From 9abf82b8bc93dd904738a71ca69aa5df356d4d24 Mon Sep 17 00:00:00 2001 From: Sage Weil Date: Mon, 10 May 2010 21:58:38 -0700 Subject: [PATCH] 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: Sage Weil --- fs/ceph/mds_client.c | 29 ++++++++++++++++------------- 1 file changed, 16 insertions(+), 13 deletions(-) diff --git a/fs/ceph/mds_client.c b/fs/ceph/mds_client.c index 60a9a4a..eccc0ec 100644 --- a/fs/ceph/mds_client.c +++ b/fs/ceph/mds_client.c @@ -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 @@ send: 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; - __wake_requests(mdsc, &session->s_waiting); - } + 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); + + ceph_put_mds_session(session); -out: up_read(&mdsc->snap_rwsem); - if (session) { - mutex_unlock(&session->s_mutex); - ceph_put_mds_session(session); - } 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; } -- 2.7.4