(mesos) branch master updated: [cgroups2] Fix controllers::enable/available empty handling.

[bm...@apache.org]

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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 0aa65cd70 [cgroups2] Fix controllers::enable/available empty handling.
0aa65cd70 is described below

commit 0aa65cd70aeee5c12e01ce3958dae849039aa47d
Author: Devin Leamy <dl...@twitter.com>
AuthorDate: Thu Mar 21 19:44:02 2024 -0400

    [cgroups2] Fix controllers::enable/available empty handling.
    
    "cgroup.controllers" and "cgroup.subtree_control" control files can be empty,
    in which case `strings::split(s, " ")` returns `[""]` which causes us to use
    an empty string for a controller.
    
    This closes #530
---
 src/linux/cgroups2.cpp | 23 ++++++++++++++++++-----
 1 file changed, 18 insertions(+), 5 deletions(-)

diff --git a/src/linux/cgroups2.cpp b/src/linux/cgroups2.cpp
index 7e1a801a3..c2892f544 100644
--- a/src/linux/cgroups2.cpp
+++ b/src/linux/cgroups2.cpp
@@ -115,7 +115,14 @@ struct State
   static State parse(const string& contents)
   {
     State control;
-    vector<string> controllers = strings::split(contents, " ");
+
+    // Trim trailing newline.
+    const string trimmed = strings::trim(contents);
+    if (trimmed.empty()) {
+      return control;
+    }
+
+    vector<string> controllers = strings::split(trimmed, " ");
     control._enabled.insert(
       std::make_move_iterator(controllers.begin()),
       std::make_move_iterator(controllers.end()));
@@ -359,15 +366,21 @@ namespace controllers {
 
 Try<set<string>> available(const string& cgroup)
 {
-  Try<string> contents =
+  Try<string> read =
     cgroups2::read<string>(cgroup, cgroups2::control::CONTROLLERS);
 
-  if (contents.isError()) {
+  if (read.isError()) {
     return Error("Failed to read cgroup.controllers in '" + cgroup + "': "
-                 + contents.error());
+                 + read.error());
+  }
+
+  // Trim trailing newline.
+  const string contents = strings::trim(*read);
+  if (contents.empty()) {
+    return set<string>();
   }
 
-  vector<string> controllers = strings::split(*contents, " ");
+  vector<string> controllers = strings::split(contents, " ");
   return set<string>(
       std::make_move_iterator(controllers.begin()),
       std::make_move_iterator(controllers.end()));