cli: only warn about mount namespace when the store actually needs remounting#15547
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amaanq wants to merge 1 commit intoNixOS:masterfrom
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cli: only warn about mount namespace when the store actually needs remounting#15547amaanq wants to merge 1 commit intoNixOS:masterfrom
amaanq wants to merge 1 commit intoNixOS:masterfrom
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xokdvium
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Previously, when unshare(CLONE_NEWNS) failed and the store was read-only, Nix warned but still remounted the store writable on the host mount table. This silently affected other processes sharing the namespace. Now it throws an error, since proceeding would mutate shared state.
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| @@ -13,9 +13,24 @@ namespace nix { | |||
| */ | |||
| void saveMountNamespace(); | |||
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Can this function be made static now?
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Motivation
The previous warning in
main.ccfired on every invocation as root whenunshare(CLONE_NEWNS)failed, which is noisy in containers. Move the warning tomakeStoreWritable()so it only triggers when the store is read-only and we lack a private mount namespace, i.e. when the remount would actually leak into the host mount table. Also switch frome.msg()toe.message()to avoid the redundant "error: " prefix.Context
@xokdvium and I chatted about this in the Nix meeting yesterday
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