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Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
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linux
1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Copyright 2019 Google LLC
4 */
5
6#include <linux/export.h>
7#include <linux/fsverity.h>
8#include <linux/pagemap.h>
9
10/**
11 * generic_read_merkle_tree_page - generic ->read_merkle_tree_page helper
12 * @inode: inode containing the Merkle tree
13 * @index: 0-based index of the Merkle tree page in the inode
14 *
15 * The caller needs to adjust @index from the Merkle-tree relative index passed
16 * to ->read_merkle_tree_page to the actual index where the Merkle tree is
17 * stored in the page cache for @inode.
18 */
19struct page *generic_read_merkle_tree_page(struct inode *inode, pgoff_t index)
20{
21 struct folio *folio;
22
23 folio = read_mapping_folio(inode->i_mapping, index, NULL);
24 if (IS_ERR(folio))
25 return ERR_CAST(folio);
26 return folio_file_page(folio, index);
27}
28EXPORT_SYMBOL_GPL(generic_read_merkle_tree_page);
29
30/**
31 * generic_readahead_merkle_tree() - generic ->readahead_merkle_tree helper
32 * @inode: inode containing the Merkle tree
33 * @index: 0-based index of the first Merkle tree page to read ahead in the
34 * inode
35 * @nr_pages: the number of Merkle tree pages that should be read ahead
36 *
37 * The caller needs to adjust @index from the Merkle-tree relative index passed
38 * to ->read_merkle_tree_page to the actual index where the Merkle tree is
39 * stored in the page cache for @inode.
40 */
41void generic_readahead_merkle_tree(struct inode *inode, pgoff_t index,
42 unsigned long nr_pages)
43{
44 struct folio *folio;
45
46 lockdep_assert_held(&inode->i_mapping->invalidate_lock);
47
48 folio = __filemap_get_folio(inode->i_mapping, index, FGP_ACCESSED, 0);
49 if (folio == ERR_PTR(-ENOENT) ||
50 (!IS_ERR(folio) && !folio_test_uptodate(folio))) {
51 DEFINE_READAHEAD(ractl, NULL, NULL, inode->i_mapping, index);
52
53 page_cache_ra_unbounded(&ractl, nr_pages, 0);
54 }
55 if (!IS_ERR(folio))
56 folio_put(folio);
57}
58EXPORT_SYMBOL_GPL(generic_readahead_merkle_tree);