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author | Matthew Heon <matthew.heon@gmail.com> | 2017-11-01 11:24:59 -0400 |
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committer | Matthew Heon <matthew.heon@gmail.com> | 2017-11-01 11:24:59 -0400 |
commit | a031b83a09a8628435317a03f199cdc18b78262f (patch) | |
tree | bc017a96769ce6de33745b8b0b1304ccf38e9df0 /vendor/golang.org/x/sys/unix/dev_linux.go | |
parent | 2b74391cd5281f6fdf391ff8ad50fd1490f6bf89 (diff) | |
download | podman-a031b83a09a8628435317a03f199cdc18b78262f.tar.gz podman-a031b83a09a8628435317a03f199cdc18b78262f.tar.bz2 podman-a031b83a09a8628435317a03f199cdc18b78262f.zip |
Initial checkin from CRI-O repo
Signed-off-by: Matthew Heon <matthew.heon@gmail.com>
Diffstat (limited to 'vendor/golang.org/x/sys/unix/dev_linux.go')
-rw-r--r-- | vendor/golang.org/x/sys/unix/dev_linux.go | 42 |
1 files changed, 42 insertions, 0 deletions
diff --git a/vendor/golang.org/x/sys/unix/dev_linux.go b/vendor/golang.org/x/sys/unix/dev_linux.go new file mode 100644 index 000000000..c902c39e8 --- /dev/null +++ b/vendor/golang.org/x/sys/unix/dev_linux.go @@ -0,0 +1,42 @@ +// Copyright 2017 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +// Functions to access/create device major and minor numbers matching the +// encoding used by the Linux kernel and glibc. +// +// The information below is extracted and adapted from bits/sysmacros.h in the +// glibc sources: +// +// dev_t in glibc is 64-bit, with 32-bit major and minor numbers. glibc's +// default encoding is MMMM Mmmm mmmM MMmm, where M is a hex digit of the major +// number and m is a hex digit of the minor number. This is backward compatible +// with legacy systems where dev_t is 16 bits wide, encoded as MMmm. It is also +// backward compatible with the Linux kernel, which for some architectures uses +// 32-bit dev_t, encoded as mmmM MMmm. + +package unix + +// Major returns the major component of a Linux device number. +func Major(dev uint64) uint32 { + major := uint32((dev & 0x00000000000fff00) >> 8) + major |= uint32((dev & 0xfffff00000000000) >> 32) + return major +} + +// Minor returns the minor component of a Linux device number. +func Minor(dev uint64) uint32 { + minor := uint32((dev & 0x00000000000000ff) >> 0) + minor |= uint32((dev & 0x00000ffffff00000) >> 12) + return minor +} + +// Mkdev returns a Linux device number generated from the given major and minor +// components. +func Mkdev(major, minor uint32) uint64 { + dev := uint64((major & 0x00000fff) << 8) + dev |= uint64((major & 0xfffff000) << 32) + dev |= uint64((minor & 0x000000ff) << 0) + dev |= uint64((minor & 0xffffff00) << 12) + return dev +} |