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// SPDX-License-Identifier: GPL-2.0
/*
* Copyright 2019 Google LLC
*/
#include <linux/export.h>
#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
*
* 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)
{
struct folio *folio;
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);
/**
* generic_readahead_merkle_tree() - generic ->readahead_merkle_tree helper
* @inode: inode containing the Merkle tree
* @index: 0-based index of the first Merkle tree page to read ahead in the
* inode
* @nr_pages: the number of Merkle tree pages that should be read ahead
*
* 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.
*/
void generic_readahead_merkle_tree(struct inode *inode, pgoff_t index,
unsigned long nr_pages)
{
struct folio *folio;
lockdep_assert_held(&inode->i_mapping->invalidate_lock);
folio = __filemap_get_folio(inode->i_mapping, index, FGP_ACCESSED, 0);
if (folio == ERR_PTR(-ENOENT) ||
(!IS_ERR(folio) && !folio_test_uptodate(folio))) {
DEFINE_READAHEAD(ractl, NULL, NULL, inode->i_mapping, index);
page_cache_ra_unbounded(&ractl, nr_pages, 0);
}
if (!IS_ERR(folio))
folio_put(folio);
}
EXPORT_SYMBOL_GPL(generic_readahead_merkle_tree);
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