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>

1 files changed, 13 insertions, 33 deletions

diff --git a/fs/ceph/caps.c b/fs/ceph/caps.c
index fb4a19ee5b6d..dd7dfdd2ba13 100644
--- 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,