Commit c71124a8 authored by Pankaj Raghav's avatar Pankaj Raghav Committed by Andrew Morton
Browse files

buffer: add folio_alloc_buffers() helper 

Folio version of alloc_page_buffers() helper.  This is required to convert
create_page_buffers() to folio_create_buffers() later in the series.

alloc_page_buffers() has been modified to call folio_alloc_buffers() which
adds one call to compound_head() but folio_alloc_buffers() removes one
call to compound_head() compared to the existing alloc_page_buffers()
implementation.

Link: https://lkml.kernel.org/r/20230417123618.22094-3-p.raghav@samsung.com


Signed-off-by: default avatarPankaj Raghav <p.raghav@samsung.com>
Reviewed-by: default avatarMatthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: default avatarHannes Reinecke <hare@suse.de>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Christian Brauner <brauner@kernel.org>
Cc: Luis Chamberlain <mcgrof@kernel.org>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
parent 465e5e6a

fs/buffer.c

+15 −8
Original line number Diff line number Diff line
@@ -843,7 +843,7 @@ int remove_inode_buffers(struct inode *inode) 
}



/*

 * Create the appropriate buffers when given a page for data area and

 * Create the appropriate buffers when given a folio for data area and

 * the size of each buffer.. Use the bh->b_this_page linked list to

 * follow the buffers created.  Return NULL if unable to create more

 * buffers.
@@ -851,7 +851,7 @@ int remove_inode_buffers(struct inode *inode) 
 * The retry flag is used to differentiate async IO (paging, swapping)

 * which may not fail from ordinary buffer allocations.

 */

struct buffer_head *alloc_page_buffers(struct page *page, unsigned long size,

struct buffer_head *folio_alloc_buffers(struct folio *folio, unsigned long size,

					bool retry)

{

	struct buffer_head *bh, *head;
@@ -862,12 +862,12 @@ struct buffer_head *alloc_page_buffers(struct page *page, unsigned long size, 
	if (retry)

		gfp |= __GFP_NOFAIL;



	/* The page lock pins the memcg */

	memcg = page_memcg(page);

	/* The folio lock pins the memcg */

	memcg = folio_memcg(folio);

	old_memcg = set_active_memcg(memcg);



	head = NULL;

	offset = PAGE_SIZE;

	offset = folio_size(folio);

	while ((offset -= size) >= 0) {

		bh = alloc_buffer_head(gfp);

		if (!bh)
@@ -879,8 +879,8 @@ struct buffer_head *alloc_page_buffers(struct page *page, unsigned long size, 


		bh->b_size = size;



		/* Link the buffer to its page */

		set_bh_page(bh, page, offset);

		/* Link the buffer to its folio */

		folio_set_bh(bh, folio, offset);

	}

out:

	set_active_memcg(old_memcg);
@@ -899,6 +899,13 @@ struct buffer_head *alloc_page_buffers(struct page *page, unsigned long size, 


	goto out;

}

EXPORT_SYMBOL_GPL(folio_alloc_buffers);



struct buffer_head *alloc_page_buffers(struct page *page, unsigned long size,

				       bool retry)

{

	return folio_alloc_buffers(page_folio(page), size, retry);

}

EXPORT_SYMBOL_GPL(alloc_page_buffers);



static inline void

include/linux/buffer_head.h

+2 −0
Original line number Diff line number Diff line
@@ -199,6 +199,8 @@ void set_bh_page(struct buffer_head *bh, 
void folio_set_bh(struct buffer_head *bh, struct folio *folio,

		  unsigned long offset);

bool try_to_free_buffers(struct folio *);

struct buffer_head *folio_alloc_buffers(struct folio *folio, unsigned long size,

					bool retry);

struct buffer_head *alloc_page_buffers(struct page *page, unsigned long size,

		bool retry);

void create_empty_buffers(struct page *, unsigned long,