ceph: refactor error handling code in ceph_reserve_caps()

Call new helper __ceph_unreserve_caps() to reduce duplicated code.

Signed-off-by: Chengguang Xu <cgxu519@gmx.com>
Reviewed-by: "Yan, Zheng" <zyan@redhat.com>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>

diff --git a/fs/ceph/caps.c b/fs/ceph/caps.c
index fb4a19ee5b6d7736f20d7fd9f76ad7f0d5599750..dd7dfdd2ba13903575aee52a0b8fc27660cda2f8 100644 (file)
--- a/fs/ceph/caps.c
+++ b/fs/ceph/caps.c
@@ -198,6 +198,7 @@ int ceph_reserve_caps(struct ceph_mds_client *mdsc,
        int have;
        int alloc = 0;
        int max_caps;
+       int err = 0;
        bool trimmed = false;
        struct ceph_mds_session *s;
        LIST_HEAD(newcaps);
@@ -264,9 +265,14 @@ int ceph_reserve_caps(struct ceph_mds_client *mdsc,
 
                pr_warn("reserve caps ctx=%p ENOMEM need=%d got=%d\n",
                        ctx, need, have + alloc);
-               goto out_nomem;
+               err = -ENOMEM;
+               break;
+       }
+
+       if (!err) {
+               BUG_ON(have + alloc != need);
+               ctx->count = need;
        }
-       BUG_ON(have + alloc != need);
 
        spin_lock(&mdsc->caps_list_lock);
        mdsc->caps_total_count += alloc;
@@ -276,42 +282,16 @@ int ceph_reserve_caps(struct ceph_mds_client *mdsc,
        BUG_ON(mdsc->caps_total_count != mdsc->caps_use_count +
                                         mdsc->caps_reserve_count +
                                         mdsc->caps_avail_count);
+
+       if (err)
+               __ceph_unreserve_caps(mdsc, have + alloc);
+
        spin_unlock(&mdsc->caps_list_lock);
 
-       ctx->count = need;
        dout("reserve caps ctx=%p %d = %d used + %d resv + %d avail\n",
             ctx, mdsc->caps_total_count, mdsc->caps_use_count,
             mdsc->caps_reserve_count, mdsc->caps_avail_count);
-       return 0;
-
-out_nomem:
-
-       spin_lock(&mdsc->caps_list_lock);
-       mdsc->caps_avail_count += have;
-       mdsc->caps_reserve_count -= have;
-
-       while (!list_empty(&newcaps)) {
-               cap = list_first_entry(&newcaps,
-                               struct ceph_cap, caps_item);
-               list_del(&cap->caps_item);
-
-               /* Keep some preallocated caps around (ceph_min_count), to
-                * avoid lots of free/alloc churn. */
-               if (mdsc->caps_avail_count >=
-                   mdsc->caps_reserve_count + mdsc->caps_min_count) {
-                       kmem_cache_free(ceph_cap_cachep, cap);
-               } else {
-                       mdsc->caps_avail_count++;
-                       mdsc->caps_total_count++;
-                       list_add(&cap->caps_item, &mdsc->caps_list);
-               }
-       }
-
-       BUG_ON(mdsc->caps_total_count != mdsc->caps_use_count +
-                                        mdsc->caps_reserve_count +
-                                        mdsc->caps_avail_count);
-       spin_unlock(&mdsc->caps_list_lock);
-       return -ENOMEM;
+       return err;
 }
 
 void ceph_unreserve_caps(struct ceph_mds_client *mdsc,