mm/bounce.c: fix a regression where MS_SNAP_STABLE (stable pages snapshotting) was...

commit 83b2944fd2532b92db099cb3ada12df32a05b368 upstream.

The "force" parameter in __blk_queue_bounce was being ignored, which
means that stable page snapshots are not always happening (on ext3).
This of course leads to DIF disks reporting checksum errors, so fix this
regression.

The regression was introduced in commit 6bc454d15004 ("bounce: Refactor
__blk_queue_bounce to not use bi_io_vec")

Reported-by: Mel Gorman <mgorman@suse.de>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Cc: Kent Overstreet <koverstreet@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/mm/bounce.c b/mm/bounce.c
index c9f0a4339a7dafc2ba7295e49ad8fcdda8fa13de..5a7d58fb883bfa1c4917e48d251cd132c8d9baf9 100644 (file)
--- a/mm/bounce.c
+++ b/mm/bounce.c
@@ -204,6 +204,8 @@ static void __blk_queue_bounce(struct request_queue *q, struct bio **bio_orig,
        struct bio_vec *to, *from;
        unsigned i;
 
+       if (force)
+               goto bounce;
        bio_for_each_segment(from, *bio_orig, i)
                if (page_to_pfn(from->bv_page) > queue_bounce_pfn(q))
                        goto bounce;