.h

#ifndef UDISKQTHREAD_H
#define UDISKQTHREAD_H
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <ctype.h>
#include <sys/un.h>
#include <sys/fcntl.h>
#include <sys/ioctl.h>
#include <sys/socket.h>
#include <sys/select.h>
#include <sys/unistd.h>
#include <sys/types.h>
#include <linux/types.h>
#include <linux/netlink.h>
#include <errno.h>
#include <QThread>
#include <QDebug>
#include <QProcess>
class UDiskQThread : public QThread
{
    Q_OBJECT
public:
    UDiskQThread(QObject *parent = 0);
    ~UDiskQThread();
    void run();
signals:
    void UDiskStatusChange(int status,QString udiskFilePath);//0:add 1:remove
private:
    int init_hotplug_sock(void);
private:
    QProcess *myProcess;
    int hotplug_sock;
    int udisk_count;
};
#endif // UDISKQTHREAD_H

.cpp

#include "UDiskQThread.h"
#define UEVENT_BUFFER_SIZE 2048
UDiskQThread::UDiskQThread(QObject * parent) :
    QThread(parent)
{
    hotplug_sock = init_hotplug_sock();
    udisk_count = 0;
}
UDiskQThread::~UDiskQThread()
{
}
int UDiskQThread::init_hotplug_sock(void)
{
    struct sockaddr_nl snl;
    const int buffersize = 16 * 1024 * 1024;
    int retval;
    memset(&snl, 0x00, sizeof(struct sockaddr_nl));
    snl.nl_family = AF_NETLINK;
    snl.nl_pid = getpid();
    snl.nl_groups = 1;
    int hotplug_sock = socket(PF_NETLINK, SOCK_DGRAM, NETLINK_KOBJECT_UEVENT);
    if (hotplug_sock == -1) {
        printf("error getting socket: %s", strerror(errno));
        return -1;
    }
    /* set receive buffersize */
    setsockopt(hotplug_sock, SOL_SOCKET, SO_RCVBUFFORCE, &buffersize, sizeof(buffersize));
    retval = bind(hotplug_sock, (struct sockaddr *) &snl, sizeof(struct sockaddr_nl));
    if (retval < 0) {
        printf("bind failed: %s", strerror(errno));
        close(hotplug_sock);
        hotplug_sock = -1;
        return -1;
    }
    return hotplug_sock;
}
void UDiskQThread::run()
{
    char buf[UEVENT_BUFFER_SIZE*2] = {0};
    QString msg;
    //fcntl(hotplug_sock, F_SETFL, fcntl(hotplug_sock, F_GETFL, 0) | O_NONBLOCK);
    fcntl(hotplug_sock, F_SETFL, fcntl(hotplug_sock, F_GETFL, 0));
    while(1)
    {
        int len = read(hotplug_sock,buf,UEVENT_BUFFER_SIZE*2);
        if(len < 0)
            continue;
// int len = recv(hotplug_sock,buf,UEVENT_BUFFER_SIZE*2,0);
        msg = QString::fromLocal8Bit(buf,len);
        if(msg.startsWith("add"))
        {
            if(msg.contains("/block/sd") && (msg.mid(msg.indexOf("/block/sd")+10, 3) == "/sd"))
            {
// QProcess::execute("chmod -R 777 /mnt");
                QProcess::execute("chmod 777 /mnt");
                QString filepath = QString("mkdir -p -m 777 /mnt/%1").arg(msg.mid(msg.indexOf("/block/sd")+11, 4));
                qDebug()<<__PRETTY_FUNCTION__<<__LINE__<<filepath;
                QProcess::execute(filepath);
                QString shell_method = QString("mount -o iocharset=utf8 -t vfat /dev/%1 /mnt/%2").arg(msg.mid(msg.indexOf("/block/sd")+11, 4)).arg(msg.mid(msg.indexOf("/block/sd")+11, 4));
                qDebug()<<__PRETTY_FUNCTION__<<__LINE__<<shell_method;
                QProcess::execute(shell_method);
                udisk_count++;
                emit UDiskStatusChange(0,QString("/mnt/%1").arg(msg.mid(msg.indexOf("/block/sd")+11, 4)));

                continue;
            }
        }
        else if(msg.startsWith("remove"))
        {
            if(msg.contains("/block/sd") && msg.mid(msg.indexOf("/block/sd")+10, 3) == "/sd")
            {
                qDebug()<<__PRETTY_FUNCTION__<<__LINE__<<"signal removeUDisk send";
                QString shell_method = QString("umount /mnt/%1").arg(msg.mid(msg.indexOf("/block/sd")+11, 4));
                qDebug()<<__PRETTY_FUNCTION__<<__LINE__<<shell_method;
                QProcess::execute(shell_method);
// QString filepath = QString("rm -rf /mnt/%1").arg(msg.mid(msg.indexOf("/block/sd")+11, 4));
// qDebug()<<__PRETTY_FUNCTION__<<__LINE__<<filepath;
// QProcess::execute(filepath);
                emit UDiskStatusChange(1,QString("/mnt/%1").arg(msg.mid(msg.indexOf("/block/sd")+11, 4)));
            }
        }
    }
}