In message: <4688791D.6050007_at_root.org> Nate Lawson <nate_at_root.org> writes: : M. Warner Losh wrote: : > In message: <46880F1C.3020602_at_root.org> : > Nate Lawson <nate_at_root.org> writes: : > : Yes, you're exactly right. However, shouldn't a read from a device : > : trigger a re-taste if the media is removable? : > : > I don't think it does. The driver is expected to poll, however... : > : > : So the fdisk of da2 : > : should have caused it to re-read the MBR and create /dev/da2s1. I think : > : maybe there should be a flag set for devices with removable media that : > : causes the device to be re-tasted on every mount request. : > : > Is there even a removable flag to disks? : : In SCSI there is, removable flag combined with medium not present: : : da2 at umass-sim1 bus 1 target 0 lun 2 : da2: <Generic STORAGE DEVICE 0001> Removable Direct Access SCSI-0 device : ^^^^^^^^^ : da2: 40.000MB/s transfers : da2: Attempt to query device size failed: NOT READY, Medium not present I think you've misunderstood my point. I know that SCSI has this flag, but I can't find anything in GEOM that it would map to. It seems a common enough situation that having such a flag in GEOM would be beneficial and easy to implement. : What if we kicked off a thread to run every 3 seconds that did a quick : poll of such devices and sent a devd notify if they arrived (i.e. medium : present)? It wouldn't work for floppy drives, but we could make this : part of the da driver or something in usermode like devd itself calling : camcontrol? In the past, people have said that polling messes up multimedia access, so it hasn't happened. But wouldn't a simple daemon in userland do the same thing? Or parsing the output of camcontrol inquiry? Camcontrol rescan is a nop for these devices. WarnerReceived on Mon Jul 02 2007 - 02:20:41 UTC
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