libimage, ManifestList: fslock and reload to provide race-free Add API
#1090
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`podman manifest add` uses `ManifestList.Add(` but of now `Add(` does not locks while adding instances to the list thus causing race scenarios where storage is not reloaded and overrided by another invocation of the command. Following problem is solved in two steps * Add -> LockByInstance: Acquire a fs lock by instance ID so other invocation waits until this invocation completes its write. * Add -> LockByInstance -> reload: Reload instance digests from storage just after acquiring lock to make sure we are not overriding any just written instance. Reproducer: containers/podman#14667 (comment) Closes: containers/podman#14667 [NO NEW TESTS NEEDED] [NO TESTS NEEDED] This needes integration tests so its hard to verify race in CI. Signed-off-by: Aditya R <arajan@redhat.com>
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/approved |
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LGTM, but I'd like an ack from @vrothberg before we merge |
vrothberg
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Jul 15, 2022
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[APPROVALNOTIFIER] This PR is APPROVED This pull-request has been approved by: flouthoc, vrothberg The full list of commands accepted by this bot can be found here. The pull request process is described here
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/lgtm |
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Thanks, Syncing this to buildah and podman so i can update the BZ |
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podman manifest addusesManifestList.Add(but as of nowAdd(doesnot locks while adding instances to the list thus causing race scenarios
where storage is not reloaded and overridden by another invocation of the
command.
Following problem is solved in two steps
invocation waits until this invocation completes its write.
just after acquiring lock to make sure we are not overriding any just
written instance.
Reproducer: containers/podman#14667 (comment)
Closes: BZ#2105173
Closes: containers/podman#14667
[NO NEW TESTS NEEDED]
[NO TESTS NEEDED]
This needs integration tests so its hard to verify race in c/common CI