generic_file_splice_write() takes the inode->i_mutex after the filesystem has taken whatever locks it needs to ensure sanity. however, this typically violates the locking order of filesystems with their own locks in that the order is usually i_mutex -> filesystem lock. XFS is such a case, and generic_file_splice_write() is generating lockdep warnings because of lock inversions between the inode->i_mutex and the XFS_I(inode)->i_iolock. There is also a reported case of fio causing a deadlock when it mixes IO types (e.g. splice vs direct IO). This patch set introduces generic_file_splice_write_unlocked() and factors the code such that __generic_file_splice_write() will only lock the i_mutex if called from the locked variant. The second patch modifies XFS to use the new function. -- To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
