Merge branch 'stable/for-jens-3.4-bugfixes' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen into for-3.4/drivers

Konrad writes:

I've two small fixes for the xen-blkback - and I think one more will show up
eventually (a partial revert), but not sure when. So in the spirit of keeping
the patches flowing, please git pull the following branch.

3 files changed, 40 insertions, 74 deletions

diff --git a/drivers/block/xen-blkback/blkback.c b/drivers/block/xen-blkback/blkback.c
index 70caa8969972..73f196ca713f 100644
--- a/drivers/block/xen-blkback/blkback.c
+++ b/drivers/block/xen-blkback/blkback.c
@@ -398,21 +398,18 @@ static int dispatch_discard_io(struct xen_blkif *blkif,
         int err = 0;
         int status = BLKIF_RSP_OKAY;
         struct block_device *bdev = blkif->vbd.bdev;
+        unsigned long secure;
 
         blkif->st_ds_req++;
 
         xen_blkif_get(blkif);
-        if (blkif->blk_backend_type == BLKIF_BACKEND_PHY ||
-            blkif->blk_backend_type == BLKIF_BACKEND_FILE) {
-                unsigned long secure = (blkif->vbd.discard_secure &&
-                        (req->u.discard.flag & BLKIF_DISCARD_SECURE)) ?
-                        BLKDEV_DISCARD_SECURE : 0;
-                err = blkdev_issue_discard(bdev,
-                                req->u.discard.sector_number,
-                                req->u.discard.nr_sectors,
-                                GFP_KERNEL, secure);
-        } else
-                err = -EOPNOTSUPP;
+        secure = (blkif->vbd.discard_secure &&
+                 (req->u.discard.flag & BLKIF_DISCARD_SECURE)) ?
+                 BLKDEV_DISCARD_SECURE : 0;
+
+        err = blkdev_issue_discard(bdev, req->u.discard.sector_number,
+                                   req->u.discard.nr_sectors,
+                                   GFP_KERNEL, secure);
 
         if (err == -EOPNOTSUPP) {
                 pr_debug(DRV_PFX "discard op failed, not supported\n");
diff --git a/drivers/block/xen-blkback/common.h b/drivers/block/xen-blkback/common.h
index d0ee7edc9be8..773cf27dc23f 100644
--- a/drivers/block/xen-blkback/common.h
+++ b/drivers/block/xen-blkback/common.h
@@ -146,11 +146,6 @@ enum blkif_protocol {
         BLKIF_PROTOCOL_X86_64 = 3,
 };
 
-enum blkif_backend_type {
-        BLKIF_BACKEND_PHY  = 1,
-        BLKIF_BACKEND_FILE = 2,
-};
-
 struct xen_vbd {
         /* What the domain refers to this vbd as. */
         blkif_vdev_t            handle;
@@ -177,7 +172,6 @@ struct xen_blkif {
         unsigned int            irq;
         /* Comms information. */
         enum blkif_protocol     blk_protocol;
-        enum blkif_backend_type blk_backend_type;
         union blkif_back_rings  blk_rings;
         void                    *blk_ring;
         /* The VBD attached to this interface. */
diff --git a/drivers/block/xen-blkback/xenbus.c b/drivers/block/xen-blkback/xenbus.c
index 24a2fb57e5d0..89860f34a7ec 100644
--- a/drivers/block/xen-blkback/xenbus.c
+++ b/drivers/block/xen-blkback/xenbus.c
@@ -381,72 +381,49 @@ int xen_blkbk_flush_diskcache(struct xenbus_transaction xbt,
         err = xenbus_printf(xbt, dev->nodename, "feature-flush-cache",
                             "%d", state);
         if (err)
-                xenbus_dev_fatal(dev, err, "writing feature-flush-cache");
+                dev_warn(&dev->dev, "writing feature-flush-cache (%d)", err);
 
         return err;
 }
 
-int xen_blkbk_discard(struct xenbus_transaction xbt, struct backend_info *be)
+static void xen_blkbk_discard(struct xenbus_transaction xbt, struct backend_info *be)
 {
         struct xenbus_device *dev = be->dev;
         struct xen_blkif *blkif = be->blkif;
-        char *type;
         int err;
         int state = 0;
+        struct block_device *bdev = be->blkif->vbd.bdev;
+        struct request_queue *q = bdev_get_queue(bdev);
 
-        type = xenbus_read(XBT_NIL, dev->nodename, "type", NULL);
-        if (!IS_ERR(type)) {
-                if (strncmp(type, "file", 4) == 0) {
-                        state = 1;
-                        blkif->blk_backend_type = BLKIF_BACKEND_FILE;
+        if (blk_queue_discard(q)) {
+                err = xenbus_printf(xbt, dev->nodename,
+                        "discard-granularity", "%u",
+                        q->limits.discard_granularity);
+                if (err) {
+                        dev_warn(&dev->dev, "writing discard-granularity (%d)", err);
+                        return;
                 }
-                if (strncmp(type, "phy", 3) == 0) {
-                        struct block_device *bdev = be->blkif->vbd.bdev;
-                        struct request_queue *q = bdev_get_queue(bdev);
-                        if (blk_queue_discard(q)) {
-                                err = xenbus_printf(xbt, dev->nodename,
-                                        "discard-granularity", "%u",
-                                        q->limits.discard_granularity);
-                                if (err) {
-                                        xenbus_dev_fatal(dev, err,
-                                                "writing discard-granularity");
-                                        goto kfree;
-                                }
-                                err = xenbus_printf(xbt, dev->nodename,
-                                        "discard-alignment", "%u",
-                                        q->limits.discard_alignment);
-                                if (err) {
-                                        xenbus_dev_fatal(dev, err,
-                                                "writing discard-alignment");
-                                        goto kfree;
-                                }
-                                state = 1;
-                                blkif->blk_backend_type = BLKIF_BACKEND_PHY;
-                        }
-                        /* Optional. */
-                        err = xenbus_printf(xbt, dev->nodename,
-                                "discard-secure", "%d",
-                                blkif->vbd.discard_secure);
-                        if (err) {
-                                xenbus_dev_fatal(dev, err,
-                                        "writting discard-secure");
-                                goto kfree;
-                        }
+                err = xenbus_printf(xbt, dev->nodename,
+                        "discard-alignment", "%u",
+                        q->limits.discard_alignment);
+                if (err) {
+                        dev_warn(&dev->dev, "writing discard-alignment (%d)", err);
+                        return;
+                }
+                state = 1;
+                /* Optional. */
+                err = xenbus_printf(xbt, dev->nodename,
+                                    "discard-secure", "%d",
+                                    blkif->vbd.discard_secure);
+                if (err) {
+                        dev_warn(dev-dev, "writing discard-secure (%d)", err);
+                        return;
                 }
-        } else {
-                err = PTR_ERR(type);
-                xenbus_dev_fatal(dev, err, "reading type");
-                goto out;
         }
-
         err = xenbus_printf(xbt, dev->nodename, "feature-discard",
                             "%d", state);
         if (err)
-                xenbus_dev_fatal(dev, err, "writing feature-discard");
-kfree:
-        kfree(type);
-out:
-        return err;
+                dev_warn(&dev->dev, "writing feature-discard (%d)", err);
 }
 int xen_blkbk_barrier(struct xenbus_transaction xbt,
                       struct backend_info *be, int state)
@@ -457,7 +434,7 @@ int xen_blkbk_barrier(struct xenbus_transaction xbt,
         err = xenbus_printf(xbt, dev->nodename, "feature-barrier",
                             "%d", state);
         if (err)
-                xenbus_dev_fatal(dev, err, "writing feature-barrier");
+                dev_warn(&dev->dev, "writing feature-barrier (%d)", err);
 
         return err;
 }
@@ -689,14 +666,12 @@ again:
                 return;
         }
 
-        err = xen_blkbk_flush_diskcache(xbt, be, be->blkif->vbd.flush_support);
-        if (err)
-                goto abort;
+        /* If we can't advertise it is OK. */
+        xen_blkbk_flush_diskcache(xbt, be, be->blkif->vbd.flush_support);
 
-        err = xen_blkbk_discard(xbt, be);
+        xen_blkbk_discard(xbt, be);
 
-        /* If we can't advertise it is OK. */
-        err = xen_blkbk_barrier(xbt, be, be->blkif->vbd.flush_support);
+        xen_blkbk_barrier(xbt, be, be->blkif->vbd.flush_support);
 
         err = xenbus_printf(xbt, dev->nodename, "sectors", "%llu",
                             (unsigned long long)vbd_sz(&be->blkif->vbd));