From: Christoph Hellwig Subject: [PATCH 2/2] dax: assert that i_rwsem is held exclusive for writes Date: Tue, 10 Jan 2017 16:48:08 +0100 Message-ID: <1484063288-18255-3-git-send-email-hch@lst.de> References: <1484063288-18255-1-git-send-email-hch@lst.de> Cc: linux-ext4@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-nvdimm@lists.01.org To: Jan Kara Return-path: In-Reply-To: <1484063288-18255-1-git-send-email-hch@lst.de> Sender: linux-fsdevel-owner@vger.kernel.org List-Id: linux-ext4.vger.kernel.org Make sure all callers follow the same locking protocol, given that DAX transparantly replaced the normal buffered I/O path. Signed-off-by: Christoph Hellwig --- fs/dax.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/fs/dax.c b/fs/dax.c index 5c74f60..04734da 100644 --- a/fs/dax.c +++ b/fs/dax.c @@ -1061,8 +1061,12 @@ dax_iomap_rw(struct kiocb *iocb, struct iov_iter *iter, loff_t pos = iocb->ki_pos, ret = 0, done = 0; unsigned flags = 0; - if (iov_iter_rw(iter) == WRITE) + if (iov_iter_rw(iter) == WRITE) { + lockdep_assert_held_exclusive(&inode->i_rwsem); flags |= IOMAP_WRITE; + } else { + lockdep_assert_held(&inode->i_rwsem); + } while (iov_iter_count(iter)) { ret = iomap_apply(inode, pos, iov_iter_count(iter), flags, ops, -- 2.1.4