Re: 2.4.9 mount error handling problem

[Alexander Viro <viro@math.psu.edu>]

On Sun, 26 Aug 2001, Andi Kleen wrote:

> 
> Hi,
> 
> I just tripped over a bug with 2.4.9+XFS, which I believe is a generic
> problem.  For some unrelated reason the XFS ->read_super failed. After
> that every df caused an kernel oops in super.c/get_filesystem_info. 
> 
> 			MANGLE(tmp->mnt_sb->s_type->name);
> 
> In this ->s_type was NULL. The error handling path of read_super sets
> s_type to NULL, but the super block was still in the list of some mount 
> with that zero s_type.
> I unfortunately don't have time to track the exact cause down now, but I guess
> it should be debuggable with this information.

Does xfs_read_super(), by any chance, have an exit path where it
	* sets ->s_root,
	* fails _after_ that (i.e. past the point when we had successfully
allocated root dentry) and
	* forgets to clean sb->s_root?