Repository: mesos
Updated Branches:
  refs/heads/1.1.x 2f910790f -> 3da5fa963


Lazily unmount persistent volumes in MesosContainerizer.

Use MNT_DETACH when unmounting persistent volumes in Linux filesystem
isolator to workaround an issue of incorrect handling of container
destroy failures. Currently, if isolator cleanup returns a failure,
the slave will treat the container as terminated, and will schedule
the cleanup of the container's sandbox. Since the mount hasn't been
removed in the sandbox (e.g., due to EBUSY), that'll result in data in
the persistent volume being incorrectly deleted. Use MNT_DETACH so
that the mount point in the sandbox will be removed immediately.  See
MESOS-7366 for more details.

Review: https://reviews.apache.org/r/58278


Project: http://git-wip-us.apache.org/repos/asf/mesos/repo
Commit: http://git-wip-us.apache.org/repos/asf/mesos/commit/389b5aaf
Tree: http://git-wip-us.apache.org/repos/asf/mesos/tree/389b5aaf
Diff: http://git-wip-us.apache.org/repos/asf/mesos/diff/389b5aaf

Branch: refs/heads/1.1.x
Commit: 389b5aaf8e30ef47546bb419ed2cbd9e616ea8a2
Parents: 2f91079
Author: Jie Yu <[email protected]>
Authored: Fri Apr 7 16:33:53 2017 -0700
Committer: Jie Yu <[email protected]>
Committed: Tue Apr 11 16:42:55 2017 -0700

----------------------------------------------------------------------
 .../mesos/isolators/filesystem/linux.cpp        | 22 ++++++++++++++++++--
 1 file changed, 20 insertions(+), 2 deletions(-)
----------------------------------------------------------------------


http://git-wip-us.apache.org/repos/asf/mesos/blob/389b5aaf/src/slave/containerizer/mesos/isolators/filesystem/linux.cpp
----------------------------------------------------------------------
diff --git a/src/slave/containerizer/mesos/isolators/filesystem/linux.cpp 
b/src/slave/containerizer/mesos/isolators/filesystem/linux.cpp
index df16b8f..0c57757 100644
--- a/src/slave/containerizer/mesos/isolators/filesystem/linux.cpp
+++ b/src/slave/containerizer/mesos/isolators/filesystem/linux.cpp
@@ -800,6 +800,8 @@ Future<Nothing> LinuxFilesystemIsolatorProcess::cleanup(
     return Failure("Failed to get mount table: " + table.error());
   }
 
+  vector<string> unmountErrors;
+
   // Reverse unmount order to handle nested mount points.
   foreach (const fs::MountInfoTable::Entry& entry,
            adaptor::reverse(table->entries)) {
@@ -810,15 +812,31 @@ Future<Nothing> LinuxFilesystemIsolatorProcess::cleanup(
       LOG(INFO) << "Unmounting volume '" << entry.target
                 << "' for container " << containerId;
 
-      Try<Nothing> unmount = fs::unmount(entry.target);
+      // TODO(jieyu): Use MNT_DETACH here to workaround an issue of
+      // incorrect handling of container destroy failures. Currently,
+      // if isolator cleanup returns a failure, the slave will treat
+      // the container as terminated, and will schedule the cleanup of
+      // the container's sandbox. Since the mount hasn't been removed
+      // in the sandbox, that'll result in data in the persistent
+      // volume being incorrectly deleted. Use MNT_DETACH here so that
+      // the mount point in the sandbox will be removed immediately.
+      // See MESOS-7366 for more details.
+      Try<Nothing> unmount = fs::unmount(entry.target, MNT_DETACH);
       if (unmount.isError()) {
-        return Failure(
+        // NOTE: Instead of short circuit, we try to perform as many
+        // unmount as possible. We'll accumulate the errors together
+        // in the end.
+        unmountErrors.push_back(
             "Failed to unmount volume '" + entry.target +
             "': " + unmount.error());
       }
     }
   }
 
+  if (!unmountErrors.empty()) {
+    return Failure(strings::join(", ", unmountErrors));
+  }
+
   return Nothing();
 }
 

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