From patchwork Fri Jun 5 20:48:37 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Goldwyn Rodrigues X-Patchwork-Id: 11590473 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 641EF159A for ; Fri, 5 Jun 2020 20:48:53 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 54D0B206FA for ; Fri, 5 Jun 2020 20:48:53 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728316AbgFEUsw (ORCPT ); Fri, 5 Jun 2020 16:48:52 -0400 Received: from mx2.suse.de ([195.135.220.15]:47762 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728226AbgFEUsw (ORCPT ); Fri, 5 Jun 2020 16:48:52 -0400 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.220.254]) by mx2.suse.de (Postfix) with ESMTP id 43E26ABE4; Fri, 5 Jun 2020 20:48:53 +0000 (UTC) From: Goldwyn Rodrigues To: darrick.wong@oracle.com Cc: linux-btrfs@vger.kernel.org, fdmanana@gmail.com, linux-fsdevel@vger.kernel.org, hch@lst.de, Goldwyn Rodrigues , Johannes Thumshirn , Nikolay Borisov Subject: [PATCH 2/3] btrfs: Wait for extent bits to release page Date: Fri, 5 Jun 2020 15:48:37 -0500 Message-Id: <20200605204838.10765-3-rgoldwyn@suse.de> X-Mailer: git-send-email 2.25.0 In-Reply-To: <20200605204838.10765-1-rgoldwyn@suse.de> References: <20200605204838.10765-1-rgoldwyn@suse.de> MIME-Version: 1.0 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. Reviewed-by: Johannes Thumshirn Reviewed-by: Nikolay Borisov Signed-off-by: Goldwyn Rodrigues --- 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 c59e07360083..0ab444d2028d 100644 --- a/fs/btrfs/extent_io.c +++ b/fs/btrfs/extent_io.c @@ -4466,33 +4466,28 @@ 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; } /* @@ -4500,7 +4495,7 @@ 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 9a10681b12bf..6cba4ad6ebc1 100644 --- a/fs/btrfs/extent_io.h +++ b/fs/btrfs/extent_io.h @@ -189,7 +189,7 @@ typedef struct extent_map *(get_extent_t)(struct btrfs_inode *inode, struct page *page, size_t pg_offset, u64 start, u64 len); -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 page *page, get_extent_t *get_extent, diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c index 1242d0aa108d..8cb44c49c1d2 100644 --- a/fs/btrfs/inode.c +++ b/fs/btrfs/inode.c @@ -7887,8 +7887,8 @@ 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);