From: Bjorn Steinbrink In 46d2277c796f9f4937bfa668c40b2e3f43e93dd0, try_to_free_buffers was changed to bail out if the page was dirty. That caused truncate_complete_page to leak massive amounts of memory, because the dirty bit was only cleared after the call to try_to_free_buffers. So the call to cancel_dirty_page was moved up to have the dirty bit cleared early in 3e67c0987d7567ad666641164a153dca9a43b11d. The problem with that fix is, that the page can be redirtied after cancel_dirty_page was called, eg. like this: truncate_complete_page() cancel_dirty_page() // PG_dirty cleared, decr. dirty pages do_invalidatepage() ext3_invalidatepage() journal_invalidatepage() journal_unmap_buffer() __dispose_buffer() __journal_unfile_buffer() __journal_temp_unlink_buffer() mark_buffer_dirty(); // PG_dirty set, incr. dirty pages And then we end up with dirty pages being wrongly accounted. In ecdfc9787fe527491baefc22dce8b2dbd5b2908d the changes to try_to_free_buffers were reverted, so the original reason for the massive memory leak is gone, so we can also revert the move of the call to cancel_dirty_page from truncate_complete_page and get the accounting right again. I'm not sure if it matters, but opposed to the final check in __remove_from_page_cache, this one also cares about the task io accounting, so maybe we want to use this instead, although it's not quite the clean fix either. Signed-off-by: Björn Steinbrink Tested-by: Krzysztof Piotr Oledzki Cc: Jan Kara Cc: Nick Piggin Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Thomas Osterried Signed-off-by: Andrew Morton --- mm/truncate.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff -puN mm/truncate.c~fix-dirty-page-accounting-leak-with-ext3-data=journal mm/truncate.c --- a/mm/truncate.c~fix-dirty-page-accounting-leak-with-ext3-data=journal +++ a/mm/truncate.c @@ -98,11 +98,11 @@ truncate_complete_page(struct address_sp if (page->mapping != mapping) return; - cancel_dirty_page(page, PAGE_CACHE_SIZE); - if (PagePrivate(page)) do_invalidatepage(page, 0); + cancel_dirty_page(page, PAGE_CACHE_SIZE); + remove_from_page_cache(page); ClearPageUptodate(page); ClearPageMappedToDisk(page); _