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-rw-r--r--block/bsg.c9
-rw-r--r--include/linux/bsg.h8
2 files changed, 15 insertions, 2 deletions
diff --git a/block/bsg.c b/block/bsg.c
index 0ce8806dd0c1..0f63b91d0af6 100644
--- a/block/bsg.c
+++ b/block/bsg.c
@@ -353,6 +353,8 @@ static void bsg_rq_end_io(struct request *rq, int uptodate)
static void bsg_add_command(struct bsg_device *bd, struct request_queue *q,
struct bsg_command *bc, struct request *rq)
{
+ int at_head = (0 == (bc->hdr.flags & BSG_FLAG_Q_AT_TAIL));
+
/*
* add bc command to busy queue and submit rq for io
*/
@@ -368,7 +370,7 @@ static void bsg_add_command(struct bsg_device *bd, struct request_queue *q,
dprintk("%s: queueing rq %p, bc %p\n", bd->name, rq, bc);
rq->end_io_data = bc;
- blk_execute_rq_nowait(q, NULL, rq, 1, bsg_rq_end_io);
+ blk_execute_rq_nowait(q, NULL, rq, at_head, bsg_rq_end_io);
}
static struct bsg_command *bsg_next_done_cmd(struct bsg_device *bd)
@@ -924,6 +926,7 @@ static long bsg_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
struct request *rq;
struct bio *bio, *bidi_bio = NULL;
struct sg_io_v4 hdr;
+ int at_head;
u8 sense[SCSI_SENSE_BUFFERSIZE];
if (copy_from_user(&hdr, uarg, sizeof(hdr)))
@@ -936,7 +939,9 @@ static long bsg_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
bio = rq->bio;
if (rq->next_rq)
bidi_bio = rq->next_rq->bio;
- blk_execute_rq(bd->queue, NULL, rq, 0);
+
+ at_head = (0 == (hdr.flags & BSG_FLAG_Q_AT_TAIL));
+ blk_execute_rq(bd->queue, NULL, rq, at_head);
ret = blk_complete_sgv4_hdr_rq(rq, &hdr, bio, bidi_bio);
if (copy_to_user(uarg, &hdr, sizeof(hdr)))
diff --git a/include/linux/bsg.h b/include/linux/bsg.h
index cf0303a60611..3f0c64ace424 100644
--- a/include/linux/bsg.h
+++ b/include/linux/bsg.h
@@ -7,6 +7,14 @@
#define BSG_SUB_PROTOCOL_SCSI_TMF 1
#define BSG_SUB_PROTOCOL_SCSI_TRANSPORT 2
+/*
+ * For flags member below
+ * sg.h sg_io_hdr also has bits defined for it's flags member. However
+ * none of these bits are implemented/used by bsg. The bits below are
+ * allocated to not conflict with sg.h ones anyway.
+ */
+#define BSG_FLAG_Q_AT_TAIL 0x10 /* default, == 0 at this bit, is Q_AT_HEAD */
+
struct sg_io_v4 {
__s32 guard; /* [i] 'Q' to differentiate from v3 */
__u32 protocol; /* [i] 0 -> SCSI , .... */