inline_data(const struct iomap_iter *iter,
> +/**
> + * iomap_read_inline_data - copy inline data into the page cache
> + * @iter: iteration structure
> + * @page: page to copy to
> + *
> + * Copy the inline data in @iter into @page and zero out the rest of the page.
> + * Only a single IOMAP_INLINE extent is allowed at the end of each file.
> + */
> +static int iomap_read_inline_data(const struct iomap_iter *iter,
>  		struct page *page)
>  {
>  	const struct iomap *iomap = iomap_iter_srcmap(iter);
> @@ -214,7 +222,7 @@ static loff_t iomap_read_inline_data(const struct iomap_iter *iter,
>  	void *addr;
>  
>  	if (PageUptodate(page))
> -		return PAGE_SIZE - poff;
> +		return 0;
>  
>  	if (WARN_ON_ONCE(size > PAGE_SIZE - poff))
>  		return -EIO;
> @@ -231,7 +239,7 @@ static loff_t iomap_read_inline_data(const struct iomap_iter *iter,
>  	memset(addr + size, 0, PAGE_SIZE - poff - size);
>  	kunmap_local(addr);
>  	iomap_set_range_uptodate(page, poff, PAGE_SIZE - poff);
> -	return PAGE_SIZE - poff;
> +	return 0;
>  }
>  
>  static inline bool iomap_block_needs_zeroing(const struct iomap_iter *iter,
> @@ -256,13 +264,8 @@ static loff_t iomap_readpage_iter(const struct iomap_iter *iter,
>  	unsigned poff, plen;
>  	sector_t sector;
>  
> -	if (iomap->type == IOMAP_INLINE) {
> -		loff_t ret = iomap_read_inline_data(iter, page);
> -
> -		if (ret < 0)
> -			return ret;
> -		return 0;
> -	}
> +	if (iomap->type == IOMAP_INLINE)
> +		return iomap_read_inline_data(iter, page);
>  
>  	/* zero post-eof blocks as the page may be mapped */
>  	iop = iomap_page_create(iter->inode, page);
> @@ -587,15 +590,10 @@ static int __iomap_write_begin(const struct iomap_iter *iter, loff_t pos,
>  static int iomap_write_begin_inline(const struct iomap_iter *iter,
>  		struct page *page)
>  {
> -	int ret;
> -
>  	/* needs more work for the tailpacking case; disable for now */
>  	if (WARN_ON_ONCE(iomap_iter_srcmap(iter)->offset != 0))
>  		return -EIO;
> -	ret = iomap_read_inline_data(iter, page);
> -	if (ret < 0)
> -		return ret;
> -	return 0;
> +	return iomap_read_inline_data(iter, page);
>  }
>  
>  static int iomap_write_begin(const struct iomap_iter *iter, loff_t pos,
> -- 
> 2.31.1
>