mirror of
https://github.com/siderolabs/talos.git
synced 2025-10-27 22:41:34 +01:00
c5bd0ac5cf
Drop loop device/mounts completely, use userspace utilities to extract and lay over module trees in the tmpfs. Discover kernel version automatically instead of hardcoding it to be current one (required for Image Service). Signed-off-by: Andrey Smirnov <andrey.smirnov@siderolabs.com>
48 lines
1.0 KiB
Go
48 lines
1.0 KiB
Go
// This Source Code Form is subject to the terms of the Mozilla Public
|
|
// License, v. 2.0. If a copy of the MPL was not distributed with this
|
|
// file, You can obtain one at http://mozilla.org/MPL/2.0/.
|
|
|
|
package extensions
|
|
|
|
import (
|
|
"fmt"
|
|
"io"
|
|
)
|
|
|
|
// discarder is used to implement ReadAt from a Reader
|
|
// by reading, and discarding, data until the offset
|
|
// is reached. It can only go forward. It is designed
|
|
// for pipe-like files.
|
|
type discarder struct {
|
|
r io.Reader
|
|
pos int64
|
|
}
|
|
|
|
// ReadAt implements ReadAt for a discarder.
|
|
// It is an error for the offset to be negative.
|
|
func (r *discarder) ReadAt(p []byte, off int64) (int, error) {
|
|
if off-r.pos < 0 {
|
|
return 0, fmt.Errorf("negative seek on discarder not allowed")
|
|
}
|
|
|
|
if off != r.pos {
|
|
i, err := io.Copy(io.Discard, io.LimitReader(r.r, off-r.pos))
|
|
if err != nil || i != off-r.pos {
|
|
return 0, err
|
|
}
|
|
|
|
r.pos += i
|
|
}
|
|
|
|
n, err := io.ReadFull(r.r, p)
|
|
if err != nil {
|
|
return n, err
|
|
}
|
|
|
|
r.pos += int64(n)
|
|
|
|
return n, err
|
|
}
|
|
|
|
var _ io.ReaderAt = &discarder{}
|