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Commit 9abf82b8 authored by Sage Weil's avatar Sage Weil
Browse files

ceph: fix locking for waking session requests after reconnect 



The session->s_waiting list is protected by mdsc->mutex, not s_mutex.  This
was causing (rare) s_waiting list corruption.

Fix errors paths too, while we're here.  A more thorough cleanup of this
function is coming soon.

Signed-off-by: default avatarSage Weil <sage@newdream.net>
parent d85b7056

fs/ceph/mds_client.c

+16 −13
Original line number Diff line number Diff line
@@ -2136,7 +2136,7 @@ static void send_mds_reconnect(struct ceph_mds_client *mdsc, int mds) 
	struct ceph_mds_session *session = NULL;

	struct ceph_msg *reply;

	struct rb_node *p;

	int err;

	int err = -ENOMEM;

	struct ceph_pagelist *pagelist;



	pr_info("reconnect to recovering mds%d\n", mds);
@@ -2185,7 +2185,7 @@ static void send_mds_reconnect(struct ceph_mds_client *mdsc, int mds) 
		goto fail;

	err = iterate_session_caps(session, encode_caps_cb, pagelist);

	if (err < 0)

		goto out;

		goto fail;



	/*

	 * snaprealms.  we provide mds with the ino, seq (version), and
@@ -2213,28 +2213,31 @@ static void send_mds_reconnect(struct ceph_mds_client *mdsc, int mds) 
	reply->nr_pages = calc_pages_for(0, pagelist->length);

	ceph_con_send(&session->s_con, reply);



	if (session) {

	session->s_state = CEPH_MDS_SESSION_OPEN;

	mutex_unlock(&session->s_mutex);



	mutex_lock(&mdsc->mutex);

	__wake_requests(mdsc, &session->s_waiting);

	}

	mutex_unlock(&mdsc->mutex);



out:

	up_read(&mdsc->snap_rwsem);

	if (session) {

		mutex_unlock(&session->s_mutex);

	ceph_put_mds_session(session);

	}



	up_read(&mdsc->snap_rwsem);

	mutex_lock(&mdsc->mutex);

	return;



fail:

	ceph_msg_put(reply);

	up_read(&mdsc->snap_rwsem);

	mutex_unlock(&session->s_mutex);

	ceph_put_mds_session(session);

fail_nomsg:

	ceph_pagelist_release(pagelist);

	kfree(pagelist);

fail_nopagelist:

	pr_err("ENOMEM preparing reconnect for mds%d\n", mds);

	goto out;

	pr_err("error %d preparing reconnect for mds%d\n", err, mds);

	mutex_lock(&mdsc->mutex);

	return;

}