Home/ Questions/Q 6581773
In Process

The Archive Base Latest Questions

Editorial Team
  • 0
Asked: 2026-05-25T16:11:45+00:00

Is it safe to call rename(tmppath, path) without calling fsync(tmppath_fd) first? I want the

  • 0

Is it safe to call rename(tmppath, path) without calling fsync(tmppath_fd) first?

I want the path to always point to a complete file.
I care mainly about Ext4. Is the rename() promised to be safe in all future Linux kernel versions?

A usage example in Python:

def store_atomically(path, data):
    tmppath = path + ".tmp"
    output = open(tmppath, "wb")
    output.write(data)

    output.flush()
    os.fsync(output.fileno())  # The needed fsync().
    output.close()
    os.rename(tmppath, path)
Share

Leave an answer

You must login to add an answer.

Need An Account,

1 Answer

  1. Editorial Team

    No.

    Look at libeatmydata, and this presentation:

    Eat My Data: How Everybody Gets File IO Wrong

    http://www.oscon.com/oscon2008/public/schedule/detail/3172

    by Stewart Smith from MySql.

    In case it is offline/no longer available, I keep a copy of it:

    • 0