ceph: switch to WARN_ON_ONCE in encode_supported_features()

...and let the errnos bubble up to the callers.

Signed-off-by: Xiubo Li <xiubli@redhat.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>

diff --git a/fs/ceph/mds_client.c b/fs/ceph/mds_client.c
index f3c71230df932ac49c0401d0a3533a42e176b424..d5e523cc40e663113e9def43998d6d2051de33ce 100644 (file)
--- a/fs/ceph/mds_client.c
+++ b/fs/ceph/mds_client.c
@@ -1168,7 +1168,7 @@ static struct ceph_msg *create_session_msg(u32 op, u64 seq)
 
 static const unsigned char feature_bits[] = CEPHFS_FEATURES_CLIENT_SUPPORTED;
 #define FEATURE_BYTES(c) (DIV_ROUND_UP((size_t)feature_bits[c - 1] + 1, 64) * 8)
-static void encode_supported_features(void **p, void *end)
+static int encode_supported_features(void **p, void *end)
 {
        static const size_t count = ARRAY_SIZE(feature_bits);
 
@@ -1176,16 +1176,22 @@ static void encode_supported_features(void **p, void *end)
                size_t i;
                size_t size = FEATURE_BYTES(count);
 
-               BUG_ON(*p + 4 + size > end);
+               if (WARN_ON_ONCE(*p + 4 + size > end))
+                       return -ERANGE;
+
                ceph_encode_32(p, size);
                memset(*p, 0, size);
                for (i = 0; i < count; i++)
                        ((unsigned char*)(*p))[i / 8] |= BIT(feature_bits[i] % 8);
                *p += size;
        } else {
-               BUG_ON(*p + 4 > end);
+               if (WARN_ON_ONCE(*p + 4 > end))
+                       return -ERANGE;
+
                ceph_encode_32(p, 0);
        }
+
+       return 0;
 }
 
 /*
@@ -1203,6 +1209,7 @@ static struct ceph_msg *create_session_open_msg(struct ceph_mds_client *mdsc, u6
        struct ceph_mount_options *fsopt = mdsc->fsc->mount_options;
        size_t size, count;
        void *p, *end;
+       int ret;
 
        const char* metadata[][2] = {
                {"hostname", mdsc->nodename},
@@ -1232,7 +1239,7 @@ static struct ceph_msg *create_session_open_msg(struct ceph_mds_client *mdsc, u6
                           GFP_NOFS, false);
        if (!msg) {
                pr_err("create_session_msg ENOMEM creating msg\n");
-               return NULL;
+               return ERR_PTR(-ENOMEM);
        }
        p = msg->front.iov_base;
        end = p + msg->front.iov_len;
@@ -1269,7 +1276,13 @@ static struct ceph_msg *create_session_open_msg(struct ceph_mds_client *mdsc, u6
                p += val_len;
        }
 
-       encode_supported_features(&p, end);
+       ret = encode_supported_features(&p, end);
+       if (ret) {
+               pr_err("encode_supported_features failed!\n");
+               ceph_msg_put(msg);
+               return ERR_PTR(ret);
+       }
+
        msg->front.iov_len = p - msg->front.iov_base;
        msg->hdr.front_len = cpu_to_le32(msg->front.iov_len);
 
@@ -1297,8 +1310,8 @@ static int __open_session(struct ceph_mds_client *mdsc,
 
        /* send connect message */
        msg = create_session_open_msg(mdsc, session->s_seq);
-       if (!msg)
-               return -ENOMEM;
+       if (IS_ERR(msg))
+               return PTR_ERR(msg);
        ceph_con_send(&session->s_con, msg);
        return 0;
 }
@@ -1312,6 +1325,7 @@ static struct ceph_mds_session *
 __open_export_target_session(struct ceph_mds_client *mdsc, int target)
 {
        struct ceph_mds_session *session;
+       int ret;
 
        session = __ceph_lookup_mds_session(mdsc, target);
        if (!session) {
@@ -1320,8 +1334,11 @@ __open_export_target_session(struct ceph_mds_client *mdsc, int target)
                        return session;
        }
        if (session->s_state == CEPH_MDS_SESSION_NEW ||
-           session->s_state == CEPH_MDS_SESSION_CLOSING)
-               __open_session(mdsc, session);
+           session->s_state == CEPH_MDS_SESSION_CLOSING) {
+               ret = __open_session(mdsc, session);
+               if (ret)
+                       return ERR_PTR(ret);
+       }
 
        return session;
 }
@@ -2520,7 +2537,12 @@ static struct ceph_msg *create_request_message(struct ceph_mds_client *mdsc,
                ceph_encode_copy(&p, &ts, sizeof(ts));
        }
 
-       BUG_ON(p > end);
+       if (WARN_ON_ONCE(p > end)) {
+               ceph_msg_put(msg);
+               msg = ERR_PTR(-ERANGE);
+               goto out_free2;
+       }
+
        msg->front.iov_len = p - msg->front.iov_base;
        msg->hdr.front_len = cpu_to_le32(msg->front.iov_len);
 
@@ -2756,7 +2778,9 @@ static void __do_request(struct ceph_mds_client *mdsc,
                }
                if (session->s_state == CEPH_MDS_SESSION_NEW ||
                    session->s_state == CEPH_MDS_SESSION_CLOSING) {
-                       __open_session(mdsc, session);
+                       err = __open_session(mdsc, session);
+                       if (err)
+                               goto out_session;
                        /* retry the same mds later */
                        if (random)
                                req->r_resend_mds = mds;