On Thu, Jan 22, 2026 at 09:22:00AM +0100, Christoph Hellwig wrote: > 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: Christoph Hellwig <[email protected]> > --- > fs/ext4/verity.c | 17 +---------------- > fs/f2fs/verity.c | 17 +---------------- > fs/verity/pagecache.c | 38 ++++++++++++++++++++++++++++++++++++++ > include/linux/fsverity.h | 3 +++ > 4 files changed, 43 insertions(+), 32 deletions(-) > create mode 100644 fs/verity/pagecache.c > > diff --git a/fs/ext4/verity.c b/fs/ext4/verity.c > index 2ce4cf8a1e31..a071860ad36a 100644 > --- a/fs/ext4/verity.c > +++ b/fs/ext4/verity.c > @@ -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, > diff --git a/fs/f2fs/verity.c b/fs/f2fs/verity.c > index c1c4d8044681..d37e584423af 100644 > --- a/fs/f2fs/verity.c > +++ b/fs/f2fs/verity.c > @@ -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, > diff --git a/fs/verity/pagecache.c b/fs/verity/pagecache.c > new file mode 100644 > index 000000000000..1efcdde20b73 > --- /dev/null > +++ b/fs/verity/pagecache.c > @@ -0,0 +1,38 @@ > +// 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 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);
Nice hoist, though I wonder -- as an exported fs function, should we be checking that the returned folio doesn't cover EOF? Not that any of the users actually check that returned merkle tree folios fit that criterion. <shrug> as a pure hoist this is ok so Reviewed-by: "Darrick J. Wong" <[email protected]> --D > + 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); > diff --git a/include/linux/fsverity.h b/include/linux/fsverity.h > index e22cf84fe83a..121703625cc8 100644 > --- a/include/linux/fsverity.h > +++ b/include/linux/fsverity.h > @@ -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 */ > -- > 2.47.3 > > _______________________________________________ Linux-f2fs-devel mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/linux-f2fs-devel
