From patchwork Mon Jun 29 19:23:49 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Goldwyn Rodrigues X-Patchwork-Id: 11631677 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 304D66C1 for ; Mon, 29 Jun 2020 19:24:30 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 18D7C20723 for ; Mon, 29 Jun 2020 19:24:30 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732352AbgF2TYR (ORCPT ); Mon, 29 Jun 2020 15:24:17 -0400 Received: from mx2.suse.de ([195.135.220.15]:60728 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1732274AbgF2TYP (ORCPT ); Mon, 29 Jun 2020 15:24:15 -0400 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.221.27]) by mx2.suse.de (Postfix) with ESMTP id 7BE52AAC5; Mon, 29 Jun 2020 19:24:13 +0000 (UTC) From: Goldwyn Rodrigues To: linux-fsdevel@vger.kernel.org Cc: linux-btrfs@vger.kernel.org, fdmanana@gmail.com, dsterba@suse.cz, david@fromorbit.com, darrick.wong@oracle.com, hch@lst.de, Goldwyn Rodrigues Subject: [PATCH 2/6] iomap: IOMAP_DIO_RWF_NO_STALE_PAGECACHE return if page invalidation fails Date: Mon, 29 Jun 2020 14:23:49 -0500 Message-Id: <20200629192353.20841-3-rgoldwyn@suse.de> X-Mailer: git-send-email 2.26.2 In-Reply-To: <20200629192353.20841-1-rgoldwyn@suse.de> References: <20200629192353.20841-1-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 For direct I/O, add the flag IOMAP_DIO_RWF_NO_STALE_PAGECACHE to indicate that if the page invalidation fails, return back control to the filesystem so it may fallback to buffered mode. Reviewed-by: Darrick J. Wong Signed-off-by: Goldwyn Rodrigues Reviewed-by: Darrick J. Wong Reviewed-by: Matthew Wilcox (Oracle) --- fs/iomap/direct-io.c | 8 +++++++- include/linux/iomap.h | 14 ++++++++++++++ 2 files changed, 21 insertions(+), 1 deletion(-) diff --git a/fs/iomap/direct-io.c b/fs/iomap/direct-io.c index fd22bff61569..2459c76e41ab 100644 --- a/fs/iomap/direct-io.c +++ b/fs/iomap/direct-io.c @@ -484,8 +484,14 @@ iomap_dio_rw(struct kiocb *iocb, struct iov_iter *iter, */ ret = invalidate_inode_pages2_range(mapping, pos >> PAGE_SHIFT, end >> PAGE_SHIFT); - if (ret) + if (ret) { + if (dio_flags & IOMAP_DIO_RWF_NO_STALE_PAGECACHE) { + if (ret == -EBUSY) + ret = 0; + goto out_free_dio; + } dio_warn_stale_pagecache(iocb->ki_filp); + } ret = 0; if (iov_iter_rw(iter) == WRITE && !wait_for_completion && diff --git a/include/linux/iomap.h b/include/linux/iomap.h index 8a4ba1635202..2ebb8a298cd8 100644 --- a/include/linux/iomap.h +++ b/include/linux/iomap.h @@ -262,7 +262,21 @@ struct iomap_dio_ops { /* * Wait for completion of DIO */ + #define IOMAP_DIO_RWF_SYNCIO (1 << 0) +/* + * Direct IO will attempt to keep the page cache coherent by + * invalidating the inode's page cache over the range of the DIO. + * That can fail if something else is actively using the page cache. + * If this happens and the DIO continues, the data in the page + * cache will become stale. + * + * Set this flag if you want the DIO to abort without issuing any IO + * or error if it fails to invalidate the page cache successfully. + * This allows the IO submitter to fallback to buffered IO to resubmit + * IO + */ +#define IOMAP_DIO_RWF_NO_STALE_PAGECACHE (1 << 1) ssize_t iomap_dio_rw(struct kiocb *iocb, struct iov_iter *iter, const struct iomap_ops *ops, const struct iomap_dio_ops *dops,