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
*** Remember to use Documentation/SubmitChecklist when testing your code ***
See http://www.zip.com.au/~akpm/linux/patches/stuff/added-to-mm.txt to find
out what to do about this
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 <B.Steinbrink@xxxxxx>
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 <B.Steinbrink@xxxxxx>
Tested-by: Krzysztof Piotr Oledzki <ole@xxxxxx>
Cc: Jan Kara <jack@xxxxxx>
Cc: Nick Piggin <nickpiggin@xxxxxxxxxxxx>
Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Cc: Peter Zijlstra <a.p.zijlstra@xxxxxxxxx>
Cc: Thomas Osterried <osterried@xxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
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 B.Steinbrink@xxxxxx are
fix-dirty-page-accounting-leak-with-ext3-data=journal.patch
-
To unsubscribe from this list: send the line "unsubscribe mm-commits" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
