rbd: prevent busy loop when requesting exclusive lock

[linux-2.6-microblaze.git] / drivers / block / rbd.c

diff --git a/drivers/block/rbd.c b/drivers/block/rbd.c
index 24afcc9..2328cc0 100644 (file)
--- a/drivers/block/rbd.c
+++ b/drivers/block/rbd.c
@@ -3675,7 +3675,7 @@ static int rbd_lock(struct rbd_device *rbd_dev)
        ret = ceph_cls_lock(osdc, &rbd_dev->header_oid, &rbd_dev->header_oloc,
                            RBD_LOCK_NAME, CEPH_CLS_LOCK_EXCLUSIVE, cookie,
                            RBD_LOCK_TAG, "", 0);
-       if (ret)
+       if (ret && ret != -EEXIST)
                return ret;
 
        __rbd_lock(rbd_dev, cookie);
@@ -3878,7 +3878,7 @@ static struct ceph_locker *get_lock_owner_info(struct rbd_device *rbd_dev)
                                 &rbd_dev->header_oloc, RBD_LOCK_NAME,
                                 &lock_type, &lock_tag, &lockers, &num_lockers);
        if (ret) {
-               rbd_warn(rbd_dev, "failed to retrieve lockers: %d", ret);
+               rbd_warn(rbd_dev, "failed to get header lockers: %d", ret);
                return ERR_PTR(ret);
        }
 
@@ -3940,8 +3940,10 @@ static int find_watcher(struct rbd_device *rbd_dev,
        ret = ceph_osdc_list_watchers(osdc, &rbd_dev->header_oid,
                                      &rbd_dev->header_oloc, &watchers,
                                      &num_watchers);
-       if (ret)
+       if (ret) {
+               rbd_warn(rbd_dev, "failed to get watchers: %d", ret);
                return ret;
+       }
 
        sscanf(locker->id.cookie, RBD_LOCK_COOKIE_PREFIX " %llu", &cookie);
        for (i = 0; i < num_watchers; i++) {
@@ -3985,8 +3987,12 @@ static int rbd_try_lock(struct rbd_device *rbd_dev)
                locker = refreshed_locker = NULL;
 
                ret = rbd_lock(rbd_dev);
-               if (ret != -EBUSY)
+               if (!ret)
+                       goto out;
+               if (ret != -EBUSY) {
+                       rbd_warn(rbd_dev, "failed to lock header: %d", ret);
                        goto out;
+               }
 
                /* determine if the current lock holder is still alive */
                locker = get_lock_owner_info(rbd_dev);
@@ -4089,11 +4095,8 @@ static int rbd_try_acquire_lock(struct rbd_device *rbd_dev)
 
        ret = rbd_try_lock(rbd_dev);
        if (ret < 0) {
-               rbd_warn(rbd_dev, "failed to lock header: %d", ret);
-               if (ret == -EBLOCKLISTED)
-                       goto out;
-
-               ret = 1; /* request lock anyway */
+               rbd_warn(rbd_dev, "failed to acquire lock: %d", ret);
+               goto out;
        }
        if (ret > 0) {
                up_write(&rbd_dev->lock_rwsem);
@@ -6627,12 +6630,11 @@ static int rbd_add_acquire_lock(struct rbd_device *rbd_dev)
                cancel_delayed_work_sync(&rbd_dev->lock_dwork);
                if (!ret)
                        ret = -ETIMEDOUT;
-       }
 
-       if (ret) {
-               rbd_warn(rbd_dev, "failed to acquire exclusive lock: %ld", ret);
-               return ret;
+               rbd_warn(rbd_dev, "failed to acquire lock: %ld", ret);
        }
+       if (ret)
+               return ret;
 
        /*
         * The lock may have been released by now, unless automatic lock