smb: client: rename server mid_lock to mid_queue_lock

This is step 1/4 of a patch series to fix mid_q_entry memory leaks
caused by race conditions in callback execution.

The current mid_lock name is somewhat ambiguous about what it protects.
To prepare for splitting this lock into separate, more granular locks,
this patch renames mid_lock to mid_queue_lock to clearly indicate its
specific responsibility for protecting the pending_mid_q list and
related queue operations.

No functional changes are made in this patch - it only prepares the
codebase for the lock splitting that follows.

- mid_queue_lock for queue operations
- mid_counter_lock for mid counter operations
- per-mid locks for individual mid state management

Signed-off-by: Wang Zhaolong <wangzhaolong@huaweicloud.com>
Acked-by: Enzo Matsumiya <ematsumiya@suse.de>
Signed-off-by: Steve French <stfrench@microsoft.com>

1 files changed, 13 insertions, 13 deletions

diff --git a/fs/smb/client/smb2ops.c b/fs/smb/client/smb2ops.c
index bd6c1fb2a992..7935f9b433ac 100644
--- a/fs/smb/client/smb2ops.c
+++ b/fs/smb/client/smb2ops.c
@@ -374,19 +374,19 @@ smb2_get_next_mid(struct TCP_Server_Info *server)
 {
 	__u64 mid;
 	/* for SMB2 we need the current value */
-	spin_lock(&server->mid_lock);
+	spin_lock(&server->mid_queue_lock);
 	mid = server->CurrentMid++;
-	spin_unlock(&server->mid_lock);
+	spin_unlock(&server->mid_queue_lock);
 	return mid;
 }
 
 static void
 smb2_revert_current_mid(struct TCP_Server_Info *server, const unsigned int val)
 {
-	spin_lock(&server->mid_lock);
+	spin_lock(&server->mid_queue_lock);
 	if (server->CurrentMid >= val)
 		server->CurrentMid -= val;
-	spin_unlock(&server->mid_lock);
+	spin_unlock(&server->mid_queue_lock);
 }
 
 static struct mid_q_entry *
@@ -401,7 +401,7 @@ __smb2_find_mid(struct TCP_Server_Info *server, char *buf, bool dequeue)
 		return NULL;
 	}
 
-	spin_lock(&server->mid_lock);
+	spin_lock(&server->mid_queue_lock);
 	list_for_each_entry(mid, &server->pending_mid_q, qhead) {
 		if ((mid->mid == wire_mid) &&
 		    (mid->mid_state == MID_REQUEST_SUBMITTED) &&
@@ -411,11 +411,11 @@ __smb2_find_mid(struct TCP_Server_Info *server, char *buf, bool dequeue)
 				list_del_init(&mid->qhead);
 				mid->mid_flags |= MID_DELETED;
 			}
-			spin_unlock(&server->mid_lock);
+			spin_unlock(&server->mid_queue_lock);
 			return mid;
 		}
 	}
-	spin_unlock(&server->mid_lock);
+	spin_unlock(&server->mid_queue_lock);
 	return NULL;
 }
 
@@ -460,9 +460,9 @@ smb2_negotiate(const unsigned int xid,
 {
 	int rc;
 
-	spin_lock(&server->mid_lock);
+	spin_lock(&server->mid_queue_lock);
 	server->CurrentMid = 0;
-	spin_unlock(&server->mid_lock);
+	spin_unlock(&server->mid_queue_lock);
 	rc = SMB2_negotiate(xid, ses, server);
 	return rc;
 }
@@ -4809,18 +4809,18 @@ static void smb2_decrypt_offload(struct work_struct *work)
 		} else {
 			spin_lock(&dw->server->srv_lock);
 			if (dw->server->tcpStatus == CifsNeedReconnect) {
-				spin_lock(&dw->server->mid_lock);
+				spin_lock(&dw->server->mid_queue_lock);
 				mid->mid_state = MID_RETRY_NEEDED;
-				spin_unlock(&dw->server->mid_lock);
+				spin_unlock(&dw->server->mid_queue_lock);
 				spin_unlock(&dw->server->srv_lock);
 				mid->callback(mid);
 			} else {
-				spin_lock(&dw->server->mid_lock);
+				spin_lock(&dw->server->mid_queue_lock);
 				mid->mid_state = MID_REQUEST_SUBMITTED;
 				mid->mid_flags &= ~(MID_DELETED);
 				list_add_tail(&mid->qhead,
 					&dw->server->pending_mid_q);
-				spin_unlock(&dw->server->mid_lock);
+				spin_unlock(&dw->server->mid_queue_lock);
 				spin_unlock(&dw->server->srv_lock);
 			}
 		}