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SubjectRe: [PATCH] firewire: fail open() quickly if the node doesn't exist anymore
Jarod Wilson wrote:
> On Sunday 27 January 2008 12:21:56 pm Stefan Richter wrote:
>> Scenario: Process A keeps the character device file of node N open.
>> N is being unplugged. File /dev/fwN won't be destroyed as long as A
>> doesn't close it. Now, process B opens /dev/fwN as well. Previously
>> it would succeed but be unable to do any IO on it of course. With this
>> patch, process B's open() will fail immediately with -ENODEV.

> Makes perfect sense to me, no problems with it in cursory testing.

Actually I have 2nd thoughts about it. Clients should have a general
way to know that a device went away. (I.e. distinguish I/O errors from
mere stale generation from I/O errors due to the node being gone for
good.) I will check tomorrow if the ABI does this distinction already.
If yes, we don't need the patch. (But might still need improvements in
libraw1394 or/and clients to fail fast when appropriate.)
--
Stefan Richter
-=====-==--- ---= ===-=
http://arcgraph.de/sr/


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