[RFC PATCH 2/4] nfs: report the change attribute if requested

[Jeff Layton <jlayton@kernel.org>]

Allow NFS to report the i_version in statx. Since the cost to fetch it
is relatively cheap, do it unconditionally and just set the flag if it
looks like it's valid.

Signed-off-by: Jeff Layton <jlayton@kernel.org>
---
 fs/nfs/inode.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/fs/nfs/inode.c b/fs/nfs/inode.c
index b4e46b0ffa2d..8e0e7ecf6429 100644
--- a/fs/nfs/inode.c
+++ b/fs/nfs/inode.c
@@ -829,6 +829,8 @@ static u32 nfs_get_valid_attrmask(struct inode *inode)
 		reply_mask |= STATX_UID | STATX_GID;
 	if (!(cache_validity & NFS_INO_INVALID_BLOCKS))
 		reply_mask |= STATX_BLOCKS;
+	if (!(cache_validity & NFS_INO_INVALID_CHANGE))
+		reply_mask |= STATX_CHGATTR;
 	return reply_mask;
 }
 
@@ -914,6 +916,7 @@ int nfs_getattr(struct user_namespace *mnt_userns, const struct path *path,
 
 	generic_fillattr(&init_user_ns, inode, stat);
 	stat->ino = nfs_compat_user_ino64(NFS_FILEID(inode));
+	stat->chgattr = inode_peek_iversion_raw(inode);
 	if (S_ISDIR(inode->i_mode))
 		stat->blksize = NFS_SERVER(inode)->dtsize;
 out:
-- 
2.37.1