mirror of
https://github.com/ibm-s390-linux/s390-tools.git
synced 2026-08-05 02:14:52 +00:00
5d2ebe5301
Many tools need to identify the device address of a given device. So far, either the tool had its own implementation, or u2s_getbusid() was used. Though, u2s_getbusid() was mainly designed for and used by the DASD tools. Introduce util_sys with a first function util_sys_get_dev_addr() which provides a more universal way to identify the device address which is not limited to one particular device type. The device address represents either a busid (e.g. DASD), slot address (NVMe), H:C:T:L tuple (SCSI), or other id types associated with a device. Signed-off-by: Jan Höppner <hoeppner@linux.ibm.com>
78 lines
1.7 KiB
C
78 lines
1.7 KiB
C
/*
|
|
* util - Utility function library
|
|
*
|
|
* SysFS helper functions
|
|
*
|
|
* Copyright IBM Corp. 2019
|
|
*
|
|
* s390-tools is free software; you can redistribute it and/or modify
|
|
* it under the terms of the MIT license. See LICENSE for details.
|
|
*/
|
|
|
|
#include <err.h>
|
|
#include <errno.h>
|
|
#include <stdlib.h>
|
|
#include <string.h>
|
|
#include <sys/stat.h>
|
|
#include <sys/types.h>
|
|
#include <unistd.h>
|
|
|
|
#include "lib/util_path.h"
|
|
#include "lib/util_sys.h"
|
|
|
|
/* lstat() doesn't work for sysfs files, a fixed size is therefore inevitable */
|
|
#define READLINK_SIZE 256
|
|
|
|
/**
|
|
* Identify device address
|
|
*
|
|
* Identifying the device address with this function works for almost any
|
|
* character and block device (e.g. NVMe, SCSI, DASD, etc).
|
|
* The user must provide a buffer that is large enough for the desired device
|
|
* address to be read into \p addr.
|
|
*
|
|
* @param[in] dev Device node of interest
|
|
* @param[out] addr Identified device address
|
|
*
|
|
* @retval 0 Success
|
|
* @retval -1 Error while reading device information or
|
|
* constructed path
|
|
*/
|
|
int util_sys_get_dev_addr(const char *dev, char *addr)
|
|
{
|
|
char device[READLINK_SIZE], *result;
|
|
unsigned int maj, min;
|
|
struct stat s;
|
|
ssize_t len;
|
|
char *path;
|
|
|
|
if (stat(dev, &s) != 0)
|
|
return -1;
|
|
|
|
maj = major(s.st_rdev);
|
|
min = minor(s.st_rdev);
|
|
|
|
if (S_ISBLK(s.st_mode))
|
|
path = util_path_sysfs("dev/block/%u:%u/device", maj, min);
|
|
else if (S_ISCHR(s.st_mode))
|
|
path = util_path_sysfs("dev/char/%u:%u/device", maj, min);
|
|
else
|
|
return -1;
|
|
|
|
len = readlink(path, device, READLINK_SIZE - 1);
|
|
free(path);
|
|
if (len != -1)
|
|
device[len] = '\0';
|
|
else
|
|
return -1;
|
|
|
|
result = strrchr(device, '/');
|
|
if (result)
|
|
result++;
|
|
else
|
|
result = device;
|
|
strcpy(addr, result);
|
|
|
|
return 0;
|
|
}
|