
This patch introduces idmapped mounts support for container rootfs. The idmapped mounts support was merged in Linux kernel 5.12 torvalds/linux@7d6beb7. This functionality allows to address chown overhead for containers that use user namespace. The changes are based on experimental patchset published by Mauricio Vásquez #4734. Current version reiplements support of idmapped mounts using Golang. Performance measurement results: Image idmapped mount recursive chown BusyBox 00.135 04.964 Ubuntu 00.171 15.713 Fedora 00.143 38.799 Signed-off-by: Mauricio Vásquez <mauricio@kinvolk.io> Signed-off-by: Artem Kuzin <artem.kuzin@huawei.com> Signed-off-by: Alexey Perevalov <alexey.perevalov@huawei.com> Signed-off-by: Ilya Hanov <ilya.hanov@huawei-partners.com>
31 lines
889 B
Go
31 lines
889 B
Go
/*
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Copyright The containerd Authors.
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Licensed under the Apache License, Version 2.0 (the "License");
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you may not use this file except in compliance with the License.
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You may obtain a copy of the License at
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http://www.apache.org/licenses/LICENSE-2.0
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Unless required by applicable law or agreed to in writing, software
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distributed under the License is distributed on an "AS IS" BASIS,
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WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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See the License for the specific language governing permissions and
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limitations under the License.
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*/
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package sys
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import (
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_ "unsafe" // required for go:linkname.
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)
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//go:linkname beforeFork syscall.runtime_BeforeFork
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func beforeFork()
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//go:linkname afterFork syscall.runtime_AfterFork
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func afterFork()
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//go:linkname afterForkInChild syscall.runtime_AfterForkInChild
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func afterForkInChild()
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