The patch titled
     Fix dirty page accounting leak with ext3 data=journal
has been added to the -mm tree.  Its filename is
     fix-dirty-page-accounting-leak-with-ext3-data=journal.patch

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See http://www.zip.com.au/~akpm/linux/patches/stuff/added-to-mm.txt to find
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The current -mm tree may be found at http://userweb.kernel.org/~akpm/mmotm/

------------------------------------------------------
Subject: Fix dirty page accounting leak with ext3 data=journal
From: Bjorn Steinbrink <[EMAIL PROTECTED]>

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 <[EMAIL PROTECTED]>
Tested-by: Krzysztof Piotr Oledzki <[EMAIL PROTECTED]>
Cc: Jan Kara <[EMAIL PROTECTED]>
Cc: Nick Piggin <[EMAIL PROTECTED]>
Cc: Linus Torvalds <[EMAIL PROTECTED]>
Cc: Peter Zijlstra <[EMAIL PROTECTED]>
Cc: Thomas Osterried <[EMAIL PROTECTED]>
Signed-off-by: Andrew Morton <[EMAIL PROTECTED]>
---

 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);
_

Patches currently in -mm which might be from [EMAIL PROTECTED] are

fix-dirty-page-accounting-leak-with-ext3-data=journal.patch

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