udev规则执行2次

Question

我写了一个这样的 udev 规则：

SUBSYSTEM=="usb", ACTION=="add", RUN+="//root/usbmon/usb add %b"
SUBSYSTEM=="usb", ACTION=="remove", RUN+="//root/usbmon/usb remove %b"

现在，每当连接和移除 USB 时，此 USB 脚本都会发送电子邮件。

但问题是每次它发送两封电子邮件。这意味着规则执行了 2 次。这就是我在日志中得到的内容

Apr 26 14:52:00 box2 sendEmail[3374]: Email was sent successfully!
USB Added: Email sent to box2@dmz.domain.com Using Udev Rule at 04-26-14-52-00. 
Apr 26 14:52:00 box2 sendEmail[3394]: Email was sent successfully!
USB Added: Email sent to box2@dmz.domain.com Using Udev Rule at 04-26-14-52-00. 

我不知道为什么它执行了两次以及如何阻止它工作一次？我已经验证问题是在 udev 端，但不知道如何修复它。这是连接 USB 时 udev 监视器的输出：

KERNEL[1335803018.283341] add      /devices/pci0000:00/0000:00:1a.7/usb1/1-4 (usb)
KERNEL[1335803018.284456] add      /devices/pci0000:00/0000:00:1a.7/usb1/1-4/1-4:1.0 (usb)
KERNEL[1335803018.284835] add      /devices/pci0000:00/0000:00:1a.7/usb1/1-4/1-4:1.0/host6 (scsi)
KERNEL[1335803018.284863] add      /devices/pci0000:00/0000:00:1a.7/usb1/1-4/1-4:1.0/host6/scsi_host/host6 (scsi_host)
KERNEL[1335803023.524167] add      /devices/pci0000:00/0000:00:1a.7/usb1/1-4/1-4:1.0/host6/target6:0:0 (scsi)
KERNEL[1335803023.524735] add      /devices/pci0000:00/0000:00:1a.7/usb1/1-4/1-4:1.0/host6/target6:0:0/6:0:0:0 (scsi)
KERNEL[1335803023.525043] add      /devices/pci0000:00/0000:00:1a.7/usb1/1-4/1-4:1.0/host6/target6:0:0/6:0:0:0/scsi_disk/6:0:0:0 (scsi_disk)
KERNEL[1335803023.525154] add      /devices/pci0000:00/0000:00:1a.7/usb1/1-4/1-4:1.0/host6/target6:0:0/6:0:0:0/scsi_device/6:0:0:0 (scsi_device)
KERNEL[1335803023.525505] add      /devices/pci0000:00/0000:00:1a.7/usb1/1-4/1-4:1.0/host6/target6:0:0/6:0:0:0/scsi_generic/sg6 (scsi_generic)
KERNEL[1335803023.525792] add      /devices/pci0000:00/0000:00:1a.7/usb1/1-4/1-4:1.0/host6/target6:0:0/6:0:0:0/bsg/6:0:0:0 (bsg)
KERNEL[1335803023.526534] add      /devices/virtual/bdi/8:80 (bdi)
UDEV  [1335803023.526895] add      /devices/virtual/bdi/8:80 (bdi)
KERNEL[1335803023.543043] add      /devices/pci0000:00/0000:00:1a.7/usb1/1-4/1-4:1.0/host6/target6:0:0/6:0:0:0/block/sdf (block)
KERNEL[1335803023.543166] add      /devices/pci0000:00/0000:00:1a.7/usb1/1-4/1-4:1.0/host6/target6:0:0/6:0:0:0/block/sdf/sdf1 (block)
UDEV  [1335803028.541785] add      /devices/pci0000:00/0000:00:1a.7/usb1/1-4 (usb)
UDEV  [1335803038.850181] add      /devices/pci0000:00/0000:00:1a.7/usb1/1-4/1-4:1.0 (usb)
UDEV  [1335803038.850423] add      /devices/pci0000:00/0000:00:1a.7/usb1/1-4/1-4:1.0/host6 (scsi)
UDEV  [1335803038.850541] add      /devices/pci0000:00/0000:00:1a.7/usb1/1-4/1-4:1.0/host6/target6:0:0 (scsi)
UDEV  [1335803038.850568] add      /devices/pci0000:00/0000:00:1a.7/usb1/1-4/1-4:1.0/host6/scsi_host/host6 (scsi_host)
UDEV  [1335803038.851736] add      /devices/pci0000:00/0000:00:1a.7/usb1/1-4/1-4:1.0/host6/target6:0:0/6:0:0:0 (scsi)
UDEV  [1335803038.851912] add      /devices/pci0000:00/0000:00:1a.7/usb1/1-4/1-4:1.0/host6/target6:0:0/6:0:0:0/scsi_disk/6:0:0:0 (scsi_disk)
UDEV  [1335803038.861401] add      /devices/pci0000:00/0000:00:1a.7/usb1/1-4/1-4:1.0/host6/target6:0:0/6:0:0:0/scsi_device/6:0:0:0 (scsi_device)
UDEV  [1335803038.862757] add      /devices/pci0000:00/0000:00:1a.7/usb1/1-4/1-4:1.0/host6/target6:0:0/6:0:0:0/bsg/6:0:0:0 (bsg)
UDEV  [1335803038.863880] add      /devices/pci0000:00/0000:00:1a.7/usb1/1-4/1-4:1.0/host6/target6:0:0/6:0:0:0/scsi_generic/sg6 (scsi_generic)
UDEV  [1335803039.002743] add      /devices/pci0000:00/0000:00:1a.7/usb1/1-4/1-4:1.0/host6/target6:0:0/6:0:0:0/block/sdf (block)
UDEV  [1335803039.072845] add      /devices/pci0000:00/0000:00:1a.7/usb1/1-4/1-4:1.0/host6/target6:0:0/6:0:0:0/block/sdf/sdf1 (block)

现在上面的输出清楚地表明 udev 在 10 秒后再次连接设备，这就是我再次收到电子邮件的时间（10 秒后）。另外，当脚本不可执行时，我会在日志文件中收到以下消息两次：

Apr 30 10:22:37 box2 udevd-work[1990]: exec of program '/root/usbmon/usb' failed
Apr 30 10:22:37 box2 udevd-work[1991]: exec of program '/root/usbmon/usb' failed

现在我想知道我需要更改这些设置以使 udev 运行一次。我已经在两台服务器上验证了同样的事情。CentOS 和 ubuntu。

Answer 1

ENV{DEVTYPE}=="usb_device"通过添加规则解决了该问题。