From mboxrd@z Thu Jan 1 00:00:00 1970 From: Matthew Wilcox Subject: [PATCH v5 49/78] shmem: Convert shmem_free_swap to XArray Date: Fri, 15 Dec 2017 14:04:21 -0800 Message-ID: <20171215220450.7899-50-willy@infradead.org> References: <20171215220450.7899-1-willy@infradead.org> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Received: from sfi-mx-2.v28.ch3.sourceforge.com ([172.29.28.192] helo=mx.sourceforge.net) by sfs-ml-1.v29.ch3.sourceforge.com with esmtps (TLSv1.2:ECDHE-RSA-AES256-GCM-SHA384:256) (Exim 4.89) (envelope-from ) id 1ePy72-0007mP-T3 for linux-f2fs-devel@lists.sourceforge.net; Fri, 15 Dec 2017 22:05:48 +0000 Received: from bombadil.infradead.org ([65.50.211.133]) by sfi-mx-2.v28.ch3.sourceforge.com with esmtps (TLSv1.2:ECDHE-RSA-AES256-GCM-SHA384:256) (Exim 4.89) id 1ePy72-0007Cx-2t for linux-f2fs-devel@lists.sourceforge.net; Fri, 15 Dec 2017 22:05:48 +0000 In-Reply-To: <20171215220450.7899-1-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-kernel@vger.kernel.org Cc: Jens Axboe , linux-xfs@vger.kernel.org, linux-nilfs@vger.kernel.org, linux-raid@vger.kernel.org, Matthew Wilcox , Marc Zyngier , linux-usb@vger.kernel.org, linux-f2fs-devel@lists.sourceforge.net, David Howells , linux-mm@kvack.org, linux-fsdevel@vger.kernel.org, Ross Zwisler , Rehas Sachdeva , Shaohua Li , linux-btrfs@vger.kernel.org From: Matthew Wilcox This is a perfect use for xa_cmpxchg(). Note the use of 0 for GFP flags; we won't be allocating memory. Signed-off-by: Matthew Wilcox --- mm/shmem.c | 7 ++----- 1 file changed, 2 insertions(+), 5 deletions(-) diff --git a/mm/shmem.c b/mm/shmem.c index bd66bbd40499..dd663341e01e 100644 --- a/mm/shmem.c +++ b/mm/shmem.c @@ -635,16 +635,13 @@ static void shmem_delete_from_page_cache(struct page *page, void *radswap) } /* - * Remove swap entry from radix tree, free the swap and its page cache. + * Remove swap entry from page cache, free the swap and its page cache. */ static int shmem_free_swap(struct address_space *mapping, pgoff_t index, void *radswap) { - void *old; + void *old = xa_cmpxchg(&mapping->pages, index, radswap, NULL, 0); - xa_lock_irq(&mapping->pages); - old = radix_tree_delete_item(&mapping->pages, index, radswap); - xa_unlock_irq(&mapping->pages); if (old != radswap) return -ENOENT; free_swap_and_cache(radix_to_swp_entry(radswap)); -- 2.15.1 ------------------------------------------------------------------------------ Check out the vibrant tech community on one of the world's most engaging tech sites, Slashdot.org! http://sdm.link/slashdot