Re: linux-next: Tree for Jan 20 -- Kernel panic - Unable to mount root fs

On Wed, Jan 21, 2015 at 12:05:39PM +0100, Sabrina Dubroca wrote: That would indicate that somehow the refcount got unbalanced. Looking more closely it seems like the various audit_*() function do take a reference, but maybe that's not enough. But debugging this further I see no indication that the memory is ever freed, or otherwise corrupted. I did collect a bit more data, perhaps that's useful. I started seeing this issue as well on devices that boot over NFS. After reading this thread I also realized that another warning that I was seeing might be related: [ 28.261930] Warning: unable to open an initial console. I've added a couple of printks and see that the reason for this is that /dev/console doesn't get created. /dev however does get created. [ 11.786627] sys_mkdir dev:40755 returned 0 ... [ 11.978748] sys_mknod dev/console:20600 returned -2 The chain that fails turns out to be this: sys_mknod() sys_mknodat() user_path_create() kern_path_create() do_path_lookup() filename_lookup() path_lookupat() path_init() link_path_walk() walk_component() walk_components() ends up calling lookup_slow() and the result is that inode == NULL and d_is_negative(path->dentry) returns true, therefore causing -ENOENT to be returned. I tried to figure out why inode would be NULL at that point or why d_is_negative() returned true, but I ended up getting completely lost, so I thought it best to report my findings before I confuse everything. Is there anything else I can investigate to track this down? Thierry