Kernel bump from 4.1.3-rt to 4.1.7-rt.

These changes brings a vanilla kernel from kernel.org, and the patch
applied for rt is patch-4.1.7-rt8.patch. No further changes needed.

Change-Id: Id8dd03c2ddd971e4d1d69b905f3069737053b700
Signed-off-by: José Pekkarinen <jose.pekkarinen@nokia.com>

1 files changed, 12 insertions, 3 deletions

diff --git a/kernel/block/bio.c b/kernel/block/bio.c
index f66a4eae1..4441522ca 100644
--- a/kernel/block/bio.c
+++ b/kernel/block/bio.c
@@ -1814,8 +1814,9 @@ EXPORT_SYMBOL(bio_endio_nodec);
  * Allocates and returns a new bio which represents @sectors from the start of
  * @bio, and updates @bio to represent the remaining sectors.
  *
- * The newly allocated bio will point to @bio's bi_io_vec; it is the caller's
- * responsibility to ensure that @bio is not freed before the split.
+ * Unless this is a discard request the newly allocated bio will point
+ * to @bio's bi_io_vec; it is the caller's responsibility to ensure that
+ * @bio is not freed before the split.
  */
 struct bio *bio_split(struct bio *bio, int sectors,
 		      gfp_t gfp, struct bio_set *bs)
@@ -1825,7 +1826,15 @@ struct bio *bio_split(struct bio *bio, int sectors,
 	BUG_ON(sectors <= 0);
 	BUG_ON(sectors >= bio_sectors(bio));
 
-	split = bio_clone_fast(bio, gfp, bs);
+	/*
+	 * Discards need a mutable bio_vec to accommodate the payload
+	 * required by the DSM TRIM and UNMAP commands.
+	 */
+	if (bio->bi_rw & REQ_DISCARD)
+		split = bio_clone_bioset(bio, gfp, bs);
+	else
+		split = bio_clone_fast(bio, gfp, bs);
+
 	if (!split)
 		return NULL;