Commit eee25182 authored by Matthew Wilcox (Oracle)'s avatar Matthew Wilcox (Oracle) Committed by Andrew Morton
Browse files

buffer: use a folio in __find_get_block_slow() 

Saves a call to compound_head() and may be needed to support block size >
PAGE_SIZE.

Link: https://lkml.kernel.org/r/20230612210141.730128-14-willy@infradead.org


Signed-off-by: default avatarMatthew Wilcox (Oracle) <willy@infradead.org>
Cc: Andreas Gruenbacher <agruenba@redhat.com>
Cc: Bob Peterson <rpeterso@redhat.com>
Cc: Hannes Reinecke <hare@suse.com>
Cc: Luis Chamberlain <mcgrof@kernel.org>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
parent 08d84add

fs/buffer.c

+6 −6
Original line number Diff line number Diff line
@@ -195,19 +195,19 @@ __find_get_block_slow(struct block_device *bdev, sector_t block) 
	pgoff_t index;

	struct buffer_head *bh;

	struct buffer_head *head;

	struct page *page;

	struct folio *folio;

	int all_mapped = 1;

	static DEFINE_RATELIMIT_STATE(last_warned, HZ, 1);



	index = block >> (PAGE_SHIFT - bd_inode->i_blkbits);

	page = find_get_page_flags(bd_mapping, index, FGP_ACCESSED);

	if (!page)

	folio = __filemap_get_folio(bd_mapping, index, FGP_ACCESSED, 0);

	if (IS_ERR(folio))

		goto out;



	spin_lock(&bd_mapping->private_lock);

	if (!page_has_buffers(page))

	head = folio_buffers(folio);

	if (!head)

		goto out_unlock;

	head = page_buffers(page);

	bh = head;

	do {

		if (!buffer_mapped(bh))
@@ -237,7 +237,7 @@ __find_get_block_slow(struct block_device *bdev, sector_t block) 
	}

out_unlock:

	spin_unlock(&bd_mapping->private_lock);

	put_page(page);

	folio_put(folio);

out:

	return ret;

}