tree 73245c1da2c5352c526d4d25f02e69943b4b0b15
parent 45726cb43d11b288c58243a26010f397054222f0
author Nick Piggin <npiggin@suse.de> 1192523082 -0700
committer Linus Torvalds <torvalds@woody.linux-foundation.org> 1192552973 -0700

mm: clarify __add_to_swap_cache locking

__add_to_swap_cache unconditionally sets the page locked, which can be a bit
alarming to the unsuspecting reader: in the code paths where the page is
visible to other CPUs, the page should be (and is) already locked.

Instead, just add a check to ensure the page is locked here, and teach the one
path relying on the old behaviour to call SetPageLocked itself.

[hugh@veritas.com: locking fix]
Signed-off-by: Nick Piggin <npiggin@suse.de>
Signed-off-by: Hugh Dickins <hugh@veritas.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>