ceph: fix endianness bug when handling MDS session feature bits (0fa82633) · Commits · 戴 / test

Eduard reported a problem mounting cephfs on s390 arch. The feature mask sent by the MDS is little-endian, so we need to convert it before storing and testing against it. Cc: stable@vger.kernel.org Reported-and-Tested-by:

Eduard Shishkin <edward6@linux.ibm.com> Signed-off-by:

Jeff Layton <jlayton@kernel.org> Reviewed-by:

"Yan, Zheng" <zyan@redhat.com> Signed-off-by:

Ilya Dryomov <idryomov@gmail.com>

fs/ceph/mds_client.c

+3 −5

Original line number	Diff line number	Diff line
		@@ -3251,8 +3251,7 @@ static void handle_session(struct ceph_mds_session *session,
		void *end = p + msg->front.iov_len;
		struct ceph_mds_session_head *h;
		u32 op;
		u64 seq;
		unsigned long features = 0;
		u64 seq, features = 0;
		int wake = 0;
		bool blacklisted = false;

		@@ -3271,9 +3270,8 @@ static void handle_session(struct ceph_mds_session *session,
		goto bad;
		/* version >= 3, feature bits */
		ceph_decode_32_safe(&p, end, len, bad);
		ceph_decode_need(&p, end, len, bad);
		memcpy(&features, p, min_t(size_t, len, sizeof(features)));
		p += len;
		ceph_decode_64_safe(&p, end, features, bad);
		p += len - sizeof(features);
		}

		mutex_lock(&mdsc->mutex);

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