From: Ross Zwisler Subject: [PATCH v2] ext4: allow DAX writeback for hole punch Date: Wed, 17 Aug 2016 12:23:09 -0600 Message-ID: <20160817182309.28756-1-ross.zwisler@linux.intel.com> References: <20160817171955.GA30893@quack2.suse.cz> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Cc: Theodore Ts'o , linux-nvdimm-hn68Rpc1hR1g9hUCZPvPmw@public.gmane.org, stable-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, Andreas Dilger , Jan Kara , linux-ext4-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org Return-path: In-Reply-To: <20160817171955.GA30893-4I4JzKEfoa/jFM9bn6wA6Q@public.gmane.org> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: linux-nvdimm-bounces-hn68Rpc1hR1g9hUCZPvPmw@public.gmane.org Sender: "Linux-nvdimm" List-Id: linux-ext4.vger.kernel.org Currently when doing a DAX hole punch with ext4 we fail to do a writeback. This is because the logic around filemap_write_and_wait_range() in ext4_punch_hole() only looks for dirty page cache pages in the radix tree, not for dirty DAX exceptional entries. Signed-off-by: Ross Zwisler Reviewed-by: Jan Kara Cc: stable-u79uwXL29TY76Z2rM5mHXA@public.gmane.org --- This should be applied to stable kernels v4.5 and beyond. --- fs/ext4/inode.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c index 3131747..0900cb4 100644 --- a/fs/ext4/inode.c +++ b/fs/ext4/inode.c @@ -3890,7 +3890,7 @@ int ext4_update_disksize_before_punch(struct inode *inode, loff_t offset, } /* - * ext4_punch_hole: punches a hole in a file by releaseing the blocks + * ext4_punch_hole: punches a hole in a file by releasing the blocks * associated with the given offset and length * * @inode: File inode @@ -3919,7 +3919,7 @@ int ext4_punch_hole(struct inode *inode, loff_t offset, loff_t length) * Write out all dirty pages to avoid race conditions * Then release them. */ - if (mapping->nrpages && mapping_tagged(mapping, PAGECACHE_TAG_DIRTY)) { + if (mapping_tagged(mapping, PAGECACHE_TAG_DIRTY)) { ret = filemap_write_and_wait_range(mapping, offset, offset + length - 1); if (ret) -- 2.9.0