From mboxrd@z Thu Jan 1 00:00:00 1970 From: Matthew Wilcox Subject: [PATCH v14 34/74] page cache: Convert filemap_range_has_page to XArray Date: Sat, 16 Jun 2018 19:00:12 -0700 Message-ID: <20180617020052.4759-35-willy@infradead.org> References: <20180617020052.4759-1-willy@infradead.org> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=sourceforge.net; s=x; h=References:In-Reply-To:Message-Id:Date:Subject:Cc: To:From:Sender:Reply-To:MIME-Version:Content-Type:Content-Transfer-Encoding: Content-ID:Content-Description:Resent-Date:Resent-From:Resent-Sender: Resent-To:Resent-Cc:Resent-Message-ID:List-Id:List-Help:List-Unsubscribe: List-Subscribe:List-Post:List-Owner:List-Archive; bh=RmQxGBWzt2Rxic4Hz4j+/UfZAYB1EstyKVlk7zyedMk=; b=XUtZ/4UQUOShRYckDX+kjDJZcq 5Ep9lCWlJHgIzVBqmrHrV0nKtXeDPr/vQ50YpxweeOmqKOzTxayR4FiO3H4dbh08vXZ7wAvxVRdWS fXDtHwaEtg73E9IFxJxraUKZSlVo6qxMEClnSeZxmqkPNTudpeXbaA4LrwljutUbHOE4=; DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=sf.net; s=x ; h=References:In-Reply-To:Message-Id:Date:Subject:Cc:To:From:Sender:Reply-To :MIME-Version:Content-Type:Content-Transfer-Encoding:Content-ID: Content-Description:Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc :Resent-Message-ID:List-Id:List-Help:List-Unsubscribe:List-Subscribe: List-Post:List-Owner:List-Archive; bh=RmQxGBWzt2Rxic4Hz4j+/UfZAYB1EstyKVlk7zyedMk=; b=bhmQn87xsTxTBVHfJKLiwgiU+x jjjMUR/hc5NaEqR33jFNKUhT5cE5dht2UqRtQYdvAX0r+IoteD0iMfoQj+1skco/Dl+8kr3t5mxnE MLX489b0OpzSsA/b7wt+pQ+wz+Cc5F2Ra8ahJGbIlYj8FjGErvDKJ4Q1SPk1Oxx4xzc8=; DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.20170209; h=References:In-Reply-To:Message-Id: Date:Subject:Cc:To:From:Sender:Reply-To:MIME-Version:Content-Type: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Id: List-Help:List-Unsubscribe:List-Subscribe:List-Post:List-Owner:List-Archive; bh=RmQxGBWzt2Rxic4Hz4j+/UfZAYB1EstyKVlk7zyedMk=; b=VAh90YkPtkWsf2GEmVLvEr4E1 C104EEcRnq5IRFvAFey/G5674jWmMV+hNdU/hTQ7gftDOaj5R5WnyNgmhAR9dKO3bsRD/Z2HQJGG5 oi5/UoxCozYhg/lmJ5hyEarBt16rH4I10IYRPywmT5tITeI+eAUM3Oj9LgE2iB/7jcnhAUJyGJYsq f12bQ4oVBnIyWU3CqYrnoHNJ+pePxVPIMX304XhaPXRHLOnR6uDEC0R3PtGloXB+P+OBE2r4seA3/ rqDO5M8ynkmbLNZr55U3d8VF3TWOnMio6Oulv6YxSoIG1xcswpK76pwOPm6jTe7Etf4QMFOxQiMsW tKeil2txw==; In-Reply-To: <20180617020052.4759-1-willy@infradead.org> List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: linux-f2fs-devel-bounces@lists.sourceforge.net To: linux-mm@kvack.org, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org Cc: linux-nilfs@vger.kernel.org, Jan Kara , Jeff Layton , Jaegeuk Kim , Matthew Wilcox , linux-f2fs-devel@lists.sourceforge.net, Nicholas Piggin , Ryusuke Konishi , Lukas Czerner , Ross Zwisler , Christoph Hellwig , Goldwyn Rodrigues Instead of calling find_get_pages_range() and putting any reference, use xas_find() to iterate over any entries in the range, skipping the shadow/swap entries. Signed-off-by: Matthew Wilcox --- mm/filemap.c | 26 ++++++++++++++++++-------- 1 file changed, 18 insertions(+), 8 deletions(-) diff --git a/mm/filemap.c b/mm/filemap.c index e447dd2d0f5c..68890327d1f2 100644 --- a/mm/filemap.c +++ b/mm/filemap.c @@ -455,20 +455,30 @@ EXPORT_SYMBOL(filemap_flush); bool filemap_range_has_page(struct address_space *mapping, loff_t start_byte, loff_t end_byte) { - pgoff_t index = start_byte >> PAGE_SHIFT; - pgoff_t end = end_byte >> PAGE_SHIFT; struct page *page; + XA_STATE(xas, &mapping->i_pages, start_byte >> PAGE_SHIFT); + pgoff_t max = end_byte >> PAGE_SHIFT; if (end_byte < start_byte) return false; - if (mapping->nrpages == 0) - return false; + rcu_read_lock(); + do { + page = xas_find(&xas, max); + if (xas_retry(&xas, page)) + continue; + /* Shadow entries don't count */ + if (xa_is_value(page)) + continue; + /* + * We don't need to try to pin this page; we're about to + * release the RCU lock anyway. It is enough to know that + * there was a page here recently. + */ + } while (0); + rcu_read_unlock(); - if (!find_get_pages_range(mapping, &index, end, 1, &page)) - return false; - put_page(page); - return true; + return page != NULL; } EXPORT_SYMBOL(filemap_range_has_page); -- 2.17.1 ------------------------------------------------------------------------------ Check out the vibrant tech community on one of the world's most engaging tech sites, Slashdot.org! http://sdm.link/slashdot