(mesos) branch master updated: [cgroups] Add helper to find overlapping device access.

[bmahler]

This is an automated email from the ASF dual-hosted git repository.

bmahler pushed a commit to branch master
in repository https://gitbox.apache.org/repos/asf/mesos.git


The following commit(s) were added to refs/heads/master by this push:
     new fbb120740 [cgroups] Add helper to find overlapping device access.
fbb120740 is described below

commit fbb120740e05b4dc45b3873f3bca9f8632a53e6b
Author: Jason Zhou <jasonzhou...@gmail.com>
AuthorDate: Wed Jul 24 16:08:31 2024 -0400

    [cgroups] Add helper to find overlapping device access.
    
    Currently, we have to directly compare member variables to see if one
    Access object would overlap that of another, which isn't very clear
    to people that would be reading the code.
    
    We add a helper to abstract away the logic to see if the accesses
    specified in one Access instance would overlap with that of another.
    
    Review: https://reviews.apache.org/r/75107/
---
 src/linux/cgroups.cpp                     |  8 ++++++++
 src/linux/cgroups.hpp                     |  1 +
 src/tests/containerizer/cgroups_tests.cpp | 30 ++++++++++++++++++++++++++++++
 3 files changed, 39 insertions(+)

diff --git a/src/linux/cgroups.cpp b/src/linux/cgroups.cpp
index 3dae320bd..e58c2977a 100644
--- a/src/linux/cgroups.cpp
+++ b/src/linux/cgroups.cpp
@@ -2946,6 +2946,14 @@ bool Entry::encompasses(const Entry& other) const
 bool Entry::Access::none() const { return !mknod && !read && !write; }
 
 
+bool Entry::Access::overlaps(const Entry::Access& other) const
+{
+  return (read && other.read)
+      || (write && other.write)
+      || (mknod && other.mknod);
+}
+
+
 bool Entry::Selector::has_wildcard() const
 {
   return major.isNone() || minor.isNone() || type == 
Entry::Selector::Type::ALL;
diff --git a/src/linux/cgroups.hpp b/src/linux/cgroups.hpp
index 4fefb5c3b..c50ec59e3 100644
--- a/src/linux/cgroups.hpp
+++ b/src/linux/cgroups.hpp
@@ -963,6 +963,7 @@ struct Entry
     bool write;
     bool mknod;
     bool none() const;
+    bool overlaps(const Access& other) const;
   };
 
   Selector selector;
diff --git a/src/tests/containerizer/cgroups_tests.cpp 
b/src/tests/containerizer/cgroups_tests.cpp
index e4ca7933b..7e6bb0659 100644
--- a/src/tests/containerizer/cgroups_tests.cpp
+++ b/src/tests/containerizer/cgroups_tests.cpp
@@ -1493,6 +1493,36 @@ TEST(DevicesTest, AccessNoneTest)
 }
 
 
+TEST(DeviceTest, AccessOverlapsTest)
+{
+  cgroups::devices::Entry::Access access;
+  cgroups::devices::Entry::Access other;
+  access.read = true;
+  access.write = true;
+  access.mknod = true;
+
+  other.read = false;
+  other.write = false;
+  other.mknod = false;
+  EXPECT_FALSE(access.overlaps(other));
+
+  other.read = true;
+  other.write = false;
+  other.mknod = false;
+  EXPECT_TRUE(access.overlaps(other));
+
+  other.read = false;
+  other.write = true;
+  other.mknod = false;
+  EXPECT_TRUE(access.overlaps(other));
+
+  other.read = false;
+  other.write = false;
+  other.mknod = true;
+  EXPECT_TRUE(access.overlaps(other));
+}
+
+
 TEST(DeviceTest, SelectorWildcardTest)
 {
   cgroups::devices::Entry::Selector selector;