Today's linux-next merge of the akpm-current tree got a conflict in:

  fs/btrfs/file.c

between commit:

  0225a20db6d8 ("btrfs: Prevent nowait or async read from doing sync IO")

from the btrfs tree and commit:

  ddcd14c48a30 ("mm/filemap: rename generic_file_buffered_read to filemap_read")

from the akpm-current tree.

I fixed it up (see below) and can carry the fix as necessary. This
is now fixed as far as linux-next is concerned, but any non trivial
conflicts should be mentioned to your upstream maintainer when your tree
is submitted for merging.  You may also want to consider cooperating
with the maintainer of the conflicting tree to minimise any particularly
complex conflicts.

diff --cc fs/btrfs/file.c
index 5282f456c99c,898ef7b792b7..000000000000

--- a/fs/btrfs/file.c
+++ b/fs/btrfs/file.c

@@@ -3629,18 -3639,7 +3629,18 @@@ static ssize_t btrfs_file_read_iter(str
  			return ret;
  	}
  
 -	return filemap_read(iocb, to, ret);
 +	if (iocb->ki_flags & IOCB_NOWAIT)
 +		iocb->ki_flags |= IOCB_NOIO;
 +
- 	ret = generic_file_buffered_read(iocb, to, ret);
++	ret = filemap_read(iocb, to, ret);
 +
 +	if (iocb->ki_flags & IOCB_NOWAIT) {
 +		iocb->ki_flags &= ~IOCB_NOIO;
 +		if (ret == 0)
 +			ret = -EAGAIN;
 +	}
 +
 +	return ret;
  }
  
  const struct file_operations btrfs_file_operations = {