inotify的失踪事件 [英] inotify missing events

问题描述

我要监视我的系统上的USB钥匙。我知道他们总是安装在/媒体，所以我使用的inotify监视/媒体。某些USB密钥创建一个文件夹（例如SDA），插上它保持，直到他们已被拔掉，有的创建一个文件夹（例如SDA），imediately删除它并创建一个新的（例如SDA1）。这是由于在关键的分区。

I want to monitor USB-Keys on my system. I know they are always mounted in /media so I use inotify to monitor /media. Some USB Keys create a folder (e.g. sda) when plugged which stays until they are unplugged, some create a folder (e.g. sda), delete it imediately and create a new one (e.g. sda1). That's due to the partitions on the key.

然而，有时inotify的捕获仅用于创建和所述第一文件夹的删除的事件，但射门第二的创建。当我手动检查/媒体，第二个文件夹存在，但它永远不会被inotify的通知。

However, sometimes inotify catches only the events for creation and deletion of the first folder, but misses the creation of the second. When I manually check /media, the second folder exists, but it was never notified by inotify.

这种情况很少出现，当它发生，它在设备重新启动后的第一个插件总是

This happens very rarely and when it happens, it's always at the first plug of a device after reboot.

#include <sys/inotify.h>
#include <stdio.h>
#include <errno.h>
#include <stdlib.h>
#include <unistd.h>

/* size of the event structure, not counting name */
#define EVENT_SIZE  (sizeof (struct inotify_event))

/* reasonable guess as to size of 32 events */
#define BUF_LEN        (32 * (EVENT_SIZE + 16))

int main(int argc, char **argv) {
    int fd,wd,len,i;
    char buf[BUF_LEN];
    struct inotify_event *event;
    fd_set watch_set;

    fd = inotify_init();
    if (fd < 0) {
        perror("init failed");
        exit(EXIT_FAILURE);
    }

    wd = inotify_add_watch(fd,"/media",IN_ALL_EVENTS);
    if (wd < 0) {
        perror("add watch failed");
        exit(EXIT_FAILURE);
    }

    /* put the file descriptor to the watch list for select() */
    FD_ZERO(&watch_set);
    FD_SET(fd,&watch_set);

    while(1) {
        select(fd+1,&watch_set,NULL,NULL,NULL);
        len = read(fd,buf,BUF_LEN);
        i=0;
        while(i < len) {

            event = (struct inotify_event *) &buf[i];

            if ((event->mask & IN_CREATE) != 0) {
                printf ("%s created\n",event->name);
            }
            else if ((event->mask & IN_DELETE) != 0) {
                printf ("%s deleted\n",event->name);
            }
            else {
                printf ("wd=%d mask=0x%X cookie=%u len=%u name=%s\n",
                                event->wd, event->mask,
                                event->cookie, event->len, event->name);
            }

            i += EVENT_SIZE + event->len;

        }

    }

}

任何想法是怎么回事？

Any ideas what's going wrong?

推荐答案

在我发现这是inotify的已知问题的同时。如果两个事件同时出现实际上，只的inotify抓住其中之一。
我的解决方案：我不使用的inotify了，但libudev了，而不是监视插入到机器设备...

In the meanwhile I found that this is a known issue of inotify. If two events appear virtually at the same time, inotify only catches one of them. My solution: I don't use inotify anymore, but took libudev instead to monitor the devices plugged to the machine...

这篇关于inotify的失踪事件的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！