Bug 9828

Summary:	firewire-core: "kobject_add failed for fw5 with -EEXIST"
Product:	Drivers	Reporter:	Stefan Richter (stefanr)
Component:	IEEE1394	Assignee:	Stefan Richter (stefanr)
Status:	CLOSED CODE_FIX
Severity:	low	CC:	jarod
Priority:	P1
Hardware:	All
OS:	Linux
Kernel Version:	2.6.22, 2.6.23, 2.6.24	Subsystem:
Regression:	---	Bisected commit-id:

Description Stefan Richter 2008-01-26 14:58:39 UTC

There are race conditions in the handling of drivers/firewire/fw-device.c::fw_device_idr which lead to firewire-core attempting to add new devices with same name as existing devices.  This notably happens if a device is being shut down with error conditions and a new device is being created at the same time.  See the WARNING in http://bugzilla.kernel.org/attachment.cgi?id=14580 for an example.

Both fw_device_init() and fw_device_shutdown() call idr_remove() too early.

Impact of the bug:  Happens rarely, forces the user to unplug and replug the new device to get it working.

Comment 1 Stefan Richter 2008-01-26 15:30:35 UTC

Correction: fw_device_init() looks fine, because only the code after successful device_add() matters.

Comment 2 Stefan Richter 2008-01-26 16:10:05 UTC

proposed patch: http://lkml.org/lkml/2008/1/26/228

Comment 3 Stefan Richter 2008-02-17 04:37:11 UTC

patch last updated on February 2: http://lkml.org/lkml/2008/2/2/108
committed to linux1394-2.6.git
planned to be submitted to mainline before 2.6.25

Comment 4 Stefan Richter 2008-02-28 02:24:29 UTC

fix merged by Linus