ceph: decode feature bits in session message

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

diff --git a/fs/ceph/mds_client.c b/fs/ceph/mds_client.c
index 163fc74..04f1809 100644 (file)
--- a/fs/ceph/mds_client.c
+++ b/fs/ceph/mds_client.c
@@ -2777,6 +2777,25 @@ bad:
        pr_err("mdsc_handle_forward decode error err=%d\n", err);
 }
 
+static int __decode_and_drop_session_metadata(void **p, void *end)
+{
+       /* map<string,string> */
+       u32 n;
+       ceph_decode_32_safe(p, end, n, bad);
+       while (n-- > 0) {
+               u32 len;
+               ceph_decode_32_safe(p, end, len, bad);
+               ceph_decode_need(p, end, len, bad);
+               *p += len;
+               ceph_decode_32_safe(p, end, len, bad);
+               ceph_decode_need(p, end, len, bad);
+               *p += len;
+       }
+       return 0;
+bad:
+       return -1;
+}
+
 /*
  * handle a mds session control message
  */
@@ -2784,18 +2803,36 @@ static void handle_session(struct ceph_mds_session *session,
                           struct ceph_msg *msg)
 {
        struct ceph_mds_client *mdsc = session->s_mdsc;
+       int mds = session->s_mds;
+       int msg_version = le16_to_cpu(msg->hdr.version);
+       void *p = msg->front.iov_base;
+       void *end = p + msg->front.iov_len;
+       struct ceph_mds_session_head *h;
        u32 op;
        u64 seq;
-       int mds = session->s_mds;
-       struct ceph_mds_session_head *h = msg->front.iov_base;
+       unsigned long features = 0;
        int wake = 0;
 
        /* decode */
-       if (msg->front.iov_len < sizeof(*h))
-               goto bad;
+       ceph_decode_need(&p, end, sizeof(*h), bad);
+       h = p;
+       p += sizeof(*h);
+
        op = le32_to_cpu(h->op);
        seq = le64_to_cpu(h->seq);
 
+       if (msg_version >= 3) {
+               u32 len;
+               /* version >= 2, metadata */
+               if (__decode_and_drop_session_metadata(&p, end) < 0)
+                       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;
+       }
+
        mutex_lock(&mdsc->mutex);
        if (op == CEPH_SESSION_CLOSE) {
                get_session(session);
@@ -2821,6 +2858,7 @@ static void handle_session(struct ceph_mds_session *session,
                if (session->s_state == CEPH_MDS_SESSION_RECONNECTING)
                        pr_info("mds%d reconnect success\n", session->s_mds);
                session->s_state = CEPH_MDS_SESSION_OPEN;
+               session->s_features = features;
                renewed_caps(mdsc, session, 0);
                wake = 1;
                if (mdsc->stopping)

diff --git a/fs/ceph/mds_client.h b/fs/ceph/mds_client.h
index 729da15..0d3264c 100644 (file)
--- a/fs/ceph/mds_client.h
+++ b/fs/ceph/mds_client.h
@@ -152,6 +152,7 @@ struct ceph_mds_session {
        int               s_mds;
        int               s_state;
        unsigned long     s_ttl;      /* time until mds kills us */
+       unsigned long     s_features;
        u64               s_seq;      /* incoming msg seq # */
        struct mutex      s_mutex;    /* serialize session messages */
 
@@ -179,7 +180,7 @@ struct ceph_mds_session {
        unsigned long     s_renew_requested; /* last time we sent a renew req */
        u64               s_renew_seq;
 
-       refcount_t          s_ref;
+       refcount_t        s_ref;
        struct list_head  s_waiting;  /* waiting requests */
        struct list_head  s_unsafe;   /* unsafe requests */
 };