Merge tag 'mvebu-fixes-3.16-3' of git://git.infradead.org/linux-mvebu into fixes

[cascardo/linux.git] / drivers / block / rbd.c

diff --git a/drivers/block/rbd.c b/drivers/block/rbd.c
index 8295b3a..b2c98c1 100644 (file)
--- a/drivers/block/rbd.c
+++ b/drivers/block/rbd.c
@@ -541,7 +541,6 @@ static int rbd_open(struct block_device *bdev, fmode_t mode)
                return -ENOENT;
 
        (void) get_device(&rbd_dev->dev);
-       set_device_ro(bdev, rbd_dev->mapping.read_only);
 
        return 0;
 }
@@ -559,10 +558,76 @@ static void rbd_release(struct gendisk *disk, fmode_t mode)
        put_device(&rbd_dev->dev);
 }
 
+static int rbd_ioctl_set_ro(struct rbd_device *rbd_dev, unsigned long arg)
+{
+       int ret = 0;
+       int val;
+       bool ro;
+       bool ro_changed = false;
+
+       /* get_user() may sleep, so call it before taking rbd_dev->lock */
+       if (get_user(val, (int __user *)(arg)))
+               return -EFAULT;
+
+       ro = val ? true : false;
+       /* Snapshot doesn't allow to write*/
+       if (rbd_dev->spec->snap_id != CEPH_NOSNAP && !ro)
+               return -EROFS;
+
+       spin_lock_irq(&rbd_dev->lock);
+       /* prevent others open this device */
+       if (rbd_dev->open_count > 1) {
+               ret = -EBUSY;
+               goto out;
+       }
+
+       if (rbd_dev->mapping.read_only != ro) {
+               rbd_dev->mapping.read_only = ro;
+               ro_changed = true;
+       }
+
+out:
+       spin_unlock_irq(&rbd_dev->lock);
+       /* set_disk_ro() may sleep, so call it after releasing rbd_dev->lock */
+       if (ret == 0 && ro_changed)
+               set_disk_ro(rbd_dev->disk, ro ? 1 : 0);
+
+       return ret;
+}
+
+static int rbd_ioctl(struct block_device *bdev, fmode_t mode,
+                       unsigned int cmd, unsigned long arg)
+{
+       struct rbd_device *rbd_dev = bdev->bd_disk->private_data;
+       int ret = 0;
+
+       switch (cmd) {
+       case BLKROSET:
+               ret = rbd_ioctl_set_ro(rbd_dev, arg);
+               break;
+       default:
+               ret = -ENOTTY;
+       }
+
+       return ret;
+}
+
+#ifdef CONFIG_COMPAT
+static int rbd_compat_ioctl(struct block_device *bdev, fmode_t mode,
+                               unsigned int cmd, unsigned long arg)
+{
+       return rbd_ioctl(bdev, mode, cmd, arg);
+}
+#endif /* CONFIG_COMPAT */
+
 static const struct block_device_operations rbd_bd_ops = {
        .owner                  = THIS_MODULE,
        .open                   = rbd_open,
        .release                = rbd_release,
+       .ioctl                  = rbd_ioctl,
+#ifdef CONFIG_COMPAT
+       .compat_ioctl           = rbd_compat_ioctl,
+#endif
 };
 
 /*
@@ -1366,6 +1431,14 @@ static bool obj_request_exists_test(struct rbd_obj_request *obj_request)
        return test_bit(OBJ_REQ_EXISTS, &obj_request->flags) != 0;
 }
 
+static bool obj_request_overlaps_parent(struct rbd_obj_request *obj_request)
+{
+       struct rbd_device *rbd_dev = obj_request->img_request->rbd_dev;
+
+       return obj_request->img_offset <
+           round_up(rbd_dev->parent_overlap, rbd_obj_bytes(&rbd_dev->header));
+}
+
 static void rbd_obj_request_get(struct rbd_obj_request *obj_request)
 {
        dout("%s: obj %p (was %d)\n", __func__, obj_request,
@@ -2683,7 +2756,7 @@ static int rbd_img_obj_request_submit(struct rbd_obj_request *obj_request)
         */
        if (!img_request_write_test(img_request) ||
                !img_request_layered_test(img_request) ||
-               rbd_dev->parent_overlap <= obj_request->img_offset ||
+               !obj_request_overlaps_parent(obj_request) ||
                ((known = obj_request_known_test(obj_request)) &&
                        obj_request_exists_test(obj_request))) {
 
@@ -3114,7 +3187,6 @@ static void rbd_request_fn(struct request_queue *q)
                __releases(q->queue_lock) __acquires(q->queue_lock)
 {
        struct rbd_device *rbd_dev = q->queuedata;
-       bool read_only = rbd_dev->mapping.read_only;
        struct request *rq;
        int result;
 
@@ -3150,7 +3222,7 @@ static void rbd_request_fn(struct request_queue *q)
 
                if (write_request) {
                        result = -EROFS;
-                       if (read_only)
+                       if (rbd_dev->mapping.read_only)
                                goto end_request;
                        rbd_assert(rbd_dev->spec->snap_id == CEPH_NOSNAP);
                }
@@ -4995,6 +5067,7 @@ static int rbd_dev_device_setup(struct rbd_device *rbd_dev)
        if (ret)
                goto err_out_disk;
        set_capacity(rbd_dev->disk, rbd_dev->mapping.size / SECTOR_SIZE);
+       set_disk_ro(rbd_dev->disk, rbd_dev->mapping.read_only);
 
        ret = rbd_bus_add_dev(rbd_dev);
        if (ret)