diff mbox series

[v5,4/9] iomap: Add iomap_get_folio helper

Message ID 20221231150919.659533-5-agruenba@redhat.com (mailing list archive)
State New, archived
Headers show
Series Turn iomap_page_ops into iomap_folio_ops | expand

Commit Message

Andreas Gruenbacher Dec. 31, 2022, 3:09 p.m. UTC
Add an iomap_get_folio() helper that gets a folio reference based on
an iomap iterator and an offset into the address space.  Use it in
iomap_write_begin().

Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
---
 fs/iomap/buffered-io.c | 39 ++++++++++++++++++++++++++++++---------
 include/linux/iomap.h  |  1 +
 2 files changed, 31 insertions(+), 9 deletions(-)

Comments

Darrick J. Wong Jan. 4, 2023, 5:38 p.m. UTC | #1
On Sat, Dec 31, 2022 at 04:09:14PM +0100, Andreas Gruenbacher wrote:
> Add an iomap_get_folio() helper that gets a folio reference based on
> an iomap iterator and an offset into the address space.  Use it in
> iomap_write_begin().
> 
> Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>

Pretty straightforward,
Reviewed-by: Darrick J. Wong <djwong@kernel.org>

--D

> ---
>  fs/iomap/buffered-io.c | 39 ++++++++++++++++++++++++++++++---------
>  include/linux/iomap.h  |  1 +
>  2 files changed, 31 insertions(+), 9 deletions(-)
> 
> diff --git a/fs/iomap/buffered-io.c b/fs/iomap/buffered-io.c
> index 2a9bab4f3c79..b84838d2b5d8 100644
> --- a/fs/iomap/buffered-io.c
> +++ b/fs/iomap/buffered-io.c
> @@ -457,6 +457,33 @@ bool iomap_is_partially_uptodate(struct folio *folio, size_t from, size_t count)
>  }
>  EXPORT_SYMBOL_GPL(iomap_is_partially_uptodate);
>  
> +/**
> + * iomap_get_folio - get a folio reference for writing
> + * @iter: iteration structure
> + * @pos: start offset of write
> + *
> + * Returns a locked reference to the folio at @pos, or an error pointer if the
> + * folio could not be obtained.
> + */
> +struct folio *iomap_get_folio(struct iomap_iter *iter, loff_t pos)
> +{
> +	unsigned fgp = FGP_LOCK | FGP_WRITE | FGP_CREAT | FGP_STABLE | FGP_NOFS;
> +	struct folio *folio;
> +
> +	if (iter->flags & IOMAP_NOWAIT)
> +		fgp |= FGP_NOWAIT;
> +
> +	folio = __filemap_get_folio(iter->inode->i_mapping, pos >> PAGE_SHIFT,
> +			fgp, mapping_gfp_mask(iter->inode->i_mapping));
> +	if (folio)
> +		return folio;
> +
> +	if (iter->flags & IOMAP_NOWAIT)
> +		return ERR_PTR(-EAGAIN);
> +	return ERR_PTR(-ENOMEM);
> +}
> +EXPORT_SYMBOL_GPL(iomap_get_folio);
> +
>  bool iomap_release_folio(struct folio *folio, gfp_t gfp_flags)
>  {
>  	trace_iomap_release_folio(folio->mapping->host, folio_pos(folio),
> @@ -603,12 +630,8 @@ static int iomap_write_begin(struct iomap_iter *iter, loff_t pos,
>  	const struct iomap_page_ops *page_ops = iter->iomap.page_ops;
>  	const struct iomap *srcmap = iomap_iter_srcmap(iter);
>  	struct folio *folio;
> -	unsigned fgp = FGP_LOCK | FGP_WRITE | FGP_CREAT | FGP_STABLE | FGP_NOFS;
>  	int status = 0;
>  
> -	if (iter->flags & IOMAP_NOWAIT)
> -		fgp |= FGP_NOWAIT;
> -
>  	BUG_ON(pos + len > iter->iomap.offset + iter->iomap.length);
>  	if (srcmap != &iter->iomap)
>  		BUG_ON(pos + len > srcmap->offset + srcmap->length);
> @@ -625,12 +648,10 @@ static int iomap_write_begin(struct iomap_iter *iter, loff_t pos,
>  			return status;
>  	}
>  
> -	folio = __filemap_get_folio(iter->inode->i_mapping, pos >> PAGE_SHIFT,
> -			fgp, mapping_gfp_mask(iter->inode->i_mapping));
> -	if (!folio) {
> -		status = (iter->flags & IOMAP_NOWAIT) ? -EAGAIN : -ENOMEM;
> +	folio = iomap_get_folio(iter, pos);
> +	if (IS_ERR(folio)) {
>  		iomap_put_folio(iter, pos, 0, NULL);
> -		return status;
> +		return PTR_ERR(folio);
>  	}
>  
>  	/*
> diff --git a/include/linux/iomap.h b/include/linux/iomap.h
> index 10ec36f373f4..e5732cc5716b 100644
> --- a/include/linux/iomap.h
> +++ b/include/linux/iomap.h
> @@ -261,6 +261,7 @@ int iomap_file_buffered_write_punch_delalloc(struct inode *inode,
>  int iomap_read_folio(struct folio *folio, const struct iomap_ops *ops);
>  void iomap_readahead(struct readahead_control *, const struct iomap_ops *ops);
>  bool iomap_is_partially_uptodate(struct folio *, size_t from, size_t count);
> +struct folio *iomap_get_folio(struct iomap_iter *iter, loff_t pos);
>  bool iomap_release_folio(struct folio *folio, gfp_t gfp_flags);
>  void iomap_invalidate_folio(struct folio *folio, size_t offset, size_t len);
>  int iomap_file_unshare(struct inode *inode, loff_t pos, loff_t len,
> -- 
> 2.38.1
>
Christoph Hellwig Jan. 8, 2023, 5:26 p.m. UTC | #2
Looks good:

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

Patch

diff --git a/fs/iomap/buffered-io.c b/fs/iomap/buffered-io.c
index 2a9bab4f3c79..b84838d2b5d8 100644
--- a/fs/iomap/buffered-io.c
+++ b/fs/iomap/buffered-io.c
@@ -457,6 +457,33 @@  bool iomap_is_partially_uptodate(struct folio *folio, size_t from, size_t count)
 }
 EXPORT_SYMBOL_GPL(iomap_is_partially_uptodate);
 
+/**
+ * iomap_get_folio - get a folio reference for writing
+ * @iter: iteration structure
+ * @pos: start offset of write
+ *
+ * Returns a locked reference to the folio at @pos, or an error pointer if the
+ * folio could not be obtained.
+ */
+struct folio *iomap_get_folio(struct iomap_iter *iter, loff_t pos)
+{
+	unsigned fgp = FGP_LOCK | FGP_WRITE | FGP_CREAT | FGP_STABLE | FGP_NOFS;
+	struct folio *folio;
+
+	if (iter->flags & IOMAP_NOWAIT)
+		fgp |= FGP_NOWAIT;
+
+	folio = __filemap_get_folio(iter->inode->i_mapping, pos >> PAGE_SHIFT,
+			fgp, mapping_gfp_mask(iter->inode->i_mapping));
+	if (folio)
+		return folio;
+
+	if (iter->flags & IOMAP_NOWAIT)
+		return ERR_PTR(-EAGAIN);
+	return ERR_PTR(-ENOMEM);
+}
+EXPORT_SYMBOL_GPL(iomap_get_folio);
+
 bool iomap_release_folio(struct folio *folio, gfp_t gfp_flags)
 {
 	trace_iomap_release_folio(folio->mapping->host, folio_pos(folio),
@@ -603,12 +630,8 @@  static int iomap_write_begin(struct iomap_iter *iter, loff_t pos,
 	const struct iomap_page_ops *page_ops = iter->iomap.page_ops;
 	const struct iomap *srcmap = iomap_iter_srcmap(iter);
 	struct folio *folio;
-	unsigned fgp = FGP_LOCK | FGP_WRITE | FGP_CREAT | FGP_STABLE | FGP_NOFS;
 	int status = 0;
 
-	if (iter->flags & IOMAP_NOWAIT)
-		fgp |= FGP_NOWAIT;
-
 	BUG_ON(pos + len > iter->iomap.offset + iter->iomap.length);
 	if (srcmap != &iter->iomap)
 		BUG_ON(pos + len > srcmap->offset + srcmap->length);
@@ -625,12 +648,10 @@  static int iomap_write_begin(struct iomap_iter *iter, loff_t pos,
 			return status;
 	}
 
-	folio = __filemap_get_folio(iter->inode->i_mapping, pos >> PAGE_SHIFT,
-			fgp, mapping_gfp_mask(iter->inode->i_mapping));
-	if (!folio) {
-		status = (iter->flags & IOMAP_NOWAIT) ? -EAGAIN : -ENOMEM;
+	folio = iomap_get_folio(iter, pos);
+	if (IS_ERR(folio)) {
 		iomap_put_folio(iter, pos, 0, NULL);
-		return status;
+		return PTR_ERR(folio);
 	}
 
 	/*
diff --git a/include/linux/iomap.h b/include/linux/iomap.h
index 10ec36f373f4..e5732cc5716b 100644
--- a/include/linux/iomap.h
+++ b/include/linux/iomap.h
@@ -261,6 +261,7 @@  int iomap_file_buffered_write_punch_delalloc(struct inode *inode,
 int iomap_read_folio(struct folio *folio, const struct iomap_ops *ops);
 void iomap_readahead(struct readahead_control *, const struct iomap_ops *ops);
 bool iomap_is_partially_uptodate(struct folio *, size_t from, size_t count);
+struct folio *iomap_get_folio(struct iomap_iter *iter, loff_t pos);
 bool iomap_release_folio(struct folio *folio, gfp_t gfp_flags);
 void iomap_invalidate_folio(struct folio *folio, size_t offset, size_t len);
 int iomap_file_unshare(struct inode *inode, loff_t pos, loff_t len,