From patchwork Sun Sep 1 20:08:24 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Goldwyn Rodrigues X-Patchwork-Id: 11125649 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 8BB951890 for ; Sun, 1 Sep 2019 20:09:04 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 73C4E2190F for ; Sun, 1 Sep 2019 20:09:04 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728933AbfIAUIy (ORCPT ); Sun, 1 Sep 2019 16:08:54 -0400 Received: from mx2.suse.de ([195.135.220.15]:50408 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1728888AbfIAUIy (ORCPT ); Sun, 1 Sep 2019 16:08:54 -0400 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 DBDB3AE96; Sun, 1 Sep 2019 20:08:52 +0000 (UTC) From: Goldwyn Rodrigues To: linux-fsdevel@vger.kernel.org Cc: linux-btrfs@vger.kernel.org, darrick.wong@oracle.com, hch@lst.de, david@fromorbit.com, riteshh@linux.ibm.com, Goldwyn Rodrigues Subject: [PATCH 03/15] iomap: Read page from srcmap for IOMAP_COW Date: Sun, 1 Sep 2019 15:08:24 -0500 Message-Id: <20190901200836.14959-4-rgoldwyn@suse.de> X-Mailer: git-send-email 2.16.4 In-Reply-To: <20190901200836.14959-1-rgoldwyn@suse.de> References: <20190901200836.14959-1-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 In case of a IOMAP_COW, read a page from the srcmap before performing a write on the page. Signed-off-by: Goldwyn Rodrigues Reviewed-by: Darrick J. Wong --- fs/iomap/buffered-io.c | 23 ++++++++++++++--------- 1 file changed, 14 insertions(+), 9 deletions(-) diff --git a/fs/iomap/buffered-io.c b/fs/iomap/buffered-io.c index f27756c0b31c..99d63ba14d1b 100644 --- a/fs/iomap/buffered-io.c +++ b/fs/iomap/buffered-io.c @@ -581,7 +581,7 @@ __iomap_write_begin(struct inode *inode, loff_t pos, unsigned len, static int iomap_write_begin(struct inode *inode, loff_t pos, unsigned len, unsigned flags, - struct page **pagep, struct iomap *iomap) + struct page **pagep, struct iomap *iomap, struct iomap *srcmap) { const struct iomap_page_ops *page_ops = iomap->page_ops; pgoff_t index = pos >> PAGE_SHIFT; @@ -605,12 +605,17 @@ iomap_write_begin(struct inode *inode, loff_t pos, unsigned len, unsigned flags, goto out_no_page; } - if (iomap->type == IOMAP_INLINE) + if (iomap->type == IOMAP_INLINE) { iomap_read_inline_data(inode, page, iomap); - else if (iomap->flags & IOMAP_F_BUFFER_HEAD) + } else if (iomap->type == IOMAP_COW) { + iomap_assert(!(iomap->flags & IOMAP_F_BUFFER_HEAD)); + iomap_assert(srcmap->type == IOMAP_HOLE || srcmap->addr > 0); + status = __iomap_write_begin(inode, pos, len, page, srcmap); + } else if (iomap->flags & IOMAP_F_BUFFER_HEAD) { status = __block_write_begin_int(page, pos, len, NULL, iomap); - else + } else { status = __iomap_write_begin(inode, pos, len, page, iomap); + } if (unlikely(status)) goto out_unlock; @@ -772,7 +777,7 @@ iomap_write_actor(struct inode *inode, loff_t pos, loff_t length, void *data, } status = iomap_write_begin(inode, pos, bytes, flags, &page, - iomap); + iomap, srcmap); if (unlikely(status)) break; @@ -871,7 +876,7 @@ iomap_dirty_actor(struct inode *inode, loff_t pos, loff_t length, void *data, return PTR_ERR(rpage); status = iomap_write_begin(inode, pos, bytes, - AOP_FLAG_NOFS, &page, iomap); + AOP_FLAG_NOFS, &page, iomap, srcmap); put_page(rpage); if (unlikely(status)) return status; @@ -917,13 +922,13 @@ iomap_file_dirty(struct inode *inode, loff_t pos, loff_t len, EXPORT_SYMBOL_GPL(iomap_file_dirty); static int iomap_zero(struct inode *inode, loff_t pos, unsigned offset, - unsigned bytes, struct iomap *iomap) + unsigned bytes, struct iomap *iomap, struct iomap *srcmap) { struct page *page; int status; status = iomap_write_begin(inode, pos, bytes, AOP_FLAG_NOFS, &page, - iomap); + iomap, srcmap); if (status) return status; @@ -961,7 +966,7 @@ iomap_zero_range_actor(struct inode *inode, loff_t pos, loff_t count, if (IS_DAX(inode)) status = iomap_dax_zero(pos, offset, bytes, iomap); else - status = iomap_zero(inode, pos, offset, bytes, iomap); + status = iomap_zero(inode, pos, offset, bytes, iomap, srcmap); if (status < 0) return status;