From mboxrd@z Thu Jan 1 00:00:00 1970 From: Adrian Hunter Subject: Re: [PATCH 2/8] mmc: fix max_discard_sectors Date: Mon, 15 Apr 2013 10:20:22 +0300 Message-ID: <516BAA36.9030500@intel.com> References: <1365860309-21261-1-git-send-email-linkinjeon@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Return-path: Received: from mga03.intel.com ([143.182.124.21]:48100 "EHLO mga03.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932124Ab3DOHPx (ORCPT ); Mon, 15 Apr 2013 03:15:53 -0400 In-Reply-To: <1365860309-21261-1-git-send-email-linkinjeon@gmail.com> Sender: linux-mmc-owner@vger.kernel.org List-Id: linux-mmc@vger.kernel.org To: Namjae Jeon Cc: dwmw2@infradead.org, axboe@kernel.dk, shli@kernel.org, Paul.Clements@steeleye.com, npiggin@kernel.dk, neilb@suse.de, cjb@laptop.org, linux-mtd@lists.infradead.org, nbd-general@lists.sourceforge.net, linux-raid@vger.kernel.org, linux-mmc@vger.kernel.org, linux-kernel@vger.kernel.org, Namjae Jeon , Vivek Trivedi On 13/04/13 16:38, Namjae Jeon wrote: > From: Namjae Jeon > > https://lkml.org/lkml/2013/4/1/292 > As per above discussion, there is possibility that request's __data_len > field may overflow when max_discard_sectors greater than UINT_MAX >> 9 > > If multiple discard requests get merged, merged discard request's > size exceeds 4GB, there is possibility that merged discard request's > __data_len field may overflow. > > This patch fixes this issue. > > Reported-by: Max Filippov > Signed-off-by: Namjae Jeon > Signed-off-by: Vivek Trivedi > Tested-by: Max Filippov > --- > drivers/mmc/card/queue.c | 2 +- > drivers/mmc/core/core.c | 4 ++-- > 2 files changed, 3 insertions(+), 3 deletions(-) > > diff --git a/drivers/mmc/card/queue.c b/drivers/mmc/card/queue.c > index 9447a0e..54726b7 100644 > --- a/drivers/mmc/card/queue.c > +++ b/drivers/mmc/card/queue.c > @@ -166,7 +166,7 @@ static void mmc_queue_setup_discard(struct request_queue *q, > return; > > queue_flag_set_unlocked(QUEUE_FLAG_DISCARD, q); > - q->limits.max_discard_sectors = max_discard; > + blk_queue_max_discard_sectors(q, max_discard); > if (card->erased_byte == 0 && !mmc_can_discard(card)) > q->limits.discard_zeroes_data = 1; > q->limits.discard_granularity = card->pref_erase << 9; > diff --git a/drivers/mmc/core/core.c b/drivers/mmc/core/core.c > index 7b435a3..6ee530c 100644 > --- a/drivers/mmc/core/core.c > +++ b/drivers/mmc/core/core.c > @@ -2058,7 +2058,7 @@ static unsigned int mmc_do_calc_max_discard(struct mmc_card *card, > if (card->erase_shift) > max_qty = UINT_MAX >> card->erase_shift; > else if (mmc_card_sd(card)) > - max_qty = UINT_MAX; > + max_qty = UINT_MAX >> 9; No. This function calculates max discard for the card not the block layer. Apply the block layer limitation at the block layer interface e.g. in mmc_queue_setup_discard() > else > max_qty = UINT_MAX / card->erase_size; > > @@ -2100,7 +2100,7 @@ unsigned int mmc_calc_max_discard(struct mmc_card *card) > unsigned int max_discard, max_trim; > > if (!host->max_discard_to) > - return UINT_MAX; > + return UINT_MAX >> 9; Ditto. > > /* > * Without erase_group_def set, MMC erase timeout depends on clock >