SG: audit of drivers that use blk_rq_map_sg()
They need to properly init the sg table, or blk_rq_map_sg() will
complain if CONFIG_DEBUG_SG is set.
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
diff --git a/drivers/block/virtio_blk.c b/drivers/block/virtio_blk.c
index a901eee..3cf7129 100644
--- a/drivers/block/virtio_blk.c
+++ b/drivers/block/virtio_blk.c
@@ -4,7 +4,9 @@
#include <linux/hdreg.h>
#include <linux/virtio.h>
#include <linux/virtio_blk.h>
-#include <linux/virtio_blk.h>
+#include <linux/scatterlist.h>
+
+#define VIRTIO_MAX_SG (3+MAX_PHYS_SEGMENTS)
static unsigned char virtblk_index = 'a';
struct virtio_blk
@@ -23,7 +25,7 @@
mempool_t *pool;
/* Scatterlist: can be too big for stack. */
- struct scatterlist sg[3+MAX_PHYS_SEGMENTS];
+ struct scatterlist sg[VIRTIO_MAX_SG];
};
struct virtblk_req
@@ -94,8 +96,8 @@
if (blk_barrier_rq(vbr->req))
vbr->out_hdr.type |= VIRTIO_BLK_T_BARRIER;
- /* We have to zero this, otherwise blk_rq_map_sg gets upset. */
- memset(vblk->sg, 0, sizeof(vblk->sg));
+ /* This init could be done at vblk creation time */
+ sg_init_table(vblk->sg, VIRTIO_MAX_SG);
sg_set_buf(&vblk->sg[0], &vbr->out_hdr, sizeof(vbr->out_hdr));
num = blk_rq_map_sg(q, vbr->req, vblk->sg+1);
sg_set_buf(&vblk->sg[num+1], &vbr->in_hdr, sizeof(vbr->in_hdr));