Allow to inherit receive.maxObjectSizeLimit from parent project

In the current implementation it is possible to set the limit per
project in the project.config on refs/meta/config, and at global
level in $site/etc/gerrit.config. The project setting may override
the global setting if it is lower. Changing the global setting
requires a server restart.

A limitation of this implementation is that we cannot set the limit
at a project level and have it inherited to its child projects; it
is necessary to explicitly set the limit on each child project.

This limitation causes a lot of extra work in the case where for
example we have a project hierarchy like:

  |- All-Projects
     |
     -- Namespace-A
     |  |
     |  |-- Project-A
     |  |-- Project-B
     .  .   ..
     .  .   ..
     |  |-- Project-X
     |
     |
     -- Namespace-B

Where the Namespace-X projects are assumed to be "parent only"
projects, if we want to set a limit for all the projects under a
namespace hierarchy, we need to set it explicitly on all those
projects individually rather than only on the "Namespace-X".

With this change the limit is inherited from the parent project.

The global limit is still respected, and the project still can't
set a higher value than the global, either explicitly per project
or via inheritance.

Similarly, if no global limit is specified, a child project still
may not set a limit higher than its parent.

The inheritedValue is removed from the config info and replaced
by a summary string describing how the effective value was
inherited or overridden from the parent project or the global
config. This string is used as the tooltip on the effective
value in the UI.

As a side effect of this change, it is now possible to effectively
change the global limit without having to restart the server, by
setting it on the All-Projects project. Note that this only works
if the new limit is lower than what is already configured in the
actual global limit in gerrit.config.

Bug: Issue 9528
Change-Id: I5f8b333e905ed0a147526ae33ff2bab2cbe222ef

12 files changed, 167 insertions, 50 deletions

diff --git a/Documentation/rest-api-projects.txt b/Documentation/rest-api-projects.txt
index eee31519f1..8e151bc45d 100644
--- a/Documentation/rest-api-projects.txt
+++ b/Documentation/rest-api-projects.txt
@@ -2812,10 +2812,10 @@ The max object size limit that is configured on the project as a
 formatted string. +
 Not set if there is no limit for the object size configured on project
 level.
-|`inherited_value` |optional|
-The max object size limit that is inherited from the global config as a
-formatted string. +
-Not set if there is no global limit for the object size.
+|`summary`         |optional|
+A string describing whether the value was inherited or overridden from
+the parent project or global config. +
+Not set if not inherited or overridden.
 |===============================
 
 [[project-access-input]]
diff --git a/gerrit-acceptance-tests/src/test/java/com/google/gerrit/acceptance/api/project/ProjectIT.java b/gerrit-acceptance-tests/src/test/java/com/google/gerrit/acceptance/api/project/ProjectIT.java
index 7c62302192..5f97a44dcd 100644
--- a/gerrit-acceptance-tests/src/test/java/com/google/gerrit/acceptance/api/project/ProjectIT.java
+++ b/gerrit-acceptance-tests/src/test/java/com/google/gerrit/acceptance/api/project/ProjectIT.java
@@ -16,6 +16,10 @@ package com.google.gerrit.acceptance.api.project;
 
 import static com.google.common.truth.Truth.assertThat;
 import static com.google.gerrit.server.group.SystemGroupBackend.ANONYMOUS_USERS;
+import static com.google.gerrit.server.project.ProjectState.INHERITED_FROM_GLOBAL;
+import static com.google.gerrit.server.project.ProjectState.INHERITED_FROM_PARENT;
+import static com.google.gerrit.server.project.ProjectState.OVERRIDDEN_BY_GLOBAL;
+import static com.google.gerrit.server.project.ProjectState.OVERRIDDEN_BY_PARENT;
 
 import com.google.gerrit.acceptance.AbstractDaemonTest;
 import com.google.gerrit.acceptance.GerritConfig;
@@ -144,7 +148,7 @@ public class ProjectIT extends AbstractDaemonTest {
     ConfigInfo info = getConfig();
     assertThat(info.maxObjectSizeLimit.value).isNull();
     assertThat(info.maxObjectSizeLimit.configuredValue).isNull();
-    assertThat(info.maxObjectSizeLimit.inheritedValue).isNull();
+    assertThat(info.maxObjectSizeLimit.summary).isNull();
   }
 
   @Test
@@ -153,37 +157,91 @@ public class ProjectIT extends AbstractDaemonTest {
     ConfigInfo info = setMaxObjectSize("100k");
     assertThat(info.maxObjectSizeLimit.value).isEqualTo("102400");
     assertThat(info.maxObjectSizeLimit.configuredValue).isEqualTo("100k");
-    assertThat(info.maxObjectSizeLimit.inheritedValue).isNull();
+    assertThat(info.maxObjectSizeLimit.summary).isNull();
 
     // Clear the value
     info = setMaxObjectSize("0");
     assertThat(info.maxObjectSizeLimit.value).isNull();
     assertThat(info.maxObjectSizeLimit.configuredValue).isNull();
-    assertThat(info.maxObjectSizeLimit.inheritedValue).isNull();
+    assertThat(info.maxObjectSizeLimit.summary).isNull();
   }
 
   @Test
-  public void maxObjectSizeIsNotInheritedFromParentProject() throws Exception {
+  public void maxObjectSizeIsInheritedFromParentProject() throws Exception {
     Project.NameKey child = createProject(name("child"), project);
 
     ConfigInfo info = setMaxObjectSize("100k");
     assertThat(info.maxObjectSizeLimit.value).isEqualTo("102400");
     assertThat(info.maxObjectSizeLimit.configuredValue).isEqualTo("100k");
-    assertThat(info.maxObjectSizeLimit.inheritedValue).isNull();
+    assertThat(info.maxObjectSizeLimit.summary).isNull();
 
     info = getConfig(child);
+    assertThat(info.maxObjectSizeLimit.value).isEqualTo("102400");
+    assertThat(info.maxObjectSizeLimit.configuredValue).isNull();
+    assertThat(info.maxObjectSizeLimit.summary)
+        .isEqualTo(String.format(INHERITED_FROM_PARENT, project));
+  }
+
+  @Test
+  public void maxObjectSizeOverridesParentProjectWhenNotSetOnParent() throws Exception {
+    Project.NameKey child = createProject(name("child"), project);
+
+    ConfigInfo info = setMaxObjectSize("0");
     assertThat(info.maxObjectSizeLimit.value).isNull();
     assertThat(info.maxObjectSizeLimit.configuredValue).isNull();
-    assertThat(info.maxObjectSizeLimit.inheritedValue).isNull();
+    assertThat(info.maxObjectSizeLimit.summary).isNull();
+
+    info = setMaxObjectSize(child, "100k");
+    assertThat(info.maxObjectSizeLimit.value).isEqualTo("102400");
+    assertThat(info.maxObjectSizeLimit.configuredValue).isEqualTo("100k");
+    assertThat(info.maxObjectSizeLimit.summary).isNull();
+  }
+
+  @Test
+  public void maxObjectSizeOverridesParentProjectWhenLower() throws Exception {
+    Project.NameKey child = createProject(name("child"), project);
+
+    ConfigInfo info = setMaxObjectSize("200k");
+    assertThat(info.maxObjectSizeLimit.value).isEqualTo("204800");
+    assertThat(info.maxObjectSizeLimit.configuredValue).isEqualTo("200k");
+    assertThat(info.maxObjectSizeLimit.summary).isNull();
+
+    info = setMaxObjectSize(child, "100k");
+    assertThat(info.maxObjectSizeLimit.value).isEqualTo("102400");
+    assertThat(info.maxObjectSizeLimit.configuredValue).isEqualTo("100k");
+    assertThat(info.maxObjectSizeLimit.summary).isNull();
+  }
+
+  @Test
+  public void maxObjectSizeDoesNotOverrideParentProjectWhenHigher() throws Exception {
+    Project.NameKey child = createProject(name("child"), project);
+
+    ConfigInfo info = setMaxObjectSize("100k");
+    assertThat(info.maxObjectSizeLimit.value).isEqualTo("102400");
+    assertThat(info.maxObjectSizeLimit.configuredValue).isEqualTo("100k");
+    assertThat(info.maxObjectSizeLimit.summary).isNull();
+
+    info = setMaxObjectSize(child, "200k");
+    assertThat(info.maxObjectSizeLimit.value).isEqualTo("102400");
+    assertThat(info.maxObjectSizeLimit.configuredValue).isEqualTo("200k");
+    assertThat(info.maxObjectSizeLimit.summary)
+        .isEqualTo(String.format(OVERRIDDEN_BY_PARENT, project));
   }
 
   @Test
   @GerritConfig(name = "receive.maxObjectSizeLimit", value = "200k")
   public void maxObjectSizeIsInheritedFromGlobalConfig() throws Exception {
+    Project.NameKey child = createProject(name("child"), project);
+
     ConfigInfo info = getConfig();
     assertThat(info.maxObjectSizeLimit.value).isEqualTo("204800");
     assertThat(info.maxObjectSizeLimit.configuredValue).isNull();
-    assertThat(info.maxObjectSizeLimit.inheritedValue).isEqualTo("200k");
+    assertThat(info.maxObjectSizeLimit.summary).isEqualTo(INHERITED_FROM_GLOBAL);
+
+    info = getConfig(child);
+    assertThat(info.maxObjectSizeLimit.value).isEqualTo("204800");
+    assertThat(info.maxObjectSizeLimit.configuredValue).isNull();
+    assertThat(info.maxObjectSizeLimit.summary).isEqualTo(INHERITED_FROM_GLOBAL);
   }
 
   @Test
@@ -192,16 +250,39 @@ public class ProjectIT extends AbstractDaemonTest {
     ConfigInfo info = setMaxObjectSize("100k");
     assertThat(info.maxObjectSizeLimit.value).isEqualTo("102400");
     assertThat(info.maxObjectSizeLimit.configuredValue).isEqualTo("100k");
-    assertThat(info.maxObjectSizeLimit.inheritedValue).isEqualTo("200k");
+    assertThat(info.maxObjectSizeLimit.summary).isNull();
+  }
+
+  @Test
+  @GerritConfig(name = "receive.maxObjectSizeLimit", value = "300k")
+  public void inheritedMaxObjectSizeOverridesGlobalConfigWhenLower() throws Exception {
+    Project.NameKey child = createProject(name("child"), project);
+
+    ConfigInfo info = setMaxObjectSize("200k");
+    assertThat(info.maxObjectSizeLimit.value).isEqualTo("204800");
+    assertThat(info.maxObjectSizeLimit.configuredValue).isEqualTo("200k");
+    assertThat(info.maxObjectSizeLimit.summary).isNull();
+
+    info = setMaxObjectSize(child, "100k");
+    assertThat(info.maxObjectSizeLimit.value).isEqualTo("102400");
+    assertThat(info.maxObjectSizeLimit.configuredValue).isEqualTo("100k");
+    assertThat(info.maxObjectSizeLimit.summary).isNull();
   }
 
   @Test
   @GerritConfig(name = "receive.maxObjectSizeLimit", value = "200k")
   public void maxObjectSizeDoesNotOverrideGlobalConfigWhenHigher() throws Exception {
+    Project.NameKey child = createProject(name("child"), project);
+
     ConfigInfo info = setMaxObjectSize("300k");
     assertThat(info.maxObjectSizeLimit.value).isEqualTo("204800");
     assertThat(info.maxObjectSizeLimit.configuredValue).isEqualTo("300k");
-    assertThat(info.maxObjectSizeLimit.inheritedValue).isEqualTo("200k");
+    assertThat(info.maxObjectSizeLimit.summary).isEqualTo(OVERRIDDEN_BY_GLOBAL);
+
+    info = getConfig(child);
+    assertThat(info.maxObjectSizeLimit.value).isEqualTo("204800");
+    assertThat(info.maxObjectSizeLimit.configuredValue).isNull();
+    assertThat(info.maxObjectSizeLimit.summary).isEqualTo(OVERRIDDEN_BY_GLOBAL);
   }
 
   @Test
@@ -220,9 +301,13 @@ public class ProjectIT extends AbstractDaemonTest {
   }
 
   private ConfigInfo setMaxObjectSize(String value) throws Exception {
+    return setMaxObjectSize(project, value);
+  }
+
+  private ConfigInfo setMaxObjectSize(Project.NameKey name, String value) throws Exception {
     ConfigInput input = new ConfigInput();
     input.maxObjectSizeLimit = value;
-    return setConfig(input);
+    return setConfig(name, input);
   }
 
   private ConfigInfo getConfig(Project.NameKey name) throws Exception {
diff --git a/gerrit-extension-api/src/main/java/com/google/gerrit/extensions/api/projects/ConfigInfo.java b/gerrit-extension-api/src/main/java/com/google/gerrit/extensions/api/projects/ConfigInfo.java
index 09ad3281a7..36c86ed433 100644
--- a/gerrit-extension-api/src/main/java/com/google/gerrit/extensions/api/projects/ConfigInfo.java
+++ b/gerrit-extension-api/src/main/java/com/google/gerrit/extensions/api/projects/ConfigInfo.java
@@ -48,14 +48,17 @@ public class ConfigInfo {
   }
 
   public static class MaxObjectSizeLimitInfo {
-    /* The effective value. Null if not set. */
+    /** The effective value in bytes. Null if not set. */
     @Nullable public String value;
 
-    /* The value configured on the project. Null if not set. */
+    /** The value configured explicitly on the project as a formatted string. Null if not set. */
     @Nullable public String configuredValue;
 
-    /* The value configured globally. Null if not set. */
-    @Nullable public String inheritedValue;
+    /**
+     * Whether the value was inherited or overridden from the project's parent hierarchy or global
+     * config. Null if not inherited or overridden.
+     */
+    @Nullable public String summary;
   }
 
   public static class ConfigParameterInfo {
diff --git a/gerrit-gwtui/src/main/java/com/google/gerrit/client/admin/AdminMessages.java b/gerrit-gwtui/src/main/java/com/google/gerrit/client/admin/AdminMessages.java
index fe27e9c7cf..7b18a392ed 100644
--- a/gerrit-gwtui/src/main/java/com/google/gerrit/client/admin/AdminMessages.java
+++ b/gerrit-gwtui/src/main/java/com/google/gerrit/client/admin/AdminMessages.java
@@ -36,8 +36,6 @@ public interface AdminMessages extends Messages {
 
   String effectiveMaxObjectSizeLimit(String effectiveMaxObjectSizeLimit);
 
-  String globalMaxObjectSizeLimit(String globalMaxObjectSizeLimit);
-
   String noMaxObjectSizeLimit();
 
   String pluginProjectOptionsTitle(String pluginName);
diff --git a/gerrit-gwtui/src/main/java/com/google/gerrit/client/admin/AdminMessages.properties b/gerrit-gwtui/src/main/java/com/google/gerrit/client/admin/AdminMessages.properties
index f746365f18..c9aa987964 100644
--- a/gerrit-gwtui/src/main/java/com/google/gerrit/client/admin/AdminMessages.properties
+++ b/gerrit-gwtui/src/main/java/com/google/gerrit/client/admin/AdminMessages.properties
@@ -6,7 +6,6 @@ deletedGroup = Deleted Group {0}
 deletedReference = Reference {0} was deleted
 deletedSection = Section {0} was deleted
 effectiveMaxObjectSizeLimit = effective: {0} bytes
-globalMaxObjectSizeLimit = The global max object size limit is set to {0}. The limit cannot be increased on project level.
 noMaxObjectSizeLimit = No max object size limit is set.
 pluginProjectOptionsTitle = {0} Plugin Options
 pluginProjectOptionsTitle = {0} Plugin
diff --git a/gerrit-gwtui/src/main/java/com/google/gerrit/client/admin/ProjectInfoScreen.java b/gerrit-gwtui/src/main/java/com/google/gerrit/client/admin/ProjectInfoScreen.java
index 0e185eb130..2e4054ee63 100644
--- a/gerrit-gwtui/src/main/java/com/google/gerrit/client/admin/ProjectInfoScreen.java
+++ b/gerrit-gwtui/src/main/java/com/google/gerrit/client/admin/ProjectInfoScreen.java
@@ -404,9 +404,8 @@ public class ProjectInfoScreen extends ProjectScreen {
     if (result.maxObjectSizeLimit().value() != null) {
       effectiveMaxObjectSizeLimit.setText(
           AdminMessages.I.effectiveMaxObjectSizeLimit(result.maxObjectSizeLimit().value()));
-      if (result.maxObjectSizeLimit().inheritedValue() != null) {
-        effectiveMaxObjectSizeLimit.setTitle(
-            AdminMessages.I.globalMaxObjectSizeLimit(result.maxObjectSizeLimit().inheritedValue()));
+      if (result.maxObjectSizeLimit().summary() != null) {
+        effectiveMaxObjectSizeLimit.setTitle(result.maxObjectSizeLimit().summary());
       }
     } else {
       effectiveMaxObjectSizeLimit.setText(AdminMessages.I.noMaxObjectSizeLimit());
diff --git a/gerrit-gwtui/src/main/java/com/google/gerrit/client/projects/ConfigInfo.java b/gerrit-gwtui/src/main/java/com/google/gerrit/client/projects/ConfigInfo.java
index 738319d410..c96d331494 100644
--- a/gerrit-gwtui/src/main/java/com/google/gerrit/client/projects/ConfigInfo.java
+++ b/gerrit-gwtui/src/main/java/com/google/gerrit/client/projects/ConfigInfo.java
@@ -158,10 +158,10 @@ public class ConfigInfo extends JavaScriptObject {
   public static class MaxObjectSizeLimitInfo extends JavaScriptObject {
     public final native String value() /*-{ return this.value; }-*/;
 
-    public final native String inheritedValue() /*-{ return this.inherited_value; }-*/;
-
     public final native String configuredValue() /*-{ return this.configured_value }-*/;
 
+    public final native String summary() /*-{ return this.summary; }-*/;
+
     protected MaxObjectSizeLimitInfo() {}
   }
 
diff --git a/gerrit-server/src/main/java/com/google/gerrit/server/git/ReceiveCommits.java b/gerrit-server/src/main/java/com/google/gerrit/server/git/ReceiveCommits.java
index cd974647dd..4bd51cfe5e 100644
--- a/gerrit-server/src/main/java/com/google/gerrit/server/git/ReceiveCommits.java
+++ b/gerrit-server/src/main/java/com/google/gerrit/server/git/ReceiveCommits.java
@@ -446,7 +446,8 @@ public class ReceiveCommits {
     rp.setAllowNonFastForwards(true);
     rp.setRefLogIdent(user.newRefLogIdent());
     rp.setTimeout(transferConfig.getTimeout());
-    rp.setMaxObjectSizeLimit(projectControl.getProjectState().getEffectiveMaxObjectSizeLimit());
+    rp.setMaxObjectSizeLimit(
+        projectControl.getProjectState().getEffectiveMaxObjectSizeLimit().value);
     rp.setCheckReceivedObjects(ps.getConfig().getCheckReceivedObjects());
     rp.setRefFilter(
         new RefFilter() {
diff --git a/gerrit-server/src/main/java/com/google/gerrit/server/project/ConfigInfoImpl.java b/gerrit-server/src/main/java/com/google/gerrit/server/project/ConfigInfoImpl.java
index 24760b7b10..62b8c9df96 100644
--- a/gerrit-server/src/main/java/com/google/gerrit/server/project/ConfigInfoImpl.java
+++ b/gerrit-server/src/main/java/com/google/gerrit/server/project/ConfigInfoImpl.java
@@ -30,7 +30,7 @@ import com.google.gerrit.server.config.PluginConfig;
 import com.google.gerrit.server.config.PluginConfigFactory;
 import com.google.gerrit.server.config.ProjectConfigEntry;
 import com.google.gerrit.server.extensions.webui.UiActions;
-import com.google.gerrit.server.git.TransferConfig;
+import com.google.gerrit.server.project.ProjectState.EffectiveMaxObjectSizeLimit;
 import com.google.inject.util.Providers;
 import java.util.Arrays;
 import java.util.LinkedHashMap;
@@ -41,7 +41,6 @@ public class ConfigInfoImpl extends ConfigInfo {
   public ConfigInfoImpl(
       boolean serverEnableSignedPush,
       ProjectControl control,
-      TransferConfig transferConfig,
       DynamicMap<ProjectConfigEntry> pluginConfigEntries,
       PluginConfigFactory cfgFactory,
       AllProjectsName allProjects,
@@ -98,7 +97,7 @@ public class ConfigInfoImpl extends ConfigInfo {
       this.requireSignedPush = requireSignedPush;
     }
 
-    this.maxObjectSizeLimit = getMaxObjectSizeLimit(projectState, transferConfig, p);
+    this.maxObjectSizeLimit = getMaxObjectSizeLimit(projectState, p);
 
     this.submitType = p.getSubmitType();
     this.state =
@@ -122,13 +121,13 @@ public class ConfigInfoImpl extends ConfigInfo {
     this.theme = projectState.getTheme();
   }
 
-  private MaxObjectSizeLimitInfo getMaxObjectSizeLimit(
-      ProjectState projectState, TransferConfig transferConfig, Project p) {
+  private MaxObjectSizeLimitInfo getMaxObjectSizeLimit(ProjectState projectState, Project p) {
     MaxObjectSizeLimitInfo info = new MaxObjectSizeLimitInfo();
-    long value = projectState.getEffectiveMaxObjectSizeLimit();
+    EffectiveMaxObjectSizeLimit limit = projectState.getEffectiveMaxObjectSizeLimit();
+    long value = limit.value;
     info.value = value == 0 ? null : String.valueOf(value);
     info.configuredValue = p.getMaxObjectSizeLimit();
-    info.inheritedValue = transferConfig.getFormattedMaxObjectSizeLimit();
+    info.summary = limit.summary;
     return info;
   }
 
diff --git a/gerrit-server/src/main/java/com/google/gerrit/server/project/GetConfig.java b/gerrit-server/src/main/java/com/google/gerrit/server/project/GetConfig.java
index 08df3863f9..1bf001b3f8 100644
--- a/gerrit-server/src/main/java/com/google/gerrit/server/project/GetConfig.java
+++ b/gerrit-server/src/main/java/com/google/gerrit/server/project/GetConfig.java
@@ -22,14 +22,12 @@ import com.google.gerrit.server.EnableSignedPush;
 import com.google.gerrit.server.config.AllProjectsName;
 import com.google.gerrit.server.config.PluginConfigFactory;
 import com.google.gerrit.server.config.ProjectConfigEntry;
-import com.google.gerrit.server.git.TransferConfig;
 import com.google.inject.Inject;
 import com.google.inject.Singleton;
 
 @Singleton
 public class GetConfig implements RestReadView<ProjectResource> {
   private final boolean serverEnableSignedPush;
-  private final TransferConfig transferConfig;
   private final DynamicMap<ProjectConfigEntry> pluginConfigEntries;
   private final PluginConfigFactory cfgFactory;
   private final AllProjectsName allProjects;
@@ -38,13 +36,11 @@ public class GetConfig implements RestReadView<ProjectResource> {
   @Inject
   public GetConfig(
       @EnableSignedPush boolean serverEnableSignedPush,
-      TransferConfig transferConfig,
       DynamicMap<ProjectConfigEntry> pluginConfigEntries,
       PluginConfigFactory cfgFactory,
       AllProjectsName allProjects,
       DynamicMap<RestView<ProjectResource>> views) {
     this.serverEnableSignedPush = serverEnableSignedPush;
-    this.transferConfig = transferConfig;
     this.pluginConfigEntries = pluginConfigEntries;
     this.allProjects = allProjects;
     this.cfgFactory = cfgFactory;
@@ -56,7 +52,6 @@ public class GetConfig implements RestReadView<ProjectResource> {
     return new ConfigInfoImpl(
         serverEnableSignedPush,
         resource.getControl(),
-        transferConfig,
         pluginConfigEntries,
         cfgFactory,
         allProjects,
diff --git a/gerrit-server/src/main/java/com/google/gerrit/server/project/ProjectState.java b/gerrit-server/src/main/java/com/google/gerrit/server/project/ProjectState.java
index 9e9526dfdc..2e3677dea6 100644
--- a/gerrit-server/src/main/java/com/google/gerrit/server/project/ProjectState.java
+++ b/gerrit-server/src/main/java/com/google/gerrit/server/project/ProjectState.java
@@ -17,6 +17,7 @@ package com.google.gerrit.server.project;
 import static com.google.gerrit.common.data.PermissionRule.Action.ALLOW;
 import static java.nio.charset.StandardCharsets.UTF_8;
 
+import com.google.common.annotations.VisibleForTesting;
 import com.google.common.collect.FluentIterable;
 import com.google.common.collect.ImmutableList;
 import com.google.common.collect.Iterables;
@@ -245,13 +246,55 @@ public class ProjectState {
     return cfg;
   }
 
-  public long getEffectiveMaxObjectSizeLimit() {
-    long local = config.getMaxObjectSizeLimit();
-    if (globalMaxObjectSizeLimit > 0 && local > 0) {
-      return Math.min(globalMaxObjectSizeLimit, local);
+  public static class EffectiveMaxObjectSizeLimit {
+    public long value;
+    public String summary;
+  }
+
+  private static final String MAY_NOT_SET = "This project may not set a higher limit.";
+
+  @VisibleForTesting
+  public static final String INHERITED_FROM_PARENT = "Inherited from parent project '%s'.";
+
+  @VisibleForTesting
+  public static final String OVERRIDDEN_BY_PARENT =
+      "Overridden by parent project '%s'. " + MAY_NOT_SET;
+
+  @VisibleForTesting
+  public static final String INHERITED_FROM_GLOBAL = "Inherited from the global config.";
+
+  @VisibleForTesting
+  public static final String OVERRIDDEN_BY_GLOBAL =
+      "Overridden by the global config. " + MAY_NOT_SET;
+
+  public EffectiveMaxObjectSizeLimit getEffectiveMaxObjectSizeLimit() {
+    EffectiveMaxObjectSizeLimit result = new EffectiveMaxObjectSizeLimit();
+
+    result.value = config.getMaxObjectSizeLimit();
+    for (ProjectState parent : parents()) {
+      long parentValue = parent.config.getMaxObjectSizeLimit();
+      if (parentValue > 0 && result.value > 0) {
+        if (parentValue < result.value) {
+          result.value = parentValue;
+          result.summary = String.format(OVERRIDDEN_BY_PARENT, parent.config.getName());
+        }
+      } else if (parentValue > 0) {
+        result.value = parentValue;
+        result.summary = String.format(INHERITED_FROM_PARENT, parent.config.getName());
+      }
     }
-    // zero means "no limit", in this case the max is more limiting
-    return Math.max(globalMaxObjectSizeLimit, local);
+
+    if (globalMaxObjectSizeLimit > 0 && result.value > 0) {
+      if (globalMaxObjectSizeLimit < result.value) {
+        result.value = globalMaxObjectSizeLimit;
+        result.summary = OVERRIDDEN_BY_GLOBAL;
+      }
+    } else if (globalMaxObjectSizeLimit > result.value) {
+      // zero means "no limit", in this case the max is more limiting
+      result.value = globalMaxObjectSizeLimit;
+      result.summary = INHERITED_FROM_GLOBAL;
+    }
+    return result;
   }
 
   /** Get the sections that pertain only to this project. */
diff --git a/gerrit-server/src/main/java/com/google/gerrit/server/project/PutConfig.java b/gerrit-server/src/main/java/com/google/gerrit/server/project/PutConfig.java
index 4ec8a7703c..85dcfbc931 100644
--- a/gerrit-server/src/main/java/com/google/gerrit/server/project/PutConfig.java
+++ b/gerrit-server/src/main/java/com/google/gerrit/server/project/PutConfig.java
@@ -36,7 +36,6 @@ import com.google.gerrit.server.config.PluginConfigFactory;
 import com.google.gerrit.server.config.ProjectConfigEntry;
 import com.google.gerrit.server.git.MetaDataUpdate;
 import com.google.gerrit.server.git.ProjectConfig;
-import com.google.gerrit.server.git.TransferConfig;
 import com.google.inject.Inject;
 import com.google.inject.Provider;
 import com.google.inject.Singleton;
@@ -58,7 +57,6 @@ public class PutConfig implements RestModifyView<ProjectResource, ConfigInput> {
   private final Provider<MetaDataUpdate.User> metaDataUpdateFactory;
   private final ProjectCache projectCache;
   private final ProjectState.Factory projectStateFactory;
-  private final TransferConfig transferConfig;
   private final DynamicMap<ProjectConfigEntry> pluginConfigEntries;
   private final PluginConfigFactory cfgFactory;
   private final AllProjectsName allProjects;
@@ -71,7 +69,6 @@ public class PutConfig implements RestModifyView<ProjectResource, ConfigInput> {
       Provider<MetaDataUpdate.User> metaDataUpdateFactory,
       ProjectCache projectCache,
       ProjectState.Factory projectStateFactory,
-      TransferConfig transferConfig,
       DynamicMap<ProjectConfigEntry> pluginConfigEntries,
       PluginConfigFactory cfgFactory,
       AllProjectsName allProjects,
@@ -81,7 +78,6 @@ public class PutConfig implements RestModifyView<ProjectResource, ConfigInput> {
     this.metaDataUpdateFactory = metaDataUpdateFactory;
     this.projectCache = projectCache;
     this.projectStateFactory = projectStateFactory;
-    this.transferConfig = transferConfig;
     this.pluginConfigEntries = pluginConfigEntries;
     this.cfgFactory = cfgFactory;
     this.allProjects = allProjects;
@@ -176,7 +172,6 @@ public class PutConfig implements RestModifyView<ProjectResource, ConfigInput> {
       return new ConfigInfoImpl(
           serverEnableSignedPush,
           state.controlFor(user.get()),
-          transferConfig,
           pluginConfigEntries,
           cfgFactory,
           allProjects,