Merge #13039: Add logging and error handling for file syncing

cf02779 Add logging and error handling for file syncing (Wladimir J. van der Laan)

Pull request description:

  Add logging and error handling inside, and outside of FileCommit.
  Functions such as fsync, fdatasync will return error in case of hardware I/O errors, and ignoring this means it can silently continue through data corruption.
  (c.f. https://lwn.net/SubscriberLink/752063/12b232ab5039efbe/)

  EINVAL is handled specially to avoid crashing out on (network, fuse) filesystems that don't handle `f[data]sync`.

  I checked that the syncing inside leveldb is already generating an I/O error as appropriate.

Tree-SHA512: 64cc9bbedca3ecc97ff4bac0a7b7ac6526a7ed763c66f6786d03ca4f2e9e366e42b152cb908299c060448d98ca39ff03395280bffaca51d592e728aa2516f5dd

1 files changed, 11 insertions, 5 deletions

diff --git a/src/validation.cpp b/src/validation.cpp
index 21e9920b4f..7bf7df7b82 100644
--- a/src/validation.cpp
+++ b/src/validation.cpp
@@ -1615,22 +1615,27 @@ void static FlushBlockFile(bool fFinalize = false)
     LOCK(cs_LastBlockFile);
 
     CDiskBlockPos posOld(nLastBlockFile, 0);
+    bool status = true;
 
     FILE *fileOld = OpenBlockFile(posOld);
     if (fileOld) {
         if (fFinalize)
-            TruncateFile(fileOld, vinfoBlockFile[nLastBlockFile].nSize);
-        FileCommit(fileOld);
+            status &= TruncateFile(fileOld, vinfoBlockFile[nLastBlockFile].nSize);
+        status &= FileCommit(fileOld);
         fclose(fileOld);
     }
 
     fileOld = OpenUndoFile(posOld);
     if (fileOld) {
         if (fFinalize)
-            TruncateFile(fileOld, vinfoBlockFile[nLastBlockFile].nUndoSize);
-        FileCommit(fileOld);
+            status &= TruncateFile(fileOld, vinfoBlockFile[nLastBlockFile].nUndoSize);
+        status &= FileCommit(fileOld);
         fclose(fileOld);
     }
+
+    if (!status) {
+        AbortNode("Flushing block file to disk failed. This is likely the result of an I/O error.");
+    }
 }
 
 static bool FindUndoPos(CValidationState &state, int nFile, CDiskBlockPos &pos, unsigned int nAddSize);
@@ -4760,7 +4765,8 @@ bool DumpMempool(void)
         }
 
         file << mapDeltas;
-        FileCommit(file.Get());
+        if (!FileCommit(file.Get()))
+            throw std::runtime_error("FileCommit failed");
         file.fclose();
         RenameOver(GetDataDir() / "mempool.dat.new", GetDataDir() / "mempool.dat");
         int64_t last = GetTimeMicros();