Re: locking rules for ->dirty_inode()

[Nikita Danilov]

Andrew Morton writes:
 > 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.

Cannot find __free_pte, it is only mentioned in comments in mm/filemap.c
and include/asm-generic/tlb.h.

 > 
 > 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.

Nikita.