From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pf0-f173.google.com (mail-pf0-f173.google.com [209.85.192.173]) by kanga.kvack.org (Postfix) with ESMTP id 1D6466B0268 for ; Mon, 22 Feb 2016 13:59:44 -0500 (EST) Received: by mail-pf0-f173.google.com with SMTP id c10so100315127pfc.2 for ; Mon, 22 Feb 2016 10:59:44 -0800 (PST) Received: from mga01.intel.com (mga01.intel.com. [192.55.52.88]) by mx.google.com with ESMTP id af6si41329226pad.226.2016.02.22.10.59.41 for ; Mon, 22 Feb 2016 10:59:41 -0800 (PST) From: Ross Zwisler Subject: [PATCH v4 2/5] ext2, ext4: only set S_DAX for regular inodes Date: Mon, 22 Feb 2016 11:59:19 -0700 Message-Id: <1456167562-28576-3-git-send-email-ross.zwisler@linux.intel.com> In-Reply-To: <1456167562-28576-1-git-send-email-ross.zwisler@linux.intel.com> References: <1456167562-28576-1-git-send-email-ross.zwisler@linux.intel.com> Sender: owner-linux-mm@kvack.org List-ID: To: linux-kernel@vger.kernel.org Cc: Ross Zwisler , Theodore Ts'o , Alexander Viro , Andreas Dilger , Andrew Morton , Dan Williams , Dave Chinner , Jan Kara , Jens Axboe , Matthew Wilcox , linux-block@vger.kernel.org, linux-ext4@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-mm@kvack.org, linux-nvdimm@lists.01.org, xfs@oss.sgi.com When S_DAX is set on an inode we assume that if there are pages attached to the mapping (mapping->nrpages != 0), those pages are clean zero pages that were used to service reads from holes. Any dirty data associated with the inode should be in the form of DAX exceptional entries (mapping->nrexceptional) that is written back via dax_writeback_mapping_range(). With the current code, though, this isn't always true. For example, ext2 and ext4 directory inodes can have S_DAX set, but have their dirty data stored as dirty page cache entries. For these types of inodes, having S_DAX set doesn't really make sense since their I/O doesn't actually happen through the DAX code path. Instead, only allow S_DAX to be set for regular inodes for ext2 and ext4. This allows us to have strict DAX vs non-DAX paths in the writeback code. Signed-off-by: Ross Zwisler Reviewed-by: Jan Kara --- fs/ext2/inode.c | 2 +- fs/ext4/inode.c | 2 +- 2 files changed, 2 insertions(+), 2 deletions(-) diff --git a/fs/ext2/inode.c b/fs/ext2/inode.c index 338eefd..27e2cdd 100644 --- a/fs/ext2/inode.c +++ b/fs/ext2/inode.c @@ -1296,7 +1296,7 @@ void ext2_set_inode_flags(struct inode *inode) inode->i_flags |= S_NOATIME; if (flags & EXT2_DIRSYNC_FL) inode->i_flags |= S_DIRSYNC; - if (test_opt(inode->i_sb, DAX)) + if (test_opt(inode->i_sb, DAX) && S_ISREG(inode->i_mode)) inode->i_flags |= S_DAX; } diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c index 9cc57c3..5708e68 100644 --- a/fs/ext4/inode.c +++ b/fs/ext4/inode.c @@ -4155,7 +4155,7 @@ void ext4_set_inode_flags(struct inode *inode) new_fl |= S_NOATIME; if (flags & EXT4_DIRSYNC_FL) new_fl |= S_DIRSYNC; - if (test_opt(inode->i_sb, DAX)) + if (test_opt(inode->i_sb, DAX) && S_ISREG(inode->i_mode)) new_fl |= S_DAX; inode_set_flags(inode, new_fl, S_SYNC|S_APPEND|S_IMMUTABLE|S_NOATIME|S_DIRSYNC|S_DAX); -- 2.5.0 -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org