forked from ~ljy/RK356X_SDK_RELEASE
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hc
2023-12-11 072de836f53be56a70cecf70b43ae43b7ce17376 
 kernel/drivers/block/xen-blkfront.c
....@@ -151,11 +151,12 @@
151151 module_param_named(max_ring_page_order, xen_blkif_max_ring_order, int, 0444);
152152 MODULE_PARM_DESC(max_ring_page_order, "Maximum order of pages to be used for the shared ring");
153153 
154
+static bool __read_mostly xen_blkif_trusted = true;
155
+module_param_named(trusted, xen_blkif_trusted, bool, 0644);
156
+MODULE_PARM_DESC(trusted, "Is the backend trusted");
157
+
154158 #define BLK_RING_SIZE(info)	\
155159 	__CONST_RING_SIZE(blkif, XEN_PAGE_SIZE * (info)->nr_ring_pages)
156
-
157
-#define BLK_MAX_RING_SIZE	\
158
-	__CONST_RING_SIZE(blkif, XEN_PAGE_SIZE * XENBUS_MAX_RING_GRANTS)
159160 
160161 /*
161162  * ring-ref%u i=(-1UL) would take 11 characters + 'ring-ref' is 8, so 19
....@@ -180,12 +181,12 @@
180181 	unsigned int evtchn, irq;
181182 	struct work_struct work;
182183 	struct gnttab_free_callback callback;
183
-	struct blk_shadow shadow[BLK_MAX_RING_SIZE];
184184 	struct list_head indirect_pages;
185185 	struct list_head grants;
186186 	unsigned int persistent_gnts_c;
187187 	unsigned long shadow_free;
188188 	struct blkfront_info *dev_info;
189
+	struct blk_shadow shadow[];
189190 };
190191 
191192 /*
....@@ -210,7 +211,11 @@
210211 	unsigned int feature_fua:1;
211212 	unsigned int feature_discard:1;
212213 	unsigned int feature_secdiscard:1;
214
+	/* Connect-time cached feature_persistent parameter */
215
+	unsigned int feature_persistent_parm:1;
216
+	/* Persistent grants feature negotiation result */
213217 	unsigned int feature_persistent:1;
218
+	unsigned int bounce:1;
214219 	unsigned int discard_granularity;
215220 	unsigned int discard_alignment;
216221 	/* Number of 4KB segments handled */
....@@ -219,6 +224,7 @@
219224 	struct blk_mq_tag_set tag_set;
220225 	struct blkfront_ring_info *rinfo;
221226 	unsigned int nr_rings;
227
+	unsigned int rinfo_size;
222228 	/* Save uncomplete reqs and bios for migration. */
223229 	struct list_head requests;
224230 	struct bio_list bio_list;
....@@ -265,6 +271,18 @@
265271 static void blkfront_gather_backend_features(struct blkfront_info *info);
266272 static int negotiate_mq(struct blkfront_info *info);
267273 
274
+#define for_each_rinfo(info, ptr, idx)				\
275
+	for ((ptr) = (info)->rinfo, (idx) = 0;			\
276
+	     (idx) < (info)->nr_rings;				\
277
+	     (idx)++, (ptr) = (void *)(ptr) + (info)->rinfo_size)
278
+
279
+static inline struct blkfront_ring_info *
280
+get_rinfo(const struct blkfront_info *info, unsigned int i)
281
+{
282
+	BUG_ON(i >= info->nr_rings);
283
+	return (void *)info->rinfo + i * info->rinfo_size;
284
+}
285
+
268286 static int get_id_from_freelist(struct blkfront_ring_info *rinfo)
269287 {
270288 	unsigned long free = rinfo->shadow_free;
....@@ -300,8 +318,8 @@
300318 		if (!gnt_list_entry)
301319 			goto out_of_memory;
302320 
303
-		if (info->feature_persistent) {
304
-			granted_page = alloc_page(GFP_NOIO);
321
+		if (info->bounce) {
322
+			granted_page = alloc_page(GFP_NOIO | __GFP_ZERO);
305323 			if (!granted_page) {
306324 				kfree(gnt_list_entry);
307325 				goto out_of_memory;
....@@ -320,7 +338,7 @@
320338 	list_for_each_entry_safe(gnt_list_entry, n,
321339 	                         &rinfo->grants, node) {
322340 		list_del(&gnt_list_entry->node);
323
-		if (info->feature_persistent)
341
+		if (info->bounce)
324342 			__free_page(gnt_list_entry->page);
325343 		kfree(gnt_list_entry);
326344 		i--;
....@@ -366,7 +384,7 @@
366384 	/* Assign a gref to this page */
367385 	gnt_list_entry->gref = gnttab_claim_grant_reference(gref_head);
368386 	BUG_ON(gnt_list_entry->gref == -ENOSPC);
369
-	if (info->feature_persistent)
387
+	if (info->bounce)
370388 		grant_foreign_access(gnt_list_entry, info);
371389 	else {
372390 		/* Grant access to the GFN passed by the caller */
....@@ -390,7 +408,7 @@
390408 	/* Assign a gref to this page */
391409 	gnt_list_entry->gref = gnttab_claim_grant_reference(gref_head);
392410 	BUG_ON(gnt_list_entry->gref == -ENOSPC);
393
-	if (!info->feature_persistent) {
411
+	if (!info->bounce) {
394412 		struct page *indirect_page;
395413 
396414 		/* Fetch a pre-allocated page to use for indirect grefs */
....@@ -705,7 +723,7 @@
705723 		.grant_idx = 0,
706724 		.segments = NULL,
707725 		.rinfo = rinfo,
708
-		.need_copy = rq_data_dir(req) && info->feature_persistent,
726
+		.need_copy = rq_data_dir(req) && info->bounce,
709727 	};
710728 
711729 	/*
....@@ -898,8 +916,7 @@
898916 	struct blkfront_info *info = hctx->queue->queuedata;
899917 	struct blkfront_ring_info *rinfo = NULL;
900918 
901
-	BUG_ON(info->nr_rings <= qid);
902
-	rinfo = &info->rinfo[qid];
919
+	rinfo = get_rinfo(info, qid);
903920 	blk_mq_start_request(qd->rq);
904921 	spin_lock_irqsave(&rinfo->ring_lock, flags);
905922 	if (RING_FULL(&rinfo->ring))
....@@ -990,7 +1007,7 @@
9901007 	} else
9911008 		info->tag_set.queue_depth = BLK_RING_SIZE(info);
9921009 	info->tag_set.numa_node = NUMA_NO_NODE;
993
-	info->tag_set.flags = BLK_MQ_F_SHOULD_MERGE | BLK_MQ_F_SG_MERGE;
1010
+	info->tag_set.flags = BLK_MQ_F_SHOULD_MERGE;
9941011 	info->tag_set.cmd_size = sizeof(struct blkif_req);
9951012 	info->tag_set.driver_data = info;
9961013 
....@@ -1026,11 +1043,12 @@
10261043 {
10271044 	blk_queue_write_cache(info->rq, info->feature_flush ? true : false,
10281045 			      info->feature_fua ? true : false);
1029
-	pr_info("blkfront: %s: %s %s %s %s %s\n",
1046
+	pr_info("blkfront: %s: %s %s %s %s %s %s %s\n",
10301047 		info->gd->disk_name, flush_info(info),
10311048 		"persistent grants:", info->feature_persistent ?
10321049 		"enabled;" : "disabled;", "indirect descriptors:",
1033
-		info->max_indirect_segments ? "enabled;" : "disabled;");
1050
+		info->max_indirect_segments ? "enabled;" : "disabled;",
1051
+		"bounce buffer:", info->bounce ? "enabled" : "disabled;");
10341052 }
10351053 
10361054 static int xen_translate_vdev(int vdevice, int *minor, unsigned int *offset)
....@@ -1197,6 +1215,7 @@
11971215 static void xlvbd_release_gendisk(struct blkfront_info *info)
11981216 {
11991217 	unsigned int minor, nr_minors, i;
1218
+	struct blkfront_ring_info *rinfo;
12001219 
12011220 	if (info->rq == NULL)
12021221 		return;
....@@ -1204,9 +1223,7 @@
12041223 	/* No more blkif_request(). */
12051224 	blk_mq_stop_hw_queues(info->rq);
12061225 
1207
-	for (i = 0; i < info->nr_rings; i++) {
1208
-		struct blkfront_ring_info *rinfo = &info->rinfo[i];
1209
-
1226
+	for_each_rinfo(info, rinfo, i) {
12101227 		/* No more gnttab callback work. */
12111228 		gnttab_cancel_free_callback(&rinfo->callback);
12121229 
....@@ -1265,7 +1282,7 @@
12651282 	if (!list_empty(&rinfo->indirect_pages)) {
12661283 		struct page *indirect_page, *n;
12671284 
1268
-		BUG_ON(info->feature_persistent);
1285
+		BUG_ON(info->bounce);
12691286 		list_for_each_entry_safe(indirect_page, n, &rinfo->indirect_pages, lru) {
12701287 			list_del(&indirect_page->lru);
12711288 			__free_page(indirect_page);
....@@ -1282,7 +1299,7 @@
12821299 							  0, 0UL);
12831300 				rinfo->persistent_gnts_c--;
12841301 			}
1285
-			if (info->feature_persistent)
1302
+			if (info->bounce)
12861303 				__free_page(persistent_gnt->page);
12871304 			kfree(persistent_gnt);
12881305 		}
....@@ -1303,7 +1320,7 @@
13031320 		for (j = 0; j < segs; j++) {
13041321 			persistent_gnt = rinfo->shadow[i].grants_used[j];
13051322 			gnttab_end_foreign_access(persistent_gnt->gref, 0, 0UL);
1306
-			if (info->feature_persistent)
1323
+			if (info->bounce)
13071324 				__free_page(persistent_gnt->page);
13081325 			kfree(persistent_gnt);
13091326 		}
....@@ -1344,7 +1361,8 @@
13441361 			rinfo->ring_ref[i] = GRANT_INVALID_REF;
13451362 		}
13461363 	}
1347
-	free_pages((unsigned long)rinfo->ring.sring, get_order(info->nr_ring_pages * XEN_PAGE_SIZE));
1364
+	free_pages_exact(rinfo->ring.sring,
1365
+			 info->nr_ring_pages * XEN_PAGE_SIZE);
13481366 	rinfo->ring.sring = NULL;
13491367 
13501368 	if (rinfo->irq)
....@@ -1355,6 +1373,7 @@
13551373 static void blkif_free(struct blkfront_info *info, int suspend)
13561374 {
13571375 	unsigned int i;
1376
+	struct blkfront_ring_info *rinfo;
13581377 
13591378 	/* Prevent new requests being issued until we fix things up. */
13601379 	info->connected = suspend ?
....@@ -1363,8 +1382,8 @@
13631382 	if (info->rq)
13641383 		blk_mq_stop_hw_queues(info->rq);
13651384 
1366
-	for (i = 0; i < info->nr_rings; i++)
1367
-		blkif_free_ring(&info->rinfo[i]);
1385
+	for_each_rinfo(info, rinfo, i)
1386
+		blkif_free_ring(rinfo);
13681387 
13691388 	kvfree(info->rinfo);
13701389 	info->rinfo = NULL;
....@@ -1406,7 +1425,6 @@
14061425 	case BLKIF_RSP_EOPNOTSUPP:
14071426 		return REQ_EOPNOTSUPP;
14081427 	case BLKIF_RSP_ERROR:
1409
-		/* Fallthrough. */
14101428 	default:
14111429 		return REQ_ERROR;
14121430 	}
....@@ -1428,9 +1446,15 @@
14281446 	return BLKIF_RSP_OKAY;
14291447 }
14301448 
1431
-static bool blkif_completion(unsigned long *id,
1432
-			     struct blkfront_ring_info *rinfo,
1433
-			     struct blkif_response *bret)
1449
+/*
1450
+ * Return values:
1451
+ *  1 response processed.
1452
+ *  0 missing further responses.
1453
+ * -1 error while processing.
1454
+ */
1455
+static int blkif_completion(unsigned long *id,
1456
+			    struct blkfront_ring_info *rinfo,
1457
+			    struct blkif_response *bret)
14341458 {
14351459 	int i = 0;
14361460 	struct scatterlist *sg;
....@@ -1453,7 +1477,7 @@
14531477 
14541478 		/* Wait the second response if not yet here. */
14551479 		if (s2->status < REQ_DONE)
1456
-			return false;
1480
+			return 0;
14571481 
14581482 		bret->status = blkif_get_final_status(s->status,
14591483 						      s2->status);
....@@ -1486,7 +1510,7 @@
14861510 	data.s = s;
14871511 	num_sg = s->num_sg;
14881512 
1489
-	if (bret->operation == BLKIF_OP_READ && info->feature_persistent) {
1513
+	if (bret->operation == BLKIF_OP_READ && info->bounce) {
14901514 		for_each_sg(s->sg, sg, num_sg, i) {
14911515 			BUG_ON(sg->offset + sg->length > PAGE_SIZE);
14921516 
....@@ -1504,47 +1528,48 @@
15041528 	}
15051529 	/* Add the persistent grant into the list of free grants */
15061530 	for (i = 0; i < num_grant; i++) {
1507
-		if (gnttab_query_foreign_access(s->grants_used[i]->gref)) {
1531
+		if (!gnttab_try_end_foreign_access(s->grants_used[i]->gref)) {
15081532 			/*
15091533 			 * If the grant is still mapped by the backend (the
15101534 			 * backend has chosen to make this grant persistent)
15111535 			 * we add it at the head of the list, so it will be
15121536 			 * reused first.
15131537 			 */
1514
-			if (!info->feature_persistent)
1515
-				pr_alert_ratelimited("backed has not unmapped grant: %u\n",
1516
-						     s->grants_used[i]->gref);
1538
+			if (!info->feature_persistent) {
1539
+				pr_alert("backed has not unmapped grant: %u\n",
1540
+					 s->grants_used[i]->gref);
1541
+				return -1;
1542
+			}
15171543 			list_add(&s->grants_used[i]->node, &rinfo->grants);
15181544 			rinfo->persistent_gnts_c++;
15191545 		} else {
15201546 			/*
1521
-			 * If the grant is not mapped by the backend we end the
1522
-			 * foreign access and add it to the tail of the list,
1523
-			 * so it will not be picked again unless we run out of
1524
-			 * persistent grants.
1547
+			 * If the grant is not mapped by the backend we add it
1548
+			 * to the tail of the list, so it will not be picked
1549
+			 * again unless we run out of persistent grants.
15251550 			 */
1526
-			gnttab_end_foreign_access(s->grants_used[i]->gref, 0, 0UL);
15271551 			s->grants_used[i]->gref = GRANT_INVALID_REF;
15281552 			list_add_tail(&s->grants_used[i]->node, &rinfo->grants);
15291553 		}
15301554 	}
15311555 	if (s->req.operation == BLKIF_OP_INDIRECT) {
15321556 		for (i = 0; i < INDIRECT_GREFS(num_grant); i++) {
1533
-			if (gnttab_query_foreign_access(s->indirect_grants[i]->gref)) {
1534
-				if (!info->feature_persistent)
1535
-					pr_alert_ratelimited("backed has not unmapped grant: %u\n",
1536
-							     s->indirect_grants[i]->gref);
1557
+			if (!gnttab_try_end_foreign_access(s->indirect_grants[i]->gref)) {
1558
+				if (!info->feature_persistent) {
1559
+					pr_alert("backed has not unmapped grant: %u\n",
1560
+						 s->indirect_grants[i]->gref);
1561
+					return -1;
1562
+				}
15371563 				list_add(&s->indirect_grants[i]->node, &rinfo->grants);
15381564 				rinfo->persistent_gnts_c++;
15391565 			} else {
15401566 				struct page *indirect_page;
15411567 
1542
-				gnttab_end_foreign_access(s->indirect_grants[i]->gref, 0, 0UL);
15431568 				/*
15441569 				 * Add the used indirect page back to the list of
15451570 				 * available pages for indirect grefs.
15461571 				 */
1547
-				if (!info->feature_persistent) {
1572
+				if (!info->bounce) {
15481573 					indirect_page = s->indirect_grants[i]->page;
15491574 					list_add(&indirect_page->lru, &rinfo->indirect_pages);
15501575 				}
....@@ -1554,7 +1579,7 @@
15541579 		}
15551580 	}
15561581 
1557
-	return true;
1582
+	return 1;
15581583 }
15591584 
15601585 static irqreturn_t blkif_interrupt(int irq, void *dev_id)
....@@ -1620,12 +1645,17 @@
16201645 		}
16211646 
16221647 		if (bret.operation != BLKIF_OP_DISCARD) {
1648
+			int ret;
1649
+
16231650 			/*
16241651 			 * We may need to wait for an extra response if the
16251652 			 * I/O request is split in 2
16261653 			 */
1627
-			if (!blkif_completion(&id, rinfo, &bret))
1654
+			ret = blkif_completion(&id, rinfo, &bret);
1655
+			if (!ret)
16281656 				continue;
1657
+			if (unlikely(ret < 0))
1658
+				goto err;
16291659 		}
16301660 
16311661 		if (add_id_to_freelist(rinfo, id)) {
....@@ -1673,7 +1703,7 @@
16731703 				info->feature_flush = 0;
16741704 				xlvbd_flush(info);
16751705 			}
1676
-			/* fall through */
1706
+			fallthrough;
16771707 		case BLKIF_OP_READ:
16781708 		case BLKIF_OP_WRITE:
16791709 			if (unlikely(bret.status != BLKIF_RSP_OKAY))
....@@ -1686,7 +1716,8 @@
16861716 			BUG();
16871717 		}
16881718 
1689
-		blk_mq_complete_request(req);
1719
+		if (likely(!blk_should_fake_timeout(req->q)))
1720
+			blk_mq_complete_request(req);
16901721 	}
16911722 
16921723 	rinfo->ring.rsp_cons = i;
....@@ -1731,8 +1762,7 @@
17311762 	for (i = 0; i < info->nr_ring_pages; i++)
17321763 		rinfo->ring_ref[i] = GRANT_INVALID_REF;
17331764 
1734
-	sring = (struct blkif_sring *)__get_free_pages(GFP_NOIO | __GFP_HIGH,
1735
-						       get_order(ring_size));
1765
+	sring = alloc_pages_exact(ring_size, GFP_NOIO | __GFP_ZERO);
17361766 	if (!sring) {
17371767 		xenbus_dev_fatal(dev, -ENOMEM, "allocating shared ring");
17381768 		return -ENOMEM;
....@@ -1742,7 +1772,7 @@
17421772 
17431773 	err = xenbus_grant_ring(dev, rinfo->ring.sring, info->nr_ring_pages, gref);
17441774 	if (err < 0) {
1745
-		free_pages((unsigned long)sring, get_order(ring_size));
1775
+		free_pages_exact(sring, ring_size);
17461776 		rinfo->ring.sring = NULL;
17471777 		goto fail;
17481778 	}
....@@ -1822,6 +1852,12 @@
18221852 	kfree(info);
18231853 }
18241854 
1855
+/* Enable the persistent grants feature. */
1856
+static bool feature_persistent = true;
1857
+module_param(feature_persistent, bool, 0644);
1858
+MODULE_PARM_DESC(feature_persistent,
1859
+		"Enables the persistent grants feature");
1860
+
18251861 /* Common code used when first setting up, and when resuming. */
18261862 static int talk_to_blkback(struct xenbus_device *dev,
18271863 			   struct blkfront_info *info)
....@@ -1831,9 +1867,14 @@
18311867 	int err;
18321868 	unsigned int i, max_page_order;
18331869 	unsigned int ring_page_order;
1870
+	struct blkfront_ring_info *rinfo;
18341871 
18351872 	if (!info)
18361873 		return -ENODEV;
1874
+
1875
+	/* Check if backend is trusted. */
1876
+	info->bounce = !xen_blkif_trusted ||
1877
+		       !xenbus_read_unsigned(dev->nodename, "trusted", 1);
18371878 
18381879 	max_page_order = xenbus_read_unsigned(info->xbdev->otherend,
18391880 					      "max-ring-page-order", 0);
....@@ -1844,9 +1885,7 @@
18441885 	if (err)
18451886 		goto destroy_blkring;
18461887 
1847
-	for (i = 0; i < info->nr_rings; i++) {
1848
-		struct blkfront_ring_info *rinfo = &info->rinfo[i];
1849
-
1888
+	for_each_rinfo(info, rinfo, i) {
18501889 		/* Create shared ring, alloc event channel. */
18511890 		err = setup_blkring(dev, rinfo);
18521891 		if (err)
....@@ -1871,7 +1910,7 @@
18711910 
18721911 	/* We already got the number of queues/rings in _probe */
18731912 	if (info->nr_rings == 1) {
1874
-		err = write_per_ring_nodes(xbt, &info->rinfo[0], dev->nodename);
1913
+		err = write_per_ring_nodes(xbt, info->rinfo, dev->nodename);
18751914 		if (err)
18761915 			goto destroy_blkring;
18771916 	} else {
....@@ -1893,10 +1932,10 @@
18931932 			goto abort_transaction;
18941933 		}
18951934 
1896
-		for (i = 0; i < info->nr_rings; i++) {
1935
+		for_each_rinfo(info, rinfo, i) {
18971936 			memset(path, 0, pathsize);
18981937 			snprintf(path, pathsize, "%s/queue-%u", dev->nodename, i);
1899
-			err = write_per_ring_nodes(xbt, &info->rinfo[i], path);
1938
+			err = write_per_ring_nodes(xbt, rinfo, path);
19001939 			if (err) {
19011940 				kfree(path);
19021941 				goto destroy_blkring;
....@@ -1910,8 +1949,9 @@
19101949 		message = "writing protocol";
19111950 		goto abort_transaction;
19121951 	}
1913
-	err = xenbus_printf(xbt, dev->nodename,
1914
-			    "feature-persistent", "%u", 1);
1952
+	info->feature_persistent_parm = feature_persistent;
1953
+	err = xenbus_printf(xbt, dev->nodename, "feature-persistent", "%u",
1954
+			info->feature_persistent_parm);
19151955 	if (err)
19161956 		dev_warn(&dev->dev,
19171957 			 "writing persistent grants feature to xenbus");
....@@ -1924,9 +1964,8 @@
19241964 		goto destroy_blkring;
19251965 	}
19261966 
1927
-	for (i = 0; i < info->nr_rings; i++) {
1967
+	for_each_rinfo(info, rinfo, i) {
19281968 		unsigned int j;
1929
-		struct blkfront_ring_info *rinfo = &info->rinfo[i];
19301969 
19311970 		for (j = 0; j < BLK_RING_SIZE(info); j++)
19321971 			rinfo->shadow[j].req.u.rw.id = j + 1;
....@@ -1956,6 +1995,7 @@
19561995 {
19571996 	unsigned int backend_max_queues;
19581997 	unsigned int i;
1998
+	struct blkfront_ring_info *rinfo;
19591999 
19602000 	BUG_ON(info->nr_rings);
19612001 
....@@ -1967,19 +2007,16 @@
19672007 	if (!info->nr_rings)
19682008 		info->nr_rings = 1;
19692009 
1970
-	info->rinfo = kvcalloc(info->nr_rings,
1971
-			       sizeof(struct blkfront_ring_info),
1972
-			       GFP_KERNEL);
2010
+	info->rinfo_size = struct_size(info->rinfo, shadow,
2011
+				       BLK_RING_SIZE(info));
2012
+	info->rinfo = kvcalloc(info->nr_rings, info->rinfo_size, GFP_KERNEL);
19732013 	if (!info->rinfo) {
19742014 		xenbus_dev_fatal(info->xbdev, -ENOMEM, "allocating ring_info structure");
19752015 		info->nr_rings = 0;
19762016 		return -ENOMEM;
19772017 	}
19782018 
1979
-	for (i = 0; i < info->nr_rings; i++) {
1980
-		struct blkfront_ring_info *rinfo;
1981
-
1982
-		rinfo = &info->rinfo[i];
2019
+	for_each_rinfo(info, rinfo, i) {
19832020 		INIT_LIST_HEAD(&rinfo->indirect_pages);
19842021 		INIT_LIST_HEAD(&rinfo->grants);
19852022 		rinfo->dev_info = info;
....@@ -1988,6 +2025,7 @@
19882025 	}
19892026 	return 0;
19902027 }
2028
+
19912029 /**
19922030  * Entry point to this code when a new device is created.  Allocate the basic
19932031  * structures and the ring buffer for communication with the backend, and
....@@ -2072,6 +2110,7 @@
20722110 	int rc;
20732111 	struct bio *bio;
20742112 	unsigned int segs;
2113
+	struct blkfront_ring_info *rinfo;
20752114 
20762115 	blkfront_gather_backend_features(info);
20772116 	/* Reset limits changed by blk_mq_update_nr_hw_queues(). */
....@@ -2079,9 +2118,7 @@
20792118 	segs = info->max_indirect_segments ? : BLKIF_MAX_SEGMENTS_PER_REQUEST;
20802119 	blk_queue_max_segments(info->rq, segs / GRANTS_PER_PSEG);
20812120 
2082
-	for (r_index = 0; r_index < info->nr_rings; r_index++) {
2083
-		struct blkfront_ring_info *rinfo = &info->rinfo[r_index];
2084
-
2121
+	for_each_rinfo(info, rinfo, r_index) {
20852122 		rc = blkfront_setup_indirect(rinfo);
20862123 		if (rc)
20872124 			return rc;
....@@ -2091,10 +2128,7 @@
20912128 	/* Now safe for us to use the shared ring */
20922129 	info->connected = BLKIF_STATE_CONNECTED;
20932130 
2094
-	for (r_index = 0; r_index < info->nr_rings; r_index++) {
2095
-		struct blkfront_ring_info *rinfo;
2096
-
2097
-		rinfo = &info->rinfo[r_index];
2131
+	for_each_rinfo(info, rinfo, r_index) {
20982132 		/* Kick any other new requests queued since we resumed */
20992133 		kick_pending_request_queues(rinfo);
21002134 	}
....@@ -2127,13 +2161,13 @@
21272161 	struct blkfront_info *info = dev_get_drvdata(&dev->dev);
21282162 	int err = 0;
21292163 	unsigned int i, j;
2164
+	struct blkfront_ring_info *rinfo;
21302165 
21312166 	dev_dbg(&dev->dev, "blkfront_resume: %s\n", dev->nodename);
21322167 
21332168 	bio_list_init(&info->bio_list);
21342169 	INIT_LIST_HEAD(&info->requests);
2135
-	for (i = 0; i < info->nr_rings; i++) {
2136
-		struct blkfront_ring_info *rinfo = &info->rinfo[i];
2170
+	for_each_rinfo(info, rinfo, i) {
21372171 		struct bio_list merge_bio;
21382172 		struct blk_shadow *shadow = rinfo->shadow;
21392173 
....@@ -2261,17 +2295,18 @@
22612295 	if (err)
22622296 		goto out_of_memory;
22632297 
2264
-	if (!info->feature_persistent && info->max_indirect_segments) {
2298
+	if (!info->bounce && info->max_indirect_segments) {
22652299 		/*
2266
-		 * We are using indirect descriptors but not persistent
2267
-		 * grants, we need to allocate a set of pages that can be
2300
+		 * We are using indirect descriptors but don't have a bounce
2301
+		 * buffer, we need to allocate a set of pages that can be
22682302 		 * used for mapping indirect grefs
22692303 		 */
22702304 		int num = INDIRECT_GREFS(grants) * BLK_RING_SIZE(info);
22712305 
22722306 		BUG_ON(!list_empty(&rinfo->indirect_pages));
22732307 		for (i = 0; i < num; i++) {
2274
-			struct page *indirect_page = alloc_page(GFP_KERNEL);
2308
+			struct page *indirect_page = alloc_page(GFP_KERNEL |
2309
+			                                        __GFP_ZERO);
22752310 			if (!indirect_page)
22762311 				goto out_of_memory;
22772312 			list_add(&indirect_page->lru, &rinfo->indirect_pages);
....@@ -2360,9 +2395,12 @@
23602395 	if (xenbus_read_unsigned(info->xbdev->otherend, "feature-discard", 0))
23612396 		blkfront_setup_discard(info);
23622397 
2363
-	info->feature_persistent =
2364
-		!!xenbus_read_unsigned(info->xbdev->otherend,
2365
-				       "feature-persistent", 0);
2398
+	if (info->feature_persistent_parm)
2399
+		info->feature_persistent =
2400
+			!!xenbus_read_unsigned(info->xbdev->otherend,
2401
+					       "feature-persistent", 0);
2402
+	if (info->feature_persistent)
2403
+		info->bounce = true;
23662404 
23672405 	indirect_segments = xenbus_read_unsigned(info->xbdev->otherend,
23682406 					"feature-max-indirect-segments", 0);
....@@ -2389,8 +2427,8 @@
23892427 	unsigned long sector_size;
23902428 	unsigned int physical_sector_size;
23912429 	unsigned int binfo;
2392
-	char *envp[] = { "RESIZE=1", NULL };
23932430 	int err, i;
2431
+	struct blkfront_ring_info *rinfo;
23942432 
23952433 	switch (info->connected) {
23962434 	case BLKIF_STATE_CONNECTED:
....@@ -2404,10 +2442,7 @@
24042442 			return;
24052443 		printk(KERN_INFO "Setting capacity to %Lu\n",
24062444 		       sectors);
2407
-		set_capacity(info->gd, sectors);
2408
-		revalidate_disk(info->gd);
2409
-		kobject_uevent_env(&disk_to_dev(info->gd)->kobj,
2410
-				   KOBJ_CHANGE, envp);
2445
+		set_capacity_revalidate_and_notify(info->gd, sectors, true);
24112446 
24122447 		return;
24132448 	case BLKIF_STATE_SUSPENDED:
....@@ -2448,8 +2483,8 @@
24482483 						    "physical-sector-size",
24492484 						    sector_size);
24502485 	blkfront_gather_backend_features(info);
2451
-	for (i = 0; i < info->nr_rings; i++) {
2452
-		err = blkfront_setup_indirect(&info->rinfo[i]);
2486
+	for_each_rinfo(info, rinfo, i) {
2487
+		err = blkfront_setup_indirect(rinfo);
24532488 		if (err) {
24542489 			xenbus_dev_fatal(info->xbdev, err, "setup_indirect at %s",
24552490 					 info->xbdev->otherend);
....@@ -2470,10 +2505,10 @@
24702505 
24712506 	/* Kick pending requests. */
24722507 	info->connected = BLKIF_STATE_CONNECTED;
2473
-	for (i = 0; i < info->nr_rings; i++)
2474
-		kick_pending_request_queues(&info->rinfo[i]);
2508
+	for_each_rinfo(info, rinfo, i)
2509
+		kick_pending_request_queues(rinfo);
24752510 
2476
-	device_add_disk(&info->xbdev->dev, info->gd);
2511
+	device_add_disk(&info->xbdev->dev, info->gd, NULL);
24772512 
24782513 	info->is_ready = 1;
24792514 	return;
....@@ -2530,7 +2565,7 @@
25302565 	case XenbusStateClosed:
25312566 		if (dev->state == XenbusStateClosed)
25322567 			break;
2533
-		/* fall through */
2568
+		fallthrough;
25342569 	case XenbusStateClosing:
25352570 		if (info)
25362571 			blkfront_closing(info);
....@@ -2684,6 +2719,7 @@
26842719 	.release = blkif_release,
26852720 	.getgeo = blkif_getgeo,
26862721 	.ioctl = blkif_ioctl,
2722
+	.compat_ioctl = blkdev_compat_ptr_ioctl,
26872723 };
26882724 
26892725 
....@@ -2705,9 +2741,9 @@
27052741 {
27062742 	unsigned int i;
27072743 	unsigned long flags;
2744
+	struct blkfront_ring_info *rinfo;
27082745 
2709
-	for (i = 0; i < info->nr_rings; i++) {
2710
-		struct blkfront_ring_info *rinfo = &info->rinfo[i];
2746
+	for_each_rinfo(info, rinfo, i) {
27112747 		struct grant *gnt_list_entry, *tmp;
27122748 
27132749 		spin_lock_irqsave(&rinfo->ring_lock, flags);
....@@ -2720,11 +2756,10 @@
27202756 		list_for_each_entry_safe(gnt_list_entry, tmp, &rinfo->grants,
27212757 					 node) {
27222758 			if (gnt_list_entry->gref == GRANT_INVALID_REF ||
2723
-			    gnttab_query_foreign_access(gnt_list_entry->gref))
2759
+			    !gnttab_try_end_foreign_access(gnt_list_entry->gref))
27242760 				continue;
27252761 
27262762 			list_del(&gnt_list_entry->node);
2727
-			gnttab_end_foreign_access(gnt_list_entry->gref, 0, 0UL);
27282763 			rinfo->persistent_gnts_c--;
27292764 			gnt_list_entry->gref = GRANT_INVALID_REF;
27302765 			list_add_tail(&gnt_list_entry->node, &rinfo->grants);
....@@ -2739,6 +2774,13 @@
27392774 	struct blkfront_info *info;
27402775 	bool need_schedule_work = false;
27412776 
2777
+	/*
2778
+	 * Note that when using bounce buffers but not persistent grants
2779
+	 * there's no need to run blkfront_delay_work because grants are
2780
+	 * revoked in blkif_completion or else an error is reported and the
2781
+	 * connection is closed.
2782
+	 */
2783
+
27422784 	mutex_lock(&blkfront_mutex);
27432785 
27442786 	list_for_each_entry(info, &info_list, info_list) {