Merge branch 'stable/for-jens-3.9' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen into for-3.9/drivers

Konrad writes:

Please git pull the following branch:

 git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen.git stable/for-jens-3.9

which has bug-fixes that did not make it in v3.8. They all are marked as
material for the stable tree as well. There are two bug-fixes for
the code that has been in there for some time (that is the Jan's fix
and one of mine). And there are two bug-fixes for the persistent grant
feature that debuted in v3.8 for xen blk[back|front]end.

8 files changed, 87 insertions, 49 deletions

diff --git a/drivers/block/drbd/drbd_req.c b/drivers/block/drbd/drbd_req.c
index f58a4a4b4dfb..2b8303ad63c9 100644
--- a/drivers/block/drbd/drbd_req.c
+++ b/drivers/block/drbd/drbd_req.c
@@ -168,7 +168,7 @@ static void wake_all_senders(struct drbd_tconn *tconn) {
 }
 
 /* must hold resource->req_lock */
-static void start_new_tl_epoch(struct drbd_tconn *tconn)
+void start_new_tl_epoch(struct drbd_tconn *tconn)
 {
 	/* no point closing an epoch, if it is empty, anyways. */
 	if (tconn->current_tle_writes == 0)
diff --git a/drivers/block/drbd/drbd_req.h b/drivers/block/drbd/drbd_req.h
index 016de6b8bb57..c08d22964d06 100644
--- a/drivers/block/drbd/drbd_req.h
+++ b/drivers/block/drbd/drbd_req.h
@@ -267,6 +267,7 @@ struct bio_and_error {
 	int error;
 };
 
+extern void start_new_tl_epoch(struct drbd_tconn *tconn);
 extern void drbd_req_destroy(struct kref *kref);
 extern void _req_may_be_done(struct drbd_request *req,
 		struct bio_and_error *m);
diff --git a/drivers/block/drbd/drbd_state.c b/drivers/block/drbd/drbd_state.c
index 53bf6182bac4..0fe220cfb9e9 100644
--- a/drivers/block/drbd/drbd_state.c
+++ b/drivers/block/drbd/drbd_state.c
@@ -931,6 +931,7 @@ __drbd_set_state(struct drbd_conf *mdev, union drbd_state ns,
 	enum drbd_state_rv rv = SS_SUCCESS;
 	enum sanitize_state_warnings ssw;
 	struct after_state_chg_work *ascw;
+	bool did_remote, should_do_remote;
 
 	os = drbd_read_state(mdev);
 
@@ -981,11 +982,17 @@ __drbd_set_state(struct drbd_conf *mdev, union drbd_state ns,
 	    (os.disk != D_DISKLESS && ns.disk == D_DISKLESS))
 		atomic_inc(&mdev->local_cnt);
 
+	did_remote = drbd_should_do_remote(mdev->state);
 	mdev->state.i = ns.i;
+	should_do_remote = drbd_should_do_remote(mdev->state);
 	mdev->tconn->susp = ns.susp;
 	mdev->tconn->susp_nod = ns.susp_nod;
 	mdev->tconn->susp_fen = ns.susp_fen;
 
+	/* put replicated vs not-replicated requests in seperate epochs */
+	if (did_remote != should_do_remote)
+		start_new_tl_epoch(mdev->tconn);
+
 	if (os.disk == D_ATTACHING && ns.disk >= D_NEGOTIATING)
 		drbd_print_uuids(mdev, "attached to UUIDs");
 
diff --git a/drivers/block/mtip32xx/mtip32xx.c b/drivers/block/mtip32xx/mtip32xx.c
index 9790666f90f2..11cc9522cdd4 100644
--- a/drivers/block/mtip32xx/mtip32xx.c
+++ b/drivers/block/mtip32xx/mtip32xx.c
@@ -629,12 +629,13 @@ static void mtip_timeout_function(unsigned long int data)
 		}
 	}
 
-	if (cmdto_cnt && !test_bit(MTIP_PF_IC_ACTIVE_BIT, &port->flags)) {
+	if (cmdto_cnt) {
 		print_tags(port->dd, "timed out", tagaccum, cmdto_cnt);
-
-		mtip_restart_port(port);
+		if (!test_bit(MTIP_PF_IC_ACTIVE_BIT, &port->flags)) {
+			mtip_restart_port(port);
+			wake_up_interruptible(&port->svc_wait);
+		}
 		clear_bit(MTIP_PF_EH_ACTIVE_BIT, &port->flags);
-		wake_up_interruptible(&port->svc_wait);
 	}
 
 	if (port->ic_pause_timer) {
@@ -4017,7 +4018,12 @@ static int mtip_block_remove(struct driver_data *dd)
 	 * Delete our gendisk structure. This also removes the device
 	 * from /dev
 	 */
-	del_gendisk(dd->disk);
+	if (dd->disk) {
+		if (dd->disk->queue)
+			del_gendisk(dd->disk);
+		else
+			put_disk(dd->disk);
+	}
 
 	spin_lock(&rssd_index_lock);
 	ida_remove(&rssd_index_ida, dd->index);
@@ -4051,7 +4057,13 @@ static int mtip_block_shutdown(struct driver_data *dd)
 		"Shutting down %s ...\n", dd->disk->disk_name);
 
 	/* Delete our gendisk structure, and cleanup the blk queue. */
-	del_gendisk(dd->disk);
+	if (dd->disk) {
+		if (dd->disk->queue)
+			del_gendisk(dd->disk);
+		else
+			put_disk(dd->disk);
+	}
+
 
 	spin_lock(&rssd_index_lock);
 	ida_remove(&rssd_index_ida, dd->index);
diff --git a/drivers/block/virtio_blk.c b/drivers/block/virtio_blk.c
index 9d8409c02082..8ad21a25bc0d 100644
--- a/drivers/block/virtio_blk.c
+++ b/drivers/block/virtio_blk.c
@@ -889,6 +889,7 @@ static void virtblk_remove(struct virtio_device *vdev)
 {
 	struct virtio_blk *vblk = vdev->priv;
 	int index = vblk->index;
+	int refc;
 
 	/* Prevent config work handler from accessing the device. */
 	mutex_lock(&vblk->config_lock);
@@ -903,11 +904,15 @@ static void virtblk_remove(struct virtio_device *vdev)
 
 	flush_work(&vblk->config_work);
 
+	refc = atomic_read(&disk_to_dev(vblk->disk)->kobj.kref.refcount);
 	put_disk(vblk->disk);
 	mempool_destroy(vblk->pool);
 	vdev->config->del_vqs(vdev);
 	kfree(vblk);
-	ida_simple_remove(&vd_index_ida, index);
+
+	/* Only free device id if we don't have any users */
+	if (refc == 1)
+		ida_simple_remove(&vd_index_ida, index);
 }
 
 #ifdef CONFIG_PM
diff --git a/drivers/block/xen-blkback/blkback.c b/drivers/block/xen-blkback/blkback.c
index 74374fb762aa..de1f319f7bd7 100644
--- a/drivers/block/xen-blkback/blkback.c
+++ b/drivers/block/xen-blkback/blkback.c
@@ -46,6 +46,7 @@
 #include <xen/xen.h>
 #include <asm/xen/hypervisor.h>
 #include <asm/xen/hypercall.h>
+#include <xen/balloon.h>
 #include "common.h"
 
 /*
@@ -161,10 +162,12 @@ static int dispatch_rw_block_io(struct xen_blkif *blkif,
 static void make_response(struct xen_blkif *blkif, u64 id,
 			  unsigned short op, int st);
 
-#define foreach_grant(pos, rbtree, node) \
-	for ((pos) = container_of(rb_first((rbtree)), typeof(*(pos)), node); \
+#define foreach_grant_safe(pos, n, rbtree, node) \
+	for ((pos) = container_of(rb_first((rbtree)), typeof(*(pos)), node), \
+	     (n) = rb_next(&(pos)->node); \
 	     &(pos)->node != NULL; \
-	     (pos) = container_of(rb_next(&(pos)->node), typeof(*(pos)), node))
+	     (pos) = container_of(n, typeof(*(pos)), node), \
+	     (n) = (&(pos)->node != NULL) ? rb_next(&(pos)->node) : NULL)
 
 
 static void add_persistent_gnt(struct rb_root *root,
@@ -217,10 +220,11 @@ static void free_persistent_gnts(struct rb_root *root, unsigned int num)
 	struct gnttab_unmap_grant_ref unmap[BLKIF_MAX_SEGMENTS_PER_REQUEST];
 	struct page *pages[BLKIF_MAX_SEGMENTS_PER_REQUEST];
 	struct persistent_gnt *persistent_gnt;
+	struct rb_node *n;
 	int ret = 0;
 	int segs_to_unmap = 0;
 
-	foreach_grant(persistent_gnt, root, node) {
+	foreach_grant_safe(persistent_gnt, n, root, node) {
 		BUG_ON(persistent_gnt->handle ==
 			BLKBACK_INVALID_HANDLE);
 		gnttab_set_unmap_op(&unmap[segs_to_unmap],
@@ -230,17 +234,19 @@ static void free_persistent_gnts(struct rb_root *root, unsigned int num)
 			persistent_gnt->handle);
 
 		pages[segs_to_unmap] = persistent_gnt->page;
-		rb_erase(&persistent_gnt->node, root);
-		kfree(persistent_gnt);
-		num--;
 
 		if (++segs_to_unmap == BLKIF_MAX_SEGMENTS_PER_REQUEST ||
 			!rb_next(&persistent_gnt->node)) {
 			ret = gnttab_unmap_refs(unmap, NULL, pages,
 				segs_to_unmap);
 			BUG_ON(ret);
+			free_xenballooned_pages(segs_to_unmap, pages);
 			segs_to_unmap = 0;
 		}
+
+		rb_erase(&persistent_gnt->node, root);
+		kfree(persistent_gnt);
+		num--;
 	}
 	BUG_ON(num != 0);
 }
@@ -523,8 +529,8 @@ static int xen_blkbk_map(struct blkif_request *req,
 				GFP_KERNEL);
 			if (!persistent_gnt)
 				return -ENOMEM;
-			persistent_gnt->page = alloc_page(GFP_KERNEL);
-			if (!persistent_gnt->page) {
+			if (alloc_xenballooned_pages(1, &persistent_gnt->page,
+			    false)) {
 				kfree(persistent_gnt);
 				return -ENOMEM;
 			}
@@ -875,7 +881,6 @@ static int dispatch_rw_block_io(struct xen_blkif *blkif,
 		goto fail_response;
 	}
 
-	preq.dev           = req->u.rw.handle;
 	preq.sector_number = req->u.rw.sector_number;
 	preq.nr_sects      = 0;
 
diff --git a/drivers/block/xen-blkback/xenbus.c b/drivers/block/xen-blkback/xenbus.c
index 63980722db41..5e237f630c47 100644
--- a/drivers/block/xen-blkback/xenbus.c
+++ b/drivers/block/xen-blkback/xenbus.c
@@ -367,6 +367,7 @@ static int xen_blkbk_remove(struct xenbus_device *dev)
 		be->blkif = NULL;
 	}
 
+	kfree(be->mode);
 	kfree(be);
 	dev_set_drvdata(&dev->dev, NULL);
 	return 0;
@@ -502,6 +503,7 @@ static void backend_changed(struct xenbus_watch *watch,
 		= container_of(watch, struct backend_info, backend_watch);
 	struct xenbus_device *dev = be->dev;
 	int cdrom = 0;
+	unsigned long handle;
 	char *device_type;
 
 	DPRINTK("");
@@ -521,10 +523,10 @@ static void backend_changed(struct xenbus_watch *watch,
 		return;
 	}
 
-	if ((be->major || be->minor) &&
-	    ((be->major != major) || (be->minor != minor))) {
-		pr_warn(DRV_PFX "changing physical device (from %x:%x to %x:%x) not supported.\n",
-			be->major, be->minor, major, minor);
+	if (be->major | be->minor) {
+		if (be->major != major || be->minor != minor)
+			pr_warn(DRV_PFX "changing physical device (from %x:%x to %x:%x) not supported.\n",
+				be->major, be->minor, major, minor);
 		return;
 	}
 
@@ -542,36 +544,33 @@ static void backend_changed(struct xenbus_watch *watch,
 		kfree(device_type);
 	}
 
-	if (be->major == 0 && be->minor == 0) {
-		/* Front end dir is a number, which is used as the handle. */
-
-		char *p = strrchr(dev->otherend, '/') + 1;
-		long handle;
-		err = strict_strtoul(p, 0, &handle);
-		if (err)
-			return;
+	/* Front end dir is a number, which is used as the handle. */
+	err = strict_strtoul(strrchr(dev->otherend, '/') + 1, 0, &handle);
+	if (err)
+		return;
 
-		be->major = major;
-		be->minor = minor;
+	be->major = major;
+	be->minor = minor;
 
-		err = xen_vbd_create(be->blkif, handle, major, minor,
-				 (NULL == strchr(be->mode, 'w')), cdrom);
-		if (err) {
-			be->major = 0;
-			be->minor = 0;
-			xenbus_dev_fatal(dev, err, "creating vbd structure");
-			return;
-		}
+	err = xen_vbd_create(be->blkif, handle, major, minor,
+			     !strchr(be->mode, 'w'), cdrom);
 
+	if (err)
+		xenbus_dev_fatal(dev, err, "creating vbd structure");
+	else {
 		err = xenvbd_sysfs_addif(dev);
 		if (err) {
 			xen_vbd_free(&be->blkif->vbd);
-			be->major = 0;
-			be->minor = 0;
 			xenbus_dev_fatal(dev, err, "creating sysfs entries");
-			return;
 		}
+	}
 
+	if (err) {
+		kfree(be->mode);
+		be->mode = NULL;
+		be->major = 0;
+		be->minor = 0;
+	} else {
 		/* We're potentially connected now */
 		xen_update_blkif_status(be->blkif);
 	}
diff --git a/drivers/block/xen-blkfront.c b/drivers/block/xen-blkfront.c
index 96e9b00db081..c3dae2e0f290 100644
--- a/drivers/block/xen-blkfront.c
+++ b/drivers/block/xen-blkfront.c
@@ -791,7 +791,8 @@ static void blkif_restart_queue(struct work_struct *work)
 static void blkif_free(struct blkfront_info *info, int suspend)
 {
 	struct llist_node *all_gnts;
-	struct grant *persistent_gnt;
+	struct grant *persistent_gnt, *tmp;
+	struct llist_node *n;
 
 	/* Prevent new requests being issued until we fix things up. */
 	spin_lock_irq(&info->io_lock);
@@ -804,10 +805,17 @@ static void blkif_free(struct blkfront_info *info, int suspend)
 	/* Remove all persistent grants */
 	if (info->persistent_gnts_c) {
 		all_gnts = llist_del_all(&info->persistent_gnts);
-		llist_for_each_entry(persistent_gnt, all_gnts, node) {
+		persistent_gnt = llist_entry(all_gnts, typeof(*(persistent_gnt)), node);
+		while (persistent_gnt) {
 			gnttab_end_foreign_access(persistent_gnt->gref, 0, 0UL);
 			__free_page(pfn_to_page(persistent_gnt->pfn));
-			kfree(persistent_gnt);
+			tmp = persistent_gnt;
+			n = persistent_gnt->node.next;
+			if (n)
+				persistent_gnt = llist_entry(n, typeof(*(persistent_gnt)), node);
+			else
+				persistent_gnt = NULL;
+			kfree(tmp);
 		}
 		info->persistent_gnts_c = 0;
 	}
@@ -835,7 +843,7 @@ static void blkif_free(struct blkfront_info *info, int suspend)
 static void blkif_completion(struct blk_shadow *s, struct blkfront_info *info,
 			     struct blkif_response *bret)
 {
-	int i;
+	int i = 0;
 	struct bio_vec *bvec;
 	struct req_iterator iter;
 	unsigned long flags;
@@ -852,7 +860,8 @@ static void blkif_completion(struct blk_shadow *s, struct blkfront_info *info,
 		 */
 		rq_for_each_segment(bvec, s->request, iter) {
 			BUG_ON((bvec->bv_offset + bvec->bv_len) > PAGE_SIZE);
-			i = offset >> PAGE_SHIFT;
+			if (bvec->bv_offset < offset)
+				i++;
 			BUG_ON(i >= s->req.u.rw.nr_segments);
 			shared_data = kmap_atomic(
 				pfn_to_page(s->grants_used[i]->pfn));
@@ -861,7 +870,7 @@ static void blkif_completion(struct blk_shadow *s, struct blkfront_info *info,
 				bvec->bv_len);
 			bvec_kunmap_irq(bvec_data, &flags);
 			kunmap_atomic(shared_data);
-			offset += bvec->bv_len;
+			offset = bvec->bv_offset + bvec->bv_len;
 		}
 	}
 	/* Add the persistent grant into the list of free grants */