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windowstransactionsntfs

Transactional NTFS - wait for CommitTransaction

I'm using Transactional NTFS to atomize multiple writes to several files. The problem is that after commit, I may not be able to reopen a file, perhaps because of a racing condition.

The sequence of events is :

  1. NTFS transaction is created with CreateTransaction
  2. Files are opened with CreateFileTransacted
  3. Writes are done to the files
  4. Files are closed with CloseHandle
  5. Transaction is committed with CommitTransaction
  6. Files are reopened with CreateFile for read/write

The last step sometimes fails with error code 3 : ERROR_PATH_NOT_FOUND - The system cannot find the path specified. When re-executing the program, the file is then found. This happens rarely, but in a completely random manner, meaning not always when reopening the same file.

My theory is that if terminating the transaction by Windows takes a long time, the files are not available for opening in read/write mode until the transaction terminates. My program then fails when trying to open my own files in non-transaction mode.

I think that to avoid this problem, I need to wait for the transaction to complete before reopening the files. However, I have not found any documented method for doing that.

Solution

  • No clever answers, so I had to implement my own dummy one :

    If an I/O error happens on opening a file that was just closed, the solution was to loop on opening several times while in-between calling Sleep() to release the CPU, before deciding that a catastrophic error had occurred.

    Dummy solution, but it solved the problem.