swap: redirty page if page write fails on swap file

Since commit 62c230bc17 ("mm: add support for a filesystem to activate
swap files and use direct_IO for writing swap pages"), swap_writepage()
calls direct_IO on swap files.  However, in that case the page isn't
redirtied if I/O fails, and is therefore handled afterwards as if it has
been successfully written to the swap file, leading to memory corruption
when the page is eventually swapped back in.

This patch sets the page dirty when direct_IO() fails.  It fixes a
memory corruption that happened while using swap-over-NFS.

Signed-off-by: Jerome Marchand <jmarchan@redhat.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Mel Gorman <mgorman@suse.de>
Cc: Hugh Dickins <hughd@google.com>
Cc: <stable@vger.kernel.org>	[3.6+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Jerome Marchand 2013-04-29 15:08:47 -07:00 committed by Linus Torvalds
parent 465adcf1ea
commit 2d30d31ea3

View File

@ -231,6 +231,8 @@ int __swap_writepage(struct page *page, struct writeback_control *wbc,
if (ret == PAGE_SIZE) {
count_vm_event(PSWPOUT);
ret = 0;
} else {
set_page_dirty(page);
}
return ret;
}