Merge branch 'linux-linaro-lsk-v3.18' into linux-linaro-lsk-v3.18-rt

Conflicts:
	fs/dcache.c

2 files changed, 13 insertions, 3 deletions

diff --git a/block/bio.c b/block/bio.c
index 3e6e1986a5b2..78803e99c154 100644
--- a/block/bio.c
+++ b/block/bio.c
@@ -1824,8 +1824,9 @@ 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)
@@ -1835,7 +1836,15 @@ 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;
 
diff --git a/block/genhd.c b/block/genhd.c
index c2fb3f7bdec4..40a06b934b1f 100644
--- a/block/genhd.c
+++ b/block/genhd.c
@@ -829,6 +829,7 @@ static void disk_seqf_stop(struct seq_file *seqf, void *v)
 	if (iter) {
 		class_dev_iter_exit(iter);
 		kfree(iter);
+		seqf->private = NULL;
 	}
 }