Re: locking rules for ->dirty_inode()

[Andrew Morton]

Nikita Danilov wrote:
> 
> Hello,
> 
> Documentation/filesystems/Locking states that all super operations may
> block, but __set_page_dirty_buffers() calls
> 
>    __mark_inode_dirty()->s_op->dirty_inode()
> 
> under mapping->private_lock spin lock.

Actually it doesn't.  We do not call down into the filesystem
for I_DIRTY_PAGES.

set_page_dirty() is already called under locks, via __free_pte (pagetable
teardown).  2.4 does this as well.

But I'll make the change anyway.  I think it removes any
ranking requirements between mapping->page_lock and 
mapping->private_lock, which is always a nice thing.