From: Jeff Layton jlayton@kernel.org
[ 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 jlayton@kernel.org Reviewed-by: "Yan, Zheng" zyan@redhat.com Signed-off-by: Ilya Dryomov idryomov@gmail.com Signed-off-by: Sasha Levin sashal@kernel.org --- 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);