1 files changed, 162 insertions, 0 deletions

diff --git a/drivers/block/xen-blkback/vbd.c b/drivers/block/xen-blkback/vbd.c
new file mode 100644
index 000000000000..d0ff4cf91a34
--- /dev/null
+++ b/drivers/block/xen-blkback/vbd.c
@@ -0,0 +1,162 @@
+/******************************************************************************
+ * Routines for managing virtual block devices (VBDs).
+ *
+ * Copyright (c) 2003-2005, Keir Fraser & Steve Hand
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License version 2
+ * as published by the Free Software Foundation; or, when distributed
+ * separately from the Linux kernel or incorporated into other
+ * software packages, subject to the following license:
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this source file (the "Software"), to deal in the Software without
+ * restriction, including without limitation the rights to use, copy, modify,
+ * merge, publish, distribute, sublicense, and/or sell copies of the Software,
+ * and to permit persons to whom the Software is furnished to do so, subject to
+ * the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
+ * IN THE SOFTWARE.
+ */
+
+#include "common.h"
+
+#define vbd_sz(_v)      ((_v)->bdev->bd_part ? \
+                         (_v)->bdev->bd_part->nr_sects : \
+                          get_capacity((_v)->bdev->bd_disk))
+
+unsigned long long vbd_size(struct vbd *vbd)
+{
+        return vbd_sz(vbd);
+}
+
+unsigned int vbd_info(struct vbd *vbd)
+{
+        return vbd->type | (vbd->readonly ? VDISK_READONLY : 0);
+}
+
+unsigned long vbd_secsize(struct vbd *vbd)
+{
+        return bdev_logical_block_size(vbd->bdev);
+}
+
+int vbd_create(struct blkif_st *blkif, blkif_vdev_t handle, unsigned major,
+               unsigned minor, int readonly, int cdrom)
+{
+        struct vbd *vbd;
+        struct block_device *bdev;
+
+        vbd = &blkif->vbd;
+        vbd->handle   = handle;
+        vbd->readonly = readonly;
+        vbd->type     = 0;
+
+        vbd->pdevice  = MKDEV(major, minor);
+
+        bdev = blkdev_get_by_dev(vbd->pdevice, vbd->readonly ?
+                                 FMODE_READ : FMODE_WRITE, NULL);
+
+        if (IS_ERR(bdev)) {
+                DPRINTK("vbd_creat: device %08x could not be opened.\n",
+                        vbd->pdevice);
+                return -ENOENT;
+        }
+
+        vbd->bdev = bdev;
+        vbd->size = vbd_size(vbd);
+
+        if (vbd->bdev->bd_disk == NULL) {
+                DPRINTK("vbd_creat: device %08x doesn't exist.\n",
+                        vbd->pdevice);
+                vbd_free(vbd);
+                return -ENOENT;
+        }
+
+        if (vbd->bdev->bd_disk->flags & GENHD_FL_CD || cdrom)
+                vbd->type |= VDISK_CDROM;
+        if (vbd->bdev->bd_disk->flags & GENHD_FL_REMOVABLE)
+                vbd->type |= VDISK_REMOVABLE;
+
+        DPRINTK("Successful creation of handle=%04x (dom=%u)\n",
+                handle, blkif->domid);
+        return 0;
+}
+
+void vbd_free(struct vbd *vbd)
+{
+        if (vbd->bdev)
+                blkdev_put(vbd->bdev, vbd->readonly ? FMODE_READ : FMODE_WRITE);
+        vbd->bdev = NULL;
+}
+
+int vbd_translate(struct phys_req *req, struct blkif_st *blkif, int operation)
+{
+        struct vbd *vbd = &blkif->vbd;
+        int rc = -EACCES;
+
+        if ((operation != READ) && vbd->readonly)
+                goto out;
+
+        if (unlikely((req->sector_number + req->nr_sects) > vbd_sz(vbd)))
+                goto out;
+
+        req->dev  = vbd->pdevice;
+        req->bdev = vbd->bdev;
+        rc = 0;
+
+ out:
+        return rc;
+}
+
+void vbd_resize(struct blkif_st *blkif)
+{
+        struct vbd *vbd = &blkif->vbd;
+        struct xenbus_transaction xbt;
+        int err;
+        struct xenbus_device *dev = blkback_xenbus(blkif->be);
+        unsigned long long new_size = vbd_size(vbd);
+
+        printk(KERN_INFO "VBD Resize: Domid: %d, Device: (%d, %d)\n",
+                blkif->domid, MAJOR(vbd->pdevice), MINOR(vbd->pdevice));
+        printk(KERN_INFO "VBD Resize: new size %llu\n", new_size);
+        vbd->size = new_size;
+again:
+        err = xenbus_transaction_start(&xbt);
+        if (err) {
+                printk(KERN_WARNING "Error starting transaction");
+                return;
+        }
+        err = xenbus_printf(xbt, dev->nodename, "sectors", "%llu",
+                            vbd_size(vbd));
+        if (err) {
+                printk(KERN_WARNING "Error writing new size");
+                goto abort;
+        }
+        /*
+         * Write the current state; we will use this to synchronize
+         * the front-end. If the current state is "connected" the
+         * front-end will get the new size information online.
+         */
+        err = xenbus_printf(xbt, dev->nodename, "state", "%d", dev->state);
+        if (err) {
+                printk(KERN_WARNING "Error writing the state");
+                goto abort;
+        }
+
+        err = xenbus_transaction_end(xbt, 0);
+        if (err == -EAGAIN)
+                goto again;
+        if (err)
+                printk(KERN_WARNING "Error ending transaction");
+abort:
+        xenbus_transaction_end(xbt, 1);
+}