From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.linuxfoundation.org ([140.211.169.12]:36022 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932278AbeDFNkx (ORCPT ); Fri, 6 Apr 2018 09:40:53 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, stable@kernel.org, "Yan, Zheng" , Ilya Dryomov Subject: [PATCH 4.15 12/72] ceph: only dirty ITER_IOVEC pages for direct read Date: Fri, 6 Apr 2018 15:23:47 +0200 Message-Id: <20180406084350.499467735@linuxfoundation.org> In-Reply-To: <20180406084349.367583460@linuxfoundation.org> References: <20180406084349.367583460@linuxfoundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: stable-owner@vger.kernel.org List-ID: 4.15-stable review patch. If anyone has any objections, please let me know. ------------------ From: Yan, Zheng commit 85784f9395987a422fa04263e7c0fb13da11eb5c upstream. If a page is already locked, attempting to dirty it leads to a deadlock in lock_page(). This is what currently happens to ITER_BVEC pages when a dio-enabled loop device is backed by ceph: $ losetup --direct-io /dev/loop0 /mnt/cephfs/img $ xfs_io -c 'pread 0 4k' /dev/loop0 Follow other file systems and only dirty ITER_IOVEC pages. Cc: stable@kernel.org Signed-off-by: "Yan, Zheng" Reviewed-by: Ilya Dryomov Signed-off-by: Ilya Dryomov Signed-off-by: Greg Kroah-Hartman --- fs/ceph/file.c | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-) --- a/fs/ceph/file.c +++ b/fs/ceph/file.c @@ -635,7 +635,8 @@ static ssize_t ceph_sync_read(struct kio struct ceph_aio_request { struct kiocb *iocb; size_t total_len; - int write; + bool write; + bool should_dirty; int error; struct list_head osd_reqs; unsigned num_reqs; @@ -745,7 +746,7 @@ static void ceph_aio_complete_req(struct } } - ceph_put_page_vector(osd_data->pages, num_pages, !aio_req->write); + ceph_put_page_vector(osd_data->pages, num_pages, aio_req->should_dirty); ceph_osdc_put_request(req); if (rc < 0) @@ -842,6 +843,7 @@ ceph_direct_read_write(struct kiocb *ioc size_t count = iov_iter_count(iter); loff_t pos = iocb->ki_pos; bool write = iov_iter_rw(iter) == WRITE; + bool should_dirty = !write && iter_is_iovec(iter); if (write && ceph_snap(file_inode(file)) != CEPH_NOSNAP) return -EROFS; @@ -909,6 +911,7 @@ ceph_direct_read_write(struct kiocb *ioc if (aio_req) { aio_req->iocb = iocb; aio_req->write = write; + aio_req->should_dirty = should_dirty; INIT_LIST_HEAD(&aio_req->osd_reqs); if (write) { aio_req->mtime = mtime; @@ -966,7 +969,7 @@ ceph_direct_read_write(struct kiocb *ioc len = ret; } - ceph_put_page_vector(pages, num_pages, !write); + ceph_put_page_vector(pages, num_pages, should_dirty); ceph_osdc_put_request(req); if (ret < 0)