Fix rclone backend not properly handling subprocess exit#2797
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greatroar wants to merge 2 commits intorestic:masterfrom
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Fix rclone backend not properly handling subprocess exit#2797greatroar wants to merge 2 commits intorestic:masterfrom
greatroar wants to merge 2 commits intorestic:masterfrom
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This forces an error in the REST backend, which otherwise would hang indefinitely. Fixes restic#2381.
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The default behavior of Go is to trigger The root cause for restic not noticing the subprocess exit is that restic currently holds on to file descriptors for both the read and write side of the stdin and stdout pipes. That prevents the pipes from closing properly. Calling I've built a different version of this PR (including your test case) which properly fixes the pipe setup and hopefully also the rclone test failures: #2855 |
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Closing in favor of #2855. |
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What is the purpose of this change? What does it change?
When rclone exits unexpectedly, restic can hang. The problem occurs in the REST backend, which does not detect that its connection over stdin/stdout has stopped working.
This patch is a (hacky) fix for that problem: it simply closes stdin and stdout when the process is gone. Why this doesn't produce a SIGPIPE is beyond me. The error message is ugly, but at least it arrives instantly.
I have some ideas about how to fix this properly, but they may require quite a bit of code (if they even turn out correct). I suggest merging this as a hotfix.
I was hoping to fix the flaky rclone test, but I don't think this patch does that.
Was the change discussed in an issue or in the forum before?
Fixes #2381.
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changelog/unreleased/that describes the changes for our users (template here)gofmton the code in all commits