From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-9.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,USER_AGENT_NEOMUTT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 89338C282DA for ; Wed, 17 Apr 2019 16:39:36 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 65B7120821 for ; Wed, 17 Apr 2019 16:39:36 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732874AbfDQQjf (ORCPT ); Wed, 17 Apr 2019 12:39:35 -0400 Received: from mx2.suse.de ([195.135.220.15]:54946 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1729641AbfDQQjf (ORCPT ); Wed, 17 Apr 2019 12:39:35 -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 0D3FEB11A; Wed, 17 Apr 2019 16:39:33 +0000 (UTC) Date: Wed, 17 Apr 2019 11:39:30 -0500 From: Goldwyn Rodrigues To: "Darrick J. Wong" Cc: linux-btrfs@vger.kernel.org, linux-fsdevel@vger.kernel.org, jack@suse.cz, david@fromorbit.com, willy@infradead.org, hch@lst.de, kilobyte@angband.pl, dsterba@suse.cz, nborisov@suse.com, linux-nvdimm@lists.01.org Subject: Re: [PATCH 14/18] dax: memcpy before zeroing range Message-ID: <20190417163930.fpwvcj55rnzgo7dh@merlin> References: <20190416164154.30390-1-rgoldwyn@suse.de> <20190416164154.30390-15-rgoldwyn@suse.de> <20190417154504.GC4740@magnolia> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190417154504.GC4740@magnolia> User-Agent: NeoMutt/20180323 Sender: linux-btrfs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-btrfs@vger.kernel.org On 8:45 17/04, Darrick J. Wong wrote: > On Tue, Apr 16, 2019 at 11:41:50AM -0500, Goldwyn Rodrigues wrote: > > From: Goldwyn Rodrigues > > > > However, this needed more iomap fields, so it was easier > > to pass iomap and compute inside the function rather > > than passing a log of arguments. > > > > Note, there is subtle difference between iomap_sector and > > dax_iomap_sector(). Can we replace dax_iomap_sector with > > iomap_sector()? It would need pos & PAGE_MASK though or else > > bdev_dax_pgoff() return -EINVAL. > > > > Signed-off-by: Goldwyn Rodrigues > > --- > > fs/dax.c | 14 ++++++++++---- > > fs/iomap.c | 9 +-------- > > include/linux/dax.h | 11 +++++------ > > include/linux/iomap.h | 6 ++++++ > > 4 files changed, 22 insertions(+), 18 deletions(-) > > > > diff --git a/fs/dax.c b/fs/dax.c > > index abbe4a79f219..af94909640ea 100644 > > --- a/fs/dax.c > > +++ b/fs/dax.c > > @@ -1055,11 +1055,15 @@ static bool dax_range_is_aligned(struct block_device *bdev, > > return true; > > } > > > > -int __dax_zero_page_range(struct block_device *bdev, > > - struct dax_device *dax_dev, sector_t sector, > > - unsigned int offset, unsigned int size) > > +int __dax_zero_page_range(struct iomap *iomap, loff_t pos, > > + unsigned int offset, unsigned int size) > > { > > - if (dax_range_is_aligned(bdev, offset, size)) { > > + sector_t sector = dax_iomap_sector(iomap, pos & PAGE_MASK); > > + struct block_device *bdev = iomap->bdev; > > + struct dax_device *dax_dev = iomap->dax_dev; > > + > > + if (!(iomap->type == IOMAP_DAX_COW) && > > + dax_range_is_aligned(bdev, offset, size)) { > > sector_t start_sector = sector + (offset >> 9); > > > > return blkdev_issue_zeroout(bdev, start_sector, > > @@ -1079,6 +1083,8 @@ int __dax_zero_page_range(struct block_device *bdev, > > dax_read_unlock(id); > > return rc; > > } > > + if (iomap->type == IOMAP_DAX_COW) > > + memcpy(iomap->inline_data, kaddr, offset); > > I'm confused, why are we copying into the source page before zeroing > some part of the dax device? Clearly my testing was not good enough. This should be - memcpy(kaddr, iomap->inline_data, offset); We copy the part which is not zeroed to new location. > > > memset(kaddr + offset, 0, size); > > dax_flush(dax_dev, kaddr + offset, size); > > dax_read_unlock(id); > > diff --git a/fs/iomap.c b/fs/iomap.c > > index abdd18e404f8..90698c854883 100644 > > --- a/fs/iomap.c > > +++ b/fs/iomap.c > > @@ -98,12 +98,6 @@ iomap_apply(struct inode *inode, loff_t pos, loff_t length, unsigned flags, > > return written ? written : ret; > > } > > > > -static sector_t > > -iomap_sector(struct iomap *iomap, loff_t pos) > > -{ > > - return (iomap->addr + pos - iomap->offset) >> SECTOR_SHIFT; > > -} > > - > > static struct iomap_page * > > iomap_page_create(struct inode *inode, struct page *page) > > { > > @@ -990,8 +984,7 @@ static int iomap_zero(struct inode *inode, loff_t pos, unsigned offset, > > static int iomap_dax_zero(loff_t pos, unsigned offset, unsigned bytes, > > struct iomap *iomap) > > { > > - return __dax_zero_page_range(iomap->bdev, iomap->dax_dev, > > - iomap_sector(iomap, pos & PAGE_MASK), offset, bytes); > > + return __dax_zero_page_range(iomap, pos, offset, bytes); > > } > > > > static loff_t > > diff --git a/include/linux/dax.h b/include/linux/dax.h > > index a11bc7b1f526..892c478d7073 100644 > > --- a/include/linux/dax.h > > +++ b/include/linux/dax.h > > @@ -9,6 +9,7 @@ > > > > typedef unsigned long dax_entry_t; > > > > +struct iomap; > > struct iomap_ops; > > struct dax_device; > > struct dax_operations { > > @@ -161,13 +162,11 @@ int dax_file_range_compare(struct inode *src, loff_t srcoff, struct inode *dest, > > loff_t destoff, loff_t len, bool *is_same, const struct iomap_ops *ops); > > > > #ifdef CONFIG_FS_DAX > > -int __dax_zero_page_range(struct block_device *bdev, > > - struct dax_device *dax_dev, sector_t sector, > > - unsigned int offset, unsigned int length); > > +int __dax_zero_page_range(struct iomap *iomap, loff_t pos, > > + unsigned int offset, unsigned int size); > > #else > > -static inline int __dax_zero_page_range(struct block_device *bdev, > > - struct dax_device *dax_dev, sector_t sector, > > - unsigned int offset, unsigned int length) > > +static inline int __dax_zero_page_range(struct iomap *iomap, loff_t pos, > > + unsigned int offset, unsigned int size) > > { > > return -ENXIO; > > } > > diff --git a/include/linux/iomap.h b/include/linux/iomap.h > > index 6e885c5a38a3..3a803566dea1 100644 > > --- a/include/linux/iomap.h > > +++ b/include/linux/iomap.h > > @@ -7,6 +7,7 @@ > > #include > > #include > > #include > > +#include > > > > struct address_space; > > struct fiemap_extent_info; > > @@ -120,6 +121,11 @@ static inline struct iomap_page *to_iomap_page(struct page *page) > > return NULL; > > } > > > > +static inline sector_t iomap_sector(struct iomap *iomap, loff_t pos) > > +{ > > + return (iomap->addr + pos - iomap->offset) >> SECTOR_SHIFT; > > Why the double indent? Ahh.. I will fix this. > > --D > > > +} > > + > > ssize_t iomap_file_buffered_write(struct kiocb *iocb, struct iov_iter *from, > > const struct iomap_ops *ops); > > int iomap_readpage(struct page *page, const struct iomap_ops *ops); > > -- > > 2.16.4 > > > -- Goldwyn