ceph: decode feature bits in session message

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

2 files changed, 44 insertions, 5 deletions

diff --git a/fs/ceph/mds_client.c b/fs/ceph/mds_client.c
index 163fc74bf221..04f18095e306 100644
--- 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 729da155ebf0..0d3264cf3334 100644
--- 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 */
 };