From: Gwendal Grignou <gwendal@chromium.org>
To: axboe@kernel.dk, ulf.hansson@linaro.org
Cc: linux-mmc@vger.kernel.org, Gwendal Grignou <gwendal@chromium.org>,
linux-mtd@lists.infradead.org, linux-kernel@vger.kernel.org
Subject: [PATCH 3/4] Limit max_discard_sectors to UINT_MAX>>9
Date: Tue, 25 Mar 2014 16:48:25 -0700 [thread overview]
Message-ID: <1395791307-23727-4-git-send-email-gwendal@chromium.org> (raw)
In-Reply-To: <1395791307-23727-1-git-send-email-gwendal@chromium.org>
max_discard_sectors can not be larger than UINT_MAX>>9,
otherwise, there is a risk that discard requests would be merged
into a request larger than 4GB.
Ensure that max_discard_sectors is in unit of sectors.
Signed-off-by: Gwendal Grignou <gwendal@chromium.org>
---
drivers/mmc/core/core.c | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)
diff --git a/drivers/mmc/core/core.c b/drivers/mmc/core/core.c
index 57a2b40..46e7ced 100644
--- a/drivers/mmc/core/core.c
+++ b/drivers/mmc/core/core.c
@@ -2153,7 +2153,7 @@ static unsigned int mmc_do_calc_max_discard(struct mmc_card *card,
if (qty == 1)
return 1;
- /* Convert qty to sectors */
+ /* Convert qty to bytes */
if (card->erase_shift)
max_discard = --qty << card->erase_shift;
else if (mmc_card_sd(card))
@@ -2170,7 +2170,7 @@ 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;
/*
* Without erase_group_def set, MMC erase timeout depends on clock
@@ -2188,6 +2188,8 @@ unsigned int mmc_calc_max_discard(struct mmc_card *card)
} else if (max_discard < card->erase_size) {
max_discard = 0;
}
+ /* convert max_discard to sectors */
+ max_discard >>= 9;
pr_debug("%s: calculated max. discard sectors %u for timeout %u ms\n",
mmc_hostname(host), max_discard, host->max_discard_to);
return max_discard;
--
1.9.1.423.g4596e3a
next prev parent reply other threads:[~2014-03-25 23:54 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-03-25 23:48 [PATCH 0/4] Set max_discard_sectors maximal value to UINT_MAX>>9 Gwendal Grignou
2014-03-25 23:48 ` [PATCH 1/4] Limit max_discard_sectors " Gwendal Grignou
2014-03-25 23:48 ` [PATCH 2/4] " Gwendal Grignou
2014-03-25 23:48 ` Gwendal Grignou [this message]
2014-03-25 23:48 ` [PATCH 4/4] " Gwendal Grignou
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