initialized.
bdrewery@ has reported panics "newnfs_copycred: negative nfsc_ngroups".
The only way I can see that this occurs is that the credentials field of
the open structure gets used before being filled in.
I am not sure quite how this happens, but for the file create case, the
code is serialized via the vnode lock on the directory. If, somehow, a
link to the same file gets created just after file creation, this might
occur.
This patch ensures that the credentials field is initialized to a reasonable
set of credentials before the structure is linked into any list, so I
this should ensure it is initialized before use.
I am committing the patch now, since bdrewery@ notes that the panics
are intermittent and it may be months before he knows if the patch fixes
his problem.
Reported by: bdrewery
MFC after: 2 weeks
73a70b4bbb