From patchwork Tue Apr 24 23:33:13 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Dan Williams X-Patchwork-Id: 10361219 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 9A47A60209 for ; Tue, 24 Apr 2018 23:43:14 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 8AFE828DCC for ; Tue, 24 Apr 2018 23:43:14 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 7F5CE28E8F; Tue, 24 Apr 2018 23:43:14 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-2.9 required=2.0 tests=BAYES_00, MAILING_LIST_MULTI, RCVD_IN_DNSWL_NONE autolearn=ham version=3.3.1 Received: from ml01.01.org (ml01.01.org [198.145.21.10]) (using TLSv1.2 with cipher DHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id 7A98D28E7F for ; Tue, 24 Apr 2018 23:43:12 +0000 (UTC) Received: from [127.0.0.1] (localhost [IPv6:::1]) by ml01.01.org (Postfix) with ESMTP id 0D99122512127; Tue, 24 Apr 2018 16:43:12 -0700 (PDT) X-Original-To: linux-nvdimm@lists.01.org Delivered-To: linux-nvdimm@lists.01.org Received-SPF: Pass (sender SPF authorized) identity=mailfrom; client-ip=134.134.136.31; helo=mga06.intel.com; envelope-from=dan.j.williams@intel.com; receiver=linux-nvdimm@lists.01.org Received: from mga06.intel.com (mga06.intel.com [134.134.136.31]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ml01.01.org (Postfix) with ESMTPS id 5FBB9220E8E0E for ; Tue, 24 Apr 2018 16:43:10 -0700 (PDT) X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga004.fm.intel.com ([10.253.24.48]) by orsmga104.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 24 Apr 2018 16:43:10 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.49,325,1520924400"; d="scan'208";a="48828970" Received: from dwillia2-desk3.jf.intel.com (HELO dwillia2-desk3.amr.corp.intel.com) ([10.54.39.16]) by fmsmga004.fm.intel.com with ESMTP; 24 Apr 2018 16:43:09 -0700 Subject: [PATCH v9 2/9] mm, dax: enable filesystems to trigger dev_pagemap ->page_free callbacks From: Dan Williams To: linux-nvdimm@lists.01.org Date: Tue, 24 Apr 2018 16:33:13 -0700 Message-ID: <152461279341.17530.15922380333372355441.stgit@dwillia2-desk3.amr.corp.intel.com> In-Reply-To: <152461278149.17530.2867511144531572045.stgit@dwillia2-desk3.amr.corp.intel.com> References: <152461278149.17530.2867511144531572045.stgit@dwillia2-desk3.amr.corp.intel.com> User-Agent: StGit/0.18-2-gc94f MIME-Version: 1.0 X-BeenThere: linux-nvdimm@lists.01.org X-Mailman-Version: 2.1.26 Precedence: list List-Id: "Linux-nvdimm developer list." List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Michal Hocko , jack@suse.cz, david@fromorbit.com, linux-xfs@vger.kernel.org, linux-mm@kvack.org, =?utf-8?b?SsOpcsO0bWU=?= Glisse , linux-fsdevel@vger.kernel.org, hch@lst.de Errors-To: linux-nvdimm-bounces@lists.01.org Sender: "Linux-nvdimm" X-Virus-Scanned: ClamAV using ClamSMTP In order to resolve collisions between filesystem operations and DMA to DAX mapped pages we need a callback when DMA completes. With a callback we can hold off filesystem operations while DMA is in-flight and then resume those operations when the last put_page() occurs on a DMA page. Recall that the 'struct page' entries for DAX memory are created with devm_memremap_pages(). That routine arranges for the pages to be allocated, but never onlined, so a DAX page is DMA-idle when its reference count reaches one. Also recall that the HMM sub-system added infrastructure to trap the page-idle (2-to-1 reference count) transition of the pages allocated by devm_memremap_pages() and trigger a callback via the 'struct dev_pagemap' associated with the page range. Whereas the HMM callbacks are going to a device driver to manage bounce pages in device-memory in the filesystem-dax case we will call back to filesystem specified callback. Since the callback is not known at devm_memremap_pages() time we arrange for the filesystem to install it at mount time. No functional changes are expected as this only registers a nop handler for the ->page_free() event for device-mapped pages. Cc: Michal Hocko Reviewed-by: "Jérôme Glisse" Reviewed-by: Christoph Hellwig Reviewed-by: Jan Kara Signed-off-by: Dan Williams --- drivers/dax/super.c | 21 +++++++++++---------- drivers/nvdimm/pmem.c | 3 ++- fs/ext2/super.c | 6 +++--- fs/ext4/super.c | 6 +++--- fs/xfs/xfs_super.c | 20 ++++++++++---------- include/linux/dax.h | 14 ++++++++------ 6 files changed, 37 insertions(+), 33 deletions(-) diff --git a/drivers/dax/super.c b/drivers/dax/super.c index e62a64b9c9fb..e4864f319e16 100644 --- a/drivers/dax/super.c +++ b/drivers/dax/super.c @@ -63,16 +63,6 @@ int bdev_dax_pgoff(struct block_device *bdev, sector_t sector, size_t size, } EXPORT_SYMBOL(bdev_dax_pgoff); -#if IS_ENABLED(CONFIG_FS_DAX) -struct dax_device *fs_dax_get_by_bdev(struct block_device *bdev) -{ - if (!blk_queue_dax(bdev->bd_queue)) - return NULL; - return fs_dax_get_by_host(bdev->bd_disk->disk_name); -} -EXPORT_SYMBOL_GPL(fs_dax_get_by_bdev); -#endif - /** * __bdev_dax_supported() - Check if the device supports dax for filesystem * @sb: The superblock of the device @@ -575,6 +565,17 @@ struct dax_device *alloc_dax(void *private, const char *__host, } EXPORT_SYMBOL_GPL(alloc_dax); +struct dax_device *alloc_dax_devmap(void *private, const char *host, + const struct dax_operations *ops, struct dev_pagemap *pgmap) +{ + struct dax_device *dax_dev = alloc_dax(private, host, ops); + + if (dax_dev) + dax_dev->pgmap = pgmap; + return dax_dev; +} +EXPORT_SYMBOL_GPL(alloc_dax_devmap); + void put_dax(struct dax_device *dax_dev) { if (!dax_dev) diff --git a/drivers/nvdimm/pmem.c b/drivers/nvdimm/pmem.c index 9d714926ecf5..fc1a1ab25e9e 100644 --- a/drivers/nvdimm/pmem.c +++ b/drivers/nvdimm/pmem.c @@ -408,7 +408,8 @@ static int pmem_attach_disk(struct device *dev, nvdimm_badblocks_populate(nd_region, &pmem->bb, &bb_res); disk->bb = &pmem->bb; - dax_dev = alloc_dax(pmem, disk->disk_name, &pmem_dax_ops); + dax_dev = alloc_dax_devmap(pmem, disk->disk_name, &pmem_dax_ops, + &pmem->pgmap); if (!dax_dev) { put_disk(disk); return -ENOMEM; diff --git a/fs/ext2/super.c b/fs/ext2/super.c index de1694512f1f..421c7d4bed39 100644 --- a/fs/ext2/super.c +++ b/fs/ext2/super.c @@ -172,7 +172,7 @@ static void ext2_put_super (struct super_block * sb) brelse (sbi->s_sbh); sb->s_fs_info = NULL; kfree(sbi->s_blockgroup_lock); - fs_put_dax(sbi->s_daxdev); + fs_dax_release(sbi->s_daxdev, sb); kfree(sbi); } @@ -817,7 +817,7 @@ static unsigned long descriptor_loc(struct super_block *sb, static int ext2_fill_super(struct super_block *sb, void *data, int silent) { - struct dax_device *dax_dev = fs_dax_get_by_bdev(sb->s_bdev); + struct dax_device *dax_dev = fs_dax_claim_bdev(sb->s_bdev, sb); struct buffer_head * bh; struct ext2_sb_info * sbi; struct ext2_super_block * es; @@ -1213,7 +1213,7 @@ static int ext2_fill_super(struct super_block *sb, void *data, int silent) kfree(sbi->s_blockgroup_lock); kfree(sbi); failed: - fs_put_dax(dax_dev); + fs_dax_release(dax_dev, sb); return ret; } diff --git a/fs/ext4/super.c b/fs/ext4/super.c index 185f7e61f4cf..3e5d0f9e8772 100644 --- a/fs/ext4/super.c +++ b/fs/ext4/super.c @@ -954,7 +954,7 @@ static void ext4_put_super(struct super_block *sb) if (sbi->s_chksum_driver) crypto_free_shash(sbi->s_chksum_driver); kfree(sbi->s_blockgroup_lock); - fs_put_dax(sbi->s_daxdev); + fs_dax_release(sbi->s_daxdev, sb); kfree(sbi); } @@ -3407,7 +3407,7 @@ static void ext4_set_resv_clusters(struct super_block *sb) static int ext4_fill_super(struct super_block *sb, void *data, int silent) { - struct dax_device *dax_dev = fs_dax_get_by_bdev(sb->s_bdev); + struct dax_device *dax_dev = fs_dax_claim_bdev(sb->s_bdev, sb); char *orig_data = kstrdup(data, GFP_KERNEL); struct buffer_head *bh; struct ext4_super_block *es = NULL; @@ -4429,7 +4429,7 @@ static int ext4_fill_super(struct super_block *sb, void *data, int silent) out_free_base: kfree(sbi); kfree(orig_data); - fs_put_dax(dax_dev); + fs_dax_release(dax_dev, sb); return err ? err : ret; } diff --git a/fs/xfs/xfs_super.c b/fs/xfs/xfs_super.c index d71424052917..f53f8a47a526 100644 --- a/fs/xfs/xfs_super.c +++ b/fs/xfs/xfs_super.c @@ -724,7 +724,7 @@ xfs_close_devices( xfs_free_buftarg(mp->m_logdev_targp); xfs_blkdev_put(logdev); - fs_put_dax(dax_logdev); + fs_dax_release(dax_logdev, mp); } if (mp->m_rtdev_targp) { struct block_device *rtdev = mp->m_rtdev_targp->bt_bdev; @@ -732,10 +732,10 @@ xfs_close_devices( xfs_free_buftarg(mp->m_rtdev_targp); xfs_blkdev_put(rtdev); - fs_put_dax(dax_rtdev); + fs_dax_release(dax_rtdev, mp); } xfs_free_buftarg(mp->m_ddev_targp); - fs_put_dax(dax_ddev); + fs_dax_release(dax_ddev, mp); } /* @@ -753,9 +753,9 @@ xfs_open_devices( struct xfs_mount *mp) { struct block_device *ddev = mp->m_super->s_bdev; - struct dax_device *dax_ddev = fs_dax_get_by_bdev(ddev); - struct dax_device *dax_logdev = NULL, *dax_rtdev = NULL; + struct dax_device *dax_ddev = fs_dax_claim_bdev(ddev, mp); struct block_device *logdev = NULL, *rtdev = NULL; + struct dax_device *dax_logdev = NULL, *dax_rtdev = NULL; int error; /* @@ -765,7 +765,7 @@ xfs_open_devices( error = xfs_blkdev_get(mp, mp->m_logname, &logdev); if (error) goto out; - dax_logdev = fs_dax_get_by_bdev(logdev); + dax_logdev = fs_dax_claim_bdev(logdev, mp); } if (mp->m_rtname) { @@ -779,7 +779,7 @@ xfs_open_devices( error = -EINVAL; goto out_close_rtdev; } - dax_rtdev = fs_dax_get_by_bdev(rtdev); + dax_rtdev = fs_dax_claim_bdev(rtdev, mp); } /* @@ -813,14 +813,14 @@ xfs_open_devices( xfs_free_buftarg(mp->m_ddev_targp); out_close_rtdev: xfs_blkdev_put(rtdev); - fs_put_dax(dax_rtdev); + fs_dax_release(dax_rtdev, mp); out_close_logdev: if (logdev && logdev != ddev) { xfs_blkdev_put(logdev); - fs_put_dax(dax_logdev); + fs_dax_release(dax_logdev, mp); } out: - fs_put_dax(dax_ddev); + fs_dax_release(dax_ddev, mp); return error; } diff --git a/include/linux/dax.h b/include/linux/dax.h index af02f93c943a..fe322d67856e 100644 --- a/include/linux/dax.h +++ b/include/linux/dax.h @@ -33,6 +33,8 @@ extern struct attribute_group dax_attribute_group; struct dax_device *dax_get_by_host(const char *host); struct dax_device *alloc_dax(void *private, const char *host, const struct dax_operations *ops); +struct dax_device *alloc_dax_devmap(void *private, const char *host, + const struct dax_operations *ops, struct dev_pagemap *pgmap); void put_dax(struct dax_device *dax_dev); void kill_dax(struct dax_device *dax_dev); void dax_write_cache(struct dax_device *dax_dev, bool wc); @@ -51,6 +53,12 @@ static inline struct dax_device *alloc_dax(void *private, const char *host, */ return NULL; } +static inline struct dax_device *alloc_dax_devmap(void *private, + const char *host, const struct dax_operations *ops, + struct dev_pagemap *pgmap) +{ + return NULL; +} static inline void put_dax(struct dax_device *dax_dev) { } @@ -85,7 +93,6 @@ static inline void fs_put_dax(struct dax_device *dax_dev) put_dax(dax_dev); } -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 *fs_dax_claim(struct dax_device *dax_dev, void *owner); @@ -123,11 +130,6 @@ static inline void fs_put_dax(struct dax_device *dax_dev) { } -static inline struct dax_device *fs_dax_get_by_bdev(struct block_device *bdev) -{ - return NULL; -} - static inline int dax_writeback_mapping_range(struct address_space *mapping, struct block_device *bdev, struct writeback_control *wbc) {