Messages in this thread | | | From | Andrey Borzenkov <> | Subject | removable media revalidation - udev vs. devfs or static /dev | Date | Thu, 1 Jan 2004 23:33:04 +0300 |
| |
udev names are created when kernel detects corr. device. Unfortunately for removable media kernel rescans for partitions only when I try to access device. Meaning - because kernel does not know partition table it did not send hotplug event so udev did not create device nodes. But without device nodes I have no way to access device in Unix :(
specifically I have now my Jaz and I have no (reasonable) way to access partition 4 assuming device nodes are managed by udev.
devfs solved this problem by
- always exporting at least handle to the whole disk (sda as example) - using something simple like dd if=/dev/sda count=1 on lookup for non-existing partition (/dev/sda4) that would rescan partitions and create device nodes for them.
static /dev simply has all nodes available and does not suffer from this problem at all.
unfortunately there are no lookup events in case if udev ... meaning at this moment user must manually rescan partitions after inserting new media. I do not see any way to solve this problem at all given current implementation. The closest is to blindly create nodes for all partitions as soon as block device is available.
-andrey
- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
| |