Merge tag 'virtio-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux-2.6-for-linus

Pull virtio update from Rusty Russell:
 "Virtio patches, mainly hotplugging fixes."

* tag 'virtio-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux-2.6-for-linus:
  virtio-blk: return VIRTIO_BLK_F_FLUSH to header.
  virtio-blk: allow toggling host cache between writeback and writethrough
  virtio-blk: Use block layer provided spinlock
  virtio-blk: Reset device after blk_cleanup_queue()
  virtio-blk: Call del_gendisk() before disable guest kick
  virtio: rng: s3/s4 support
  virtio: rng: split out common code in probe / remove for s3/s4 ops
  virtio: rng: don't wait on host when module is going away
  virtio: rng: allow tasks to be killed that are waiting for rng input
  virtio ids: fix comment for virtio-rng

4 files changed, 137 insertions, 27 deletions

diff --git a/drivers/block/virtio_blk.c b/drivers/block/virtio_blk.c
index 693187df7601..c0bbeb470754 100644
--- a/drivers/block/virtio_blk.c
+++ b/drivers/block/virtio_blk.c
@@ -21,8 +21,6 @@ struct workqueue_struct *virtblk_wq;
 
 struct virtio_blk
 {
-        spinlock_t lock;
-
         struct virtio_device *vdev;
         struct virtqueue *vq;
 
@@ -65,7 +63,7 @@ static void blk_done(struct virtqueue *vq)
         unsigned int len;
         unsigned long flags;
 
-        spin_lock_irqsave(&vblk->lock, flags);
+        spin_lock_irqsave(vblk->disk->queue->queue_lock, flags);
         while ((vbr = virtqueue_get_buf(vblk->vq, &len)) != NULL) {
                 int error;
 
@@ -99,7 +97,7 @@ static void blk_done(struct virtqueue *vq)
         }
         /* In case queue is stopped waiting for more buffers. */
         blk_start_queue(vblk->disk->queue);
-        spin_unlock_irqrestore(&vblk->lock, flags);
+        spin_unlock_irqrestore(vblk->disk->queue->queue_lock, flags);
 }
 
 static bool do_req(struct request_queue *q, struct virtio_blk *vblk,
@@ -397,6 +395,83 @@ static int virtblk_name_format(char *prefix, int index, char *buf, int buflen)
         return 0;
 }
 
+static int virtblk_get_cache_mode(struct virtio_device *vdev)
+{
+        u8 writeback;
+        int err;
+
+        err = virtio_config_val(vdev, VIRTIO_BLK_F_CONFIG_WCE,
+                                offsetof(struct virtio_blk_config, wce),
+                                &writeback);
+        if (err)
+                writeback = virtio_has_feature(vdev, VIRTIO_BLK_F_WCE);
+
+        return writeback;
+}
+
+static void virtblk_update_cache_mode(struct virtio_device *vdev)
+{
+        u8 writeback = virtblk_get_cache_mode(vdev);
+        struct virtio_blk *vblk = vdev->priv;
+
+        if (writeback)
+                blk_queue_flush(vblk->disk->queue, REQ_FLUSH);
+        else
+                blk_queue_flush(vblk->disk->queue, 0);
+
+        revalidate_disk(vblk->disk);
+}
+
+static const char *const virtblk_cache_types[] = {
+        "write through", "write back"
+};
+
+static ssize_t
+virtblk_cache_type_store(struct device *dev, struct device_attribute *attr,
+                         const char *buf, size_t count)
+{
+        struct gendisk *disk = dev_to_disk(dev);
+        struct virtio_blk *vblk = disk->private_data;
+        struct virtio_device *vdev = vblk->vdev;
+        int i;
+        u8 writeback;
+
+        BUG_ON(!virtio_has_feature(vblk->vdev, VIRTIO_BLK_F_CONFIG_WCE));
+        for (i = ARRAY_SIZE(virtblk_cache_types); --i >= 0; )
+                if (sysfs_streq(buf, virtblk_cache_types[i]))
+                        break;
+
+        if (i < 0)
+                return -EINVAL;
+
+        writeback = i;
+        vdev->config->set(vdev,
+                          offsetof(struct virtio_blk_config, wce),
+                          &writeback, sizeof(writeback));
+
+        virtblk_update_cache_mode(vdev);
+        return count;
+}
+
+static ssize_t
+virtblk_cache_type_show(struct device *dev, struct device_attribute *attr,
+                         char *buf)
+{
+        struct gendisk *disk = dev_to_disk(dev);
+        struct virtio_blk *vblk = disk->private_data;
+        u8 writeback = virtblk_get_cache_mode(vblk->vdev);
+
+        BUG_ON(writeback >= ARRAY_SIZE(virtblk_cache_types));
+        return snprintf(buf, 40, "%s\n", virtblk_cache_types[writeback]);
+}
+
+static const struct device_attribute dev_attr_cache_type_ro =
+        __ATTR(cache_type, S_IRUGO,
+               virtblk_cache_type_show, NULL);
+static const struct device_attribute dev_attr_cache_type_rw =
+        __ATTR(cache_type, S_IRUGO|S_IWUSR,
+               virtblk_cache_type_show, virtblk_cache_type_store);
+
 static int __devinit virtblk_probe(struct virtio_device *vdev)
 {
         struct virtio_blk *vblk;
@@ -431,7 +506,6 @@ static int __devinit virtblk_probe(struct virtio_device *vdev)
                 goto out_free_index;
         }
 
-        spin_lock_init(&vblk->lock);
         vblk->vdev = vdev;
         vblk->sg_elems = sg_elems;
         sg_init_table(vblk->sg, vblk->sg_elems);
@@ -456,7 +530,7 @@ static int __devinit virtblk_probe(struct virtio_device *vdev)
                 goto out_mempool;
         }
 
-        q = vblk->disk->queue = blk_init_queue(do_virtblk_request, &vblk->lock);
+        q = vblk->disk->queue = blk_init_queue(do_virtblk_request, NULL);
         if (!q) {
                 err = -ENOMEM;
                 goto out_put_disk;
@@ -474,8 +548,7 @@ static int __devinit virtblk_probe(struct virtio_device *vdev)
         vblk->index = index;
 
         /* configure queue flush support */
-        if (virtio_has_feature(vdev, VIRTIO_BLK_F_FLUSH))
-                blk_queue_flush(q, REQ_FLUSH);
+        virtblk_update_cache_mode(vdev);
 
         /* If disk is read-only in the host, the guest should obey */
         if (virtio_has_feature(vdev, VIRTIO_BLK_F_RO))
@@ -553,6 +626,14 @@ static int __devinit virtblk_probe(struct virtio_device *vdev)
         if (err)
                 goto out_del_disk;
 
+        if (virtio_has_feature(vdev, VIRTIO_BLK_F_CONFIG_WCE))
+                err = device_create_file(disk_to_dev(vblk->disk),
+                                         &dev_attr_cache_type_rw);
+        else
+                err = device_create_file(disk_to_dev(vblk->disk),
+                                         &dev_attr_cache_type_ro);
+        if (err)
+                goto out_del_disk;
         return 0;
 
 out_del_disk:
@@ -576,30 +657,20 @@ static void __devexit virtblk_remove(struct virtio_device *vdev)
 {
         struct virtio_blk *vblk = vdev->priv;
         int index = vblk->index;
-        struct virtblk_req *vbr;
-        unsigned long flags;
 
         /* Prevent config work handler from accessing the device. */
         mutex_lock(&vblk->config_lock);
         vblk->config_enable = false;
         mutex_unlock(&vblk->config_lock);
 
+        del_gendisk(vblk->disk);
+        blk_cleanup_queue(vblk->disk->queue);
+
         /* Stop all the virtqueues. */
         vdev->config->reset(vdev);
 
         flush_work(&vblk->config_work);
 
-        del_gendisk(vblk->disk);
-
-        /* Abort requests dispatched to driver. */
-        spin_lock_irqsave(&vblk->lock, flags);
-        while ((vbr = virtqueue_detach_unused_buf(vblk->vq))) {
-                __blk_end_request_all(vbr->req, -EIO);
-                mempool_free(vbr, vblk->pool);
-        }
-        spin_unlock_irqrestore(&vblk->lock, flags);
-
-        blk_cleanup_queue(vblk->disk->queue);
         put_disk(vblk->disk);
         mempool_destroy(vblk->pool);
         vdev->config->del_vqs(vdev);
@@ -655,7 +726,7 @@ static const struct virtio_device_id id_table[] = {
 static unsigned int features[] = {
         VIRTIO_BLK_F_SEG_MAX, VIRTIO_BLK_F_SIZE_MAX, VIRTIO_BLK_F_GEOMETRY,
         VIRTIO_BLK_F_RO, VIRTIO_BLK_F_BLK_SIZE, VIRTIO_BLK_F_SCSI,
-        VIRTIO_BLK_F_FLUSH, VIRTIO_BLK_F_TOPOLOGY
+        VIRTIO_BLK_F_WCE, VIRTIO_BLK_F_TOPOLOGY, VIRTIO_BLK_F_CONFIG_WCE
 };
 
 /*
diff --git a/drivers/char/hw_random/virtio-rng.c b/drivers/char/hw_random/virtio-rng.c
index 723725bbb96b..5708299507d0 100644
--- a/drivers/char/hw_random/virtio-rng.c
+++ b/drivers/char/hw_random/virtio-rng.c
@@ -55,6 +55,7 @@ static void register_buffer(u8 *buf, size_t size)
 
 static int virtio_read(struct hwrng *rng, void *buf, size_t size, bool wait)
 {
+        int ret;
 
         if (!busy) {
                 busy = true;
@@ -65,7 +66,9 @@ static int virtio_read(struct hwrng *rng, void *buf, size_t size, bool wait)
         if (!wait)
                 return 0;
 
-        wait_for_completion(&have_data);
+        ret = wait_for_completion_killable(&have_data);
+        if (ret < 0)
+                return ret;
 
         busy = false;
 
@@ -85,7 +88,7 @@ static struct hwrng virtio_hwrng = {
         .read           = virtio_read,
 };
 
-static int virtrng_probe(struct virtio_device *vdev)
+static int probe_common(struct virtio_device *vdev)
 {
         int err;
 
@@ -103,13 +106,37 @@ static int virtrng_probe(struct virtio_device *vdev)
         return 0;
 }
 
-static void __devexit virtrng_remove(struct virtio_device *vdev)
+static void remove_common(struct virtio_device *vdev)
 {
         vdev->config->reset(vdev);
+        busy = false;
         hwrng_unregister(&virtio_hwrng);
         vdev->config->del_vqs(vdev);
 }
 
+static int virtrng_probe(struct virtio_device *vdev)
+{
+        return probe_common(vdev);
+}
+
+static void __devexit virtrng_remove(struct virtio_device *vdev)
+{
+        remove_common(vdev);
+}
+
+#ifdef CONFIG_PM
+static int virtrng_freeze(struct virtio_device *vdev)
+{
+        remove_common(vdev);
+        return 0;
+}
+
+static int virtrng_restore(struct virtio_device *vdev)
+{
+        return probe_common(vdev);
+}
+#endif
+
 static struct virtio_device_id id_table[] = {
         { VIRTIO_ID_RNG, VIRTIO_DEV_ANY_ID },
         { 0 },
@@ -121,6 +148,10 @@ static struct virtio_driver virtio_rng_driver = {
         .id_table =     id_table,
         .probe =        virtrng_probe,
         .remove =       __devexit_p(virtrng_remove),
+#ifdef CONFIG_PM
+        .freeze =       virtrng_freeze,
+        .restore =      virtrng_restore,
+#endif
 };
 
 static int __init init(void)
diff --git a/include/linux/virtio_blk.h b/include/linux/virtio_blk.h
index e0edb40ca7aa..6d8e61c48563 100644
--- a/include/linux/virtio_blk.h
+++ b/include/linux/virtio_blk.h
@@ -37,8 +37,14 @@
 #define VIRTIO_BLK_F_RO         5       /* Disk is read-only */
 #define VIRTIO_BLK_F_BLK_SIZE   6       /* Block size of disk is available*/
 #define VIRTIO_BLK_F_SCSI       7       /* Supports scsi command passthru */
-#define VIRTIO_BLK_F_FLUSH      9       /* Cache flush command support */
+#define VIRTIO_BLK_F_WCE        9       /* Writeback mode enabled after reset */
 #define VIRTIO_BLK_F_TOPOLOGY   10      /* Topology information is available */
+#define VIRTIO_BLK_F_CONFIG_WCE 11      /* Writeback mode available in config */
+
+#ifndef __KERNEL__
+/* Old (deprecated) name for VIRTIO_BLK_F_WCE. */
+#define VIRTIO_BLK_F_FLUSH VIRTIO_BLK_F_WCE
+#endif
 
 #define VIRTIO_BLK_ID_BYTES     20      /* ID string length */
 
@@ -69,6 +75,8 @@ struct virtio_blk_config {
         /* optimal sustained I/O size in logical blocks. */
         __u32 opt_io_size;
 
+        /* writeback mode (if VIRTIO_BLK_F_CONFIG_WCE) */
+        __u8 wce;
 } __attribute__((packed));
 
 /*
diff --git a/include/linux/virtio_ids.h b/include/linux/virtio_ids.h
index 7529b854b7fd..270fb22c5811 100644
--- a/include/linux/virtio_ids.h
+++ b/include/linux/virtio_ids.h
@@ -32,7 +32,7 @@
 #define VIRTIO_ID_NET           1 /* virtio net */
 #define VIRTIO_ID_BLOCK         2 /* virtio block */
 #define VIRTIO_ID_CONSOLE       3 /* virtio console */
-#define VIRTIO_ID_RNG           4 /* virtio ring */
+#define VIRTIO_ID_RNG           4 /* virtio rng */
 #define VIRTIO_ID_BALLOON       5 /* virtio balloon */
 #define VIRTIO_ID_RPMSG         7 /* virtio remote processor messaging */
 #define VIRTIO_ID_SCSI          8 /* virtio scsi */