From 39f36b47caae1443eb37c34c6def108bb79f8d25 Mon Sep 17 00:00:00 2001
From: Tejun Heo <tj@kernel.org>
Date: Tue, 28 Apr 2009 12:38:32 +0900
Subject: [PATCH] mg_disk: fix locking
IRQ and timeout handlers call functions which expect locked queue lock
without locking it. Fix it.
While at it, convert 0s used as null pointer constant to NULLs.
[ Impact: fix locking, cleanup ]
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: unsik Kim <donari75@gmail.com>
---
drivers/block/mg_disk.c | 17 +++++++++++++----
1 file changed, 13 insertions(+), 4 deletions(-)
diff --git a/drivers/block/mg_disk.c b/drivers/block/mg_disk.c
index fb39d9aa3cdcc..d3e72ad08dbe1 100644
--- a/drivers/block/mg_disk.c
+++ b/drivers/block/mg_disk.c
@@ -160,11 +160,16 @@ static irqreturn_t mg_irq(int irq, void *dev_id)
struct mg_host *host = dev_id;
void (*handler)(struct mg_host *) = host->mg_do_intr;
- host->mg_do_intr = 0;
+ spin_lock(&host->lock);
+
+ host->mg_do_intr = NULL;
del_timer(&host->timer);
if (!handler)
handler = mg_unexpected_intr;
handler(host);
+
+ spin_unlock(&host->lock);
+
return IRQ_HANDLED;
}
@@ -319,7 +324,7 @@ static void mg_read(struct request *req)
remains = req->nr_sectors;
- if (mg_out(host, req->sector, req->nr_sectors, MG_CMD_RD, 0) !=
+ if (mg_out(host, req->sector, req->nr_sectors, MG_CMD_RD, NULL) !=
MG_ERR_NONE)
mg_bad_rw_intr(host);
@@ -363,7 +368,7 @@ static void mg_write(struct request *req)
remains = req->nr_sectors;
- if (mg_out(host, req->sector, req->nr_sectors, MG_CMD_WR, 0) !=
+ if (mg_out(host, req->sector, req->nr_sectors, MG_CMD_WR, NULL) !=
MG_ERR_NONE) {
mg_bad_rw_intr(host);
return;
@@ -521,9 +526,11 @@ void mg_times_out(unsigned long data)
char *name;
struct request *req;
+ spin_lock_irq(&host->lock);
+
req = elv_next_request(host->breq);
if (!req)
- return;
+ goto out_unlock;
host->mg_do_intr = NULL;
@@ -534,6 +541,8 @@ void mg_times_out(unsigned long data)
mg_bad_rw_intr(host);
mg_request(host->breq);
+out_unlock:
+ spin_unlock_irq(&host->lock);
}
static void mg_request_poll(struct request_queue *q)
--
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