From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mga11.intel.com (mga11.intel.com [192.55.52.93]) (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 BB45A220C2A4B for ; Thu, 15 Mar 2018 09:01:58 -0700 (PDT) Subject: [PATCH v6 02/15] fs, dax: prepare for dax-specific address_space_operations From: Dan Williams Date: Thu, 15 Mar 2018 08:51:33 -0700 Message-ID: <152112909383.24669.7898033239205318865.stgit@dwillia2-desk3.amr.corp.intel.com> In-Reply-To: <152112908134.24669.10222746224538377035.stgit@dwillia2-desk3.amr.corp.intel.com> References: <152112908134.24669.10222746224538377035.stgit@dwillia2-desk3.amr.corp.intel.com> MIME-Version: 1.0 List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: linux-nvdimm-bounces@lists.01.org Sender: "Linux-nvdimm" To: linux-nvdimm@lists.01.org Cc: jack@suse.cz, Matthew Wilcox , Dave Chinner , linux-kernel@vger.kernel.org, linux-xfs@vger.kernel.org, linux-fsdevel@vger.kernel.org, hch@lst.de List-ID: In preparation for the dax implementation to start associating dax pages to inodes via page->mapping, we need to provide a 'struct address_space_operations' instance for dax. Define some generic VFS aops helpers for dax. These noop implementations are there in the dax case to prevent the VFS from falling back to operations with page-cache assumptions, dax_writeback_mapping_range() may not be referenced in the FS_DAX=n case. Cc: Jeff Moyer Cc: Ross Zwisler Suggested-by: Matthew Wilcox Suggested-by: Jan Kara Suggested-by: Christoph Hellwig Suggested-by: Dave Chinner Signed-off-by: Dan Williams --- fs/libfs.c | 27 +++++++++++++++++++++++++++ include/linux/dax.h | 12 +++++++++--- include/linux/fs.h | 3 +++ 3 files changed, 39 insertions(+), 3 deletions(-) diff --git a/fs/libfs.c b/fs/libfs.c index 7ff3cb904acd..e49d0ac6f800 100644 --- a/fs/libfs.c +++ b/fs/libfs.c @@ -1060,6 +1060,33 @@ int noop_fsync(struct file *file, loff_t start, loff_t end, int datasync) } EXPORT_SYMBOL(noop_fsync); +int noop_set_page_dirty(struct page *page) +{ + /* + * Unlike __set_page_dirty_no_writeback that handles dirty page + * tracking in the page object, dax does all dirty tracking in + * the inode address_space in response to mkwrite faults. In the + * dax case we only need to worry about potentially dirty CPU + * caches, not dirty page cache pages to write back. + * + * This callback is defined to prevent fallback to + * __set_page_dirty_buffers() in set_page_dirty(). + */ + return 0; +} +EXPORT_SYMBOL_GPL(noop_set_page_dirty); + +void noop_invalidatepage(struct page *page, unsigned int offset, + unsigned int length) +{ + /* + * There is no page cache to invalidate in the dax case, however + * we need this callback defined to prevent falling back to + * block_invalidatepage() in do_invalidatepage(). + */ +} +EXPORT_SYMBOL_GPL(noop_invalidatepage); + /* Because kfree isn't assignment-compatible with void(void*) ;-/ */ void kfree_link(void *p) { diff --git a/include/linux/dax.h b/include/linux/dax.h index 0185ecdae135..ae27a7efe7ab 100644 --- a/include/linux/dax.h +++ b/include/linux/dax.h @@ -38,6 +38,7 @@ static inline void put_dax(struct dax_device *dax_dev) } #endif +struct writeback_control; int bdev_dax_pgoff(struct block_device *, sector_t, size_t, pgoff_t *pgoff); #if IS_ENABLED(CONFIG_FS_DAX) int __bdev_dax_supported(struct super_block *sb, int blocksize); @@ -57,6 +58,8 @@ static inline void fs_put_dax(struct dax_device *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); #else static inline int bdev_dax_supported(struct super_block *sb, int blocksize) { @@ -76,6 +79,12 @@ 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) +{ + return -EOPNOTSUPP; +} #endif int dax_read_lock(void); @@ -121,7 +130,4 @@ static inline bool dax_mapping(struct address_space *mapping) return mapping->host && IS_DAX(mapping->host); } -struct writeback_control; -int dax_writeback_mapping_range(struct address_space *mapping, - struct block_device *bdev, struct writeback_control *wbc); #endif diff --git a/include/linux/fs.h b/include/linux/fs.h index 79c413985305..b57db31d294d 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -3129,6 +3129,9 @@ extern int simple_rmdir(struct inode *, struct dentry *); extern int simple_rename(struct inode *, struct dentry *, struct inode *, struct dentry *, unsigned int); extern int noop_fsync(struct file *, loff_t, loff_t, int); +extern int noop_set_page_dirty(struct page *page); +extern void noop_invalidatepage(struct page *page, unsigned int offset, + unsigned int length); extern int simple_empty(struct dentry *); extern int simple_readpage(struct file *file, struct page *page); extern int simple_write_begin(struct file *file, struct address_space *mapping, _______________________________________________ Linux-nvdimm mailing list Linux-nvdimm@lists.01.org https://lists.01.org/mailman/listinfo/linux-nvdimm