[PATCH 4/8] xfs: introduce xfs_rw_lock() helpers for locking the inode

[Christoph Hellwig]

> -	xfs_ilock(ip, XFS_IOLOCK_EXCL);
> +	xfs_rw_ilock(ip, XFS_ILOCK_EXCL|XFS_IOLOCK_EXCL);

this now takes i_mutex, which will be taken again by
generic_file_splice_write.