buffer: make block_write_full_page() handle large folios correctly

Keep the interface as struct page, but work entirely on the folio
internally.  Removes several PAGE_SIZE assumptions and removes some
references to page->index and page->mapping.

Link: https://lkml.kernel.org/r/20230612210141.730128-7-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Tested-by: Bob Peterson <rpeterso@redhat.com>
Reviewed-by: Bob Peterson <rpeterso@redhat.com>
Cc: Andreas Gruenbacher <agruenba@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 22:01:33 +01:00 committed by Andrew Morton
parent 285e0fc95a
commit bb0ea5989c

View file

@ -2678,33 +2678,31 @@ int block_write_full_page(struct page *page, get_block_t *get_block,
struct writeback_control *wbc)
{
struct folio *folio = page_folio(page);
struct inode * const inode = page->mapping->host;
struct inode * const inode = folio->mapping->host;
loff_t i_size = i_size_read(inode);
const pgoff_t end_index = i_size >> PAGE_SHIFT;
unsigned offset;
/* Is the page fully inside i_size? */
if (page->index < end_index)
/* Is the folio fully inside i_size? */
if (folio_pos(folio) + folio_size(folio) <= i_size)
return __block_write_full_folio(inode, folio, get_block, wbc,
end_buffer_async_write);
/* Is the page fully outside i_size? (truncate in progress) */
offset = i_size & (PAGE_SIZE-1);
if (page->index >= end_index+1 || !offset) {
/* Is the folio fully outside i_size? (truncate in progress) */
if (folio_pos(folio) >= i_size) {
folio_unlock(folio);
return 0; /* don't care */
}
/*
* The page straddles i_size. It must be zeroed out on each and every
* The folio straddles i_size. It must be zeroed out on each and every
* writepage invocation because it may be mmapped. "A file is mapped
* in multiples of the page size. For a file that is not a multiple of
* the page size, the remaining memory is zeroed when mapped, and
* the page size, the remaining memory is zeroed when mapped, and
* writes to that region are not written out to the file."
*/
zero_user_segment(page, offset, PAGE_SIZE);
folio_zero_segment(folio, offset_in_folio(folio, i_size),
folio_size(folio));
return __block_write_full_folio(inode, folio, get_block, wbc,
end_buffer_async_write);
end_buffer_async_write);
}
EXPORT_SYMBOL(block_write_full_page);