[PATCH 4/9] MTD: make mtdtrans thread freezeable.

Maxim Levitsky
2010-01-12T19:32:45Z

>From c50bb924c12c742e53d66837ad8be48d93fc5fbe Mon Sep 17 00:00:00 2001
From: Maxim Levitsky <maximlevitsky@gmail.com>
Date: Tue, 12 Jan 2010 20:59:27 +0200
Subject: [PATCH 4/9] MTD: make mtdtrans thread freezeable.

This makes the mtd blktrans thread enter the freezer in between accesses
to nand device.
This will ensure that we aren't suspening the system in the middle
of page read/write and even worse erase, which is a bad idea.

Signed-off-by: Maxim Levitsky <maximlevitsky@gmail.com>
---
drivers/mtd/mtd_blkdevs.c | 14 +++++++-------
1 files changed, 7 insertions(+), 7 deletions(-)

diff --git a/drivers/mtd/mtd_blkdevs.c b/drivers/mtd/mtd_blkdevs.c
index 04a875f..db996d6 100644
--- a/drivers/mtd/mtd_blkdevs.c
+++ b/drivers/mtd/mtd_blkdevs.c
@@ -20,6 +20,7 @@
#include <linux/init.h>
#include <linux/mutex.h>
#include <linux/kthread.h>
+#include <linux/freezer.h>
#include <asm/uaccess.h>

#include "mtdcore.h"
@@ -79,36 +80,35 @@ static int mtd_blktrans_thread(void *arg)
struct request_queue *rq = dev->rq;
struct request *req = NULL;

- spin_lock_irq(rq->queue_lock);
+ set_freezable();

while (!kthread_should_stop()) {
int res;

+ try_to_freeze();
+
+ spin_lock_irq(rq->queue_lock);
if (!req && !(req = blk_fetch_request(rq))) {
set_current_state(TASK_INTERRUPTIBLE);
spin_unlock_irq(rq->queue_lock);
schedule();
- spin_lock_irq(rq->queue_lock);
continue;
}
-
spin_unlock_irq(rq->queue_lock);

+
mutex_lock(&dev->lock);
res = do_blktrans_request(dev->tr, dev, req);
mutex_unlock(&dev->lock);

spin_lock_irq(rq->queue_lock);
-
if (!__blk_end_request_cur(req, res))
req = NULL;
+ spin_unlock_irq(rq->queue_lock);
}

if (req)
__blk_end_request_all(req, -EIO);
-
- spin_unlock_irq(rq->queue_lock);
-
return 0;
}

--
1.6.3.3