From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mga03.intel.com ([134.134.136.65]:36145 "EHLO mga03.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726823AbfFFBpR (ORCPT ); Wed, 5 Jun 2019 21:45:17 -0400 From: ira.weiny@intel.com Subject: [PATCH RFC 05/10] fs/ext4: Teach ext4 to break layout leases Date: Wed, 5 Jun 2019 18:45:38 -0700 Message-Id: <20190606014544.8339-6-ira.weiny@intel.com> In-Reply-To: <20190606014544.8339-1-ira.weiny@intel.com> References: <20190606014544.8339-1-ira.weiny@intel.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: linux-xfs-owner@vger.kernel.org List-ID: List-Id: xfs To: Dan Williams , Jan Kara , Theodore Ts'o , Jeff Layton , Dave Chinner Cc: Ira Weiny , Matthew Wilcox , linux-xfs@vger.kernel.org, Andrew Morton , John Hubbard , =?UTF-8?q?J=C3=A9r=C3=B4me=20Glisse?= , linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, linux-nvdimm@lists.01.org, linux-ext4@vger.kernel.org, linux-mm@kvack.org From: Ira Weiny ext4 needs to break a layout lease if it is held to inform a user holding a layout lease that a truncate is about to happen. This allows the user knowledge of, and choice in how to handle, some other thread attempting to modify a file they are actively using. Split out the logic to determine if a mapping is DAX, export it, and then break layout leases if a mapping is DAX. Signed-off-by: Ira Weiny --- fs/dax.c | 23 ++++++++++++++++------- fs/ext4/inode.c | 4 ++++ include/linux/dax.h | 6 ++++++ 3 files changed, 26 insertions(+), 7 deletions(-) diff --git a/fs/dax.c b/fs/dax.c index f74386293632..29ff3b683657 100644 --- a/fs/dax.c +++ b/fs/dax.c @@ -552,6 +552,21 @@ static void *grab_mapping_entry(struct xa_state *xas, return xa_mk_internal(VM_FAULT_FALLBACK); } +bool dax_mapping_is_dax(struct address_space *mapping) +{ + /* + * In the 'limited' case get_user_pages() for dax is disabled. + */ + if (IS_ENABLED(CONFIG_FS_DAX_LIMITED)) + return false; + + if (!dax_mapping(mapping) || !mapping_mapped(mapping)) + return false; + + return true; +} +EXPORT_SYMBOL_GPL(dax_mapping_is_dax); + /** * dax_layout_busy_page - find first pinned page in @mapping * @mapping: address space to scan for a page with ref count > 1 @@ -574,13 +589,7 @@ struct page *dax_layout_busy_page(struct address_space *mapping) unsigned int scanned = 0; struct page *page = NULL; - /* - * In the 'limited' case get_user_pages() for dax is disabled. - */ - if (IS_ENABLED(CONFIG_FS_DAX_LIMITED)) - return NULL; - - if (!dax_mapping(mapping) || !mapping_mapped(mapping)) + if (!dax_mapping_is_dax(mapping)) return NULL; /* diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c index c16071547c9c..c7c99f51961f 100644 --- a/fs/ext4/inode.c +++ b/fs/ext4/inode.c @@ -4241,6 +4241,10 @@ int ext4_break_layouts(struct inode *inode) if (WARN_ON_ONCE(!rwsem_is_locked(&ei->i_mmap_sem))) return -EINVAL; + /* Break layout leases if active */ + if (dax_mapping_is_dax(inode->i_mapping)) + break_layout(inode, true); + do { page = dax_layout_busy_page(inode->i_mapping); if (!page) diff --git a/include/linux/dax.h b/include/linux/dax.h index becaea5f4488..ee6cbd56ddc4 100644 --- a/include/linux/dax.h +++ b/include/linux/dax.h @@ -106,6 +106,7 @@ 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); +bool dax_mapping_is_dax(struct address_space *mapping); struct page *dax_layout_busy_page(struct address_space *mapping); dax_entry_t dax_lock_page(struct page *page); void dax_unlock_page(struct page *page, dax_entry_t cookie); @@ -137,6 +138,11 @@ static inline struct dax_device *fs_dax_get_by_bdev(struct block_device *bdev) return NULL; } +bool dax_mapping_is_dax(struct address_space *mapping) +{ + return false; +} + static inline struct page *dax_layout_busy_page(struct address_space *mapping) { return NULL; -- 2.20.1