From patchwork Wed Oct 31 22:13:10 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Long Li X-Patchwork-Id: 991738 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=none (mailfrom) smtp.mailfrom=vger.kernel.org (client-ip=209.132.180.67; helo=vger.kernel.org; envelope-from=linux-cifs-owner@vger.kernel.org; receiver=) Authentication-Results: ozlabs.org; dmarc=none (p=none dis=none) header.from=linuxonhyperv.com Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 42ljbM2dX4z9s0t for ; Thu, 1 Nov 2018 09:25:51 +1100 (AEDT) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1725812AbeKAHZv (ORCPT ); Thu, 1 Nov 2018 03:25:51 -0400 Received: from a2nlsmtp01-04.prod.iad2.secureserver.net ([198.71.225.38]:40652 "EHLO a2nlsmtp01-04.prod.iad2.secureserver.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725755AbeKAHZv (ORCPT ); Thu, 1 Nov 2018 03:25:51 -0400 X-Greylist: delayed 678 seconds by postgrey-1.27 at vger.kernel.org; Thu, 01 Nov 2018 03:25:50 EDT Received: from linuxonhyperv2.linuxonhyperv.com ([107.180.71.197]) by : HOSTING RELAY : with ESMTP id Hyk0gaSwUCT0vHyk0gWfTC; Wed, 31 Oct 2018 15:13:32 -0700 x-originating-ip: 107.180.71.197 Received: from longli by linuxonhyperv2.linuxonhyperv.com with local (Exim 4.91) (envelope-from ) id 1gHyk0-0000ge-DM; Wed, 31 Oct 2018 15:13:32 -0700 From: Long Li To: Steve French , linux-cifs@vger.kernel.org, samba-technical@lists.samba.org, linux-kernel@vger.kernel.org Cc: Long Li Subject: [Patch v4 2/3] CIFS: Add support for direct I/O write Date: Wed, 31 Oct 2018 22:13:10 +0000 Message-Id: <20181031221311.2596-2-longli@linuxonhyperv.com> X-Mailer: git-send-email 2.18.0 In-Reply-To: <20181031221311.2596-1-longli@linuxonhyperv.com> References: <20181031221311.2596-1-longli@linuxonhyperv.com> Reply-To: longli@microsoft.com X-CMAE-Envelope: MS4wfD0nyaf9yJp8tqibuk+c6xuZTH+7qHSuaJlIgvX0CPtkUCddZqdpp4qycklYnWC3ZR+ZdbQbhFp+BmepjRnv0dDpT3KvMv+DXSFEO2IZsO6IHV4qQt+u Dh7d0tOU+mpObRw1HXA29E7aVfkTvGOBId7jz8NaMiFYI1lk3WFHwk3EhBEQd8m/9H3AMexqmc2jExanyWuEUrFzFIWuLzb6HmYZwuOK5uJupGhnW/zfw7Xu xYLfIP8Ai0DtoXYxz5fprqngmQY2r6s2wT2OuWcapxeAfwKcsYVArIJORX9NgcvTiekRk4h4//x9LgyEoD4b5305q5xyohIgnjFt7qJgAmo1gXPdObShSVJZ UvByYx7WovZpKMIKa23PZLIyDBgXgw== Sender: linux-cifs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-cifs@vger.kernel.org From: Long Li With direct I/O write, user supplied buffers are pinned to the memory and data are transferred directly from user buffers to the transport layer. Change in v3: add support for kernel AIO Change in v4: Refactor common write code to __cifs_writev for direct and non-direct I/O. Retry on direct I/O failure. Signed-off-by: Long Li --- fs/cifs/cifsfs.h | 1 + fs/cifs/file.c | 194 +++++++++++++++++++++++++++++++++++++++++++------------ 2 files changed, 154 insertions(+), 41 deletions(-) diff --git a/fs/cifs/cifsfs.h b/fs/cifs/cifsfs.h index 7fba9aa..e9c5103 100644 --- a/fs/cifs/cifsfs.h +++ b/fs/cifs/cifsfs.h @@ -105,6 +105,7 @@ extern ssize_t cifs_user_readv(struct kiocb *iocb, struct iov_iter *to); extern ssize_t cifs_direct_readv(struct kiocb *iocb, struct iov_iter *to); extern ssize_t cifs_strict_readv(struct kiocb *iocb, struct iov_iter *to); extern ssize_t cifs_user_writev(struct kiocb *iocb, struct iov_iter *from); +extern ssize_t cifs_direct_writev(struct kiocb *iocb, struct iov_iter *from); extern ssize_t cifs_strict_writev(struct kiocb *iocb, struct iov_iter *from); extern int cifs_lock(struct file *, int, struct file_lock *); extern int cifs_fsync(struct file *, loff_t, loff_t, int); diff --git a/fs/cifs/file.c b/fs/cifs/file.c index daab878..1a41c04 100644 --- a/fs/cifs/file.c +++ b/fs/cifs/file.c @@ -2524,6 +2524,55 @@ wdata_fill_from_iovec(struct cifs_writedata *wdata, struct iov_iter *from, } static int +cifs_resend_wdata(struct cifs_writedata *wdata, struct list_head *wdata_list, struct cifs_aio_ctx *ctx) +{ + int wait_retry = 0; + unsigned int wsize, credits; + int rc; + struct TCP_Server_Info *server = tlink_tcon(wdata->cfile->tlink)->ses->server; + + /* + * Try to resend this wdata, waiting for credits up to 3 seconds. + * Note: we are attempting to resend the whole wdata not in segments + */ + do { + rc = server->ops->wait_mtu_credits(server, wdata->bytes, &wsize, &credits); + + if (rc) + break; + + if (wsize < wdata->bytes) { + add_credits_and_wake_if(server, credits, 0); + msleep(1000); + wait_retry++; + } + } while (wsize < wdata->bytes && wait_retry < 3); + + if (wsize < wdata->bytes) { + rc = -EBUSY; + goto out; + } + + rc = -EAGAIN; + while (rc == -EAGAIN) + if (!wdata->cfile->invalidHandle || + !(rc = cifs_reopen_file(wdata->cfile, false))) + rc = server->ops->async_writev(wdata, + cifs_uncached_writedata_release); + + if (!rc) { + list_add_tail(&wdata->list, wdata_list); + return 0; + } + + add_credits_and_wake_if(server, wdata->credits, 0); +out: + kref_put(&wdata->refcount, cifs_uncached_writedata_release); + + return rc; +} + +static int cifs_write_from_iter(loff_t offset, size_t len, struct iov_iter *from, struct cifsFileInfo *open_file, struct cifs_sb_info *cifs_sb, struct list_head *wdata_list, @@ -2537,6 +2586,8 @@ cifs_write_from_iter(loff_t offset, size_t len, struct iov_iter *from, loff_t saved_offset = offset; pid_t pid; struct TCP_Server_Info *server; + struct page **pagevec; + size_t start; if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_RWPIDFORWARD) pid = open_file->pid; @@ -2553,38 +2604,74 @@ cifs_write_from_iter(loff_t offset, size_t len, struct iov_iter *from, if (rc) break; - nr_pages = get_numpages(wsize, len, &cur_len); - wdata = cifs_writedata_alloc(nr_pages, + if (ctx->direct_io) { + cur_len = iov_iter_get_pages_alloc( + from, &pagevec, wsize, &start); + if (cur_len < 0) { + cifs_dbg(VFS, + "direct_writev couldn't get user pages " + "(rc=%zd) iter type %d iov_offset %zd count" + " %zd\n", + cur_len, from->type, + from->iov_offset, from->count); + dump_stack(); + break; + } + iov_iter_advance(from, cur_len); + + nr_pages = (cur_len + start + PAGE_SIZE - 1) / PAGE_SIZE; + + wdata = cifs_writedata_direct_alloc(pagevec, cifs_uncached_writev_complete); - if (!wdata) { - rc = -ENOMEM; - add_credits_and_wake_if(server, credits, 0); - break; - } + if (!wdata) { + rc = -ENOMEM; + add_credits_and_wake_if(server, credits, 0); + break; + } - rc = cifs_write_allocate_pages(wdata->pages, nr_pages); - if (rc) { - kfree(wdata); - add_credits_and_wake_if(server, credits, 0); - break; - } - num_pages = nr_pages; - rc = wdata_fill_from_iovec(wdata, from, &cur_len, &num_pages); - if (rc) { - for (i = 0; i < nr_pages; i++) - put_page(wdata->pages[i]); - kfree(wdata); - add_credits_and_wake_if(server, credits, 0); - break; - } + wdata->page_offset = start; + wdata->tailsz = + nr_pages > 1 ? + cur_len - (PAGE_SIZE - start) - + (nr_pages - 2) * PAGE_SIZE : + cur_len; + } else { + nr_pages = get_numpages(wsize, len, &cur_len); + wdata = cifs_writedata_alloc(nr_pages, + cifs_uncached_writev_complete); + if (!wdata) { + rc = -ENOMEM; + add_credits_and_wake_if(server, credits, 0); + break; + } - /* - * Bring nr_pages down to the number of pages we actually used, - * and free any pages that we didn't use. - */ - for ( ; nr_pages > num_pages; nr_pages--) - put_page(wdata->pages[nr_pages - 1]); + rc = cifs_write_allocate_pages(wdata->pages, nr_pages); + if (rc) { + kfree(wdata); + add_credits_and_wake_if(server, credits, 0); + break; + } + + num_pages = nr_pages; + rc = wdata_fill_from_iovec(wdata, from, &cur_len, &num_pages); + if (rc) { + for (i = 0; i < nr_pages; i++) + put_page(wdata->pages[i]); + kfree(wdata); + add_credits_and_wake_if(server, credits, 0); + break; + } + + /* + * Bring nr_pages down to the number of pages we actually used, + * and free any pages that we didn't use. + */ + for ( ; nr_pages > num_pages; nr_pages--) + put_page(wdata->pages[nr_pages - 1]); + + wdata->tailsz = cur_len - ((nr_pages - 1) * PAGE_SIZE); + } wdata->sync_mode = WB_SYNC_ALL; wdata->nr_pages = nr_pages; @@ -2593,7 +2680,6 @@ cifs_write_from_iter(loff_t offset, size_t len, struct iov_iter *from, wdata->pid = pid; wdata->bytes = cur_len; wdata->pagesz = PAGE_SIZE; - wdata->tailsz = cur_len - ((nr_pages - 1) * PAGE_SIZE); wdata->credits = credits; wdata->ctx = ctx; kref_get(&ctx->refcount); @@ -2668,13 +2754,17 @@ static void collect_uncached_write_data(struct cifs_aio_ctx *ctx) INIT_LIST_HEAD(&tmp_list); list_del_init(&wdata->list); - iov_iter_advance(&tmp_from, + if (ctx->direct_io) + rc = cifs_resend_wdata(wdata, &tmp_list, ctx); + else { + iov_iter_advance(&tmp_from, wdata->offset - ctx->pos); - rc = cifs_write_from_iter(wdata->offset, + rc = cifs_write_from_iter(wdata->offset, wdata->bytes, &tmp_from, ctx->cfile, cifs_sb, &tmp_list, ctx); + } list_splice(&tmp_list, &ctx->list); @@ -2687,8 +2777,9 @@ static void collect_uncached_write_data(struct cifs_aio_ctx *ctx) kref_put(&wdata->refcount, cifs_uncached_writedata_release); } - for (i = 0; i < ctx->npages; i++) - put_page(ctx->bv[i].bv_page); + if (!ctx->direct_io) + for (i = 0; i < ctx->npages; i++) + put_page(ctx->bv[i].bv_page); cifs_stats_bytes_written(tcon, ctx->total_len); set_bit(CIFS_INO_INVALID_MAPPING, &CIFS_I(dentry->d_inode)->flags); @@ -2703,7 +2794,7 @@ static void collect_uncached_write_data(struct cifs_aio_ctx *ctx) complete(&ctx->done); } -ssize_t cifs_user_writev(struct kiocb *iocb, struct iov_iter *from) +static ssize_t __cifs_writev(struct kiocb *iocb, struct iov_iter *from, bool direct) { struct file *file = iocb->ki_filp; ssize_t total_written = 0; @@ -2712,13 +2803,18 @@ ssize_t cifs_user_writev(struct kiocb *iocb, struct iov_iter *from) struct cifs_sb_info *cifs_sb; struct cifs_aio_ctx *ctx; struct iov_iter saved_from = *from; + size_t len = iov_iter_count(from); int rc; /* - * BB - optimize the way when signing is disabled. We can drop this - * extra memory-to-memory copying and use iovec buffers for constructing - * write request. + * iov_iter_get_pages_alloc doesn't work with ITER_KVEC. + * In this case, fall back to non-direct write function. + * this could be improved by getting pages directly in ITER_KVEC */ + if (direct && from->type & ITER_KVEC) { + cifs_dbg(FYI, "use non-direct cifs_writev for kvec I/O\n"); + direct = false; + } rc = generic_write_checks(iocb, from); if (rc <= 0) @@ -2742,10 +2838,16 @@ ssize_t cifs_user_writev(struct kiocb *iocb, struct iov_iter *from) ctx->pos = iocb->ki_pos; - rc = setup_aio_ctx_iter(ctx, from, WRITE); - if (rc) { - kref_put(&ctx->refcount, cifs_aio_ctx_release); - return rc; + if (direct) { + ctx->direct_io = true; + ctx->iter = *from; + ctx->len = len; + } else { + rc = setup_aio_ctx_iter(ctx, from, WRITE); + if (rc) { + kref_put(&ctx->refcount, cifs_aio_ctx_release); + return rc; + } } /* grab a lock here due to read response handlers can access ctx */ @@ -2795,6 +2897,16 @@ ssize_t cifs_user_writev(struct kiocb *iocb, struct iov_iter *from) return total_written; } +ssize_t cifs_direct_writev(struct kiocb *iocb, struct iov_iter *from) +{ + return __cifs_writev(iocb, from, true); +} + +ssize_t cifs_user_writev(struct kiocb *iocb, struct iov_iter *from) +{ + return __cifs_writev(iocb, from, false); +} + static ssize_t cifs_writev(struct kiocb *iocb, struct iov_iter *from) {