CIFS: Fix an issue with re-sending wdata when transport returning -EAGAIN

When sending a wdata, transport may return -EAGAIN. In this case
we should re-obtain credits because the session may have been
reconnected.

Change in v2: adjust_credits before re-sending

Signed-off-by: Long Li <longli@microsoft.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>

diff --git a/fs/cifs/file.c b/fs/cifs/file.c
index 2a6d20c0ce0288d37ad2405424200be3fefaa9f4..2aa3e62af764c68edde1537bd72328f39707a78d 100644 (file)
--- a/fs/cifs/file.c
+++ b/fs/cifs/file.c
@@ -2632,43 +2632,56 @@ cifs_resend_wdata(struct cifs_writedata *wdata, struct list_head *wdata_list,
        struct TCP_Server_Info *server =
                tlink_tcon(wdata->cfile->tlink)->ses->server;
 
-       /*
-        * Wait for credits to resend this wdata.
-        * Note: we are attempting to resend the whole wdata not in segments
-        */
        do {
-               rc = server->ops->wait_mtu_credits(server, wdata->bytes, &wsize,
-                                                  &credits);
+               if (wdata->cfile->invalidHandle) {
+                       rc = cifs_reopen_file(wdata->cfile, false);
+                       if (rc == -EAGAIN)
+                               continue;
+                       else if (rc)
+                               break;
+               }
 
-               if (rc)
-                       goto out;
 
-               if (wsize < wdata->bytes) {
-                       add_credits_and_wake_if(server, &credits, 0);
-                       msleep(1000);
-               }
-       } while (wsize < wdata->bytes);
+               /*
+                * Wait for credits to resend this wdata.
+                * Note: we are attempting to resend the whole wdata not in
+                * segments
+                */
+               do {
+                       rc = server->ops->wait_mtu_credits(server, wdata->bytes,
+                                               &wsize, &credits);
+                       if (rc)
+                               goto fail;
+
+                       if (wsize < wdata->bytes) {
+                               add_credits_and_wake_if(server, &credits, 0);
+                               msleep(1000);
+                       }
+               } while (wsize < wdata->bytes);
+               wdata->credits = credits;
 
-       wdata->credits = credits;
-       rc = -EAGAIN;
-       while (rc == -EAGAIN) {
-               rc = 0;
-               if (wdata->cfile->invalidHandle)
-                       rc = cifs_reopen_file(wdata->cfile, false);
-               if (!rc)
-                       rc = server->ops->async_writev(wdata,
+               rc = adjust_credits(server, &wdata->credits, wdata->bytes);
+
+               if (!rc) {
+                       if (wdata->cfile->invalidHandle)
+                               rc = -EAGAIN;
+                       else
+                               rc = server->ops->async_writev(wdata,
                                        cifs_uncached_writedata_release);
-       }
+               }
 
-       if (!rc) {
-               list_add_tail(&wdata->list, wdata_list);
-               return 0;
-       }
+               /* If the write was successfully sent, we are done */
+               if (!rc) {
+                       list_add_tail(&wdata->list, wdata_list);
+                       return 0;
+               }
 
-       add_credits_and_wake_if(server, &wdata->credits, 0);
-out:
-       kref_put(&wdata->refcount, cifs_uncached_writedata_release);
+               /* Roll back credits and retry if needed */
+               add_credits_and_wake_if(server, &wdata->credits, 0);
+       } while (rc == -EAGAIN);
 
+fail:
+       kref_put(&wdata->refcount, cifs_uncached_writedata_release);
        return rc;
 }
 
@@ -2896,12 +2909,12 @@ restart_loop:
                                                wdata->bytes, &tmp_from,
                                                ctx->cfile, cifs_sb, &tmp_list,
                                                ctx);
+
+                                       kref_put(&wdata->refcount,
+                                               cifs_uncached_writedata_release);
                                }
 
                                list_splice(&tmp_list, &ctx->list);
-
-                               kref_put(&wdata->refcount,
-                                        cifs_uncached_writedata_release);
                                goto restart_loop;
                        }
                }