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From:   Souptick Joarder <jrdr.linux@gmail.com>
To:     mporter@kernel.crashing.org, alex.bou9@gmail.com,
        akpm@linux-foundation.org, gustavoars@kernel.org,
        jhubbard@nvidia.com, madhuparnabhowmik10@gmail.com,
        dan.carpenter@oracle.com
Cc:     linux-kernel@vger.kernel.org,
        Souptick Joarder <jrdr.linux@gmail.com>,
        Ira Weiny <ira.weiny@intel.com>,
        Matthew Wilcox <willy@infradead.org>
Subject: [linux-next PATCH] rapidio: Fix error handling path
Date:   Wed, 16 Sep 2020 09:12:17 +0530
Message-Id: <1600227737-20785-1-git-send-email-jrdr.linux@gmail.com>
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

There is an error when pin_user_pages_fast() returns -ERRNO and
inside error handling path driver end up calling unpin_user_pages()
with -ERRNO which is not correct.

This patch will fix the problem.

Fixes: e8de370188d09 ("rapidio: add mport char device driver")
Signed-off-by: Souptick Joarder <jrdr.linux@gmail.com>
Cc: Ira Weiny <ira.weiny@intel.com>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: Matthew Wilcox <willy@infradead.org>
---
 drivers/rapidio/devices/rio_mport_cdev.c | 13 +++++++------
 1 file changed, 7 insertions(+), 6 deletions(-)

diff --git a/drivers/rapidio/devices/rio_mport_cdev.c b/drivers/rapidio/devices/rio_mport_cdev.c
index a303429..163b6c72 100644
--- a/drivers/rapidio/devices/rio_mport_cdev.c
+++ b/drivers/rapidio/devices/rio_mport_cdev.c
@@ -871,15 +871,16 @@ static int do_dma_request(struct mport_dma_req *req,
 				rmcd_error("pin_user_pages_fast err=%ld",
 					   pinned);
 				nr_pages = 0;
-			} else
+			} else {
 				rmcd_error("pinned %ld out of %ld pages",
 					   pinned, nr_pages);
+				/*
+				 * Set nr_pages up to mean "how many pages to unpin, in
+				 * the error handler:
+				 */
+				nr_pages = pinned;
+			}
 			ret = -EFAULT;
-			/*
-			 * Set nr_pages up to mean "how many pages to unpin, in
-			 * the error handler:
-			 */
-			nr_pages = pinned;
 			goto err_pg;
 		}
 
-- 
1.9.1