5 files changed, 34 insertions, 10 deletions

diff --git a/fs/cifs/cifsglob.h b/fs/cifs/cifsglob.h
index a73dd1d5e7ef..d153d0b89d39 100644
--- a/fs/cifs/cifsglob.h
+++ b/fs/cifs/cifsglob.h
@@ -656,8 +656,24 @@ static inline void cifs_stats_bytes_read(struct cifs_tcon *tcon,
 struct mid_q_entry;
 
 /*
- * This is the prototype for the mid callback function. When creating one,
- * take special care to avoid deadlocks. Things to bear in mind:
+ * This is the prototype for the mid receive function. This function is for
+ * receiving the rest of the SMB frame, starting with the WordCount (which is
+ * just after the MID in struct smb_hdr). Note:
+ *
+ * - This will be called by cifsd, with no locks held.
+ * - The mid will still be on the pending_mid_q.
+ * - mid->resp_buf will point to the current buffer.
+ *
+ * Returns zero on a successful receive, or an error. The receive state in
+ * the TCP_Server_Info will also be updated.
+ */
+typedef int (mid_receive_t)(struct TCP_Server_Info *server,
+                            struct mid_q_entry *mid);
+
+/*
+ * This is the prototype for the mid callback function. This is called once the
+ * mid has been received off of the socket. When creating one, take special
+ * care to avoid deadlocks. Things to bear in mind:
  *
  * - it will be called by cifsd, with no locks held
  * - the mid will be removed from any lists
@@ -675,9 +691,10 @@ struct mid_q_entry {
         unsigned long when_sent; /* time when smb send finished */
         unsigned long when_received; /* when demux complete (taken off wire) */
 #endif
+        mid_receive_t *receive; /* call receive callback */
         mid_callback_t *callback; /* call completion callback */
         void *callback_data;      /* general purpose pointer for callback */
-        struct smb_hdr *resp_buf;       /* response buffer */
+        struct smb_hdr *resp_buf;       /* pointer to received SMB header */
         int midState;   /* wish this were enum but can not pass to wait_event */
         __u8 command;   /* smb command code */
         bool largeBuf:1;        /* if valid response, is pointer to large buf */
diff --git a/fs/cifs/cifsproto.h b/fs/cifs/cifsproto.h
index a1fa9cec05d6..8a7adb31ffed 100644
--- a/fs/cifs/cifsproto.h
+++ b/fs/cifs/cifsproto.h
@@ -69,8 +69,9 @@ extern struct mid_q_entry *AllocMidQEntry(const struct smb_hdr *smb_buffer,
                                         struct TCP_Server_Info *server);
 extern void DeleteMidQEntry(struct mid_q_entry *midEntry);
 extern int cifs_call_async(struct TCP_Server_Info *server, struct kvec *iov,
-                           unsigned int nvec, mid_callback_t *callback,
-                           void *cbdata, bool ignore_pend);
+                           unsigned int nvec, mid_receive_t *receive,
+                           mid_callback_t *callback, void *cbdata,
+                           bool ignore_pend);
 extern int SendReceive(const unsigned int /* xid */ , struct cifs_ses *,
                         struct smb_hdr * /* input */ ,
                         struct smb_hdr * /* out */ ,
diff --git a/fs/cifs/cifssmb.c b/fs/cifs/cifssmb.c
index c824c106b2b7..0613df4d8e74 100644
--- a/fs/cifs/cifssmb.c
+++ b/fs/cifs/cifssmb.c
@@ -737,7 +737,8 @@ CIFSSMBEcho(struct TCP_Server_Info *server)
         iov.iov_base = smb;
         iov.iov_len = be32_to_cpu(smb->hdr.smb_buf_length) + 4;
 
-        rc = cifs_call_async(server, &iov, 1, cifs_echo_callback, server, true);
+        rc = cifs_call_async(server, &iov, 1, NULL, cifs_echo_callback,
+                             server, true);
         if (rc)
                 cFYI(1, "Echo request failed: %d", rc);
 
@@ -1834,7 +1835,7 @@ cifs_async_writev(struct cifs_writedata *wdata)
 
         kref_get(&wdata->refcount);
         rc = cifs_call_async(tcon->ses->server, iov, wdata->nr_pages + 1,
-                             cifs_writev_callback, wdata, false);
+                             NULL, cifs_writev_callback, wdata, false);
 
         if (rc == 0)
                 cifs_stats_inc(&tcon->num_writes);
diff --git a/fs/cifs/connect.c b/fs/cifs/connect.c
index f05dedda37c6..eeee2f5d13ce 100644
--- a/fs/cifs/connect.c
+++ b/fs/cifs/connect.c
@@ -824,7 +824,11 @@ cifs_demultiplex_thread(void *p)
 
                 mid_entry = find_mid(server, smb_buffer);
 
-                length = standard_receive3(server, mid_entry);
+                if (!mid_entry || !mid_entry->receive)
+                        length = standard_receive3(server, mid_entry);
+                else
+                        length = mid_entry->receive(server, mid_entry);
+
                 if (length < 0)
                         continue;
 
diff --git a/fs/cifs/transport.c b/fs/cifs/transport.c
index 33a3fbf3a3a5..e7398d0cd054 100644
--- a/fs/cifs/transport.c
+++ b/fs/cifs/transport.c
@@ -339,8 +339,8 @@ wait_for_response(struct TCP_Server_Info *server, struct mid_q_entry *midQ)
  */
 int
 cifs_call_async(struct TCP_Server_Info *server, struct kvec *iov,
-                unsigned int nvec, mid_callback_t *callback, void *cbdata,
-                bool ignore_pend)
+                unsigned int nvec, mid_receive_t *receive,
+                mid_callback_t *callback, void *cbdata, bool ignore_pend)
 {
         int rc;
         struct mid_q_entry *mid;
@@ -374,6 +374,7 @@ cifs_call_async(struct TCP_Server_Info *server, struct kvec *iov,
                 goto out_err;
         }
 
+        mid->receive = receive;
         mid->callback = callback;
         mid->callback_data = cbdata;
         mid->midState = MID_REQUEST_SUBMITTED;