Merge branch 'rcu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip...

[linux-2.6-omap-h63xx.git] / drivers / block / loop.c

diff --git a/drivers/block/loop.c b/drivers/block/loop.c
index 2621ed2ce6d299c186391ddfb19635fc3470bf73..40b17d3b55a1b2559b0f69cd2f507dae5e243bd1 100644 (file)
--- a/drivers/block/loop.c
+++ b/drivers/block/loop.c
@@ -1192,6 +1192,30 @@ loop_get_status64(struct loop_device *lo, struct loop_info64 __user *arg) {
        return err;
 }
 
+static int loop_set_capacity(struct loop_device *lo, struct block_device *bdev)
+{
+       int err;
+       sector_t sec;
+       loff_t sz;
+
+       err = -ENXIO;
+       if (unlikely(lo->lo_state != Lo_bound))
+               goto out;
+       err = figure_loop_size(lo);
+       if (unlikely(err))
+               goto out;
+       sec = get_capacity(lo->lo_disk);
+       /* the width of sector_t may be narrow for bit-shift */
+       sz = sec;
+       sz <<= 9;
+       mutex_lock(&bdev->bd_mutex);
+       bd_set_size(bdev, sz);
+       mutex_unlock(&bdev->bd_mutex);
+
+ out:
+       return err;
+}
+
 static int lo_ioctl(struct block_device *bdev, fmode_t mode,
        unsigned int cmd, unsigned long arg)
 {
@@ -1224,6 +1248,11 @@ static int lo_ioctl(struct block_device *bdev, fmode_t mode,
        case LOOP_GET_STATUS64:
                err = loop_get_status64(lo, (struct loop_info64 __user *) arg);
                break;
+       case LOOP_SET_CAPACITY:
+               err = -EPERM;
+               if ((mode & FMODE_WRITE) || capable(CAP_SYS_ADMIN))
+                       err = loop_set_capacity(lo, bdev);
+               break;
        default:
                err = lo->ioctl ? lo->ioctl(lo, cmd, arg) : -EINVAL;
        }
@@ -1371,6 +1400,7 @@ static int lo_compat_ioctl(struct block_device *bdev, fmode_t mode,
                        lo, (struct compat_loop_info __user *) arg);
                mutex_unlock(&lo->lo_ctl_mutex);
                break;
+       case LOOP_SET_CAPACITY:
        case LOOP_CLR_FD:
        case LOOP_GET_STATUS64:
        case LOOP_SET_STATUS64: