From patchwork Thu Dec 12 00:30:41 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Goldwyn Rodrigues X-Patchwork-Id: 11286643 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 44D4515AB for ; Thu, 12 Dec 2019 00:31:06 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 2E42B2173E for ; Thu, 12 Dec 2019 00:31:06 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727440AbfLLAbF (ORCPT ); Wed, 11 Dec 2019 19:31:05 -0500 Received: from mx2.suse.de ([195.135.220.15]:42268 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1727359AbfLLAbF (ORCPT ); Wed, 11 Dec 2019 19:31:05 -0500 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.220.254]) by mx1.suse.de (Postfix) with ESMTP id 7F614ADF1; Thu, 12 Dec 2019 00:31:02 +0000 (UTC) From: Goldwyn Rodrigues To: linux-btrfs@vger.kernel.org Cc: linux-fsdevel@vger.kernel.org, hch@infradead.org, darrick.wong@oracle.com, fdmanana@kernel.org, dsterba@suse.cz, jthumshirn@suse.de, nborisov@suse.com, Goldwyn Rodrigues Subject: [PATCH 6/8] btrfs: Wait for extent bits to release page Date: Wed, 11 Dec 2019 18:30:41 -0600 Message-Id: <20191212003043.31093-7-rgoldwyn@suse.de> X-Mailer: git-send-email 2.16.4 In-Reply-To: <20191212003043.31093-1-rgoldwyn@suse.de> References: <20191212003043.31093-1-rgoldwyn@suse.de> Sender: linux-btrfs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-btrfs@vger.kernel.org From: Goldwyn Rodrigues While trying to release a page, the extent containing the page may be locked which would stop the page from being released. Wait for the extent lock to be cleared, if blocking is allowed and then clear the bits. While we are at it, clean the code of try_release_extent_state() to make it simpler. Signed-off-by: Goldwyn Rodrigues Reviewed-by: Johannes Thumshirn Reviewed-by: Nikolay Borisov --- fs/btrfs/extent_io.c | 37 ++++++++++++++++--------------------- fs/btrfs/extent_io.h | 2 +- fs/btrfs/inode.c | 4 ++-- 3 files changed, 19 insertions(+), 24 deletions(-) diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c index eb8bd0258360..193785981183 100644 --- a/fs/btrfs/extent_io.c +++ b/fs/btrfs/extent_io.c @@ -4360,33 +4360,28 @@ int extent_invalidatepage(struct extent_io_tree *tree, * are locked or under IO and drops the related state bits if it is safe * to drop the page. */ -static int try_release_extent_state(struct extent_io_tree *tree, +static bool try_release_extent_state(struct extent_io_tree *tree, struct page *page, gfp_t mask) { u64 start = page_offset(page); u64 end = start + PAGE_SIZE - 1; - int ret = 1; if (test_range_bit(tree, start, end, EXTENT_LOCKED, 0, NULL)) { - ret = 0; - } else { - /* - * at this point we can safely clear everything except the - * locked bit and the nodatasum bit - */ - ret = __clear_extent_bit(tree, start, end, - ~(EXTENT_LOCKED | EXTENT_NODATASUM), - 0, 0, NULL, mask, NULL); - - /* if clear_extent_bit failed for enomem reasons, - * we can't allow the release to continue. - */ - if (ret < 0) - ret = 0; - else - ret = 1; + if (!gfpflags_allow_blocking(mask)) + return false; + wait_extent_bit(tree, start, end, EXTENT_LOCKED); } - return ret; + /* + * At this point we can safely clear everything except the locked and + * nodatasum bits. If clear_extent_bit failed due to -ENOMEM, + * don't allow release. + */ + if (__clear_extent_bit(tree, start, end, + ~(EXTENT_LOCKED | EXTENT_NODATASUM), 0, 0, + NULL, mask, NULL) < 0) + return false; + + return true; } /* @@ -4394,7 +4389,7 @@ static int try_release_extent_state(struct extent_io_tree *tree, * in the range corresponding to the page, both state records and extent * map records are removed */ -int try_release_extent_mapping(struct page *page, gfp_t mask) +bool try_release_extent_mapping(struct page *page, gfp_t mask) { struct extent_map *em; u64 start = page_offset(page); diff --git a/fs/btrfs/extent_io.h b/fs/btrfs/extent_io.h index a8551a1f56e2..89cc0cf8a7fd 100644 --- a/fs/btrfs/extent_io.h +++ b/fs/btrfs/extent_io.h @@ -188,7 +188,7 @@ typedef struct extent_map *(get_extent_t)(struct btrfs_inode *inode, u64 start, u64 len, int create); -int try_release_extent_mapping(struct page *page, gfp_t mask); +bool try_release_extent_mapping(struct page *page, gfp_t mask); int try_release_extent_buffer(struct page *page); int extent_read_full_page(struct extent_io_tree *tree, struct page *page, diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c index 91b830022146..2e7452c7fe61 100644 --- a/fs/btrfs/inode.c +++ b/fs/btrfs/inode.c @@ -8809,8 +8809,8 @@ btrfs_readpages(struct file *file, struct address_space *mapping, static int __btrfs_releasepage(struct page *page, gfp_t gfp_flags) { - int ret = try_release_extent_mapping(page, gfp_flags); - if (ret == 1) { + bool ret = try_release_extent_mapping(page, gfp_flags); + if (ret) { ClearPagePrivate(page); set_page_private(page, 0); put_page(page);