fs: add sync_inode_metadata

Add a new helper to write out the inode using the writeback code,
that is including the correct dirty bit and list manipulation.  A few
of filesystems already opencode this, and a lot of others should be
using it instead of using write_inode_now which also writes out the
data.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

1 files changed, 3 insertions, 13 deletions

diff --git a/fs/nfsd/vfs.c b/fs/nfsd/vfs.c
index 661a6cf8e826..184938fcff04 100644
--- a/fs/nfsd/vfs.c
+++ b/fs/nfsd/vfs.c
@@ -281,23 +281,13 @@ commit_metadata(struct svc_fh *fhp)
 {
 	struct inode *inode = fhp->fh_dentry->d_inode;
 	const struct export_operations *export_ops = inode->i_sb->s_export_op;
-	int error = 0;
 
 	if (!EX_ISSYNC(fhp->fh_export))
 		return 0;
 
-	if (export_ops->commit_metadata) {
-		error = export_ops->commit_metadata(inode);
-	} else {
-		struct writeback_control wbc = {
-			.sync_mode = WB_SYNC_ALL,
-			.nr_to_write = 0, /* metadata only */
-		};
-
-		error = sync_inode(inode, &wbc);
-	}
-
-	return error;
+	if (export_ops->commit_metadata)
+		return export_ops->commit_metadata(inode);
+	return sync_inode_metadata(inode, 1);
 }
 
 /*