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From:   ira.weiny@intel.com
To:     linux-kernel@vger.kernel.org
Cc:     Ira Weiny <ira.weiny@intel.com>,
        Alexander Viro <viro@zeniv.linux.org.uk>,
        "Darrick J. Wong" <darrick.wong@oracle.com>,
        Dan Williams <dan.j.williams@intel.com>,
        Dave Chinner <david@fromorbit.com>,
        Christoph Hellwig <hch@lst.de>,
        "Theodore Y. Ts'o" <tytso@mit.edu>, Jan Kara <jack@suse.cz>,
        linux-ext4@vger.kernel.org, linux-xfs@vger.kernel.org,
        linux-fsdevel@vger.kernel.org
Subject: [PATCH V4 06/13] fs/xfs: Create function xfs_inode_enable_dax()
Date:   Thu, 20 Feb 2020 16:41:27 -0800
Message-Id: <20200221004134.30599-7-ira.weiny@intel.com>
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From: Ira Weiny <ira.weiny@intel.com>

xfs_inode_supports_dax() should reflect if the inode can support DAX not
that it is enabled for DAX.

Change the use of xfs_inode_supports_dax() to reflect only if the inode
and underlying storage support dax.

Add a new function xfs_inode_enable_dax() which reflects if the inode
should be enabled for DAX.

Signed-off-by: Ira Weiny <ira.weiny@intel.com>

---
Changes from v3:
	Update functions and names to be more clear
	Update commit message
	Merge with
		'fs/xfs: Clean up DAX support check'
		don't allow IS_DAX() on a directory
		use STATIC macro for static
		make xfs_inode_supports_dax() static
---
 fs/xfs/xfs_iops.c | 25 +++++++++++++++++++------
 1 file changed, 19 insertions(+), 6 deletions(-)

diff --git a/fs/xfs/xfs_iops.c b/fs/xfs/xfs_iops.c
index 81f2f93caec0..ff711efc5247 100644
--- a/fs/xfs/xfs_iops.c
+++ b/fs/xfs/xfs_iops.c
@@ -1237,19 +1237,18 @@ static const struct inode_operations xfs_inline_symlink_inode_operations = {
 };
 
 /* Figure out if this file actually supports DAX. */
-static bool
+STATIC bool
 xfs_inode_supports_dax(
 	struct xfs_inode	*ip)
 {
 	struct xfs_mount	*mp = ip->i_mount;
 
 	/* Only supported on non-reflinked files. */
-	if (!S_ISREG(VFS_I(ip)->i_mode) || xfs_is_reflink_inode(ip))
+	if (xfs_is_reflink_inode(ip))
 		return false;
 
-	/* DAX mount option or DAX iflag must be set. */
-	if (!(mp->m_flags & XFS_MOUNT_DAX) &&
-	    !(ip->i_d.di_flags2 & XFS_DIFLAG2_DAX))
+	/* Only supported on regular files. */
+	if (!S_ISREG(VFS_I(ip)->i_mode))
 		return false;
 
 	/* Block size must match page size */
@@ -1260,6 +1259,20 @@ xfs_inode_supports_dax(
 	return xfs_inode_buftarg(ip)->bt_daxdev != NULL;
 }
 
+STATIC bool
+xfs_inode_enable_dax(
+	struct xfs_inode *ip)
+{
+	if (!xfs_inode_supports_dax(ip))
+		return false;
+
+	if (ip->i_d.di_flags2 & XFS_DIFLAG2_DAX)
+		return true;
+	if (ip->i_mount->m_flags & XFS_MOUNT_DAX)
+		return true;
+	return false;
+}
+
 STATIC void
 xfs_diflags_to_iflags(
 	struct inode		*inode,
@@ -1278,7 +1291,7 @@ xfs_diflags_to_iflags(
 		inode->i_flags |= S_SYNC;
 	if (flags & XFS_DIFLAG_NOATIME)
 		inode->i_flags |= S_NOATIME;
-	if (xfs_inode_supports_dax(ip))
+	if (xfs_inode_enable_dax(ip))
 		inode->i_flags |= S_DAX;
 }
 
-- 
2.21.0