On 9/15/09, Soh Kam Yung <sohkamyung@xxxxxxxxx> wrote: > I am helping to design a small user-space daemon for an embedded > system that will mount external storage media (SD cards, USB mass > storage). > > The daemon receives udev events via a socket. It determines which > events are filesystem related (using the ID_FS_xxx keys) and executes > a mount/unmount using the event information. > > This works fine if the media is inserted/removed after the daemon runs. > > But what about media that is inserted before my daemon has a change to run? > > One solution may be to use "udevadm trigger --subsystem-match=block" > after my daemon has started. Is this recommended? > > I was wondering whether I can use the output of "udevadm info > --export-db" to scan for mountable filesystems as part of the daemon > initialisation (before it receives udev events). > > Any comments on this? Why not use libudev (with a udev_monitor to read your socket, if you're not already)? You should be able to scan the block devices using udev_enumerate_*. In any case, make sure you do the scan _after_ you open the event socket. Otherwise you could miss a block device which appears at just the wrong time. Alan -- To unsubscribe from this list: send the line "unsubscribe linux-hotplug" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
