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: Matthew 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: Andrew Morton <akpm@linux-foundation.org>
This commit is contained in:
Matthew Wilcox (Oracle) 2023-06-12 22:01:40 +01:00 committed by Andrew Morton
parent 08d84add43
commit eee25182a8

View File

@ -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;
}