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/* SPDX-License-Identifier: LGPL-2.1-or-later */
#pragma once
#include <inttypes.h>
#include <stdbool.h>
#include <sys/types.h>
#include "stdio-util.h"
int parse_devnum(const char *s, dev_t *ret);
/* 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 < (UINT32_C(1) << 12); \
\
})
#define DEVICE_MINOR_VALID(x) \
({ \
typeof(x) _x = (x), _y = 0; \
_x >= _y && _x < (UINT32_C(1) << 20); \
})
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)
static inline char *format_devnum(dev_t d, char buf[static DEVNUM_STR_MAX]) {
return ASSERT_PTR(snprintf_ok(buf, DEVNUM_STR_MAX, DEVNUM_FORMAT_STR, DEVNUM_FORMAT_VAL(d)));
}
#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;
}
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