[RFC PATCH V2 04/12] fs/xfs: Clean up DAX support check

From: ira . weiny
Date: Fri Jan 10 2020 - 14:30:06 EST


From: Ira Weiny <ira.weiny@xxxxxxxxx>

Rather than open coding xfs_inode_supports_dax() in
xfs_ioctl_setattr_dax_invalidate() export xfs_inode_supports_dax() and
call it in preparation for swapping dax flags.

This also means updating xfs_inode_supports_dax() to return true for a
directory.

Signed-off-by: Ira Weiny <ira.weiny@xxxxxxxxx>
---
fs/xfs/xfs_ioctl.c | 16 +++-------------
fs/xfs/xfs_iops.c | 8 ++++++--
fs/xfs/xfs_iops.h | 2 ++
3 files changed, 11 insertions(+), 15 deletions(-)

diff --git a/fs/xfs/xfs_ioctl.c b/fs/xfs/xfs_ioctl.c
index fe37708cea8f..b5e00b67c297 100644
--- a/fs/xfs/xfs_ioctl.c
+++ b/fs/xfs/xfs_ioctl.c
@@ -1176,23 +1176,13 @@ xfs_ioctl_setattr_dax_invalidate(
int *join_flags)
{
struct inode *inode = VFS_I(ip);
- struct super_block *sb = inode->i_sb;
int error;

*join_flags = 0;

- /*
- * It is only valid to set the DAX flag on regular files and
- * directories on filesystems where the block size is equal to the page
- * size. On directories it serves as an inherited hint so we don't
- * have to check the device for dax support or flush pagecache.
- */
- if (fa->fsx_xflags & FS_XFLAG_DAX) {
- struct xfs_buftarg *target = xfs_inode_buftarg(ip);
-
- if (!bdev_dax_supported(target->bt_bdev, sb->s_blocksize))
- return -EINVAL;
- }
+ if ((fa->fsx_xflags & FS_XFLAG_DAX) == FS_XFLAG_DAX &&
+ !xfs_inode_supports_dax(ip))
+ return -EINVAL;

/* If the DAX state is not changing, we have nothing to do here. */
if ((fa->fsx_xflags & FS_XFLAG_DAX) &&
diff --git a/fs/xfs/xfs_iops.c b/fs/xfs/xfs_iops.c
index 0a0ea90259e9..d6843cdb51d0 100644
--- a/fs/xfs/xfs_iops.c
+++ b/fs/xfs/xfs_iops.c
@@ -1244,14 +1244,18 @@ xfs_inode_mount_is_dax(
}

/* Figure out if this file actually supports DAX. */
-static bool
+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;
+
+ /* Only supported on regular files and directories. */
+ if (!(S_ISREG(VFS_I(ip)->i_mode) || S_ISDIR(VFS_I(ip)->i_mode)))
return false;

/* Block size must match page size */
diff --git a/fs/xfs/xfs_iops.h b/fs/xfs/xfs_iops.h
index 4d24ff309f59..f24fec8de1d6 100644
--- a/fs/xfs/xfs_iops.h
+++ b/fs/xfs/xfs_iops.h
@@ -24,4 +24,6 @@ extern int xfs_setattr_nonsize(struct xfs_inode *ip, struct iattr *vap,
extern int xfs_vn_setattr_nonsize(struct dentry *dentry, struct iattr *vap);
extern int xfs_vn_setattr_size(struct dentry *dentry, struct iattr *vap);

+extern bool xfs_inode_supports_dax(struct xfs_inode *ip);
+
#endif /* __XFS_IOPS_H__ */
--
2.21.0