mirror of
https://github.com/morgan9e/systemd
synced 2026-04-14 08:25:20 +09:00
59 lines
2.6 KiB
C
59 lines
2.6 KiB
C
/* SPDX-License-Identifier: LGPL-2.1-or-later */
|
|
#pragma once
|
|
|
|
#include <sys/sysmacros.h>
|
|
|
|
#include "forward.h"
|
|
|
|
int parse_devnum(const char *s, dev_t *ret);
|
|
|
|
#define DEVNUM_MAJOR_MAX ((UINT32_C(1) << 12) - 1U)
|
|
#define DEVNUM_MINOR_MAX ((UINT32_C(1) << 20) - 1U)
|
|
|
|
/* glibc and the Linux kernel have different ideas about the major/minor size. These calls will check whether the
|
|
* specified major is valid by the Linux kernel's standards, not by glibc's. Linux has 20bits of minor, and 12 bits of
|
|
* major space. See MINORBITS in linux/kdev_t.h in the kernel sources. (If you wonder why we define _y here, instead of
|
|
* comparing directly >= 0: it's to trick out -Wtype-limits, which would otherwise complain if the type is unsigned, as
|
|
* such a test would be pointless in such a case.) */
|
|
|
|
#define DEVICE_MAJOR_VALID(x) \
|
|
({ \
|
|
typeof(x) _x = (x), _y = 0; \
|
|
_x >= _y && _x <= DEVNUM_MAJOR_MAX; \
|
|
\
|
|
})
|
|
|
|
#define DEVICE_MINOR_VALID(x) \
|
|
({ \
|
|
typeof(x) _x = (x), _y = 0; \
|
|
_x >= _y && _x <= DEVNUM_MINOR_MAX; \
|
|
})
|
|
|
|
int device_path_make_major_minor(mode_t mode, dev_t devnum, char **ret);
|
|
int device_path_make_inaccessible(mode_t mode, char **ret);
|
|
int device_path_make_canonical(mode_t mode, dev_t devnum, char **ret);
|
|
int device_path_parse_major_minor(const char *path, mode_t *ret_mode, dev_t *ret_devnum);
|
|
|
|
static inline bool devnum_set_and_equal(dev_t a, dev_t b) {
|
|
/* Returns true if a and b definitely refer to the same device. If either is zero, this means "don't
|
|
* know" and we'll return false */
|
|
return a == b && a != 0;
|
|
}
|
|
|
|
/* Maximum string length for a major:minor string. (Note that DECIMAL_STR_MAX includes space for a trailing NUL) */
|
|
#define DEVNUM_STR_MAX (DECIMAL_STR_MAX(dev_t)-1+1+DECIMAL_STR_MAX(dev_t))
|
|
|
|
#define DEVNUM_FORMAT_STR "%u:%u"
|
|
#define DEVNUM_FORMAT_VAL(d) major(d), minor(d)
|
|
|
|
char *format_devnum(dev_t d, char buf[static DEVNUM_STR_MAX]);
|
|
|
|
#define FORMAT_DEVNUM(d) format_devnum((d), (char[DEVNUM_STR_MAX]) {})
|
|
|
|
static inline bool devnum_is_zero(dev_t d) {
|
|
return major(d) == 0 && minor(d) == 0;
|
|
}
|
|
|
|
#define DEVNUM_TO_PTR(u) ((void*) (uintptr_t) (u))
|
|
#define PTR_TO_DEVNUM(p) ((dev_t) ((uintptr_t) (p)))
|