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Subject: [PATCH 2/2] statx: move STATX_ATTR_DAX attribute handling to
 filesystems
To:     torvalds@linux-foundation.org,
        Miklos Szeredi <mszeredi@redhat.com>,
        Ira Weiny <ira.weiny@intel.com>,
        David Howells <dhowells@redhat.com>
Cc:     linux-fsdevel@vger.kernel.org, linux-man@vger.kernel.org,
        linux-kernel@vger.kernel.org, xfs <linux-xfs@vger.kernel.org>,
        linux-ext4@vger.kernel.org, Xiaoli Feng <xifeng@redhat.com>
References: <e388f379-cd11-a5d2-db82-aa1aa518a582@redhat.com>
From:   Eric Sandeen <sandeen@redhat.com>
Message-ID: <05a0f4fd-7f62-8fbc-378d-886ccd5b3f11@redhat.com>
Date:   Tue, 1 Dec 2020 10:59:36 -0600
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It's a bit odd to set STATX_ATTR_DAX into the statx attributes in the VFS;
while the VFS can detect the current DAX state, it is the filesystem which
actually sets S_DAX on the inode, and the filesystem is the place that
knows whether DAX is something that the "filesystem actually supports" [1]
so that the statx attributes_mask can be properly set.

So, move STATX_ATTR_DAX attribute setting to the individual dax-capable
filesystems, and update the attributes_mask there as well.

[1] 3209f68b3ca4 statx: Include a mask for stx_attributes in struct statx

Signed-off-by: Eric Sandeen <sandeen@redhat.com>
---
 fs/ext2/inode.c   | 6 +++++-
 fs/ext4/inode.c   | 5 ++++-
 fs/stat.c         | 3 ---
 fs/xfs/xfs_iops.c | 5 ++++-
 4 files changed, 13 insertions(+), 6 deletions(-)

diff --git a/fs/ext2/inode.c b/fs/ext2/inode.c
index 11c5c6fe75bb..3550783a6ea0 100644
--- a/fs/ext2/inode.c
+++ b/fs/ext2/inode.c
@@ -1653,11 +1653,15 @@ int ext2_getattr(const struct path *path, struct kstat *stat,
 		stat->attributes |= STATX_ATTR_IMMUTABLE;
 	if (flags & EXT2_NODUMP_FL)
 		stat->attributes |= STATX_ATTR_NODUMP;
+	if (IS_DAX(inode))
+		stat->attributes |= STATX_ATTR_DAX;
+
 	stat->attributes_mask |= (STATX_ATTR_APPEND |
 			STATX_ATTR_COMPRESSED |
 			STATX_ATTR_ENCRYPTED |
 			STATX_ATTR_IMMUTABLE |
-			STATX_ATTR_NODUMP);
+			STATX_ATTR_NODUMP |
+			STATX_ATTR_DAX);
 
 	generic_fillattr(inode, stat);
 	return 0;
diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
index 0d8385aea898..848a0f2b154e 100644
--- a/fs/ext4/inode.c
+++ b/fs/ext4/inode.c
@@ -5550,13 +5550,16 @@ int ext4_getattr(const struct path *path, struct kstat *stat,
 		stat->attributes |= STATX_ATTR_NODUMP;
 	if (flags & EXT4_VERITY_FL)
 		stat->attributes |= STATX_ATTR_VERITY;
+	if (IS_DAX(inode))
+		stat->attributes |= STATX_ATTR_DAX;
 
 	stat->attributes_mask |= (STATX_ATTR_APPEND |
 				  STATX_ATTR_COMPRESSED |
 				  STATX_ATTR_ENCRYPTED |
 				  STATX_ATTR_IMMUTABLE |
 				  STATX_ATTR_NODUMP |
-				  STATX_ATTR_VERITY);
+				  STATX_ATTR_VERITY |
+				  STATX_ATTR_DAX);
 
 	generic_fillattr(inode, stat);
 	return 0;
diff --git a/fs/stat.c b/fs/stat.c
index dacecdda2e79..5bd90949c69b 100644
--- a/fs/stat.c
+++ b/fs/stat.c
@@ -80,9 +80,6 @@ int vfs_getattr_nosec(const struct path *path, struct kstat *stat,
 	if (IS_AUTOMOUNT(inode))
 		stat->attributes |= STATX_ATTR_AUTOMOUNT;
 
-	if (IS_DAX(inode))
-		stat->attributes |= STATX_ATTR_DAX;
-
 	if (inode->i_op->getattr)
 		return inode->i_op->getattr(path, stat, request_mask,
 					    query_flags);
diff --git a/fs/xfs/xfs_iops.c b/fs/xfs/xfs_iops.c
index 1414ab79eacf..56deda7042fd 100644
--- a/fs/xfs/xfs_iops.c
+++ b/fs/xfs/xfs_iops.c
@@ -575,10 +575,13 @@ xfs_vn_getattr(
 		stat->attributes |= STATX_ATTR_APPEND;
 	if (ip->i_d.di_flags & XFS_DIFLAG_NODUMP)
 		stat->attributes |= STATX_ATTR_NODUMP;
+	if (IS_DAX(inode))
+		stat->attributes |= STATX_ATTR_DAX;
 
 	stat->attributes_mask |= (STATX_ATTR_IMMUTABLE |
 				  STATX_ATTR_APPEND |
-				  STATX_ATTR_NODUMP);
+				  STATX_ATTR_NODUMP |
+				  STATX_ATTR_DAX);
 
 	switch (inode->i_mode & S_IFMT) {
 	case S_IFBLK:
-- 
2.17.0