bonding: sysfs patch broke module renaming

bonding: sysfs patch broke module renaming

[Patrick McHardy]

The sysfs patch broke using multiple instances of the bonding module
through module renaming (modprobe -o). In recent kernels it fails
with -EEXIST when trying to add the bonding_masters file for the
second time, in older kernels (where sysfs_add_file didn't check
for duplicates) it will crash when unloading the modules.

I don't see a good way to fix it, can someone please look into this?

Re: bonding: sysfs patch broke module renaming

[Jay Vosburgh]

Patrick McHardy <kaber@trash.net> wrote:

>The sysfs patch broke using multiple instances of the bonding module
>through module renaming (modprobe -o). In recent kernels it fails
>with -EEXIST when trying to add the bonding_masters file for the
>second time, in older kernels (where sysfs_add_file didn't check
>for duplicates) it will crash when unloading the modules.

	Ok, I see what the problem is; it's got to do with out device
creation was changed at some point for the sysfs stuff that broke the
multiple load logic.  I don't think it has to do with the sysfs_add_file
duplicate check business; I can see the error in how bond_create() is
called in the new (post-sysfs) stuff, although I haven't tracked it down
to a particular changeset.

	There'a also a separate error handling bug I see in
bond_create() that I don't even get to because it bails out first.

	Anyway, let me see what I can work out to fix this up.

	-J

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	-Jay Vosburgh, IBM Linux Technology Center, fubar@us.ibm.com