diff options
author | Matthew Wilcox <willy@infradead.org> | 2018-05-16 16:12:50 -0400 |
---|---|---|
committer | Matthew Wilcox <willy@infradead.org> | 2018-10-21 10:46:34 -0400 |
commit | 4c7472c0df2f889df417a37571e622e02b5058fe (patch) | |
tree | 15557c1b56edf6cc1f0092b59eb2145a80ce5a29 | |
parent | 5c024e6a4ebc1740db9f0f075aaa476210108a97 (diff) | |
download | linux-4c7472c0df2f889df417a37571e622e02b5058fe.tar.bz2 |
page cache: Convert find_get_entry to XArray
Slightly shorter and simpler code.
Signed-off-by: Matthew Wilcox <willy@infradead.org>
-rw-r--r-- | mm/filemap.c | 63 |
1 files changed, 28 insertions, 35 deletions
diff --git a/mm/filemap.c b/mm/filemap.c index 414efbdc95df..2bf9f0742082 100644 --- a/mm/filemap.c +++ b/mm/filemap.c @@ -1382,47 +1382,40 @@ EXPORT_SYMBOL(page_cache_prev_miss); */ struct page *find_get_entry(struct address_space *mapping, pgoff_t offset) { - void **pagep; + XA_STATE(xas, &mapping->i_pages, offset); struct page *head, *page; rcu_read_lock(); repeat: - page = NULL; - pagep = radix_tree_lookup_slot(&mapping->i_pages, offset); - if (pagep) { - page = radix_tree_deref_slot(pagep); - if (unlikely(!page)) - goto out; - if (radix_tree_exception(page)) { - if (radix_tree_deref_retry(page)) - goto repeat; - /* - * A shadow entry of a recently evicted page, - * or a swap entry from shmem/tmpfs. Return - * it without attempting to raise page count. - */ - goto out; - } + xas_reset(&xas); + page = xas_load(&xas); + if (xas_retry(&xas, page)) + goto repeat; + /* + * A shadow entry of a recently evicted page, or a swap entry from + * shmem/tmpfs. Return it without attempting to raise page count. + */ + if (!page || xa_is_value(page)) + goto out; - head = compound_head(page); - if (!page_cache_get_speculative(head)) - goto repeat; + head = compound_head(page); + if (!page_cache_get_speculative(head)) + goto repeat; - /* The page was split under us? */ - if (compound_head(page) != head) { - put_page(head); - goto repeat; - } + /* The page was split under us? */ + if (compound_head(page) != head) { + put_page(head); + goto repeat; + } - /* - * Has the page moved? - * This is part of the lockless pagecache protocol. See - * include/linux/pagemap.h for details. - */ - if (unlikely(page != *pagep)) { - put_page(head); - goto repeat; - } + /* + * Has the page moved? + * This is part of the lockless pagecache protocol. See + * include/linux/pagemap.h for details. + */ + if (unlikely(page != xas_reload(&xas))) { + put_page(head); + goto repeat; } out: rcu_read_unlock(); @@ -1453,7 +1446,7 @@ struct page *find_lock_entry(struct address_space *mapping, pgoff_t offset) repeat: page = find_get_entry(mapping, offset); - if (page && !radix_tree_exception(page)) { + if (page && !xa_is_value(page)) { lock_page(page); /* Has the page been truncated? */ if (unlikely(page_mapping(page) != mapping)) { |