[people/pmueller/ipfire-2.x.git] / src / patches / 60044_xen-blktap-write-barriers.patch1

From: kwolf@suse.de
Subject: blktap: Write Barriers
Patch-mainline: obsolete

Index: head-2008-11-10/drivers/xen/blktap/blktap.c
===================================================================
--- head-2008-11-10.orig/drivers/xen/blktap/blktap.c	2008-11-10 12:10:23.000000000 +0100
+++ head-2008-11-10/drivers/xen/blktap/blktap.c	2008-11-10 12:14:32.000000000 +0100
@@ -1324,6 +1324,9 @@ static int do_block_io_op(blkif_t *blkif
 			dispatch_rw_block_io(blkif, &req, pending_req);
 			break;
 
+		case BLKIF_OP_WRITE_BARRIER:
+			/* TODO Some counter? */
+			/* Fall through */
 		case BLKIF_OP_WRITE:
 			blkif->st_wr_req++;
 			dispatch_rw_block_io(blkif, &req, pending_req);
@@ -1355,7 +1358,7 @@ static void dispatch_rw_block_io(blkif_t
 				 pending_req_t *pending_req)
 {
 	extern void ll_rw_block(int rw, int nr, struct buffer_head * bhs[]);
-	int op, operation = (req->operation == BLKIF_OP_WRITE) ? WRITE : READ;
+	int op, operation;
 	struct gnttab_map_grant_ref map[BLKIF_MAX_SEGMENTS_PER_REQUEST*2];
 	unsigned int nseg;
 	int ret, i, nr_sects = 0;
@@ -1366,6 +1369,21 @@ static void dispatch_rw_block_io(blkif_t
 	uint16_t mmap_idx = pending_req->mem_idx;
 	struct mm_struct *mm;
 
+	switch (req->operation) {
+	case BLKIF_OP_READ:
+		operation = READ;
+		break;
+	case BLKIF_OP_WRITE:
+		operation = WRITE;
+		break;
+	case BLKIF_OP_WRITE_BARRIER:
+		operation = WRITE_BARRIER;
+		break;
+	default:
+		operation = 0; /* make gcc happy */
+		BUG();
+	}
+
 	if (blkif->dev_num < 0 || blkif->dev_num > MAX_TAP_DEV)
 		goto fail_response;
 
@@ -1404,7 +1422,7 @@ static void dispatch_rw_block_io(blkif_t
 
 	pending_req->blkif     = blkif;
 	pending_req->id        = req->id;
-	pending_req->operation = operation;
+	pending_req->operation = req->operation;
 	pending_req->status    = BLKIF_RSP_OKAY;
 	pending_req->nr_pages  = nseg;
 	op = 0;
@@ -1421,7 +1439,7 @@ static void dispatch_rw_block_io(blkif_t
 		kvaddr = idx_to_kaddr(mmap_idx, pending_idx, i);
 
 		flags = GNTMAP_host_map;
-		if (operation == WRITE)
+		if (operation != READ)
 			flags |= GNTMAP_readonly;
 		gnttab_set_map_op(&map[op], kvaddr, flags,
 				  req->seg[i].gref, blkif->domid);
@@ -1438,7 +1456,7 @@ static void dispatch_rw_block_io(blkif_t
 
 			flags = GNTMAP_host_map | GNTMAP_application_map
 				| GNTMAP_contains_pte;
-			if (operation == WRITE)
+			if (operation != READ)
 				flags |= GNTMAP_readonly;
 			gnttab_set_map_op(&map[op], ptep, flags,
 					  req->seg[i].gref, blkif->domid);
Index: head-2008-11-10/drivers/xen/blktap/xenbus.c
===================================================================
--- head-2008-11-10.orig/drivers/xen/blktap/xenbus.c	2008-11-10 12:14:29.000000000 +0100
+++ head-2008-11-10/drivers/xen/blktap/xenbus.c	2008-11-10 12:14:32.000000000 +0100
@@ -395,7 +395,28 @@ static void connect(struct backend_info 
 	int err;
 
 	struct xenbus_device *dev = be->dev;
+	struct xenbus_transaction xbt;
 
+	/* Write feature-barrier to xenstore */
+again:
+	err = xenbus_transaction_start(&xbt);
+	if (err) {
+		xenbus_dev_fatal(dev, err, "starting transaction");
+		return;
+	}
+
+	err = xenbus_printf(xbt, dev->nodename, "feature-barrier",  "1");
+	if (err) {
+		xenbus_dev_fatal(dev, err, "writing feature-barrier");
+		xenbus_transaction_end(xbt, 1);
+		return;
+	}
+
+	err = xenbus_transaction_end(xbt, 0);
+	if (err == -EAGAIN)
+		goto again;
+
+	/* Switch state */
 	err = xenbus_switch_state(dev, XenbusStateConnected);
 	if (err)
 		xenbus_dev_fatal(dev, err, "switching to Connected state",
Commit	Line	Data
cc90b958 BS	1	From: kwolf@suse.de
	2	Subject: blktap: Write Barriers
	3	Patch-mainline: obsolete
	4
	5	Index: head-2008-11-10/drivers/xen/blktap/blktap.c
	6	===================================================================
	7	--- head-2008-11-10.orig/drivers/xen/blktap/blktap.c 2008-11-10 12:10:23.000000000 +0100
	8	+++ head-2008-11-10/drivers/xen/blktap/blktap.c 2008-11-10 12:14:32.000000000 +0100
	9	@@ -1324,6 +1324,9 @@ static int do_block_io_op(blkif_t *blkif
	10	dispatch_rw_block_io(blkif, &req, pending_req);
	11	break;
	12
	13	+ case BLKIF_OP_WRITE_BARRIER:
	14	+ /* TODO Some counter? */
	15	+ /* Fall through */
	16	case BLKIF_OP_WRITE:
	17	blkif->st_wr_req++;
	18	dispatch_rw_block_io(blkif, &req, pending_req);
	19	@@ -1355,7 +1358,7 @@ static void dispatch_rw_block_io(blkif_t
	20	pending_req_t *pending_req)
	21	{
	22	extern void ll_rw_block(int rw, int nr, struct buffer_head * bhs[]);
	23	- int op, operation = (req->operation == BLKIF_OP_WRITE) ? WRITE : READ;
	24	+ int op, operation;
	25	struct gnttab_map_grant_ref map[BLKIF_MAX_SEGMENTS_PER_REQUEST*2];
	26	unsigned int nseg;
	27	int ret, i, nr_sects = 0;
	28	@@ -1366,6 +1369,21 @@ static void dispatch_rw_block_io(blkif_t
	29	uint16_t mmap_idx = pending_req->mem_idx;
	30	struct mm_struct *mm;
	31
	32	+ switch (req->operation) {
	33	+ case BLKIF_OP_READ:
	34	+ operation = READ;
	35	+ break;
	36	+ case BLKIF_OP_WRITE:
	37	+ operation = WRITE;
	38	+ break;
	39	+ case BLKIF_OP_WRITE_BARRIER:
	40	+ operation = WRITE_BARRIER;
	41	+ break;
	42	+ default:
	43	+ operation = 0; /* make gcc happy */
	44	+ BUG();
	45	+ }
	46	+
	47	if (blkif->dev_num < 0 \|\| blkif->dev_num > MAX_TAP_DEV)
	48	goto fail_response;
	49
	50	@@ -1404,7 +1422,7 @@ static void dispatch_rw_block_io(blkif_t
	51
	52	pending_req->blkif = blkif;
	53	pending_req->id = req->id;
	54	- pending_req->operation = operation;
	55	+ pending_req->operation = req->operation;
	56	pending_req->status = BLKIF_RSP_OKAY;
	57	pending_req->nr_pages = nseg;
	58	op = 0;
	59	@@ -1421,7 +1439,7 @@ static void dispatch_rw_block_io(blkif_t
	60	kvaddr = idx_to_kaddr(mmap_idx, pending_idx, i);
	61
	62	flags = GNTMAP_host_map;
	63	- if (operation == WRITE)
	64	+ if (operation != READ)
65	flags \|= GNTMAP_readonly;
66	gnttab_set_map_op(&map[op], kvaddr, flags,
67	req->seg[i].gref, blkif->domid);
68	@@ -1438,7 +1456,7 @@ static void dispatch_rw_block_io(blkif_t
69
70	flags = GNTMAP_host_map \| GNTMAP_application_map
71	\| GNTMAP_contains_pte;
72	- if (operation == WRITE)
73	+ if (operation != READ)
74	flags \|= GNTMAP_readonly;
75	gnttab_set_map_op(&map[op], ptep, flags,
76	req->seg[i].gref, blkif->domid);
77	Index: head-2008-11-10/drivers/xen/blktap/xenbus.c
78	===================================================================
79	--- head-2008-11-10.orig/drivers/xen/blktap/xenbus.c 2008-11-10 12:14:29.000000000 +0100
80	+++ head-2008-11-10/drivers/xen/blktap/xenbus.c 2008-11-10 12:14:32.000000000 +0100
81	@@ -395,7 +395,28 @@ static void connect(struct backend_info
82	int err;
83
84	struct xenbus_device *dev = be->dev;
85	+ struct xenbus_transaction xbt;
86
87	+ /* Write feature-barrier to xenstore */
88	+again:
89	+ err = xenbus_transaction_start(&xbt);
90	+ if (err) {
91	+ xenbus_dev_fatal(dev, err, "starting transaction");
92	+ return;
93	+ }
94	+
95	+ err = xenbus_printf(xbt, dev->nodename, "feature-barrier", "1");
96	+ if (err) {
97	+ xenbus_dev_fatal(dev, err, "writing feature-barrier");
98	+ xenbus_transaction_end(xbt, 1);
99	+ return;
100	+ }
101	+
102	+ err = xenbus_transaction_end(xbt, 0);
103	+ if (err == -EAGAIN)
104	+ goto again;
105	+
106	+ /* Switch state */
107	err = xenbus_switch_state(dev, XenbusStateConnected);
108	if (err)
109	xenbus_dev_fatal(dev, err, "switching to Connected state",