Merge pull request #1159 from trapexit/wait

More actively report to syslog when waiting for branches to mount

src/branches.cpp

@@ -188,6 +188,9 @@ namespace l
       branch.set_minfreespace(minfreespace.value());
 
     fs::glob(glob,&paths);
+    if(paths.empty())
+      paths.push_back(glob);
+
     fs::realpathize(&paths);
     for(auto &path : paths)
       {

src/fs_wait_for_mount.cpp

@@ -17,96 +17,116 @@
 */
 
 #include "fs_wait_for_mount.hpp"
+#include "syslog.hpp"
 
 #include <thread>
+#include <unordered_set>
+
+
+namespace fs
+{
+  typedef std::unordered_set<fs::Path> PathSet;
+}
 
 constexpr std::chrono::milliseconds SLEEP_DURATION = std::chrono::milliseconds(333);
 
+template<>
+struct std::hash<fs::Path>
+{
+  std::size_t
+  operator()(fs::Path const &path_) const noexcept
+  {
+    return std::hash<std::string>{}(path_.string());
+  }
+};
 
-bool
-fs::wait_for_mount(const struct stat               &src_st_,
-                   const ghc::filesystem::path     &tgtpath_,
-                   const std::chrono::milliseconds &timeout_)
+static
+void
+_check_mounted(const struct stat &src_st_,
+               const fs::PathSet &tgt_paths_,
+               fs::PathVector    *successes_,
+               fs::PathVector    *failures_)
 {
-  int rv;
-  std::chrono::duration<double> time_diff;
-  std::chrono::time_point<std::chrono::steady_clock> start_time;
+  fs::PathVector &successes = *successes_;
+  fs::PathVector &failures  = *failures_;
 
-  start_time = std::chrono::steady_clock::now();
-  while(true)
+  for(auto const &tgt_path : tgt_paths_)
     {
+      int         rv;
       struct stat tgt_st;
 
-      rv = fs::stat(tgtpath_,&tgt_st);
+      rv = fs::stat(tgt_path,&tgt_st);
       if(rv == 0)
         {
           if(tgt_st.st_dev != src_st_.st_dev)
-            return true;
+            successes.push_back(tgt_path);
+          else
+            failures.push_back(tgt_path);
+        }
+      else
+        {
+          failures.push_back(tgt_path);
         }
-
-      time_diff = (std::chrono::steady_clock::now() - start_time);
-      if(time_diff > timeout_)
-        return false;
-
-      std::this_thread::sleep_for(SLEEP_DURATION);
     }
-
-  return false;
 }
 
 static
 void
 _wait_for_mount(const struct stat               &src_st_,
-                const fs::PathVector            &tgtpaths_,
-                const std::chrono::milliseconds &timeout_,
-                fs::PathVector                  &failed_paths_)
+                const fs::PathVector            &tgt_paths_,
+                const std::chrono::milliseconds &timeout_)
 {
-  bool rv;
-  fs::PathVector::const_iterator i;
-  std::chrono::milliseconds timeout;
-  std::chrono::milliseconds diff;
+  fs::PathVector                                     successes;
+  fs::PathVector                                     failures;
+  std::unordered_set<fs::Path>                       tgt_paths;
   std::chrono::time_point<std::chrono::steady_clock> now;
-  std::chrono::time_point<std::chrono::steady_clock> start_time;
+  std::chrono::time_point<std::chrono::steady_clock> deadline;
 
-  timeout = timeout_;
-  now = start_time = std::chrono::steady_clock::now();
-  for(auto i = tgtpaths_.begin(); i != tgtpaths_.end(); ++i)
-    {
-      diff = std::chrono::duration_cast<std::chrono::milliseconds>(now - start_time);
-      timeout -= diff;
+  tgt_paths.insert(tgt_paths_.begin(),tgt_paths_.end());
+  now      = std::chrono::steady_clock::now();
+  deadline = now + timeout_;
 
-      rv = fs::wait_for_mount(src_st_,*i,timeout);
-      if(rv == false)
-        failed_paths_.push_back(*i);
+  while(true)
+    {
+      if(tgt_paths.empty())
+        break;
+      if(now >= deadline)
+        break;
+
+      successes.clear();
+      failures.clear();
+      ::_check_mounted(src_st_,tgt_paths,&successes,&failures);
+      for(auto const &path : successes)
+        {
+          tgt_paths.erase(path);
+          syslog_info("%s is mounted",path.string().c_str());
+        }
 
+      std::this_thread::sleep_for(SLEEP_DURATION);
       now = std::chrono::steady_clock::now();
     }
-}
-
-void
-fs::wait_for_mount(const struct stat               &src_st_,
-                   const fs::PathVector            &tgtpaths_,
-                   const std::chrono::milliseconds &timeout_,
-                   fs::PathVector                  &failed_paths_)
-{
-  if(tgtpaths_.empty())
-    return;
 
-  _wait_for_mount(src_st_,tgtpaths_,timeout_,failed_paths_);
+  for(auto const &path : failures)
+    syslog_notice("%s not mounted within timeout",path.string().c_str());
+  if(!failures.empty())
+    syslog_warning("Continuing to mount mergerfs despite %u branches not "
+                   "being different from the mountpoint filesystem",
+                   failures.size());
 }
 
 void
-fs::wait_for_mount(const ghc::filesystem::path     &srcpath_,
-                   const fs::PathVector            &tgtpaths_,
-                   const std::chrono::milliseconds &timeout_,
-                   fs::PathVector                  &failed_paths_)
+fs::wait_for_mount(const fs::Path                  &src_path_,
+                   const fs::PathVector            &tgt_paths_,
+                   const std::chrono::milliseconds &timeout_)
 {
   int rv;
   struct stat src_st;
 
-  rv = fs::stat(srcpath_,&src_st);
+  rv = fs::stat(src_path_,&src_st);
   if(rv == -1)
-    return;
+    return syslog_error("Error stat'ing mount path: %s (%s)",
+                        src_path_.c_str(),
+                        strerror(errno));
 
-  fs::wait_for_mount(src_st,tgtpaths_,timeout_,failed_paths_);
+  ::_wait_for_mount(src_st,tgt_paths_,timeout_);
 }

src/fs_wait_for_mount.hpp

@@ -29,22 +29,8 @@
 
 namespace fs
 {
-  typedef std::vector<ghc::filesystem::path> PathVector;
-
-  bool
-  wait_for_mount(const struct stat               &st,
-                 const ghc::filesystem::path     &tgtpath,
-                 const std::chrono::milliseconds &timeout);
-
   void
-  wait_for_mount(const struct stat               &st,
+  wait_for_mount(const fs::Path                  &srcpath,
                  const fs::PathVector            &tgtpaths,
-                 const std::chrono::milliseconds &timeout,
-                 fs::PathVector                  &failed_paths);
-
-  void
-  wait_for_mount(const ghc::filesystem::path     &srcpath,
-                 const fs::PathVector            &tgtpaths,
-                 const std::chrono::milliseconds &timeout,
-                 fs::PathVector                  &failed_paths);
+                 const std::chrono::milliseconds &timeout);
 }

src/mergerfs.cpp

@@ -156,7 +156,6 @@ namespace l
   wait_for_mount(const Config::Read &cfg_)
   {
     fs::PathVector paths;
-    fs::PathVector failed;
     std::chrono::milliseconds timeout;
 
     paths = cfg_->branches->to_paths();
@@ -167,15 +166,7 @@ namespace l
     timeout = std::chrono::milliseconds(cfg_->branches_mount_timeout * 1000);
     fs::wait_for_mount((std::string)cfg_->mountpoint,
                        paths,
-                       timeout,
-                       failed);
-    for(auto &path : failed)
-      syslog_warning("Branch %s was not mounted within timeout",
-                     path.c_str());
-    if(failed.size())
-      syslog_warning("Continuing to mount mergerfs despite %u branches not "
-                     "being different from the mountpoint filesystem",
-                     failed.size());
+                       timeout);
   }
 
   static