7 files changed, 85 insertions, 69 deletions

diff --git a/drivers/block/cciss.c b/drivers/block/cciss.c
index 9f7c543cc04b..01e69383d9c0 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 24a7efa993ab..15e2b84734e3 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 43bf5593b59b..24e22dea1a99 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 fb06ed659212..edbaac6c0573 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 d3a91cacee8c..7bcc1d8bc967 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 300078b02e5d..5d34764c8a87 100644
--- a/drivers/block/virtio_blk.c
+++ b/drivers/block/virtio_blk.c
@@ -249,6 +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) {
diff --git a/drivers/block/xen-blkfront.c b/drivers/block/xen-blkfront.c
index 2d19f0cc47f2..918ef725de41 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);