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ceph: fix endianness bug when handling MDS session feature bits

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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>
This commit is contained in:
Jeff Layton 2020-04-28 08:10:22 -04:00 committed by Ilya Dryomov
parent 0e698dfa28
commit 0fa8263367
1 changed files with 3 additions and 5 deletions
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8
fs/ceph/mds_client.c
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@ -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);