Commit 606d1023 authored by Jeff Layton's avatar Jeff Layton Committed by Ilya Dryomov
Browse files

ceph: fetch cap_gen under spinlock in ceph_add_cap 



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: default avatarJeff Layton <jlayton@kernel.org>
Reviewed-by: default avatar"Yan, Zheng" <zyan@redhat.com>
Signed-off-by: default avatarIlya Dryomov <idryomov@gmail.com>
parent 5de16b30

fs/ceph/caps.c

+7 −2
Original line number Diff line number Diff line
@@ -614,6 +614,7 @@ 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);
@@ -625,6 +626,10 @@ 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;
@@ -650,7 +655,7 @@ 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;



		/*
@@ -744,7 +749,7 @@ 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);

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