Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932301AbbGPBWD (ORCPT ); Wed, 15 Jul 2015 21:22:03 -0400 Received: from youngberry.canonical.com ([91.189.89.112]:56281 "EHLO youngberry.canonical.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932204AbbGPBLu (ORCPT ); Wed, 15 Jul 2015 21:11:50 -0400 From: Kamal Mostafa To: linux-kernel@vger.kernel.org, stable@vger.kernel.org, kernel-team@lists.ubuntu.com Cc: Ding Wang , Ulf Hansson , Kamal Mostafa Subject: [PATCH 3.19.y-ckt 222/251] mmc: card: Fixup request missing in mmc_blk_issue_rw_rq Date: Wed, 15 Jul 2015 18:09:03 -0700 Message-Id: <1437008972-9140-223-git-send-email-kamal@canonical.com> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1437008972-9140-1-git-send-email-kamal@canonical.com> References: <1437008972-9140-1-git-send-email-kamal@canonical.com> X-Extended-Stable: 3.19 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2298 Lines: 63 3.19.8-ckt4 -stable review patch. If anyone has any objections, please let me know. ------------------ From: Ding Wang commit 29535f7b797df35cc9b6b3bca635591cdd3dd2a8 upstream. The current handler of MMC_BLK_CMD_ERR in mmc_blk_issue_rw_rq function may cause new coming request permanent missing when the ongoing request (previoulsy started) complete end. The problem scenario is as follows: (1) Request A is ongoing; (2) Request B arrived, and finally mmc_blk_issue_rw_rq() is called; (3) Request A encounters the MMC_BLK_CMD_ERR error; (4) In the error handling of MMC_BLK_CMD_ERR, suppose mmc_blk_cmd_err() end request A completed and return zero. Continue the error handling, suppose mmc_blk_reset() reset device success; (5) Continue the execution, while loop completed because variable ret is zero now; (6) Finally, mmc_blk_issue_rw_rq() return without processing request B. The process related to the missing request may wait that IO request complete forever, possibly crashing the application or hanging the system. Fix this issue by starting new request when reset success. Signed-off-by: Ding Wang Fixes: 67716327eec7 ("mmc: block: add eMMC hardware reset support") Signed-off-by: Ulf Hansson Signed-off-by: Kamal Mostafa --- drivers/mmc/card/block.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-) diff --git a/drivers/mmc/card/block.c b/drivers/mmc/card/block.c index 4e5d36a..c972b97 100644 --- a/drivers/mmc/card/block.c +++ b/drivers/mmc/card/block.c @@ -1910,9 +1910,11 @@ static int mmc_blk_issue_rw_rq(struct mmc_queue *mq, struct request *rqc) break; case MMC_BLK_CMD_ERR: ret = mmc_blk_cmd_err(md, card, brq, req, ret); - if (!mmc_blk_reset(md, card->host, type)) - break; - goto cmd_abort; + if (mmc_blk_reset(md, card->host, type)) + goto cmd_abort; + if (!ret) + goto start_new_req; + break; case MMC_BLK_RETRY: if (retry++ < 5) break; -- 1.9.1 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/