9p: add bdi backing to mount session

This ensures that dirty data gets flushed properly.

Signed-off-by: Jens Axboe <jens.axboe@oracle.com>

1 files changed, 10 insertions, 0 deletions

diff --git a/fs/9p/v9fs.c b/fs/9p/v9fs.c
index 5c5bc848007..f8b86e92cd6 100644
--- a/fs/9p/v9fs.c
+++ b/fs/9p/v9fs.c
@@ -238,6 +238,13 @@ struct p9_fid *v9fs_session_init(struct v9fs_session_info *v9ses,
 		return ERR_PTR(-ENOMEM);
 	}
 
+	rc = bdi_setup_and_register(&v9ses->bdi, "9p", BDI_CAP_MAP_COPY);
+	if (rc) {
+		__putname(v9ses->aname);
+		__putname(v9ses->uname);
+		return ERR_PTR(rc);
+	}
+
 	spin_lock(&v9fs_sessionlist_lock);
 	list_add(&v9ses->slist, &v9fs_sessionlist);
 	spin_unlock(&v9fs_sessionlist_lock);
@@ -301,6 +308,7 @@ struct p9_fid *v9fs_session_init(struct v9fs_session_info *v9ses,
 	return fid;
 
 error:
+	bdi_destroy(&v9ses->bdi);
 	return ERR_PTR(retval);
 }
 
@@ -326,6 +334,8 @@ void v9fs_session_close(struct v9fs_session_info *v9ses)
 	__putname(v9ses->uname);
 	__putname(v9ses->aname);
 
+	bdi_destroy(&v9ses->bdi);
+
 	spin_lock(&v9fs_sessionlist_lock);
 	list_del(&v9ses->slist);
 	spin_unlock(&v9fs_sessionlist_lock);