From mboxrd@z Thu Jan 1 00:00:00 1970 From: Long Li Subject: [Patch v2 18/19] CIFS: SMBD: Deregister memory when finishing SMB READ Date: Sun, 20 Aug 2017 12:04:42 -0700 Message-ID: <1503255883-3041-19-git-send-email-longli@exchange.microsoft.com> References: <1503255883-3041-1-git-send-email-longli@exchange.microsoft.com> Cc: 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 Return-path: In-Reply-To: <1503255883-3041-1-git-send-email-longli@exchange.microsoft.com> Sender: linux-kernel-owner@vger.kernel.org List-Id: linux-cifs.vger.kernel.org From: Long Li 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. Signed-off-by: Long Li --- fs/cifs/smb2pdu.c | 10 ++++++++++ 1 file changed, 10 insertions(+) diff --git a/fs/cifs/smb2pdu.c b/fs/cifs/smb2pdu.c index 1f08c75..43a7b60 100644 --- a/fs/cifs/smb2pdu.c +++ b/fs/cifs/smb2pdu.c @@ -2504,6 +2504,16 @@ smb2_readv_callback(struct mid_q_entry *mid) rdata->result = -EIO; } + /* + * 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; + } + if (rdata->result) cifs_stats_fail_inc(tcon, SMB2_READ_HE); -- 2.7.4