[Intel-gfx] NPE in i915_gemfs_init

[Chris Wilson]

Quoting Heiner Kallweit (2019-07-14 13:39:15)
> On 14.07.2019 14:34, Chris Wilson wrote:
> > Quoting Heiner Kallweit (2019-07-13 12:12:56)
> >> I debugged a little bit and remount_fs isn't set in sb->s_op.
> >> The following at least avoids the NPE, not sure whether it's the correct fix.
> > 
> > I take it you don't have CONFIG_TMPFS set?
> > 
> This option is set:
> 
> [root at zotac linux-next]# grep TMPFS .config
> CONFIG_DEVTMPFS=y
> CONFIG_DEVTMPFS_MOUNT=y
> CONFIG_TMPFS=y
> CONFIG_TMPFS_POSIX_ACL=y
> CONFIG_TMPFS_XATTR=y

Now that's weird, as

static const struct super_operations shmem_ops = {
        .alloc_inode    = shmem_alloc_inode,
        .free_inode     = shmem_free_in_core_inode,
        .destroy_inode  = shmem_destroy_inode,
#ifdef CONFIG_TMPFS
        .statfs         = shmem_statfs,
        .remount_fs     = shmem_remount_fs,
        .show_options   = shmem_show_options,
#endif
        .evict_inode    = shmem_evict_inode,
        .drop_inode     = generic_delete_inode,
        .put_super      = shmem_put_super,
#ifdef CONFIG_TRANSPARENT_HUGE_PAGECACHE
        .nr_cached_objects      = shmem_unused_huge_count,
        .free_cached_objects    = shmem_unused_huge_scan,
#endif
};

the only way it should be unset was if !CONFIG_TMPFS.

Hmm, we even select TMPFS so it should never be absent.

So the question is what mount did we get if it was not a shmemfs one?
-Chris