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hc
2024-05-14 bedbef8ad3e75a304af6361af235302bcc61d06b 
 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 	/*
....@@ -774,7 +792,8 @@
774792 		ring_req->u.rw.handle = info->handle;
775793 		ring_req->operation = rq_data_dir(req) ?
776794 			BLKIF_OP_WRITE : BLKIF_OP_READ;
777
-		if (req_op(req) == REQ_OP_FLUSH || req->cmd_flags & REQ_FUA) {
795
+		if (req_op(req) == REQ_OP_FLUSH ||
796
+		    (req_op(req) == REQ_OP_WRITE && (req->cmd_flags & REQ_FUA))) {
778797 			/*
779798 			 * Ideally we can do an unordered flush-to-disk.
780799 			 * In case the backend onlysupports barriers, use that.
....@@ -898,8 +917,7 @@
898917 	struct blkfront_info *info = hctx->queue->queuedata;
899918 	struct blkfront_ring_info *rinfo = NULL;
900919 
901
-	BUG_ON(info->nr_rings <= qid);
902
-	rinfo = &info->rinfo[qid];
920
+	rinfo = get_rinfo(info, qid);
903921 	blk_mq_start_request(qd->rq);
904922 	spin_lock_irqsave(&rinfo->ring_lock, flags);
905923 	if (RING_FULL(&rinfo->ring))
....@@ -990,7 +1008,7 @@
9901008 	} else
9911009 		info->tag_set.queue_depth = BLK_RING_SIZE(info);
9921010 	info->tag_set.numa_node = NUMA_NO_NODE;
993
-	info->tag_set.flags = BLK_MQ_F_SHOULD_MERGE | BLK_MQ_F_SG_MERGE;
1011
+	info->tag_set.flags = BLK_MQ_F_SHOULD_MERGE;
9941012 	info->tag_set.cmd_size = sizeof(struct blkif_req);
9951013 	info->tag_set.driver_data = info;
9961014 
....@@ -1026,11 +1044,12 @@
10261044 {
10271045 	blk_queue_write_cache(info->rq, info->feature_flush ? true : false,
10281046 			      info->feature_fua ? true : false);
1029
-	pr_info("blkfront: %s: %s %s %s %s %s\n",
1047
+	pr_info("blkfront: %s: %s %s %s %s %s %s %s\n",
10301048 		info->gd->disk_name, flush_info(info),
10311049 		"persistent grants:", info->feature_persistent ?
10321050 		"enabled;" : "disabled;", "indirect descriptors:",
1033
-		info->max_indirect_segments ? "enabled;" : "disabled;");
1051
+		info->max_indirect_segments ? "enabled;" : "disabled;",
1052
+		"bounce buffer:", info->bounce ? "enabled" : "disabled;");
10341053 }
10351054 
10361055 static int xen_translate_vdev(int vdevice, int *minor, unsigned int *offset)
....@@ -1197,6 +1216,7 @@
11971216 static void xlvbd_release_gendisk(struct blkfront_info *info)
11981217 {
11991218 	unsigned int minor, nr_minors, i;
1219
+	struct blkfront_ring_info *rinfo;
12001220 
12011221 	if (info->rq == NULL)
12021222 		return;
....@@ -1204,9 +1224,7 @@
12041224 	/* No more blkif_request(). */
12051225 	blk_mq_stop_hw_queues(info->rq);
12061226 
1207
-	for (i = 0; i < info->nr_rings; i++) {
1208
-		struct blkfront_ring_info *rinfo = &info->rinfo[i];
1209
-
1227
+	for_each_rinfo(info, rinfo, i) {
12101228 		/* No more gnttab callback work. */
12111229 		gnttab_cancel_free_callback(&rinfo->callback);
12121230 
....@@ -1265,7 +1283,7 @@
12651283 	if (!list_empty(&rinfo->indirect_pages)) {
12661284 		struct page *indirect_page, *n;
12671285 
1268
-		BUG_ON(info->feature_persistent);
1286
+		BUG_ON(info->bounce);
12691287 		list_for_each_entry_safe(indirect_page, n, &rinfo->indirect_pages, lru) {
12701288 			list_del(&indirect_page->lru);
12711289 			__free_page(indirect_page);
....@@ -1282,7 +1300,7 @@
12821300 							  0, 0UL);
12831301 				rinfo->persistent_gnts_c--;
12841302 			}
1285
-			if (info->feature_persistent)
1303
+			if (info->bounce)
12861304 				__free_page(persistent_gnt->page);
12871305 			kfree(persistent_gnt);
12881306 		}
....@@ -1303,7 +1321,7 @@
13031321 		for (j = 0; j < segs; j++) {
13041322 			persistent_gnt = rinfo->shadow[i].grants_used[j];
13051323 			gnttab_end_foreign_access(persistent_gnt->gref, 0, 0UL);
1306
-			if (info->feature_persistent)
1324
+			if (info->bounce)
13071325 				__free_page(persistent_gnt->page);
13081326 			kfree(persistent_gnt);
13091327 		}
....@@ -1344,7 +1362,8 @@
13441362 			rinfo->ring_ref[i] = GRANT_INVALID_REF;
13451363 		}
13461364 	}
1347
-	free_pages((unsigned long)rinfo->ring.sring, get_order(info->nr_ring_pages * XEN_PAGE_SIZE));
1365
+	free_pages_exact(rinfo->ring.sring,
1366
+			 info->nr_ring_pages * XEN_PAGE_SIZE);
13481367 	rinfo->ring.sring = NULL;
13491368 
13501369 	if (rinfo->irq)
....@@ -1355,6 +1374,7 @@
13551374 static void blkif_free(struct blkfront_info *info, int suspend)
13561375 {
13571376 	unsigned int i;
1377
+	struct blkfront_ring_info *rinfo;
13581378 
13591379 	/* Prevent new requests being issued until we fix things up. */
13601380 	info->connected = suspend ?
....@@ -1363,8 +1383,8 @@
13631383 	if (info->rq)
13641384 		blk_mq_stop_hw_queues(info->rq);
13651385 
1366
-	for (i = 0; i < info->nr_rings; i++)
1367
-		blkif_free_ring(&info->rinfo[i]);
1386
+	for_each_rinfo(info, rinfo, i)
1387
+		blkif_free_ring(rinfo);
13681388 
13691389 	kvfree(info->rinfo);
13701390 	info->rinfo = NULL;
....@@ -1406,7 +1426,6 @@
14061426 	case BLKIF_RSP_EOPNOTSUPP:
14071427 		return REQ_EOPNOTSUPP;
14081428 	case BLKIF_RSP_ERROR:
1409
-		/* Fallthrough. */
14101429 	default:
14111430 		return REQ_ERROR;
14121431 	}
....@@ -1428,9 +1447,15 @@
14281447 	return BLKIF_RSP_OKAY;
14291448 }
14301449 
1431
-static bool blkif_completion(unsigned long *id,
1432
-			     struct blkfront_ring_info *rinfo,
1433
-			     struct blkif_response *bret)
1450
+/*
1451
+ * Return values:
1452
+ *  1 response processed.
1453
+ *  0 missing further responses.
1454
+ * -1 error while processing.
1455
+ */
1456
+static int blkif_completion(unsigned long *id,
1457
+			    struct blkfront_ring_info *rinfo,
1458
+			    struct blkif_response *bret)
14341459 {
14351460 	int i = 0;
14361461 	struct scatterlist *sg;
....@@ -1453,7 +1478,7 @@
14531478 
14541479 		/* Wait the second response if not yet here. */
14551480 		if (s2->status < REQ_DONE)
1456
-			return false;
1481
+			return 0;
14571482 
14581483 		bret->status = blkif_get_final_status(s->status,
14591484 						      s2->status);
....@@ -1486,7 +1511,7 @@
14861511 	data.s = s;
14871512 	num_sg = s->num_sg;
14881513 
1489
-	if (bret->operation == BLKIF_OP_READ && info->feature_persistent) {
1514
+	if (bret->operation == BLKIF_OP_READ && info->bounce) {
14901515 		for_each_sg(s->sg, sg, num_sg, i) {
14911516 			BUG_ON(sg->offset + sg->length > PAGE_SIZE);
14921517 
....@@ -1504,47 +1529,48 @@
15041529 	}
15051530 	/* Add the persistent grant into the list of free grants */
15061531 	for (i = 0; i < num_grant; i++) {
1507
-		if (gnttab_query_foreign_access(s->grants_used[i]->gref)) {
1532
+		if (!gnttab_try_end_foreign_access(s->grants_used[i]->gref)) {
15081533 			/*
15091534 			 * If the grant is still mapped by the backend (the
15101535 			 * backend has chosen to make this grant persistent)
15111536 			 * we add it at the head of the list, so it will be
15121537 			 * reused first.
15131538 			 */
1514
-			if (!info->feature_persistent)
1515
-				pr_alert_ratelimited("backed has not unmapped grant: %u\n",
1516
-						     s->grants_used[i]->gref);
1539
+			if (!info->feature_persistent) {
1540
+				pr_alert("backed has not unmapped grant: %u\n",
1541
+					 s->grants_used[i]->gref);
1542
+				return -1;
1543
+			}
15171544 			list_add(&s->grants_used[i]->node, &rinfo->grants);
15181545 			rinfo->persistent_gnts_c++;
15191546 		} else {
15201547 			/*
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.
1548
+			 * If the grant is not mapped by the backend we add it
1549
+			 * to the tail of the list, so it will not be picked
1550
+			 * again unless we run out of persistent grants.
15251551 			 */
1526
-			gnttab_end_foreign_access(s->grants_used[i]->gref, 0, 0UL);
15271552 			s->grants_used[i]->gref = GRANT_INVALID_REF;
15281553 			list_add_tail(&s->grants_used[i]->node, &rinfo->grants);
15291554 		}
15301555 	}
15311556 	if (s->req.operation == BLKIF_OP_INDIRECT) {
15321557 		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);
1558
+			if (!gnttab_try_end_foreign_access(s->indirect_grants[i]->gref)) {
1559
+				if (!info->feature_persistent) {
1560
+					pr_alert("backed has not unmapped grant: %u\n",
1561
+						 s->indirect_grants[i]->gref);
1562
+					return -1;
1563
+				}
15371564 				list_add(&s->indirect_grants[i]->node, &rinfo->grants);
15381565 				rinfo->persistent_gnts_c++;
15391566 			} else {
15401567 				struct page *indirect_page;
15411568 
1542
-				gnttab_end_foreign_access(s->indirect_grants[i]->gref, 0, 0UL);
15431569 				/*
15441570 				 * Add the used indirect page back to the list of
15451571 				 * available pages for indirect grefs.
15461572 				 */
1547
-				if (!info->feature_persistent) {
1573
+				if (!info->bounce) {
15481574 					indirect_page = s->indirect_grants[i]->page;
15491575 					list_add(&indirect_page->lru, &rinfo->indirect_pages);
15501576 				}
....@@ -1554,7 +1580,7 @@
15541580 		}
15551581 	}
15561582 
1557
-	return true;
1583
+	return 1;
15581584 }
15591585 
15601586 static irqreturn_t blkif_interrupt(int irq, void *dev_id)
....@@ -1620,12 +1646,17 @@
16201646 		}
16211647 
16221648 		if (bret.operation != BLKIF_OP_DISCARD) {
1649
+			int ret;
1650
+
16231651 			/*
16241652 			 * We may need to wait for an extra response if the
16251653 			 * I/O request is split in 2
16261654 			 */
1627
-			if (!blkif_completion(&id, rinfo, &bret))
1655
+			ret = blkif_completion(&id, rinfo, &bret);
1656
+			if (!ret)
16281657 				continue;
1658
+			if (unlikely(ret < 0))
1659
+				goto err;
16291660 		}
16301661 
16311662 		if (add_id_to_freelist(rinfo, id)) {
....@@ -1673,7 +1704,7 @@
16731704 				info->feature_flush = 0;
16741705 				xlvbd_flush(info);
16751706 			}
1676
-			/* fall through */
1707
+			fallthrough;
16771708 		case BLKIF_OP_READ:
16781709 		case BLKIF_OP_WRITE:
16791710 			if (unlikely(bret.status != BLKIF_RSP_OKAY))
....@@ -1686,7 +1717,8 @@
16861717 			BUG();
16871718 		}
16881719 
1689
-		blk_mq_complete_request(req);
1720
+		if (likely(!blk_should_fake_timeout(req->q)))
1721
+			blk_mq_complete_request(req);
16901722 	}
16911723 
16921724 	rinfo->ring.rsp_cons = i;
....@@ -1731,8 +1763,7 @@
17311763 	for (i = 0; i < info->nr_ring_pages; i++)
17321764 		rinfo->ring_ref[i] = GRANT_INVALID_REF;
17331765 
1734
-	sring = (struct blkif_sring *)__get_free_pages(GFP_NOIO | __GFP_HIGH,
1735
-						       get_order(ring_size));
1766
+	sring = alloc_pages_exact(ring_size, GFP_NOIO | __GFP_ZERO);
17361767 	if (!sring) {
17371768 		xenbus_dev_fatal(dev, -ENOMEM, "allocating shared ring");
17381769 		return -ENOMEM;
....@@ -1742,7 +1773,7 @@
17421773 
17431774 	err = xenbus_grant_ring(dev, rinfo->ring.sring, info->nr_ring_pages, gref);
17441775 	if (err < 0) {
1745
-		free_pages((unsigned long)sring, get_order(ring_size));
1776
+		free_pages_exact(sring, ring_size);
17461777 		rinfo->ring.sring = NULL;
17471778 		goto fail;
17481779 	}
....@@ -1822,6 +1853,12 @@
18221853 	kfree(info);
18231854 }
18241855 
1856
+/* Enable the persistent grants feature. */
1857
+static bool feature_persistent = true;
1858
+module_param(feature_persistent, bool, 0644);
1859
+MODULE_PARM_DESC(feature_persistent,
1860
+		"Enables the persistent grants feature");
1861
+
18251862 /* Common code used when first setting up, and when resuming. */
18261863 static int talk_to_blkback(struct xenbus_device *dev,
18271864 			   struct blkfront_info *info)
....@@ -1831,9 +1868,14 @@
18311868 	int err;
18321869 	unsigned int i, max_page_order;
18331870 	unsigned int ring_page_order;
1871
+	struct blkfront_ring_info *rinfo;
18341872 
18351873 	if (!info)
18361874 		return -ENODEV;
1875
+
1876
+	/* Check if backend is trusted. */
1877
+	info->bounce = !xen_blkif_trusted ||
1878
+		       !xenbus_read_unsigned(dev->nodename, "trusted", 1);
18371879 
18381880 	max_page_order = xenbus_read_unsigned(info->xbdev->otherend,
18391881 					      "max-ring-page-order", 0);
....@@ -1844,9 +1886,7 @@
18441886 	if (err)
18451887 		goto destroy_blkring;
18461888 
1847
-	for (i = 0; i < info->nr_rings; i++) {
1848
-		struct blkfront_ring_info *rinfo = &info->rinfo[i];
1849
-
1889
+	for_each_rinfo(info, rinfo, i) {
18501890 		/* Create shared ring, alloc event channel. */
18511891 		err = setup_blkring(dev, rinfo);
18521892 		if (err)
....@@ -1871,7 +1911,7 @@
18711911 
18721912 	/* We already got the number of queues/rings in _probe */
18731913 	if (info->nr_rings == 1) {
1874
-		err = write_per_ring_nodes(xbt, &info->rinfo[0], dev->nodename);
1914
+		err = write_per_ring_nodes(xbt, info->rinfo, dev->nodename);
18751915 		if (err)
18761916 			goto destroy_blkring;
18771917 	} else {
....@@ -1893,10 +1933,10 @@
18931933 			goto abort_transaction;
18941934 		}
18951935 
1896
-		for (i = 0; i < info->nr_rings; i++) {
1936
+		for_each_rinfo(info, rinfo, i) {
18971937 			memset(path, 0, pathsize);
18981938 			snprintf(path, pathsize, "%s/queue-%u", dev->nodename, i);
1899
-			err = write_per_ring_nodes(xbt, &info->rinfo[i], path);
1939
+			err = write_per_ring_nodes(xbt, rinfo, path);
19001940 			if (err) {
19011941 				kfree(path);
19021942 				goto destroy_blkring;
....@@ -1910,8 +1950,9 @@
19101950 		message = "writing protocol";
19111951 		goto abort_transaction;
19121952 	}
1913
-	err = xenbus_printf(xbt, dev->nodename,
1914
-			    "feature-persistent", "%u", 1);
1953
+	info->feature_persistent_parm = feature_persistent;
1954
+	err = xenbus_printf(xbt, dev->nodename, "feature-persistent", "%u",
1955
+			info->feature_persistent_parm);
19151956 	if (err)
19161957 		dev_warn(&dev->dev,
19171958 			 "writing persistent grants feature to xenbus");
....@@ -1924,9 +1965,8 @@
19241965 		goto destroy_blkring;
19251966 	}
19261967 
1927
-	for (i = 0; i < info->nr_rings; i++) {
1968
+	for_each_rinfo(info, rinfo, i) {
19281969 		unsigned int j;
1929
-		struct blkfront_ring_info *rinfo = &info->rinfo[i];
19301970 
19311971 		for (j = 0; j < BLK_RING_SIZE(info); j++)
19321972 			rinfo->shadow[j].req.u.rw.id = j + 1;
....@@ -1956,6 +1996,7 @@
19561996 {
19571997 	unsigned int backend_max_queues;
19581998 	unsigned int i;
1999
+	struct blkfront_ring_info *rinfo;
19592000 
19602001 	BUG_ON(info->nr_rings);
19612002 
....@@ -1967,19 +2008,16 @@
19672008 	if (!info->nr_rings)
19682009 		info->nr_rings = 1;
19692010 
1970
-	info->rinfo = kvcalloc(info->nr_rings,
1971
-			       sizeof(struct blkfront_ring_info),
1972
-			       GFP_KERNEL);
2011
+	info->rinfo_size = struct_size(info->rinfo, shadow,
2012
+				       BLK_RING_SIZE(info));
2013
+	info->rinfo = kvcalloc(info->nr_rings, info->rinfo_size, GFP_KERNEL);
19732014 	if (!info->rinfo) {
19742015 		xenbus_dev_fatal(info->xbdev, -ENOMEM, "allocating ring_info structure");
19752016 		info->nr_rings = 0;
19762017 		return -ENOMEM;
19772018 	}
19782019 
1979
-	for (i = 0; i < info->nr_rings; i++) {
1980
-		struct blkfront_ring_info *rinfo;
1981
-
1982
-		rinfo = &info->rinfo[i];
2020
+	for_each_rinfo(info, rinfo, i) {
19832021 		INIT_LIST_HEAD(&rinfo->indirect_pages);
19842022 		INIT_LIST_HEAD(&rinfo->grants);
19852023 		rinfo->dev_info = info;
....@@ -1988,6 +2026,7 @@
19882026 	}
19892027 	return 0;
19902028 }
2029
+
19912030 /**
19922031  * Entry point to this code when a new device is created.  Allocate the basic
19932032  * structures and the ring buffer for communication with the backend, and
....@@ -2072,6 +2111,7 @@
20722111 	int rc;
20732112 	struct bio *bio;
20742113 	unsigned int segs;
2114
+	struct blkfront_ring_info *rinfo;
20752115 
20762116 	blkfront_gather_backend_features(info);
20772117 	/* Reset limits changed by blk_mq_update_nr_hw_queues(). */
....@@ -2079,9 +2119,7 @@
20792119 	segs = info->max_indirect_segments ? : BLKIF_MAX_SEGMENTS_PER_REQUEST;
20802120 	blk_queue_max_segments(info->rq, segs / GRANTS_PER_PSEG);
20812121 
2082
-	for (r_index = 0; r_index < info->nr_rings; r_index++) {
2083
-		struct blkfront_ring_info *rinfo = &info->rinfo[r_index];
2084
-
2122
+	for_each_rinfo(info, rinfo, r_index) {
20852123 		rc = blkfront_setup_indirect(rinfo);
20862124 		if (rc)
20872125 			return rc;
....@@ -2091,10 +2129,7 @@
20912129 	/* Now safe for us to use the shared ring */
20922130 	info->connected = BLKIF_STATE_CONNECTED;
20932131 
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];
2132
+	for_each_rinfo(info, rinfo, r_index) {
20982133 		/* Kick any other new requests queued since we resumed */
20992134 		kick_pending_request_queues(rinfo);
21002135 	}
....@@ -2127,13 +2162,13 @@
21272162 	struct blkfront_info *info = dev_get_drvdata(&dev->dev);
21282163 	int err = 0;
21292164 	unsigned int i, j;
2165
+	struct blkfront_ring_info *rinfo;
21302166 
21312167 	dev_dbg(&dev->dev, "blkfront_resume: %s\n", dev->nodename);
21322168 
21332169 	bio_list_init(&info->bio_list);
21342170 	INIT_LIST_HEAD(&info->requests);
2135
-	for (i = 0; i < info->nr_rings; i++) {
2136
-		struct blkfront_ring_info *rinfo = &info->rinfo[i];
2171
+	for_each_rinfo(info, rinfo, i) {
21372172 		struct bio_list merge_bio;
21382173 		struct blk_shadow *shadow = rinfo->shadow;
21392174 
....@@ -2261,17 +2296,18 @@
22612296 	if (err)
22622297 		goto out_of_memory;
22632298 
2264
-	if (!info->feature_persistent && info->max_indirect_segments) {
2299
+	if (!info->bounce && info->max_indirect_segments) {
22652300 		/*
2266
-		 * We are using indirect descriptors but not persistent
2267
-		 * grants, we need to allocate a set of pages that can be
2301
+		 * We are using indirect descriptors but don't have a bounce
2302
+		 * buffer, we need to allocate a set of pages that can be
22682303 		 * used for mapping indirect grefs
22692304 		 */
22702305 		int num = INDIRECT_GREFS(grants) * BLK_RING_SIZE(info);
22712306 
22722307 		BUG_ON(!list_empty(&rinfo->indirect_pages));
22732308 		for (i = 0; i < num; i++) {
2274
-			struct page *indirect_page = alloc_page(GFP_KERNEL);
2309
+			struct page *indirect_page = alloc_page(GFP_KERNEL |
2310
+			                                        __GFP_ZERO);
22752311 			if (!indirect_page)
22762312 				goto out_of_memory;
22772313 			list_add(&indirect_page->lru, &rinfo->indirect_pages);
....@@ -2360,9 +2396,12 @@
23602396 	if (xenbus_read_unsigned(info->xbdev->otherend, "feature-discard", 0))
23612397 		blkfront_setup_discard(info);
23622398 
2363
-	info->feature_persistent =
2364
-		!!xenbus_read_unsigned(info->xbdev->otherend,
2365
-				       "feature-persistent", 0);
2399
+	if (info->feature_persistent_parm)
2400
+		info->feature_persistent =
2401
+			!!xenbus_read_unsigned(info->xbdev->otherend,
2402
+					       "feature-persistent", 0);
2403
+	if (info->feature_persistent)
2404
+		info->bounce = true;
23662405 
23672406 	indirect_segments = xenbus_read_unsigned(info->xbdev->otherend,
23682407 					"feature-max-indirect-segments", 0);
....@@ -2389,8 +2428,8 @@
23892428 	unsigned long sector_size;
23902429 	unsigned int physical_sector_size;
23912430 	unsigned int binfo;
2392
-	char *envp[] = { "RESIZE=1", NULL };
23932431 	int err, i;
2432
+	struct blkfront_ring_info *rinfo;
23942433 
23952434 	switch (info->connected) {
23962435 	case BLKIF_STATE_CONNECTED:
....@@ -2404,10 +2443,7 @@
24042443 			return;
24052444 		printk(KERN_INFO "Setting capacity to %Lu\n",
24062445 		       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);
2446
+		set_capacity_revalidate_and_notify(info->gd, sectors, true);
24112447 
24122448 		return;
24132449 	case BLKIF_STATE_SUSPENDED:
....@@ -2448,8 +2484,8 @@
24482484 						    "physical-sector-size",
24492485 						    sector_size);
24502486 	blkfront_gather_backend_features(info);
2451
-	for (i = 0; i < info->nr_rings; i++) {
2452
-		err = blkfront_setup_indirect(&info->rinfo[i]);
2487
+	for_each_rinfo(info, rinfo, i) {
2488
+		err = blkfront_setup_indirect(rinfo);
24532489 		if (err) {
24542490 			xenbus_dev_fatal(info->xbdev, err, "setup_indirect at %s",
24552491 					 info->xbdev->otherend);
....@@ -2470,10 +2506,10 @@
24702506 
24712507 	/* Kick pending requests. */
24722508 	info->connected = BLKIF_STATE_CONNECTED;
2473
-	for (i = 0; i < info->nr_rings; i++)
2474
-		kick_pending_request_queues(&info->rinfo[i]);
2509
+	for_each_rinfo(info, rinfo, i)
2510
+		kick_pending_request_queues(rinfo);
24752511 
2476
-	device_add_disk(&info->xbdev->dev, info->gd);
2512
+	device_add_disk(&info->xbdev->dev, info->gd, NULL);
24772513 
24782514 	info->is_ready = 1;
24792515 	return;
....@@ -2530,7 +2566,7 @@
25302566 	case XenbusStateClosed:
25312567 		if (dev->state == XenbusStateClosed)
25322568 			break;
2533
-		/* fall through */
2569
+		fallthrough;
25342570 	case XenbusStateClosing:
25352571 		if (info)
25362572 			blkfront_closing(info);
....@@ -2684,6 +2720,7 @@
26842720 	.release = blkif_release,
26852721 	.getgeo = blkif_getgeo,
26862722 	.ioctl = blkif_ioctl,
2723
+	.compat_ioctl = blkdev_compat_ptr_ioctl,
26872724 };
26882725 
26892726 
....@@ -2705,9 +2742,9 @@
27052742 {
27062743 	unsigned int i;
27072744 	unsigned long flags;
2745
+	struct blkfront_ring_info *rinfo;
27082746 
2709
-	for (i = 0; i < info->nr_rings; i++) {
2710
-		struct blkfront_ring_info *rinfo = &info->rinfo[i];
2747
+	for_each_rinfo(info, rinfo, i) {
27112748 		struct grant *gnt_list_entry, *tmp;
27122749 
27132750 		spin_lock_irqsave(&rinfo->ring_lock, flags);
....@@ -2720,11 +2757,10 @@
27202757 		list_for_each_entry_safe(gnt_list_entry, tmp, &rinfo->grants,
27212758 					 node) {
27222759 			if (gnt_list_entry->gref == GRANT_INVALID_REF ||
2723
-			    gnttab_query_foreign_access(gnt_list_entry->gref))
2760
+			    !gnttab_try_end_foreign_access(gnt_list_entry->gref))
27242761 				continue;
27252762 
27262763 			list_del(&gnt_list_entry->node);
2727
-			gnttab_end_foreign_access(gnt_list_entry->gref, 0, 0UL);
27282764 			rinfo->persistent_gnts_c--;
27292765 			gnt_list_entry->gref = GRANT_INVALID_REF;
27302766 			list_add_tail(&gnt_list_entry->node, &rinfo->grants);
....@@ -2739,6 +2775,13 @@
27392775 	struct blkfront_info *info;
27402776 	bool need_schedule_work = false;
27412777 
2778
+	/*
2779
+	 * Note that when using bounce buffers but not persistent grants
2780
+	 * there's no need to run blkfront_delay_work because grants are
2781
+	 * revoked in blkif_completion or else an error is reported and the
2782
+	 * connection is closed.
2783
+	 */
2784
+
27422785 	mutex_lock(&blkfront_mutex);
27432786 
27442787 	list_for_each_entry(info, &info_list, info_list) {