From: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Date: Wed, 26 Jun 2013 12:28:39 +0000 (+0300)
Subject: staging: zram: protect zram_reset_device() call
X-Git-Tag: MMI-PSA29.97-13-9~13944^2~3
X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=644d478793c6594277f8ae76954da4ace7ac6f96;p=GitHub%2FMotorolaMobilityLLC%2Fkernel-slsi.git

staging: zram: protect zram_reset_device() call

Commit 9b3bb7abcdf2df0f1b2657e6cbc9d06bc2b3b36f (remove
zram_sysfs file (v2)) accidentally made zram_reset_device()
racy. Protect zram_reset_device() call with zram->lock.

Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Acked-by: Jerome Marchand <jmarchand@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---

diff --git a/drivers/staging/zram/zram_drv.c b/drivers/staging/zram/zram_drv.c
index 82c7202fd5cc..e77fb6ea40c9 100644
--- a/drivers/staging/zram/zram_drv.c
+++ b/drivers/staging/zram/zram_drv.c
@@ -527,8 +527,11 @@ static void zram_reset_device(struct zram *zram)
 	size_t index;
 	struct zram_meta *meta;
 
-	if (!zram->init_done)
+	down_write(&zram->init_lock);
+	if (!zram->init_done) {
+		up_write(&zram->init_lock);
 		return;
+	}
 
 	meta = zram->meta;
 	zram->init_done = 0;
@@ -549,6 +552,7 @@ static void zram_reset_device(struct zram *zram)
 
 	zram->disksize = 0;
 	set_capacity(zram->disk, 0);
+	up_write(&zram->init_lock);
 }
 
 static void zram_init_device(struct zram *zram, struct zram_meta *meta)