UPSTREAM: loop: add ioctl for changing logical block size

[GitHub/exynos8895/android_kernel_samsung_universal8895.git] / drivers / block / loop.c

diff --git a/drivers/block/loop.c b/drivers/block/loop.c
index d02afeb11197d4e9dfe1c1a4f2e6384eae20319c..81cdad14df7920c258062a444bd6f594a9d4f195 100644 (file)
--- a/drivers/block/loop.c
+++ b/drivers/block/loop.c
@@ -1061,6 +1061,7 @@ static int loop_clr_fd(struct loop_device *lo)
        memset(lo->lo_encrypt_key, 0, LO_KEY_SIZE);
        memset(lo->lo_crypt_name, 0, LO_NAME_SIZE);
        memset(lo->lo_file_name, 0, LO_NAME_SIZE);
+       blk_queue_logical_block_size(lo->lo_queue, 512);
        if (bdev) {
                bdput(bdev);
                invalidate_bdev(bdev);
@@ -1342,6 +1343,24 @@ static int loop_set_dio(struct loop_device *lo, unsigned long arg)
        return error;
 }
 
+static int loop_set_block_size(struct loop_device *lo, unsigned long arg)
+{
+       if (lo->lo_state != Lo_bound)
+               return -ENXIO;
+
+       if (arg < 512 || arg > PAGE_SIZE || !is_power_of_2(arg))
+               return -EINVAL;
+
+       blk_mq_freeze_queue(lo->lo_queue);
+
+       blk_queue_logical_block_size(lo->lo_queue, arg);
+       loop_update_dio(lo);
+
+       blk_mq_unfreeze_queue(lo->lo_queue);
+
+       return 0;
+}
+
 static int lo_ioctl(struct block_device *bdev, fmode_t mode,
        unsigned int cmd, unsigned long arg)
 {
@@ -1390,6 +1409,11 @@ static int lo_ioctl(struct block_device *bdev, fmode_t mode,
                if ((mode & FMODE_WRITE) || capable(CAP_SYS_ADMIN))
                        err = loop_set_dio(lo, arg);
                break;
+       case LOOP_SET_BLOCK_SIZE:
+               err = -EPERM;
+               if ((mode & FMODE_WRITE) || capable(CAP_SYS_ADMIN))
+                       err = loop_set_block_size(lo, arg);
+               break;
        default:
                err = lo->ioctl ? lo->ioctl(lo, cmd, arg) : -EINVAL;
        }