3 files changed, 38 insertions, 27 deletions

diff --git a/net/ceph/messenger.c b/net/ceph/messenger.c
index 3b65f6e6911b..98ca23726ea6 100644
--- a/net/ceph/messenger.c
+++ b/net/ceph/messenger.c
@@ -1655,9 +1655,8 @@ static int read_partial_message_section(struct ceph_connection *con,
         return 1;
 }
 
-static struct ceph_msg *ceph_alloc_msg(struct ceph_connection *con,
-                                struct ceph_msg_header *hdr,
-                                int *skip);
+static bool ceph_con_in_msg_alloc(struct ceph_connection *con,
+                                struct ceph_msg_header *hdr);
 
 
 static int read_partial_message_pages(struct ceph_connection *con,
@@ -1740,7 +1739,6 @@ static int read_partial_message(struct ceph_connection *con)
         int ret;
         unsigned front_len, middle_len, data_len;
         bool do_datacrc = !con->msgr->nocrc;
-        int skip;
         u64 seq;
         u32 crc;
 
@@ -1793,9 +1791,7 @@ static int read_partial_message(struct ceph_connection *con)
         if (!con->in_msg) {
                 dout("got hdr type %d front %d data %d\n", con->in_hdr.type,
                      con->in_hdr.front_len, con->in_hdr.data_len);
-                skip = 0;
-                con->in_msg = ceph_alloc_msg(con, &con->in_hdr, &skip);
-                if (skip) {
+                if (ceph_con_in_msg_alloc(con, &con->in_hdr)) {
                         /* skip this message */
                         dout("alloc_msg said skip message\n");
                         BUG_ON(con->in_msg);
@@ -2577,46 +2573,57 @@ static int ceph_alloc_middle(struct ceph_connection *con, struct ceph_msg *msg)
 }
 
 /*
- * Generic message allocator, for incoming messages.
+ * Allocate a message for receiving an incoming message on a
+ * connection, and save the result in con->in_msg.  Uses the
+ * connection's private alloc_msg op if available.
+ *
+ * Returns true if the message should be skipped, false otherwise.
+ * If true is returned (skip message), con->in_msg will be NULL.
+ * If false is returned, con->in_msg will contain a pointer to the
+ * newly-allocated message, or NULL in case of memory exhaustion.
  */
-static struct ceph_msg *ceph_alloc_msg(struct ceph_connection *con,
-                                struct ceph_msg_header *hdr,
-                                int *skip)
+static bool ceph_con_in_msg_alloc(struct ceph_connection *con,
+                                struct ceph_msg_header *hdr)
 {
         int type = le16_to_cpu(hdr->type);
         int front_len = le32_to_cpu(hdr->front_len);
         int middle_len = le32_to_cpu(hdr->middle_len);
-        struct ceph_msg *msg = NULL;
         int ret;
 
+        BUG_ON(con->in_msg != NULL);
+
         if (con->ops->alloc_msg) {
+                int skip = 0;
+
                 mutex_unlock(&con->mutex);
-                msg = con->ops->alloc_msg(con, hdr, skip);
+                con->in_msg = con->ops->alloc_msg(con, hdr, &skip);
                 mutex_lock(&con->mutex);
-                if (!msg || *skip)
-                        return NULL;
+                if (skip)
+                        con->in_msg = NULL;
+
+                if (!con->in_msg)
+                        return skip != 0;
         }
-        if (!msg) {
-                *skip = 0;
-                msg = ceph_msg_new(type, front_len, GFP_NOFS, false);
-                if (!msg) {
+        if (!con->in_msg) {
+                con->in_msg = ceph_msg_new(type, front_len, GFP_NOFS, false);
+                if (!con->in_msg) {
                         pr_err("unable to allocate msg type %d len %d\n",
                                type, front_len);
-                        return NULL;
+                        return false;
                 }
-                msg->page_alignment = le16_to_cpu(hdr->data_off);
+                con->in_msg->page_alignment = le16_to_cpu(hdr->data_off);
         }
-        memcpy(&msg->hdr, &con->in_hdr, sizeof(con->in_hdr));
+        memcpy(&con->in_msg->hdr, &con->in_hdr, sizeof(con->in_hdr));
 
-        if (middle_len && !msg->middle) {
-                ret = ceph_alloc_middle(con, msg);
+        if (middle_len && !con->in_msg->middle) {
+                ret = ceph_alloc_middle(con, con->in_msg);
                 if (ret < 0) {
-                        ceph_msg_put(msg);
-                        return NULL;
+                        ceph_msg_put(con->in_msg);
+                        con->in_msg = NULL;
                 }
         }
 
-        return msg;
+        return false;
 }
 
 
diff --git a/net/ceph/mon_client.c b/net/ceph/mon_client.c
index ab6b24a5169e..8462ccec6333 100644
--- a/net/ceph/mon_client.c
+++ b/net/ceph/mon_client.c
@@ -442,6 +442,7 @@ static struct ceph_msg *get_generic_reply(struct ceph_connection *con,
                 m = NULL;
         } else {
                 dout("get_generic_reply %lld got %p\n", tid, req->reply);
+                *skip = 0;
                 m = ceph_msg_get(req->reply);
                 /*
                  * we don't need to track the connection reading into
@@ -982,6 +983,8 @@ static struct ceph_msg *mon_alloc_msg(struct ceph_connection *con,
         case CEPH_MSG_MDS_MAP:
         case CEPH_MSG_OSD_MAP:
                 m = ceph_msg_new(type, front_len, GFP_NOFS, false);
+                if (!m)
+                        return NULL;    /* ENOMEM--return skip == 0 */
                 break;
         }
 
diff --git a/net/ceph/osd_client.c b/net/ceph/osd_client.c
index 448c9da8beff..24b427b1eca4 100644
--- a/net/ceph/osd_client.c
+++ b/net/ceph/osd_client.c
@@ -2077,6 +2077,7 @@ static struct ceph_msg *alloc_msg(struct ceph_connection *con,
         int type = le16_to_cpu(hdr->type);
         int front = le32_to_cpu(hdr->front_len);
 
+        *skip = 0;
         switch (type) {
         case CEPH_MSG_OSD_MAP:
         case CEPH_MSG_WATCH_NOTIFY: