fsync before overwriting previous persist file #36
Conversation
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Standard process for an atomic update on unix systems is: 1. Write new contents to a temp file on same filesystem/folder 2. fsync the file 3. Close the file 4. Rename the temp file over top of the existing file The existing code was missing seladb#2. If you lose power soon after persisting a new file, the file rename can be synced through without the new data contents. If that happens you end up losing your settings.
|
@jmckaskill I'm not sure I understand. Why do we need fsync here? 🤔 |
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
Standard process for an atomic update on unix systems is:
The existing code was missing #2. If you lose power soon after persisting a new file, the file rename can be synced through without the new data contents. If that happens you end up losing your settings.