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.
Signed-off-by: Björn Steinbrink <[email protected]>
Tested-by: Krzysztof Piotr Oledzki <[email protected]>
---
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.
diff --git a/mm/truncate.c b/mm/truncate.c
index cadc156..2974903 100644
--- a/mm/truncate.c
+++ b/mm/truncate.c
@@ -98,11 +98,11 @@ truncate_complete_page(struct address_space *mapping, struct page *page)
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);
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to [email protected]
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
[Index of Archives]
[Kernel Newbies]
[Netfilter]
[Bugtraq]
[Photo]
[Stuff]
[Gimp]
[Yosemite News]
[MIPS Linux]
[ARM Linux]
[Linux Security]
[Linux RAID]
[Video 4 Linux]
[Linux for the blind]
[Linux Resources]