Commit 128d1f82 authored by Matthew Wilcox (Oracle)'s avatar Matthew Wilcox (Oracle)
Browse files

fs: Add invalidate_folio() aops method 



This is used in preference to invalidatepage, if defined.

Signed-off-by: default avatarMatthew Wilcox (Oracle) <willy@infradead.org>
Tested-by: default avatarDamien Le Moal <damien.lemoal@opensource.wdc.com>
Acked-by: default avatarDamien Le Moal <damien.lemoal@opensource.wdc.com>
Tested-by: Mike Marshall <hubcap@omnibond.com> # orangefs
Tested-by: David Howells <dhowells@redhat.com> # afs
parent 020df9ba

Documentation/filesystems/locking.rst

+7 −6
Original line number Diff line number Diff line
@@ -250,6 +250,7 @@ prototypes:: 
				loff_t pos, unsigned len, unsigned copied,

				struct page *page, void *fsdata);

	sector_t (*bmap)(struct address_space *, sector_t);

	void (*invalidate_folio) (struct folio *, size_t start, size_t len);

	void (*invalidatepage) (struct page *, unsigned int, unsigned int);

	int (*releasepage) (struct page *, int);

	void (*freepage)(struct page *);
@@ -278,6 +279,7 @@ readpages: no shared 
write_begin:		locks the page		 exclusive

write_end:		yes, unlocks		 exclusive

bmap:

invalidate_folio:	yes					exclusive

invalidatepage:		yes					exclusive

releasepage:		yes

freepage:		yes
@@ -370,13 +372,12 @@ not locked. 
filesystems and by the swapper. The latter will eventually go away.  Please,

keep it that way and don't breed new callers.



->invalidatepage() is called when the filesystem must attempt to drop

->invalidate_folio() is called when the filesystem must attempt to drop

some or all of the buffers from the page when it is being truncated. It

returns zero on success. If ->invalidatepage is zero, the kernel uses

block_invalidatepage() instead. The filesystem must exclusively acquire

invalidate_lock before invalidating page cache in truncate / hole punch path

(and thus calling into ->invalidatepage) to block races between page cache

invalidation and page cache filling functions (fault, read, ...).

returns zero on success.  The filesystem must exclusively acquire

invalidate_lock before invalidating page cache in truncate / hole punch

path (and thus calling into ->invalidate_folio) to block races between page

cache invalidation and page cache filling functions (fault, read, ...).



->releasepage() is called when the kernel is about to try to drop the

buffers from the page in preparation for freeing it.  It returns zero to

Documentation/filesystems/vfs.rst

+6 −5
Original line number Diff line number Diff line
@@ -735,6 +735,7 @@ cache in your filesystem. The following members are defined: 
				 loff_t pos, unsigned len, unsigned copied,

				 struct page *page, void *fsdata);

		sector_t (*bmap)(struct address_space *, sector_t);

		void (*invalidate_folio) (struct folio *, size_t start, size_t len);

		void (*invalidatepage) (struct page *, unsigned int, unsigned int);

		int (*releasepage) (struct page *, int);

		void (*freepage)(struct page *);
@@ -868,15 +869,15 @@ cache in your filesystem. The following members are defined: 
	to find out where the blocks in the file are and uses those

	addresses directly.



``invalidatepage``

	If a page has PagePrivate set, then invalidatepage will be

	called when part or all of the page is to be removed from the

``invalidate_folio``

	If a folio has private data, then invalidate_folio will be

	called when part or all of the folio is to be removed from the

	address space.  This generally corresponds to either a

	truncation, punch hole or a complete invalidation of the address

	space (in the latter case 'offset' will always be 0 and 'length'

	will be PAGE_SIZE).  Any private data associated with the page

	will be folio_size()).  Any private data associated with the page

	should be updated to reflect this truncation.  If offset is 0

	and length is PAGE_SIZE, then the private data should be

	and length is folio_size(), then the private data should be

	released, because the page must be able to be completely

	discarded.  This may be done by calling the ->releasepage

	function, but in this case the release MUST succeed.

include/linux/fs.h

+1 −0
Original line number Diff line number Diff line
@@ -387,6 +387,7 @@ struct address_space_operations { 


	/* Unfortunately this kludge is needed for FIBMAP. Don't use it */

	sector_t (*bmap)(struct address_space *, sector_t);

	void (*invalidate_folio) (struct folio *, size_t offset, size_t len);

	void (*invalidatepage) (struct page *, unsigned int, unsigned int);

	int (*releasepage) (struct page *, gfp_t);

	void (*freepage)(struct page *);

mm/truncate.c

+7 −1
Original line number Diff line number Diff line
@@ -154,9 +154,15 @@ static int invalidate_exceptional_entry2(struct address_space *mapping, 
 */

void folio_invalidate(struct folio *folio, size_t offset, size_t length)

{

	const struct address_space_operations *aops = folio->mapping->a_ops;

	void (*invalidatepage)(struct page *, unsigned int, unsigned int);



	invalidatepage = folio->mapping->a_ops->invalidatepage;

	if (aops->invalidate_folio) {

		aops->invalidate_folio(folio, offset, length);

		return;

	}



	invalidatepage = aops->invalidatepage;

#ifdef CONFIG_BLOCK

	if (!invalidatepage)

		invalidatepage = block_invalidatepage;