[PATCH v4 17/19] cifs: discard functions to ensure that mid callbacks get called

[nspmangalore@gmail.com]

From: Shyam Prasad N <sprasad@microsoft.com>

If discard functions for readv and query_dir return error, the
callback functions can be skipped. This can end up with hung
syscalls due to the completion functions not getting called.

This change ensures that both these discard functions call
the callback function when discard from socket returned error.
This ensures that at least after the mid for the response is found,
the callback doesn't get skipped, and we do not leave syscalls
waiting.

Signed-off-by: Shyam Prasad N <sprasad@microsoft.com>
---
 fs/smb/client/transport.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/fs/smb/client/transport.c b/fs/smb/client/transport.c
index 24ccadb00f568..a11e6eba008a6 100644
--- a/fs/smb/client/transport.c
+++ b/fs/smb/client/transport.c
@@ -1143,6 +1143,11 @@ __cifs_discard_and_dequeue(struct TCP_Server_Info *server, struct mid_q_entry *m
 	dequeue_mid(server, mid, malformed);
 	mid->resp_buf = server->smallbuf;
 	server->smallbuf = NULL;
+
+	/* Once the mid is dequeued, the callback must run to terminate the subreq */
+	if (length < 0)
+		mid_execute_callback(server, mid);
+
 	return length;
 }
 
-- 
2.43.0