Merge branch 'linus' into x86/cleanups

Conflicts:
	arch/x86/kernel/reboot.c

7 files changed, 113 insertions, 82 deletions

diff --git a/drivers/block/cciss.c b/drivers/block/cciss.c
index 9f7c543cc04..01e69383d9c 100644
--- a/drivers/block/cciss.c
+++ b/drivers/block/cciss.c
@@ -164,7 +164,7 @@ static int cciss_getgeo(struct block_device *bdev, struct hd_geometry *geo);
 
 static int cciss_revalidate(struct gendisk *disk);
 static int rebuild_lun_table(ctlr_info_t *h, int first_time);
-static int deregister_disk(struct gendisk *disk, drive_info_struct *drv,
+static int deregister_disk(ctlr_info_t *h, int drv_index,
 			   int clear_all);
 
 static void cciss_read_capacity(int ctlr, int logvol, int withirq,
@@ -215,31 +215,17 @@ static struct block_device_operations cciss_fops = {
 /*
  * Enqueuing and dequeuing functions for cmdlists.
  */
-static inline void addQ(CommandList_struct **Qptr, CommandList_struct *c)
+static inline void addQ(struct hlist_head *list, CommandList_struct *c)
 {
-	if (*Qptr == NULL) {
-		*Qptr = c;
-		c->next = c->prev = c;
-	} else {
-		c->prev = (*Qptr)->prev;
-		c->next = (*Qptr);
-		(*Qptr)->prev->next = c;
-		(*Qptr)->prev = c;
-	}
+	hlist_add_head(&c->list, list);
 }
 
-static inline CommandList_struct *removeQ(CommandList_struct **Qptr,
-					  CommandList_struct *c)
+static inline void removeQ(CommandList_struct *c)
 {
-	if (c && c->next != c) {
-		if (*Qptr == c)
-			*Qptr = c->next;
-		c->prev->next = c->next;
-		c->next->prev = c->prev;
-	} else {
-		*Qptr = NULL;
-	}
-	return c;
+	if (WARN_ON(hlist_unhashed(&c->list)))
+		return;
+
+	hlist_del_init(&c->list);
 }
 
 #include "cciss_scsi.c"		/* For SCSI tape support */
@@ -506,6 +492,7 @@ static CommandList_struct *cmd_alloc(ctlr_info_t *h, int get_from_pool)
 		c->cmdindex = i;
 	}
 
+	INIT_HLIST_NODE(&c->list);
 	c->busaddr = (__u32) cmd_dma_handle;
 	temp64.val = (__u64) err_dma_handle;
 	c->ErrDesc.Addr.lower = temp64.val32.lower;
@@ -1492,8 +1479,7 @@ static void cciss_update_drive_info(int ctlr, int drv_index, int first_time)
 		 * which keeps the interrupt handler from starting
 		 * the queue.
 		 */
-		ret = deregister_disk(h->gendisk[drv_index],
-				      &h->drv[drv_index], 0);
+		ret = deregister_disk(h, drv_index, 0);
 		h->drv[drv_index].busy_configuring = 0;
 	}
 
@@ -1711,8 +1697,7 @@ static int rebuild_lun_table(ctlr_info_t *h, int first_time)
 			spin_lock_irqsave(CCISS_LOCK(h->ctlr), flags);
 			h->drv[i].busy_configuring = 1;
 			spin_unlock_irqrestore(CCISS_LOCK(h->ctlr), flags);
-			return_code = deregister_disk(h->gendisk[i],
-				&h->drv[i], 1);
+			return_code = deregister_disk(h, i, 1);
 			h->drv[i].busy_configuring = 0;
 		}
 	}
@@ -1782,15 +1767,19 @@ mem_msg:
  *             the highest_lun should be left unchanged and the LunID
  *             should not be cleared.
 */
-static int deregister_disk(struct gendisk *disk, drive_info_struct *drv,
+static int deregister_disk(ctlr_info_t *h, int drv_index,
 			   int clear_all)
 {
 	int i;
-	ctlr_info_t *h = get_host(disk);
+	struct gendisk *disk;
+	drive_info_struct *drv;
 
 	if (!capable(CAP_SYS_RAWIO))
 		return -EPERM;
 
+	drv = &h->drv[drv_index];
+	disk = h->gendisk[drv_index];
+
 	/* make sure logical volume is NOT is use */
 	if (clear_all || (h->gendisk[0] == disk)) {
 		if (drv->usage_count > 1)
@@ -2548,7 +2537,8 @@ static void start_io(ctlr_info_t *h)
 {
 	CommandList_struct *c;
 
-	while ((c = h->reqQ) != NULL) {
+	while (!hlist_empty(&h->reqQ)) {
+		c = hlist_entry(h->reqQ.first, CommandList_struct, list);
 		/* can't do anything if fifo is full */
 		if ((h->access.fifo_full(h))) {
 			printk(KERN_WARNING "cciss: fifo full\n");
@@ -2556,14 +2546,14 @@ static void start_io(ctlr_info_t *h)
 		}
 
 		/* Get the first entry from the Request Q */
-		removeQ(&(h->reqQ), c);
+		removeQ(c);
 		h->Qdepth--;
 
 		/* Tell the controller execute command */
 		h->access.submit_command(h, c);
 
 		/* Put job onto the completed Q */
-		addQ(&(h->cmpQ), c);
+		addQ(&h->cmpQ, c);
 	}
 }
 
@@ -2576,7 +2566,7 @@ static inline void resend_cciss_cmd(ctlr_info_t *h, CommandList_struct *c)
 	memset(c->err_info, 0, sizeof(ErrorInfo_struct));
 
 	/* add it to software queue and then send it to the controller */
-	addQ(&(h->reqQ), c);
+	addQ(&h->reqQ, c);
 	h->Qdepth++;
 	if (h->Qdepth > h->maxQsinceinit)
 		h->maxQsinceinit = h->Qdepth;
@@ -2897,7 +2887,7 @@ static void do_cciss_request(struct request_queue *q)
 
 	spin_lock_irq(q->queue_lock);
 
-	addQ(&(h->reqQ), c);
+	addQ(&h->reqQ, c);
 	h->Qdepth++;
 	if (h->Qdepth > h->maxQsinceinit)
 		h->maxQsinceinit = h->Qdepth;
@@ -2985,16 +2975,12 @@ static irqreturn_t do_cciss_intr(int irq, void *dev_id)
 				a = c->busaddr;
 
 			} else {
+				struct hlist_node *tmp;
+
 				a &= ~3;
-				if ((c = h->cmpQ) == NULL) {
-					printk(KERN_WARNING
-					       "cciss: Completion of %08x ignored\n",
-					       a1);
-					continue;
-				}
-				while (c->busaddr != a) {
-					c = c->next;
-					if (c == h->cmpQ)
+				c = NULL;
+				hlist_for_each_entry(c, tmp, &h->cmpQ, list) {
+					if (c->busaddr == a)
 						break;
 				}
 			}
@@ -3002,8 +2988,8 @@ static irqreturn_t do_cciss_intr(int irq, void *dev_id)
 			 * If we've found the command, take it off the
 			 * completion Q and free it
 			 */
-			if (c->busaddr == a) {
-				removeQ(&h->cmpQ, c);
+			if (c && c->busaddr == a) {
+				removeQ(c);
 				if (c->cmd_type == CMD_RWREQ) {
 					complete_command(h, c, 0);
 				} else if (c->cmd_type == CMD_IOCTL_PEND) {
@@ -3423,6 +3409,8 @@ static int __devinit cciss_init_one(struct pci_dev *pdev,
 		return -1;
 
 	hba[i]->busy_initializing = 1;
+	INIT_HLIST_HEAD(&hba[i]->cmpQ);
+	INIT_HLIST_HEAD(&hba[i]->reqQ);
 
 	if (cciss_pci_init(hba[i], pdev) != 0)
 		goto clean1;
@@ -3730,15 +3718,17 @@ static void fail_all_cmds(unsigned long ctlr)
 	pci_disable_device(h->pdev);	/* Make sure it is really dead. */
 
 	/* move everything off the request queue onto the completed queue */
-	while ((c = h->reqQ) != NULL) {
-		removeQ(&(h->reqQ), c);
+	while (!hlist_empty(&h->reqQ)) {
+		c = hlist_entry(h->reqQ.first, CommandList_struct, list);
+		removeQ(c);
 		h->Qdepth--;
-		addQ(&(h->cmpQ), c);
+		addQ(&h->cmpQ, c);
 	}
 
 	/* Now, fail everything on the completed queue with a HW error */
-	while ((c = h->cmpQ) != NULL) {
-		removeQ(&h->cmpQ, c);
+	while (!hlist_empty(&h->cmpQ)) {
+		c = hlist_entry(h->cmpQ.first, CommandList_struct, list);
+		removeQ(c);
 		c->err_info->CommandStatus = CMD_HARDWARE_ERR;
 		if (c->cmd_type == CMD_RWREQ) {
 			complete_command(h, c, 0);
diff --git a/drivers/block/cciss.h b/drivers/block/cciss.h
index 24a7efa993a..15e2b84734e 100644
--- a/drivers/block/cciss.h
+++ b/drivers/block/cciss.h
@@ -89,8 +89,8 @@ struct ctlr_info
 	struct access_method access;
 
 	/* queue and queue Info */ 
-	CommandList_struct *reqQ;
-	CommandList_struct  *cmpQ;
+	struct hlist_head reqQ;
+	struct hlist_head cmpQ;
 	unsigned int Qdepth;
 	unsigned int maxQsinceinit;
 	unsigned int maxSG;
diff --git a/drivers/block/cciss_cmd.h b/drivers/block/cciss_cmd.h
index 43bf5593b59..24e22dea1a9 100644
--- a/drivers/block/cciss_cmd.h
+++ b/drivers/block/cciss_cmd.h
@@ -265,8 +265,7 @@ typedef struct _CommandList_struct {
   int			   ctlr;
   int			   cmd_type; 
   long			   cmdindex;
-  struct _CommandList_struct *prev;
-  struct _CommandList_struct *next;
+  struct hlist_node list;
   struct request *	   rq;
   struct completion *waiting;
   int	 retry_count;
diff --git a/drivers/block/loop.c b/drivers/block/loop.c
index fb06ed65921..edbaac6c057 100644
--- a/drivers/block/loop.c
+++ b/drivers/block/loop.c
@@ -624,20 +624,38 @@ static int loop_switch(struct loop_device *lo, struct file *file)
 }
 
 /*
+ * Helper to flush the IOs in loop, but keeping loop thread running
+ */
+static int loop_flush(struct loop_device *lo)
+{
+	/* loop not yet configured, no running thread, nothing to flush */
+	if (!lo->lo_thread)
+		return 0;
+
+	return loop_switch(lo, NULL);
+}
+
+/*
  * Do the actual switch; called from the BIO completion routine
  */
 static void do_loop_switch(struct loop_device *lo, struct switch_request *p)
 {
 	struct file *file = p->file;
 	struct file *old_file = lo->lo_backing_file;
-	struct address_space *mapping = file->f_mapping;
+	struct address_space *mapping;
+
+	/* if no new file, only flush of queued bios requested */
+	if (!file)
+		goto out;
 
+	mapping = file->f_mapping;
 	mapping_set_gfp_mask(old_file->f_mapping, lo->old_gfp_mask);
 	lo->lo_backing_file = file;
 	lo->lo_blocksize = S_ISBLK(mapping->host->i_mode) ?
 		mapping->host->i_bdev->bd_block_size : PAGE_SIZE;
 	lo->old_gfp_mask = mapping_gfp_mask(mapping);
 	mapping_set_gfp_mask(mapping, lo->old_gfp_mask & ~(__GFP_IO|__GFP_FS));
+out:
 	complete(&p->wait);
 }
 
@@ -901,6 +919,7 @@ static int loop_clr_fd(struct loop_device *lo, struct block_device *bdev)
 
 	kthread_stop(lo->lo_thread);
 
+	lo->lo_queue->unplug_fn = NULL;
 	lo->lo_backing_file = NULL;
 
 	loop_release_xfer(lo);
@@ -1345,11 +1364,25 @@ static int lo_release(struct gendisk *disk, fmode_t mode)
 	struct loop_device *lo = disk->private_data;
 
 	mutex_lock(&lo->lo_ctl_mutex);
-	--lo->lo_refcnt;
 
-	if ((lo->lo_flags & LO_FLAGS_AUTOCLEAR) && !lo->lo_refcnt)
+	if (--lo->lo_refcnt)
+		goto out;
+
+	if (lo->lo_flags & LO_FLAGS_AUTOCLEAR) {
+		/*
+		 * In autoclear mode, stop the loop thread
+		 * and remove configuration after last close.
+		 */
 		loop_clr_fd(lo, NULL);
+	} else {
+		/*
+		 * Otherwise keep thread (if running) and config,
+		 * but flush possible ongoing bios in thread.
+		 */
+		loop_flush(lo);
+	}
 
+out:
 	mutex_unlock(&lo->lo_ctl_mutex);
 
 	return 0;
diff --git a/drivers/block/nbd.c b/drivers/block/nbd.c
index d3a91cacee8..7bcc1d8bc96 100644
--- a/drivers/block/nbd.c
+++ b/drivers/block/nbd.c
@@ -722,7 +722,6 @@ static int __init nbd_init(void)
 
 	for (i = 0; i < nbds_max; i++) {
 		struct gendisk *disk = alloc_disk(1 << part_shift);
-		elevator_t *old_e;
 		if (!disk)
 			goto out;
 		nbd_dev[i].disk = disk;
@@ -736,11 +735,10 @@ static int __init nbd_init(void)
 			put_disk(disk);
 			goto out;
 		}
-		old_e = disk->queue->elevator;
-		if (elevator_init(disk->queue, "deadline") == 0 ||
-			elevator_init(disk->queue, "noop") == 0) {
-				elevator_exit(old_e);
-		}
+		/*
+		 * Tell the block layer that we are not a rotational device
+		 */
+		queue_flag_set_unlocked(QUEUE_FLAG_NONROT, disk->queue);
 	}
 
 	if (register_blkdev(NBD_MAJOR, "nbd")) {
diff --git a/drivers/block/virtio_blk.c b/drivers/block/virtio_blk.c
index 85d79a02d48..5d34764c8a8 100644
--- a/drivers/block/virtio_blk.c
+++ b/drivers/block/virtio_blk.c
@@ -6,7 +6,6 @@
 #include <linux/virtio_blk.h>
 #include <linux/scatterlist.h>
 
-#define VIRTIO_MAX_SG	(3+MAX_PHYS_SEGMENTS)
 #define PART_BITS 4
 
 static int major, index;
@@ -26,8 +25,11 @@ struct virtio_blk
 
 	mempool_t *pool;
 
+	/* What host tells us, plus 2 for header & tailer. */
+	unsigned int sg_elems;
+
 	/* Scatterlist: can be too big for stack. */
-	struct scatterlist sg[VIRTIO_MAX_SG];
+	struct scatterlist sg[/*sg_elems*/];
 };
 
 struct virtblk_req
@@ -97,8 +99,6 @@ static bool do_req(struct request_queue *q, struct virtio_blk *vblk,
 	if (blk_barrier_rq(vbr->req))
 		vbr->out_hdr.type |= VIRTIO_BLK_T_BARRIER;
 
-	/* This init could be done at vblk creation time */
-	sg_init_table(vblk->sg, VIRTIO_MAX_SG);
 	sg_set_buf(&vblk->sg[0], &vbr->out_hdr, sizeof(vbr->out_hdr));
 	num = blk_rq_map_sg(q, vbr->req, vblk->sg+1);
 	sg_set_buf(&vblk->sg[num+1], &vbr->status, sizeof(vbr->status));
@@ -130,7 +130,7 @@ static void do_virtblk_request(struct request_queue *q)
 
 	while ((req = elv_next_request(q)) != NULL) {
 		vblk = req->rq_disk->private_data;
-		BUG_ON(req->nr_phys_segments > ARRAY_SIZE(vblk->sg));
+		BUG_ON(req->nr_phys_segments + 2 > vblk->sg_elems);
 
 		/* If this request fails, stop queue and wait for something to
 		   finish to restart it. */
@@ -196,12 +196,22 @@ static int virtblk_probe(struct virtio_device *vdev)
 	int err;
 	u64 cap;
 	u32 v;
-	u32 blk_size;
+	u32 blk_size, sg_elems;
 
 	if (index_to_minor(index) >= 1 << MINORBITS)
 		return -ENOSPC;
 
-	vdev->priv = vblk = kmalloc(sizeof(*vblk), GFP_KERNEL);
+	/* We need to know how many segments before we allocate. */
+	err = virtio_config_val(vdev, VIRTIO_BLK_F_SEG_MAX,
+				offsetof(struct virtio_blk_config, seg_max),
+				&sg_elems);
+	if (err)
+		sg_elems = 1;
+
+	/* We need an extra sg elements at head and tail. */
+	sg_elems += 2;
+	vdev->priv = vblk = kmalloc(sizeof(*vblk) +
+				    sizeof(vblk->sg[0]) * sg_elems, GFP_KERNEL);
 	if (!vblk) {
 		err = -ENOMEM;
 		goto out;
@@ -210,6 +220,8 @@ static int virtblk_probe(struct virtio_device *vdev)
 	INIT_LIST_HEAD(&vblk->reqs);
 	spin_lock_init(&vblk->lock);
 	vblk->vdev = vdev;
+	vblk->sg_elems = sg_elems;
+	sg_init_table(vblk->sg, vblk->sg_elems);
 
 	/* We expect one virtqueue, for output. */
 	vblk->vq = vdev->config->find_vq(vdev, 0, blk_done);
@@ -237,6 +249,8 @@ static int virtblk_probe(struct virtio_device *vdev)
 		goto out_put_disk;
 	}
 
+	queue_flag_set_unlocked(QUEUE_FLAG_VIRT, vblk->disk->queue);
+
 	if (index < 26) {
 		sprintf(vblk->disk->disk_name, "vd%c", 'a' + index % 26);
 	} else if (index < (26 + 1) * 26) {
@@ -277,6 +291,13 @@ static int virtblk_probe(struct virtio_device *vdev)
 	}
 	set_capacity(vblk->disk, cap);
 
+	/* We can handle whatever the host told us to handle. */
+	blk_queue_max_phys_segments(vblk->disk->queue, vblk->sg_elems-2);
+	blk_queue_max_hw_segments(vblk->disk->queue, vblk->sg_elems-2);
+
+	/* No real sector limit. */
+	blk_queue_max_sectors(vblk->disk->queue, -1U);
+
 	/* Host can optionally specify maximum segment size and number of
 	 * segments. */
 	err = virtio_config_val(vdev, VIRTIO_BLK_F_SIZE_MAX,
@@ -284,12 +305,8 @@ static int virtblk_probe(struct virtio_device *vdev)
 				&v);
 	if (!err)
 		blk_queue_max_segment_size(vblk->disk->queue, v);
-
-	err = virtio_config_val(vdev, VIRTIO_BLK_F_SEG_MAX,
-				offsetof(struct virtio_blk_config, seg_max),
-				&v);
-	if (!err)
-		blk_queue_max_hw_segments(vblk->disk->queue, v);
+	else
+		blk_queue_max_segment_size(vblk->disk->queue, -1U);
 
 	/* Host can optionally specify the block size of the device */
 	err = virtio_config_val(vdev, VIRTIO_BLK_F_BLK_SIZE,
diff --git a/drivers/block/xen-blkfront.c b/drivers/block/xen-blkfront.c
index 2d19f0cc47f..918ef725de4 100644
--- a/drivers/block/xen-blkfront.c
+++ b/drivers/block/xen-blkfront.c
@@ -338,18 +338,12 @@ wait:
 static int xlvbd_init_blk_queue(struct gendisk *gd, u16 sector_size)
 {
 	struct request_queue *rq;
-	elevator_t *old_e;
 
 	rq = blk_init_queue(do_blkif_request, &blkif_io_lock);
 	if (rq == NULL)
 		return -1;
 
-	old_e = rq->elevator;
-	if (IS_ERR_VALUE(elevator_init(rq, "noop")))
-		printk(KERN_WARNING
-			"blkfront: Switch elevator failed, use default\n");
-	else
-		elevator_exit(old_e);
+	queue_flag_set_unlocked(QUEUE_FLAG_VIRT, rq);
 
 	/* Hard sector size and max sectors impersonate the equiv. hardware. */
 	blk_queue_hardsect_size(rq, sector_size);