From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755832AbdKGJAz (ORCPT ); Tue, 7 Nov 2017 04:00:55 -0500 Received: from a2nlsmtp01-04.prod.iad2.secureserver.net ([198.71.225.38]:39002 "EHLO a2nlsmtp01-04.prod.iad2.secureserver.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753308AbdKGI5J (ORCPT ); Tue, 7 Nov 2017 03:57:09 -0500 x-originating-ip: 107.180.71.197 From: Long Li To: Steve French , linux-cifs@vger.kernel.org, samba-technical@lists.samba.org, linux-kernel@vger.kernel.org, linux-rdma@vger.kernel.org, Christoph Hellwig , Tom Talpey , Matthew Wilcox , Stephen Hemminger Cc: Long Li Subject: [Patch v7 21/22] CIFS: SMBD: Upper layer performs SMB read via RDMA write through memory registration Date: Tue, 7 Nov 2017 01:55:13 -0700 Message-Id: <20171107085514.12693-22-longli@exchange.microsoft.com> X-Mailer: git-send-email 2.14.1 In-Reply-To: <20171107085514.12693-1-longli@exchange.microsoft.com> References: <20171107085514.12693-1-longli@exchange.microsoft.com> X-CMAE-Envelope: MS4wfF8i4O/0Ho5FkUKPV/D3rffDpagbqHas5BADeIknaixcqFOVAO4jizlh1d8PGM/muU8VKeS+swNrzckuStzijmprWSqB8x236KhhABmK+k6UcNq+6WTU FtteOgf+Dio2nZGdiWHpMz08FhYN5tocipEB8GrLTTfS1KCplWXZG7PHsrgnxaHkn4CHF8UmSUyhaYJBSIzAzJTCOrF+YPqV/7ysglI1LQA2ApZiwSChMEVx z/+COsEJHQztbupgHhyHiX5NfVqderSbBVTPALyAOSIagicNYuMUkmFJcaQWEHLTMbSZB/Vx97O6cGQqCjBI6k7yPbePT/B1QvD2gcCNxrfjY+oO9W30nDTd 9qA4esvwOoJ5Ocfk+Sq0Uywe/nP+z9X80jKAHiH9VJPLi+EUXKRhMq7k3lwwrvH1cBTuLzepdApr3KmkODDltp14YQnGvwymdm7BhwDWL6007PXx7SBAe1QT G6GwuhLqHD0T9yNlQNAPJmcw6+h4xs/6CjTexA== Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Long Li If I/O size is larger than rdma_readwrite_threshold, use RDMA write for SMB read by specifying channel SMB2_CHANNEL_RDMA_V1 or SMB2_CHANNEL_RDMA_V1_INVALIDATE in the SMB packet, depending on SMB dialect used. Append a smbd_buffer_descriptor_v1 to the end of the SMB packet and fill in other values to indicate this SMB read uses RDMA write. There is no need to read from the transport for incoming payload. At the time SMB read response comes back, the data is already transfered and placed in the pages by RDMA hardware. When SMB read is finished, deregister the memory regions if RDMA write is used for this SMB read. smbd_deregister_mr may need to do local invalidation and sleep, if server remote invalidation is not used. There are situations where the MID may not be created on I/O failure, under which memory region is deregistered when read data context is released. Signed-off-by: Long Li --- fs/cifs/file.c | 17 +++++++++++++++-- fs/cifs/smb2pdu.c | 45 ++++++++++++++++++++++++++++++++++++++++++++- 2 files changed, 59 insertions(+), 3 deletions(-) diff --git a/fs/cifs/file.c b/fs/cifs/file.c index 0786f19..464776a 100644 --- a/fs/cifs/file.c +++ b/fs/cifs/file.c @@ -42,7 +42,7 @@ #include "cifs_debug.h" #include "cifs_fs_sb.h" #include "fscache.h" - +#include "smbdirect.h" static inline int cifs_convert_flags(unsigned int flags) { @@ -2908,7 +2908,12 @@ cifs_readdata_release(struct kref *refcount) { struct cifs_readdata *rdata = container_of(refcount, struct cifs_readdata, refcount); - +#ifdef CONFIG_CIFS_SMB_DIRECT + if (rdata->mr) { + smbd_deregister_mr(rdata->mr); + rdata->mr = NULL; + } +#endif if (rdata->cfile) cifsFileInfo_put(rdata->cfile); @@ -3037,6 +3042,10 @@ uncached_fill_pages(struct TCP_Server_Info *server, } if (iter) result = copy_page_from_iter(page, 0, n, iter); +#ifdef CONFIG_CIFS_SMB_DIRECT + else if (rdata->mr) + result = n; +#endif else result = cifs_read_page_from_socket(server, page, n); if (result < 0) @@ -3606,6 +3615,10 @@ readpages_fill_pages(struct TCP_Server_Info *server, if (iter) result = copy_page_from_iter(page, 0, n, iter); +#ifdef CONFIG_CIFS_SMB_DIRECT + else if (rdata->mr) + result = n; +#endif else result = cifs_read_page_from_socket(server, page, n); if (result < 0) diff --git a/fs/cifs/smb2pdu.c b/fs/cifs/smb2pdu.c index c8afb83..8a5ff90 100644 --- a/fs/cifs/smb2pdu.c +++ b/fs/cifs/smb2pdu.c @@ -2379,7 +2379,40 @@ smb2_new_read_req(void **buf, unsigned int *total_len, req->MinimumCount = 0; req->Length = cpu_to_le32(io_parms->length); req->Offset = cpu_to_le64(io_parms->offset); +#ifdef CONFIG_CIFS_SMB_DIRECT + /* + * If we want to do a RDMA write, fill in and append + * smbd_buffer_descriptor_v1 to the end of read request + */ + if (server->rdma && rdata && + rdata->bytes >= server->smbd_conn->rdma_readwrite_threshold) { + + struct smbd_buffer_descriptor_v1 *v1; + bool need_invalidate = + io_parms->tcon->ses->server->dialect == SMB30_PROT_ID; + + rdata->mr = smbd_register_mr( + server->smbd_conn, rdata->pages, + rdata->nr_pages, rdata->tailsz, + true, need_invalidate); + if (!rdata->mr) + return -ENOBUFS; + + req->Channel = SMB2_CHANNEL_RDMA_V1_INVALIDATE; + if (need_invalidate) + req->Channel = SMB2_CHANNEL_RDMA_V1; + req->ReadChannelInfoOffset = + offsetof(struct smb2_read_plain_req, Buffer); + req->ReadChannelInfoLength = + sizeof(struct smbd_buffer_descriptor_v1); + v1 = (struct smbd_buffer_descriptor_v1 *) &req->Buffer[0]; + v1->offset = rdata->mr->mr->iova; + v1->token = rdata->mr->mr->rkey; + v1->length = rdata->mr->mr->length; + *total_len += sizeof(*v1) - 1; + } +#endif if (request_type & CHAINED_REQUEST) { if (!(request_type & END_OF_CHAIN)) { /* next 8-byte aligned request */ @@ -2458,7 +2491,17 @@ smb2_readv_callback(struct mid_q_entry *mid) if (rdata->result != -ENODATA) rdata->result = -EIO; } - +#ifdef CONFIG_CIFS_SMB_DIRECT + /* + * If this rdata has a memmory registered, the MR can be freed + * MR needs to be freed as soon as I/O finishes to prevent deadlock + * because they have limited number and are used for future I/Os + */ + if (rdata->mr) { + smbd_deregister_mr(rdata->mr); + rdata->mr = NULL; + } +#endif if (rdata->result) cifs_stats_fail_inc(tcon, SMB2_READ_HE); -- 2.7.4