From mboxrd@z Thu Jan 1 00:00:00 1970 From: Matthew Wilcox Subject: [PATCH v13 33/72] page cache: Convert filemap_range_has_page to XArray Date: Mon, 11 Jun 2018 07:06:00 -0700 Message-ID: <20180611140639.17215-34-willy@infradead.org> References: <20180611140639.17215-1-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=sqW1jfi9fXH0Wb9SlzcbfFhp+ufIQamOcMd7GrKgp30=; b=HNimodX/24Jss5ewOHC6HGVpkq mT2IUc27xh4lFLCU7mIFBkvXxLeEyNhD+HJJeCbw6xsweLPNj+x3J2ilTSUGRBfmuWTowqQESzNFy i6l8XSsnRt4Ht7nG5sx2s+s79QxCCPYpc+60BH6fuVBWXedtSNf0zEHyg3VVpJmR0s6o=; 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=sqW1jfi9fXH0Wb9SlzcbfFhp+ufIQamOcMd7GrKgp30=; b=OoCOj6+GxabKG5LoVMbl4PdjAE PnbQNR51ZH+uZEzzmv7F3hv1QvD4uvDtTsMkyIoz7U9Y/Zfvi4GdQLihhqQBRlDODWdKhZWozwOn2 TJ/aN1bHjtxd4+M/83/j102oynCxu6YO2EhZw6Vd3E1f3PJvpxCelJis1UdWjo1JK9ew=; 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=sqW1jfi9fXH0Wb9SlzcbfFhp+ufIQamOcMd7GrKgp30=; b=ti2BeWGG2O8VtFgPTXfuBL08A fYuk5wfFSIALiyRyiOVZYMYGq+cmtU7k/7WXmu/wpYRpkoqK/AbVGMoB/HOQ4tqx3PvwRRjOUurEe JI5AJhhxiDZt2xzHTex3R+REArl+nCwQmFWVa3J0S4I63THIuPrc8ogqn7p6LwNx6ZkxWgRHtq0ku 5tNiZUKBM26rVuzmNRYclzQueBCbuMka4yXBMeKWR08d2DxcTmJ2hg21SWBs6jeNwjwR8uW9n1MmE ewJyWeyMdDWApJSBc9BXzQW3QdLeCg5G9kOiJFQf/I03iUZ6UEEZ9tymI2JW/Fh9/gA/dWQrrfvuh J8mFNoFmQ==; In-Reply-To: <20180611140639.17215-1-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 , Matthew Wilcox , Jaegeuk Kim , Nicholas Piggin , linux-f2fs-devel@lists.sourceforge.net, Ryusuke Konishi , Lukas Czerner , Ross Zwisler , Christoph Hellwig , Goldwyn Rodrigues From: Matthew Wilcox 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