From: Ronnie Sahlberg <lsahlber@redhat.com>
Date: Tue, 5 Feb 2019 12:56:44 +1000
Subject: [PATCH] cifs: add credits from unmatched responses/messages
Git-commit: eca004523811f816bcfca3046ab54e1278e0973b
Patch-mainline: v5.1-rc1
References: bsc#1144333

We should add any credits granted to us from unmatched server responses.

Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>
Acked-by: Aurelien Aptel <aaptel@suse.com>
---
 fs/cifs/connect.c  | 22 ++++++++++++++++++++++
 fs/cifs/smb2misc.c |  7 -------
 2 files changed, 22 insertions(+), 7 deletions(-)

diff --git a/fs/cifs/connect.c b/fs/cifs/connect.c
index 7c9108ce3de0..a825ac219bbd 100644
--- a/fs/cifs/connect.c
+++ b/fs/cifs/connect.c
@@ -1063,6 +1063,26 @@ cifs_handle_standard(struct TCP_Server_Info *server, struct mid_q_entry *mid)
 	return 0;
 }
 
+static void
+smb2_add_credits_from_hdr(char *buffer, struct TCP_Server_Info *server)
+{
+	struct smb2_sync_hdr *shdr = (struct smb2_sync_hdr *)buffer;
+
+	/*
+	 * SMB1 does not use credits.
+	 */
+	if (server->vals->header_preamble_size)
+		return;
+
+	if (shdr->CreditRequest) {
+		spin_lock(&server->req_lock);
+		server->credits += le16_to_cpu(shdr->CreditRequest);
+		spin_unlock(&server->req_lock);
+		wake_up(&server->request_q);
+	}
+}
+
+
 static int
 cifs_demultiplex_thread(void *p)
 {
@@ -1192,6 +1212,7 @@ cifs_demultiplex_thread(void *p)
 			} else if (server->ops->is_oplock_break &&
 				   server->ops->is_oplock_break(bufs[i],
 								server)) {
+				smb2_add_credits_from_hdr(bufs[i], server);
 				cifs_dbg(FYI, "Received oplock break\n");
 			} else {
 				cifs_dbg(VFS, "No task to wake, unknown frame "
@@ -1203,6 +1224,7 @@ cifs_demultiplex_thread(void *p)
 				if (server->ops->dump_detail)
 					server->ops->dump_detail(bufs[i],
 								 server);
+				smb2_add_credits_from_hdr(bufs[i], server);
 				cifs_dump_mids(server);
 #endif /* CIFS_DEBUG2 */
 			}
diff --git a/fs/cifs/smb2misc.c b/fs/cifs/smb2misc.c
index 7b8b58fb4d3f..6a9c47541c53 100644
--- a/fs/cifs/smb2misc.c
+++ b/fs/cifs/smb2misc.c
@@ -648,13 +648,6 @@ smb2_is_valid_oplock_break(char *buffer, struct TCP_Server_Info *server)
 	if (rsp->sync_hdr.Command != SMB2_OPLOCK_BREAK)
 		return false;
 
-	if (rsp->sync_hdr.CreditRequest) {
-		spin_lock(&server->req_lock);
-		server->credits += le16_to_cpu(rsp->sync_hdr.CreditRequest);
-		spin_unlock(&server->req_lock);
-		wake_up(&server->request_q);
-	}
-
 	if (rsp->StructureSize !=
 				smb2_rsp_struct_sizes[SMB2_OPLOCK_BREAK_HE]) {
 		if (le16_to_cpu(rsp->StructureSize) == 44)
-- 
2.16.4