Re: [Patch] blktrace: remove debugfs entries on bad path

[Stefan Raspl]

Li Zefan wrote:
> A better title:
> 	[Patch] blktrace: remove debugfs entries on bad path
> 
> Stefan Raspl wrote:
>> debugfs directory entries for devices are not removed on bad path.
> 
> Can you be more elaborate on how to reproduce this issue?

It can happen for most bad pathes within do_blk_trace_setup(). One
way to trigger is to set the Vmalloc space via the respective kernel
parameter to a value that is so small that it will not suffice for
the 2MB per device and cpu that is required. For instance, set
vmalloc=10M and start blktrace on a system with 2 cpus on 7 devices.
Depending on how much Vmalloc space is still free, the final 2 or 3
devices will fail with a message like this:

	BLKTRACESETUP(2) /dev/sdu failed: 5/Input/output error

Best regards,
Stefan Raspl
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/