[PATCH V10 07/11] fs/xfs: Create function xfs_inode_should_enable_dax()

ira.weiny
2020-04-22T21:22:07Z

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_should_enable_dax() which reflects if the
inode should be enabled for DAX.

Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Ira Weiny <ira.weiny@intel.com>

---
Changes from V8
Change to 'should enable' (feedback given by Jan in ext4 series)
Darrick I've preserved your Reviewed-by for now LMK if
that is an issue.

Changes from v7:
Move S_ISREG check first
use IS_ENABLED(CONFIG_FS_DAX) rather than duplicated function

Changes from v6:
Change enable checks to be sequential logic.
Update for 2 bit tri-state option.
Make 'static' consistent.
Don't set S_DAX if !CONFIG_FS_DAX

Changes from v5:
Update to reflect the new tri-state mount option

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 | 28 ++++++++++++++++++++++------
1 file changed, 22 insertions(+), 6 deletions(-)

diff --git a/fs/xfs/xfs_iops.c b/fs/xfs/xfs_iops.c
index 462f89af479a..1814f10e43d3 100644
--- a/fs/xfs/xfs_iops.c
+++ b/fs/xfs/xfs_iops.c
@@ -1243,13 +1243,12 @@ xfs_inode_supports_dax(
{
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))
+ /* Only supported on regular files. */
+ if (!S_ISREG(VFS_I(ip)->i_mode))
return false;

- /* DAX mount option or DAX iflag must be set. */
- if (!(mp->m_flags & XFS_MOUNT_DAX_ALWAYS) &&
- !(ip->i_d.di_flags2 & XFS_DIFLAG2_DAX))
+ /* Only supported on non-reflinked files. */
+ if (xfs_is_reflink_inode(ip))
return false;

/* Block size must match page size */
@@ -1260,6 +1259,23 @@ xfs_inode_supports_dax(
return xfs_inode_buftarg(ip)->bt_daxdev != NULL;
}

+static bool
+xfs_inode_should_enable_dax(
+ struct xfs_inode *ip)
+{
+ if (!IS_ENABLED(CONFIG_FS_DAX))
+ return false;
+ if (ip->i_mount->m_flags & XFS_MOUNT_DAX_NEVER)
+ return false;
+ if (!xfs_inode_supports_dax(ip))
+ return false;
+ if (ip->i_mount->m_flags & XFS_MOUNT_DAX_ALWAYS)
+ return true;
+ if (ip->i_d.di_flags2 & XFS_DIFLAG2_DAX)
+ return true;
+ return false;
+}
+
STATIC void
xfs_diflags_to_iflags(
struct inode *inode,
@@ -1278,7 +1294,7 @@ 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_should_enable_dax(ip))
inode->i_flags |= S_DAX;
}

--
2.25.1