From mboxrd@z Thu Jan 1 00:00:00 1970 From: Sasha Levin Subject: [PATCH AUTOSEL 5.3 13/71] ceph: fetch cap_gen under spinlock in ceph_add_cap Date: Tue, 1 Oct 2019 12:38:23 -0400 Message-ID: <20191001163922.14735-13-sashal@kernel.org> References: <20191001163922.14735-1-sashal@kernel.org> Mime-Version: 1.0 Content-Transfer-Encoding: 8bit Return-path: In-Reply-To: <20191001163922.14735-1-sashal@kernel.org> Sender: stable-owner@vger.kernel.org To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Jeff Layton , "Yan, Zheng" , Ilya Dryomov , Sasha Levin , ceph-devel@vger.kernel.org List-Id: ceph-devel.vger.kernel.org From: Jeff Layton [ Upstream commit 606d102327a45a49d293557527802ee7fbfd7af1 ] It's protected by the s_gen_ttl_lock, so we should fetch under it and ensure that we're using the same generation in both places. Signed-off-by: Jeff Layton Reviewed-by: "Yan, Zheng" Signed-off-by: Ilya Dryomov Signed-off-by: Sasha Levin --- fs/ceph/caps.c | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-) diff --git a/fs/ceph/caps.c b/fs/ceph/caps.c index ce0f5658720ab..8fd5301128106 100644 --- a/fs/ceph/caps.c +++ b/fs/ceph/caps.c @@ -645,6 +645,7 @@ void ceph_add_cap(struct inode *inode, struct ceph_cap *cap; int mds = session->s_mds; int actual_wanted; + u32 gen; dout("add_cap %p mds%d cap %llx %s seq %d\n", inode, session->s_mds, cap_id, ceph_cap_string(issued), seq); @@ -656,6 +657,10 @@ void ceph_add_cap(struct inode *inode, if (fmode >= 0) wanted |= ceph_caps_for_mode(fmode); + spin_lock(&session->s_gen_ttl_lock); + gen = session->s_cap_gen; + spin_unlock(&session->s_gen_ttl_lock); + cap = __get_cap_for_mds(ci, mds); if (!cap) { cap = *new_cap; @@ -681,7 +686,7 @@ void ceph_add_cap(struct inode *inode, list_move_tail(&cap->session_caps, &session->s_caps); spin_unlock(&session->s_cap_lock); - if (cap->cap_gen < session->s_cap_gen) + if (cap->cap_gen < gen) cap->issued = cap->implemented = CEPH_CAP_PIN; /* @@ -775,7 +780,7 @@ void ceph_add_cap(struct inode *inode, cap->seq = seq; cap->issue_seq = seq; cap->mseq = mseq; - cap->cap_gen = session->s_cap_gen; + cap->cap_gen = gen; if (fmode >= 0) __ceph_get_fmode(ci, fmode); -- 2.20.1