From: Anna Lemehova <EXT-Anna.Lemehova@nokia.com>
Date: Fri, 8 Jan 2010 22:42:58 +0000 (-0800)
Subject: mmc_block: add dev_t initialization check
X-Git-Tag: v2.6.33-rc4~44
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=7d92df692994472cab6045bbd9d0e2c4afa4365f;p=platform%2Fupstream%2Fkernel-adaptation-pc.git

mmc_block: add dev_t initialization check

When a card is removed before mmc_blk_probe() has called add_disk(), then
the minor field is uninitialized and has value 0.  This caused
mmc_blk_put() to always release devidx 0 even if 0 was still in use.  Then
the next mmc_blk_probe() used the first free idx of 0, which oopses in
sysfs, since it is used by another card.

Signed-off-by: Anna Lemehova <EXT-Anna.Lemehova@nokia.com>
Signed-off-by: Adrian Hunter <adrian.hunter@nokia.com>
Cc: <linux-mmc@vger.kernel.org>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
---

diff --git a/drivers/mmc/card/block.c b/drivers/mmc/card/block.c
index 85f0e8c..5988573 100644
--- a/drivers/mmc/card/block.c
+++ b/drivers/mmc/card/block.c
@@ -85,7 +85,12 @@ static void mmc_blk_put(struct mmc_blk_data *md)
 	mutex_lock(&open_lock);
 	md->usage--;
 	if (md->usage == 0) {
+		int devmaj = MAJOR(disk_devt(md->disk));
 		int devidx = MINOR(disk_devt(md->disk)) >> MMC_SHIFT;
+
+		if (!devmaj)
+			devidx = md->disk->first_minor >> MMC_SHIFT;
+
 		__clear_bit(devidx, dev_use);
 
 		put_disk(md->disk);