1 files changed, 28 insertions, 1 deletions

diff --git a/fs/block_dev.c b/fs/block_dev.c
index 94dfda24c06e..3581a4e53942 100644
--- a/fs/block_dev.c
+++ b/fs/block_dev.c
@@ -1405,6 +1405,33 @@ static long block_ioctl(struct file *file, unsigned cmd, unsigned long arg)
 }
 
 /*
+ * Write data to the block device.  Only intended for the block device itself
+ * and the raw driver which basically is a fake block device.
+ *
+ * Does not take i_mutex for the write and thus is not for general purpose
+ * use.
+ */
+ssize_t blkdev_aio_write(struct kiocb *iocb, const struct iovec *iov,
+                         unsigned long nr_segs, loff_t pos)
+{
+        struct file *file = iocb->ki_filp;
+        ssize_t ret;
+
+        BUG_ON(iocb->ki_pos != pos);
+
+        ret = __generic_file_aio_write(iocb, iov, nr_segs, &iocb->ki_pos);
+        if (ret > 0 || ret == -EIOCBQUEUED) {
+                ssize_t err;
+
+                err = generic_write_sync(file, pos, ret);
+                if (err < 0 && ret > 0)
+                        ret = err;
+        }
+        return ret;
+}
+EXPORT_SYMBOL_GPL(blkdev_aio_write);
+
+/*
  * Try to release a page associated with block device when the system
  * is under memory pressure.
  */
@@ -1436,7 +1463,7 @@ const struct file_operations def_blk_fops = {
         .read           = do_sync_read,
         .write          = do_sync_write,
         .aio_read       = generic_file_aio_read,
-        .aio_write      = generic_file_aio_write_nolock,
+        .aio_write      = blkdev_aio_write,
         .mmap           = generic_file_mmap,
         .fsync          = block_fsync,
         .unlocked_ioctl = block_ioctl,