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

On Tue, Jan 20, 2015 at 10:50:41PM +0000, Al Viro wrote: > doesn't look at _anything_ other than name->name other than for audit_inode(). > And name->name is apparently the same. > > It looks like something ends up buggering name->name in process, but then > the damn thing appears to be normal after return from filename_lookup()... If my reconstruction of what's going on is correct, the call chain here is do_path_lookup() <- kern_path() <- lookup_bdev() <- blkdev_get_by_path() <- mount_bdev() <- some_type.mount() <- mount_fs() <- vfs_kern_mount() <- do_new_mount() <- do_mount() <- sys_mount() <- do_mount_root() <- mount_block_root() <- mount_root(). Which is obscenely long, BTW, but that's a separate story... Could you slap struct stat buf; int n = sys_newstat(name, &buf); printk(KERN_ERR "stat(\"%s\") -> %d\n", name, n); n = sys_newstat("/dev", &buf); printk(KERN_ERR "stat(\"dev\") -> %d\n", n); in the beginning of mount_block_root() (init/do_mounts.c) and see what it prints?