tree ffe1e90a761aa358ef95e351e0718cb3c377ad37
parent 4cbf2aa35e1c189db234190fefc6c83b139ef963
author Nick Piggin <nickpiggin@yahoo.com.au> 1170128187 +1100
committer Linus Torvalds <torvalds@woody.linux-foundation.org> 1170130842 -0800

[PATCH] Fix try_to_free_buffer() locking

Fix commit ecdfc9787fe527491baefc22dce8b2dbd5b2908d

Not to put too fine a point on it, but in a nutshell...

	__set_page_dirty_buffers() | try_to_free_buffers()
	---------------------------+---------------------------
	                           | spin_lock(private_lock);
	                           | drop_bufers()
	                           | spin_unlock(private_lock);
	spin_lock(private_lock)    |
	!page_has_buffers()        |
	spin_unlock(private_lock)  |
	SetPageDirty()             |
	                           | cancel_dirty_page()

                          oops!

Signed-off-by: Nick Piggin <npiggin@suse.de>
Acked-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>