ceph: warn on allocation from msgpool with larger front_len

Pass the front_len we need when pulling a message off a msgpool,
and WARN if it is greater than the pool's size.  Then try to
allocate a new message (to continue without failing).

Signed-off-by: Sage Weil <sage@newdream.net>

4 files changed, 26 insertions, 9 deletions

diff --git a/fs/ceph/mon_client.c b/fs/ceph/mon_client.c
index d52e52968d0..e6e954cac6b 100644
--- a/fs/ceph/mon_client.c
+++ b/fs/ceph/mon_client.c
@@ -639,14 +639,15 @@ static struct ceph_msg *mon_alloc_msg(struct ceph_connection *con,
 {
         struct ceph_mon_client *monc = con->private;
         int type = le16_to_cpu(hdr->type);
+        int front = le32_to_cpu(hdr->front_len);
 
         switch (type) {
         case CEPH_MSG_CLIENT_MOUNT_ACK:
-                return ceph_msgpool_get(&monc->msgpool_mount_ack);
+                return ceph_msgpool_get(&monc->msgpool_mount_ack, front);
         case CEPH_MSG_MON_SUBSCRIBE_ACK:
-                return ceph_msgpool_get(&monc->msgpool_subscribe_ack);
+                return ceph_msgpool_get(&monc->msgpool_subscribe_ack, front);
         case CEPH_MSG_STATFS_REPLY:
-                return ceph_msgpool_get(&monc->msgpool_statfs_reply);
+                return ceph_msgpool_get(&monc->msgpool_statfs_reply, front);
         }
         return ceph_alloc_msg(con, hdr);
 }
diff --git a/fs/ceph/msgpool.c b/fs/ceph/msgpool.c
index 39d4d7ed82c..7599b338207 100644
--- a/fs/ceph/msgpool.c
+++ b/fs/ceph/msgpool.c
@@ -101,14 +101,28 @@ int ceph_msgpool_resv(struct ceph_msgpool *pool, int delta)
         return ret;
 }
 
-struct ceph_msg *ceph_msgpool_get(struct ceph_msgpool *pool)
+struct ceph_msg *ceph_msgpool_get(struct ceph_msgpool *pool, int front_len)
 {
         wait_queue_t wait;
         struct ceph_msg *msg;
 
+        if (front_len && front_len > pool->front_len) {
+                pr_err("msgpool_get pool %p need front %d, pool size is %d\n",
+                       pool, front_len, pool->front_len);
+                WARN_ON(1);
+
+                /* try to alloc a fresh message */
+                msg = ceph_msg_new(0, front_len, 0, 0, NULL);
+                if (!IS_ERR(msg))
+                        return msg;
+        }
+
+        if (!front_len)
+                front_len = pool->front_len;
+
         if (pool->blocking) {
                 /* mempool_t behavior; first try to alloc */
-                msg = ceph_msg_new(0, pool->front_len, 0, 0, NULL);
+                msg = ceph_msg_new(0, front_len, 0, 0, NULL);
                 if (!IS_ERR(msg))
                         return msg;
         }
@@ -133,7 +147,7 @@ struct ceph_msg *ceph_msgpool_get(struct ceph_msgpool *pool)
                         WARN_ON(1);
 
                         /* maybe we can allocate it now? */
-                        msg = ceph_msg_new(0, pool->front_len, 0, 0, NULL);
+                        msg = ceph_msg_new(0, front_len, 0, 0, NULL);
                         if (!IS_ERR(msg))
                                 return msg;
 
diff --git a/fs/ceph/msgpool.h b/fs/ceph/msgpool.h
index 07a2decaa6d..bc834bfcd72 100644
--- a/fs/ceph/msgpool.h
+++ b/fs/ceph/msgpool.h
@@ -20,7 +20,8 @@ extern int ceph_msgpool_init(struct ceph_msgpool *pool,
                              int front_len, int size, bool blocking);
 extern void ceph_msgpool_destroy(struct ceph_msgpool *pool);
 extern int ceph_msgpool_resv(struct ceph_msgpool *, int delta);
-extern struct ceph_msg *ceph_msgpool_get(struct ceph_msgpool *);
+extern struct ceph_msg *ceph_msgpool_get(struct ceph_msgpool *,
+                                         int front_len);
 extern void ceph_msgpool_put(struct ceph_msgpool *, struct ceph_msg *);
 
 #endif
diff --git a/fs/ceph/osd_client.c b/fs/ceph/osd_client.c
index bbd9a5d2371..0a254054a82 100644
--- a/fs/ceph/osd_client.c
+++ b/fs/ceph/osd_client.c
@@ -161,7 +161,7 @@ struct ceph_osd_request *ceph_osdc_new_request(struct ceph_osd_client *osdc,
         if (snapc)
                 msg_size += sizeof(u64) * snapc->num_snaps;
         if (use_mempool)
-                msg = ceph_msgpool_get(&osdc->msgpool_op);
+                msg = ceph_msgpool_get(&osdc->msgpool_op, 0);
         else
                 msg = ceph_msg_new(CEPH_MSG_OSD_OP, msg_size, 0, 0, NULL);
         if (IS_ERR(msg)) {
@@ -1271,10 +1271,11 @@ static struct ceph_msg *alloc_msg(struct ceph_connection *con,
         struct ceph_osd *osd = con->private;
         struct ceph_osd_client *osdc = osd->o_osdc;
         int type = le16_to_cpu(hdr->type);
+        int front = le32_to_cpu(hdr->front_len);
 
         switch (type) {
         case CEPH_MSG_OSD_OPREPLY:
-                return ceph_msgpool_get(&osdc->msgpool_op_reply);
+                return ceph_msgpool_get(&osdc->msgpool_op_reply, front);
         }
         return ceph_alloc_msg(con, hdr);
 }