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=-5.0 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE, SPF_PASS,USER_AGENT_SANE_1 autolearn=unavailable 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 8077DC2D0C2 for ; Fri, 3 Jan 2020 18:33:22 +0000 (UTC) Received: from ml01.01.org (ml01.01.org [198.145.21.10]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 3166C2253D for ; Fri, 3 Jan 2020 18:33:22 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="F4jZz1Yk" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 3166C2253D Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-nvdimm-bounces@lists.01.org Received: from ml01.vlan13.01.org (localhost [IPv6:::1]) by ml01.01.org (Postfix) with ESMTP id 4DB3910097DF5; Fri, 3 Jan 2020 10:36:41 -0800 (PST) Received-SPF: Pass (mailfrom) identity=mailfrom; client-ip=207.211.31.81; helo=us-smtp-delivery-1.mimecast.com; envelope-from=vgoyal@redhat.com; receiver= Received: from us-smtp-delivery-1.mimecast.com (us-smtp-2.mimecast.com [207.211.31.81]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-SHA384 (256/256 bits)) (No client certificate requested) by ml01.01.org (Postfix) with ESMTPS id EED2D10097DF1 for ; Fri, 3 Jan 2020 10:36:38 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1578076398; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=k9B8DZHWqzTB+Kt3rFqrnVZ5tO/IU+S24gouCA4CSXo=; b=F4jZz1Yk3WEdoRwk8jyXXb9lbOkqvg6ZdrLYzqE6ZQgToWUFE93XchR4RN4IbxYgHLsq8i 6pQ/p44UCi05P5SoyWkSfByY6KeZYwEKHeqFjz9A+NUexlKSPXvYfSZOcJI0ztHsWGu+RU Gz2Vtjsbq5z1NuqXNv248Dboj5Aww5Y= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-237-ymZGaeSoOde_Db7plRlGWA-1; Fri, 03 Jan 2020 13:33:14 -0500 X-MC-Unique: ymZGaeSoOde_Db7plRlGWA-1 Received: from smtp.corp.redhat.com (int-mx05.intmail.prod.int.phx2.redhat.com [10.5.11.15]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id E90F164A7F; Fri, 3 Jan 2020 18:33:12 +0000 (UTC) Received: from horse.redhat.com (unknown [10.18.25.35]) by smtp.corp.redhat.com (Postfix) with ESMTP id B09397BA32; Fri, 3 Jan 2020 18:33:07 +0000 (UTC) Received: by horse.redhat.com (Postfix, from userid 10451) id 446632202E9; Fri, 3 Jan 2020 13:33:07 -0500 (EST) Date: Fri, 3 Jan 2020 13:33:07 -0500 From: Vivek Goyal To: Dan Williams Subject: Re: [PATCH 02/19] dax: Pass dax_dev to dax_writeback_mapping_range() Message-ID: <20200103183307.GB13350@redhat.com> References: <20190821175720.25901-1-vgoyal@redhat.com> <20190821175720.25901-3-vgoyal@redhat.com> <20190826115316.GB21051@infradead.org> <20190826203326.GB13860@redhat.com> <20190826205829.GC13860@redhat.com> <20200103141235.GA13350@redhat.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.12.1 (2019-06-15) X-Scanned-By: MIMEDefang 2.79 on 10.5.11.15 Message-ID-Hash: 5J35BRM5B5STYFM4LAPYBIKHLE7CEMGI X-Message-ID-Hash: 5J35BRM5B5STYFM4LAPYBIKHLE7CEMGI X-MailFrom: vgoyal@redhat.com X-Mailman-Rule-Misses: dmarc-mitigation; no-senders; approved; emergency; loop; banned-address; member-moderation; nonmember-moderation; administrivia; implicit-dest; max-recipients; max-size; news-moderation; no-subject; suspicious-header CC: linux-fsdevel , Linux Kernel Mailing List , linux-nvdimm , virtio-fs@redhat.com, Miklos Szeredi , Stefan Hajnoczi , "Dr. David Alan Gilbert" , Christoph Hellwig X-Mailman-Version: 3.1.1 Precedence: list List-Id: "Linux-nvdimm developer list." Archived-At: List-Archive: List-Help: List-Post: List-Subscribe: List-Unsubscribe: Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit On Fri, Jan 03, 2020 at 10:18:22AM -0800, Dan Williams wrote: > On Fri, Jan 3, 2020 at 10:12 AM Dan Williams wrote: > > > > On Fri, Jan 3, 2020 at 6:12 AM Vivek Goyal wrote: > [..] > > > Hi Dan, > > > > > > Ping for this patch. I see christoph and Jan acked it. Can we take it. Not > > > sure how to get ack from ext4 developers. > > > > Jan counts for ext4, I just missed this. Now merged. > > Oh, this now collides with: > > 30fa529e3b2e xfs: add a xfs_inode_buftarg helper > > Care to rebase? I'll also circle back to your question about > partitions on patch1. Hi Dan, Here is the updated patch. Thanks Vivek Subject: dax: Pass dax_dev instead of bdev to dax_writeback_mapping_range() As of now dax_writeback_mapping_range() takes "struct block_device" as a parameter and dax_dev is searched from bdev name. This also involves taking a fresh reference on dax_dev and putting that reference at the end of function. We are developing a new filesystem virtio-fs and using dax to access host page cache directly. But there is no block device. IOW, we want to make use of dax but want to get rid of this assumption that there is always a block device associated with dax_dev. So pass in "struct dax_device" as parameter instead of bdev. ext2/ext4/xfs are current users and they already have a reference on dax_device. So there is no need to take reference and drop reference to dax_device on each call of this function. Suggested-by: Christoph Hellwig Reviewed-by: Christoph Hellwig Reviewed-by: Jan Kara Signed-off-by: Vivek Goyal --- fs/dax.c | 8 +------- fs/ext2/inode.c | 5 +++-- fs/ext4/inode.c | 2 +- fs/xfs/xfs_aops.c | 2 +- include/linux/dax.h | 4 ++-- 5 files changed, 8 insertions(+), 13 deletions(-) Index: rhvgoyal-linux-fuse/fs/dax.c =================================================================== --- rhvgoyal-linux-fuse.orig/fs/dax.c 2020-01-03 11:19:59.151186062 -0500 +++ rhvgoyal-linux-fuse/fs/dax.c 2020-01-03 11:20:05.602186062 -0500 @@ -937,12 +937,11 @@ static int dax_writeback_one(struct xa_s * on persistent storage prior to completion of the operation. */ int dax_writeback_mapping_range(struct address_space *mapping, - struct block_device *bdev, struct writeback_control *wbc) + struct dax_device *dax_dev, struct writeback_control *wbc) { XA_STATE(xas, &mapping->i_pages, wbc->range_start >> PAGE_SHIFT); struct inode *inode = mapping->host; pgoff_t end_index = wbc->range_end >> PAGE_SHIFT; - struct dax_device *dax_dev; void *entry; int ret = 0; unsigned int scanned = 0; @@ -953,10 +952,6 @@ int dax_writeback_mapping_range(struct a if (!mapping->nrexceptional || wbc->sync_mode != WB_SYNC_ALL) return 0; - dax_dev = dax_get_by_host(bdev->bd_disk->disk_name); - if (!dax_dev) - return -EIO; - trace_dax_writeback_range(inode, xas.xa_index, end_index); tag_pages_for_writeback(mapping, xas.xa_index, end_index); @@ -977,7 +972,6 @@ int dax_writeback_mapping_range(struct a xas_lock_irq(&xas); } xas_unlock_irq(&xas); - put_dax(dax_dev); trace_dax_writeback_range_done(inode, xas.xa_index, end_index); return ret; } Index: rhvgoyal-linux-fuse/include/linux/dax.h =================================================================== --- rhvgoyal-linux-fuse.orig/include/linux/dax.h 2020-01-03 11:19:59.151186062 -0500 +++ rhvgoyal-linux-fuse/include/linux/dax.h 2020-01-03 11:20:05.603186062 -0500 @@ -141,7 +141,7 @@ static inline void fs_put_dax(struct dax struct dax_device *fs_dax_get_by_bdev(struct block_device *bdev); int dax_writeback_mapping_range(struct address_space *mapping, - struct block_device *bdev, struct writeback_control *wbc); + struct dax_device *dax_dev, struct writeback_control *wbc); struct page *dax_layout_busy_page(struct address_space *mapping); dax_entry_t dax_lock_page(struct page *page); @@ -180,7 +180,7 @@ static inline struct page *dax_layout_bu } static inline int dax_writeback_mapping_range(struct address_space *mapping, - struct block_device *bdev, struct writeback_control *wbc) + struct dax_device *dax_dev, struct writeback_control *wbc) { return -EOPNOTSUPP; } Index: rhvgoyal-linux-fuse/fs/xfs/xfs_aops.c =================================================================== --- rhvgoyal-linux-fuse.orig/fs/xfs/xfs_aops.c 2020-01-03 11:19:59.151186062 -0500 +++ rhvgoyal-linux-fuse/fs/xfs/xfs_aops.c 2020-01-03 11:20:05.605186062 -0500 @@ -587,7 +587,7 @@ xfs_dax_writepages( xfs_iflags_clear(ip, XFS_ITRUNCATED); return dax_writeback_mapping_range(mapping, - xfs_inode_buftarg(ip)->bt_bdev, wbc); + xfs_inode_buftarg(ip)->bt_daxdev, wbc); } STATIC sector_t Index: rhvgoyal-linux-fuse/fs/ext4/inode.c =================================================================== --- rhvgoyal-linux-fuse.orig/fs/ext4/inode.c 2020-01-03 11:19:59.151186062 -0500 +++ rhvgoyal-linux-fuse/fs/ext4/inode.c 2020-01-03 11:20:05.606186062 -0500 @@ -2866,7 +2866,7 @@ static int ext4_dax_writepages(struct ad percpu_down_read(&sbi->s_journal_flag_rwsem); trace_ext4_writepages(inode, wbc); - ret = dax_writeback_mapping_range(mapping, inode->i_sb->s_bdev, wbc); + ret = dax_writeback_mapping_range(mapping, sbi->s_daxdev, wbc); trace_ext4_writepages_result(inode, wbc, ret, nr_to_write - wbc->nr_to_write); percpu_up_read(&sbi->s_journal_flag_rwsem); Index: rhvgoyal-linux-fuse/fs/ext2/inode.c =================================================================== --- rhvgoyal-linux-fuse.orig/fs/ext2/inode.c 2020-01-03 11:19:59.151186062 -0500 +++ rhvgoyal-linux-fuse/fs/ext2/inode.c 2020-01-03 11:20:05.608186062 -0500 @@ -960,8 +960,9 @@ ext2_writepages(struct address_space *ma static int ext2_dax_writepages(struct address_space *mapping, struct writeback_control *wbc) { - return dax_writeback_mapping_range(mapping, - mapping->host->i_sb->s_bdev, wbc); + struct ext2_sb_info *sbi = EXT2_SB(mapping->host->i_sb); + + return dax_writeback_mapping_range(mapping, sbi->s_daxdev, wbc); } const struct address_space_operations ext2_aops = { _______________________________________________ Linux-nvdimm mailing list -- linux-nvdimm@lists.01.org To unsubscribe send an email to linux-nvdimm-leave@lists.01.org From mboxrd@z Thu Jan 1 00:00:00 1970 Date: Fri, 3 Jan 2020 13:33:07 -0500 From: Vivek Goyal Message-ID: <20200103183307.GB13350@redhat.com> References: <20190821175720.25901-1-vgoyal@redhat.com> <20190821175720.25901-3-vgoyal@redhat.com> <20190826115316.GB21051@infradead.org> <20190826203326.GB13860@redhat.com> <20190826205829.GC13860@redhat.com> <20200103141235.GA13350@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Subject: Re: [Virtio-fs] [PATCH 02/19] dax: Pass dax_dev to dax_writeback_mapping_range() List-Id: Development discussions about virtio-fs List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Dan Williams Cc: Christoph Hellwig , Miklos Szeredi , linux-nvdimm , Linux Kernel Mailing List , virtio-fs@redhat.com, linux-fsdevel On Fri, Jan 03, 2020 at 10:18:22AM -0800, Dan Williams wrote: > On Fri, Jan 3, 2020 at 10:12 AM Dan Williams wrote: > > > > On Fri, Jan 3, 2020 at 6:12 AM Vivek Goyal wrote: > [..] > > > Hi Dan, > > > > > > Ping for this patch. I see christoph and Jan acked it. Can we take it. Not > > > sure how to get ack from ext4 developers. > > > > Jan counts for ext4, I just missed this. Now merged. > > Oh, this now collides with: > > 30fa529e3b2e xfs: add a xfs_inode_buftarg helper > > Care to rebase? I'll also circle back to your question about > partitions on patch1. Hi Dan, Here is the updated patch. Thanks Vivek Subject: dax: Pass dax_dev instead of bdev to dax_writeback_mapping_range() As of now dax_writeback_mapping_range() takes "struct block_device" as a parameter and dax_dev is searched from bdev name. This also involves taking a fresh reference on dax_dev and putting that reference at the end of function. We are developing a new filesystem virtio-fs and using dax to access host page cache directly. But there is no block device. IOW, we want to make use of dax but want to get rid of this assumption that there is always a block device associated with dax_dev. So pass in "struct dax_device" as parameter instead of bdev. ext2/ext4/xfs are current users and they already have a reference on dax_device. So there is no need to take reference and drop reference to dax_device on each call of this function. Suggested-by: Christoph Hellwig Reviewed-by: Christoph Hellwig Reviewed-by: Jan Kara Signed-off-by: Vivek Goyal --- fs/dax.c | 8 +------- fs/ext2/inode.c | 5 +++-- fs/ext4/inode.c | 2 +- fs/xfs/xfs_aops.c | 2 +- include/linux/dax.h | 4 ++-- 5 files changed, 8 insertions(+), 13 deletions(-) Index: rhvgoyal-linux-fuse/fs/dax.c =================================================================== --- rhvgoyal-linux-fuse.orig/fs/dax.c 2020-01-03 11:19:59.151186062 -0500 +++ rhvgoyal-linux-fuse/fs/dax.c 2020-01-03 11:20:05.602186062 -0500 @@ -937,12 +937,11 @@ static int dax_writeback_one(struct xa_s * on persistent storage prior to completion of the operation. */ int dax_writeback_mapping_range(struct address_space *mapping, - struct block_device *bdev, struct writeback_control *wbc) + struct dax_device *dax_dev, struct writeback_control *wbc) { XA_STATE(xas, &mapping->i_pages, wbc->range_start >> PAGE_SHIFT); struct inode *inode = mapping->host; pgoff_t end_index = wbc->range_end >> PAGE_SHIFT; - struct dax_device *dax_dev; void *entry; int ret = 0; unsigned int scanned = 0; @@ -953,10 +952,6 @@ int dax_writeback_mapping_range(struct a if (!mapping->nrexceptional || wbc->sync_mode != WB_SYNC_ALL) return 0; - dax_dev = dax_get_by_host(bdev->bd_disk->disk_name); - if (!dax_dev) - return -EIO; - trace_dax_writeback_range(inode, xas.xa_index, end_index); tag_pages_for_writeback(mapping, xas.xa_index, end_index); @@ -977,7 +972,6 @@ int dax_writeback_mapping_range(struct a xas_lock_irq(&xas); } xas_unlock_irq(&xas); - put_dax(dax_dev); trace_dax_writeback_range_done(inode, xas.xa_index, end_index); return ret; } Index: rhvgoyal-linux-fuse/include/linux/dax.h =================================================================== --- rhvgoyal-linux-fuse.orig/include/linux/dax.h 2020-01-03 11:19:59.151186062 -0500 +++ rhvgoyal-linux-fuse/include/linux/dax.h 2020-01-03 11:20:05.603186062 -0500 @@ -141,7 +141,7 @@ static inline void fs_put_dax(struct dax struct dax_device *fs_dax_get_by_bdev(struct block_device *bdev); int dax_writeback_mapping_range(struct address_space *mapping, - struct block_device *bdev, struct writeback_control *wbc); + struct dax_device *dax_dev, struct writeback_control *wbc); struct page *dax_layout_busy_page(struct address_space *mapping); dax_entry_t dax_lock_page(struct page *page); @@ -180,7 +180,7 @@ static inline struct page *dax_layout_bu } static inline int dax_writeback_mapping_range(struct address_space *mapping, - struct block_device *bdev, struct writeback_control *wbc) + struct dax_device *dax_dev, struct writeback_control *wbc) { return -EOPNOTSUPP; } Index: rhvgoyal-linux-fuse/fs/xfs/xfs_aops.c =================================================================== --- rhvgoyal-linux-fuse.orig/fs/xfs/xfs_aops.c 2020-01-03 11:19:59.151186062 -0500 +++ rhvgoyal-linux-fuse/fs/xfs/xfs_aops.c 2020-01-03 11:20:05.605186062 -0500 @@ -587,7 +587,7 @@ xfs_dax_writepages( xfs_iflags_clear(ip, XFS_ITRUNCATED); return dax_writeback_mapping_range(mapping, - xfs_inode_buftarg(ip)->bt_bdev, wbc); + xfs_inode_buftarg(ip)->bt_daxdev, wbc); } STATIC sector_t Index: rhvgoyal-linux-fuse/fs/ext4/inode.c =================================================================== --- rhvgoyal-linux-fuse.orig/fs/ext4/inode.c 2020-01-03 11:19:59.151186062 -0500 +++ rhvgoyal-linux-fuse/fs/ext4/inode.c 2020-01-03 11:20:05.606186062 -0500 @@ -2866,7 +2866,7 @@ static int ext4_dax_writepages(struct ad percpu_down_read(&sbi->s_journal_flag_rwsem); trace_ext4_writepages(inode, wbc); - ret = dax_writeback_mapping_range(mapping, inode->i_sb->s_bdev, wbc); + ret = dax_writeback_mapping_range(mapping, sbi->s_daxdev, wbc); trace_ext4_writepages_result(inode, wbc, ret, nr_to_write - wbc->nr_to_write); percpu_up_read(&sbi->s_journal_flag_rwsem); Index: rhvgoyal-linux-fuse/fs/ext2/inode.c =================================================================== --- rhvgoyal-linux-fuse.orig/fs/ext2/inode.c 2020-01-03 11:19:59.151186062 -0500 +++ rhvgoyal-linux-fuse/fs/ext2/inode.c 2020-01-03 11:20:05.608186062 -0500 @@ -960,8 +960,9 @@ ext2_writepages(struct address_space *ma static int ext2_dax_writepages(struct address_space *mapping, struct writeback_control *wbc) { - return dax_writeback_mapping_range(mapping, - mapping->host->i_sb->s_bdev, wbc); + struct ext2_sb_info *sbi = EXT2_SB(mapping->host->i_sb); + + return dax_writeback_mapping_range(mapping, sbi->s_daxdev, wbc); } const struct address_space_operations ext2_aops = { 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=-5.4 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 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 20B97C2D0C2 for ; Fri, 3 Jan 2020 18:33:19 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id DDA48222C3 for ; Fri, 3 Jan 2020 18:33:18 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="EF7vPmGg" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728373AbgACSdS (ORCPT ); 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Fri, 3 Jan 2020 18:33:12 +0000 (UTC) Received: from horse.redhat.com (unknown [10.18.25.35]) by smtp.corp.redhat.com (Postfix) with ESMTP id B09397BA32; Fri, 3 Jan 2020 18:33:07 +0000 (UTC) Received: by horse.redhat.com (Postfix, from userid 10451) id 446632202E9; Fri, 3 Jan 2020 13:33:07 -0500 (EST) Date: Fri, 3 Jan 2020 13:33:07 -0500 From: Vivek Goyal To: Dan Williams Cc: linux-fsdevel , Linux Kernel Mailing List , linux-nvdimm , virtio-fs@redhat.com, Miklos Szeredi , Stefan Hajnoczi , "Dr. David Alan Gilbert" , Christoph Hellwig Subject: Re: [PATCH 02/19] dax: Pass dax_dev to dax_writeback_mapping_range() Message-ID: <20200103183307.GB13350@redhat.com> References: <20190821175720.25901-1-vgoyal@redhat.com> <20190821175720.25901-3-vgoyal@redhat.com> <20190826115316.GB21051@infradead.org> <20190826203326.GB13860@redhat.com> <20190826205829.GC13860@redhat.com> <20200103141235.GA13350@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.12.1 (2019-06-15) X-Scanned-By: MIMEDefang 2.79 on 10.5.11.15 Sender: linux-fsdevel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org On Fri, Jan 03, 2020 at 10:18:22AM -0800, Dan Williams wrote: > On Fri, Jan 3, 2020 at 10:12 AM Dan Williams wrote: > > > > On Fri, Jan 3, 2020 at 6:12 AM Vivek Goyal wrote: > [..] > > > Hi Dan, > > > > > > Ping for this patch. I see christoph and Jan acked it. Can we take it. Not > > > sure how to get ack from ext4 developers. > > > > Jan counts for ext4, I just missed this. Now merged. > > Oh, this now collides with: > > 30fa529e3b2e xfs: add a xfs_inode_buftarg helper > > Care to rebase? I'll also circle back to your question about > partitions on patch1. Hi Dan, Here is the updated patch. Thanks Vivek Subject: dax: Pass dax_dev instead of bdev to dax_writeback_mapping_range() As of now dax_writeback_mapping_range() takes "struct block_device" as a parameter and dax_dev is searched from bdev name. This also involves taking a fresh reference on dax_dev and putting that reference at the end of function. We are developing a new filesystem virtio-fs and using dax to access host page cache directly. But there is no block device. IOW, we want to make use of dax but want to get rid of this assumption that there is always a block device associated with dax_dev. So pass in "struct dax_device" as parameter instead of bdev. ext2/ext4/xfs are current users and they already have a reference on dax_device. So there is no need to take reference and drop reference to dax_device on each call of this function. Suggested-by: Christoph Hellwig Reviewed-by: Christoph Hellwig Reviewed-by: Jan Kara Signed-off-by: Vivek Goyal --- fs/dax.c | 8 +------- fs/ext2/inode.c | 5 +++-- fs/ext4/inode.c | 2 +- fs/xfs/xfs_aops.c | 2 +- include/linux/dax.h | 4 ++-- 5 files changed, 8 insertions(+), 13 deletions(-) Index: rhvgoyal-linux-fuse/fs/dax.c =================================================================== --- rhvgoyal-linux-fuse.orig/fs/dax.c 2020-01-03 11:19:59.151186062 -0500 +++ rhvgoyal-linux-fuse/fs/dax.c 2020-01-03 11:20:05.602186062 -0500 @@ -937,12 +937,11 @@ static int dax_writeback_one(struct xa_s * on persistent storage prior to completion of the operation. */ int dax_writeback_mapping_range(struct address_space *mapping, - struct block_device *bdev, struct writeback_control *wbc) + struct dax_device *dax_dev, struct writeback_control *wbc) { XA_STATE(xas, &mapping->i_pages, wbc->range_start >> PAGE_SHIFT); struct inode *inode = mapping->host; pgoff_t end_index = wbc->range_end >> PAGE_SHIFT; - struct dax_device *dax_dev; void *entry; int ret = 0; unsigned int scanned = 0; @@ -953,10 +952,6 @@ int dax_writeback_mapping_range(struct a if (!mapping->nrexceptional || wbc->sync_mode != WB_SYNC_ALL) return 0; - dax_dev = dax_get_by_host(bdev->bd_disk->disk_name); - if (!dax_dev) - return -EIO; - trace_dax_writeback_range(inode, xas.xa_index, end_index); tag_pages_for_writeback(mapping, xas.xa_index, end_index); @@ -977,7 +972,6 @@ int dax_writeback_mapping_range(struct a xas_lock_irq(&xas); } xas_unlock_irq(&xas); - put_dax(dax_dev); trace_dax_writeback_range_done(inode, xas.xa_index, end_index); return ret; } Index: rhvgoyal-linux-fuse/include/linux/dax.h =================================================================== --- rhvgoyal-linux-fuse.orig/include/linux/dax.h 2020-01-03 11:19:59.151186062 -0500 +++ rhvgoyal-linux-fuse/include/linux/dax.h 2020-01-03 11:20:05.603186062 -0500 @@ -141,7 +141,7 @@ static inline void fs_put_dax(struct dax struct dax_device *fs_dax_get_by_bdev(struct block_device *bdev); int dax_writeback_mapping_range(struct address_space *mapping, - struct block_device *bdev, struct writeback_control *wbc); + struct dax_device *dax_dev, struct writeback_control *wbc); struct page *dax_layout_busy_page(struct address_space *mapping); dax_entry_t dax_lock_page(struct page *page); @@ -180,7 +180,7 @@ static inline struct page *dax_layout_bu } static inline int dax_writeback_mapping_range(struct address_space *mapping, - struct block_device *bdev, struct writeback_control *wbc) + struct dax_device *dax_dev, struct writeback_control *wbc) { return -EOPNOTSUPP; } Index: rhvgoyal-linux-fuse/fs/xfs/xfs_aops.c =================================================================== --- rhvgoyal-linux-fuse.orig/fs/xfs/xfs_aops.c 2020-01-03 11:19:59.151186062 -0500 +++ rhvgoyal-linux-fuse/fs/xfs/xfs_aops.c 2020-01-03 11:20:05.605186062 -0500 @@ -587,7 +587,7 @@ xfs_dax_writepages( xfs_iflags_clear(ip, XFS_ITRUNCATED); return dax_writeback_mapping_range(mapping, - xfs_inode_buftarg(ip)->bt_bdev, wbc); + xfs_inode_buftarg(ip)->bt_daxdev, wbc); } STATIC sector_t Index: rhvgoyal-linux-fuse/fs/ext4/inode.c =================================================================== --- rhvgoyal-linux-fuse.orig/fs/ext4/inode.c 2020-01-03 11:19:59.151186062 -0500 +++ rhvgoyal-linux-fuse/fs/ext4/inode.c 2020-01-03 11:20:05.606186062 -0500 @@ -2866,7 +2866,7 @@ static int ext4_dax_writepages(struct ad percpu_down_read(&sbi->s_journal_flag_rwsem); trace_ext4_writepages(inode, wbc); - ret = dax_writeback_mapping_range(mapping, inode->i_sb->s_bdev, wbc); + ret = dax_writeback_mapping_range(mapping, sbi->s_daxdev, wbc); trace_ext4_writepages_result(inode, wbc, ret, nr_to_write - wbc->nr_to_write); percpu_up_read(&sbi->s_journal_flag_rwsem); Index: rhvgoyal-linux-fuse/fs/ext2/inode.c =================================================================== --- rhvgoyal-linux-fuse.orig/fs/ext2/inode.c 2020-01-03 11:19:59.151186062 -0500 +++ rhvgoyal-linux-fuse/fs/ext2/inode.c 2020-01-03 11:20:05.608186062 -0500 @@ -960,8 +960,9 @@ ext2_writepages(struct address_space *ma static int ext2_dax_writepages(struct address_space *mapping, struct writeback_control *wbc) { - return dax_writeback_mapping_range(mapping, - mapping->host->i_sb->s_bdev, wbc); + struct ext2_sb_info *sbi = EXT2_SB(mapping->host->i_sb); + + return dax_writeback_mapping_range(mapping, sbi->s_daxdev, wbc); } const struct address_space_operations ext2_aops = {