Commit 821ddd25 authored by Christoph Hellwig's avatar Christoph Hellwig Committed by Eric Biggers
Browse files

fsverity: start consolidating pagecache code 



ext4 and f2fs are largely using the same code to read a page full
of Merkle tree blocks from the page cache, and the upcoming xfs
fsverity support would add another copy.

Move the ext4 code to fs/verity/ and use it in f2fs as well.  For f2fs
this removes the previous f2fs-specific error injection, but otherwise
the behavior remains unchanged.

Signed-off-by: default avatarChristoph Hellwig <hch@lst.de>
Reviewed-by: default avatarAndrey Albershteyn <aalbersh@redhat.com>
Reviewed-by: default avatarJan Kara <jack@suse.cz>
Reviewed-by: default avatar"Darrick J. Wong" <djwong@kernel.org>
Link: https://lore.kernel.org/r/20260128152630.627409-7-hch@lst.de


Signed-off-by: default avatarEric Biggers <ebiggers@kernel.org>
parent ac09a309

fs/ext4/verity.c

+1 −16
Original line number Diff line number Diff line
@@ -361,23 +361,8 @@ static struct page *ext4_read_merkle_tree_page(struct inode *inode, 
					       pgoff_t index,

					       unsigned long num_ra_pages)

{

	struct folio *folio;



	index += ext4_verity_metadata_pos(inode) >> PAGE_SHIFT;



	folio = __filemap_get_folio(inode->i_mapping, index, FGP_ACCESSED, 0);

	if (IS_ERR(folio) || !folio_test_uptodate(folio)) {

		DEFINE_READAHEAD(ractl, NULL, NULL, inode->i_mapping, index);



		if (!IS_ERR(folio))

			folio_put(folio);

		else if (num_ra_pages > 1)

			page_cache_ra_unbounded(&ractl, num_ra_pages, 0);

		folio = read_mapping_folio(inode->i_mapping, index, NULL);

		if (IS_ERR(folio))

			return ERR_CAST(folio);

	}

	return folio_file_page(folio, index);

	return generic_read_merkle_tree_page(inode, index, num_ra_pages);

}



static int ext4_write_merkle_tree_block(struct file *file, const void *buf,

fs/f2fs/verity.c

+1 −16
Original line number Diff line number Diff line
@@ -259,23 +259,8 @@ static struct page *f2fs_read_merkle_tree_page(struct inode *inode, 
					       pgoff_t index,

					       unsigned long num_ra_pages)

{

	struct folio *folio;



	index += f2fs_verity_metadata_pos(inode) >> PAGE_SHIFT;



	folio = f2fs_filemap_get_folio(inode->i_mapping, index, FGP_ACCESSED, 0);

	if (IS_ERR(folio) || !folio_test_uptodate(folio)) {

		DEFINE_READAHEAD(ractl, NULL, NULL, inode->i_mapping, index);



		if (!IS_ERR(folio))

			folio_put(folio);

		else if (num_ra_pages > 1)

			page_cache_ra_unbounded(&ractl, num_ra_pages, 0);

		folio = read_mapping_folio(inode->i_mapping, index, NULL);

		if (IS_ERR(folio))

			return ERR_CAST(folio);

	}

	return folio_file_page(folio, index);

	return generic_read_merkle_tree_page(inode, index, num_ra_pages);

}



static int f2fs_write_merkle_tree_block(struct file *file, const void *buf,

fs/verity/Makefile

+1 −0
Original line number Diff line number Diff line
@@ -5,6 +5,7 @@ obj-$(CONFIG_FS_VERITY) += enable.o \ 
			   init.o \

			   measure.o \

			   open.o \

			   pagecache.o \

			   read_metadata.o \

			   verify.o

fs/verity/pagecache.c

0 → 100644
+38 −0
Original line number Diff line number Diff line 
// SPDX-License-Identifier: GPL-2.0

/*

 * Copyright 2019 Google LLC

 */



#include <linux/fsverity.h>

#include <linux/pagemap.h>



/**

 * generic_read_merkle_tree_page - generic ->read_merkle_tree_page helper

 * @inode:	inode containing the Merkle tree

 * @index:	0-based index of the Merkle tree page in the inode

 * @num_ra_pages: The number of Merkle tree pages that should be prefetched.

 *

 * The caller needs to adjust @index from the Merkle-tree relative index passed

 * to ->read_merkle_tree_page to the actual index where the Merkle tree is

 * stored in the page cache for @inode.

 */

struct page *generic_read_merkle_tree_page(struct inode *inode, pgoff_t index,

					   unsigned long num_ra_pages)

{

	struct folio *folio;



	folio = __filemap_get_folio(inode->i_mapping, index, FGP_ACCESSED, 0);

	if (IS_ERR(folio) || !folio_test_uptodate(folio)) {

		DEFINE_READAHEAD(ractl, NULL, NULL, inode->i_mapping, index);



		if (!IS_ERR(folio))

			folio_put(folio);

		else if (num_ra_pages > 1)

			page_cache_ra_unbounded(&ractl, num_ra_pages, 0);

		folio = read_mapping_folio(inode->i_mapping, index, NULL);

		if (IS_ERR(folio))

			return ERR_CAST(folio);

	}

	return folio_file_page(folio, index);

}

EXPORT_SYMBOL_GPL(generic_read_merkle_tree_page);

include/linux/fsverity.h

+3 −0
Original line number Diff line number Diff line
@@ -309,4 +309,7 @@ static inline int fsverity_file_open(struct inode *inode, struct file *filp) 


void fsverity_cleanup_inode(struct inode *inode);



struct page *generic_read_merkle_tree_page(struct inode *inode, pgoff_t index,

					   unsigned long num_ra_pages);



#endif	/* _LINUX_FSVERITY_H */