Commits
Hugh Dickins committed 752dc185dac
mm: fix warning in __set_page_dirty_nobuffers New tmpfs use of !PageUptodate pages for fallocate() is triggering the WARNING: at mm/page-writeback.c:1990 when __set_page_dirty_nobuffers() is called from migrate_page_copy() for compaction. It is anomalous that migration should use __set_page_dirty_nobuffers() on an address_space that does not participate in dirty and writeback accounting; and this has also been observed to insert surprising dirty tags into a tmpfs radix_tree, despite tmpfs not using tags at all. We should probably give migrate_page_copy() a better way to preserve the tag and migrate accounting info, when mapping_cap_account_dirty(). But that needs some more work: so in the interim, avoid the warning by using a simple SetPageDirty on PageSwapBacked pages. Reported-and-tested-by: Dave Jones <davej@redhat.com> Signed-off-by: Hugh Dickins <hughd@google.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>