From: Thadeu Lima de Souza Cascardo <cascardo@holoscopio.com>
Date: Thu, 20 May 2010 14:21:36 +0000 (-0400)
Subject: USe interruptible version of down.
X-Git-Url: http://git.cascardo.info/?p=cascardo%2Fkernel%2Fsamples%2Fchar2%2F.git;a=commitdiff_plain;h=0ac89f0fe059f1985e9ad39c15794938b5eda7fd

USe interruptible version of down.
---

diff --git a/hellochar.c b/hellochar.c
index 85510f7..628f53c 100644
--- a/hellochar.c
+++ b/hellochar.c
@@ -39,7 +39,8 @@ static DECLARE_MUTEX(hello_mtx);
 
 static int hello_open(struct inode *ino, struct file *fp)
 {
-	down(&hello_mtx);
+	if (down_interruptible(&hello_mtx))
+		return -ERESTARTSYS;
 	if (fp->f_flags & O_TRUNC) {
 		memset(hello->buffer, 0, MAXLEN);
 		hello->len = 0;
@@ -54,7 +55,8 @@ static ssize_t hello_read(struct file *fp, char __user *buf, size_t sz,
 	loff_t *pos)
 {
 	int r;
-	down(&hello_mtx);
+	if (down_interruptible(&hello_mtx))
+		return -ERESTARTSYS;
 	if (sz + *pos > hello->len)
 		sz = hello->len - *pos;
 	r = copy_to_user(buf, hello->buffer + *pos, sz);
@@ -69,7 +71,8 @@ static ssize_t hello_write(struct file *fp, const char __user *buf, size_t sz,
 	loff_t *pos)
 {
 	int r;
-	down(&hello_mtx);
+	if (down_interruptible(&hello_mtx))
+		return -ERESTARTSYS;
 	if (sz + *pos > MAXLEN)
 		sz = MAXLEN - *pos;
 	r = copy_from_user(hello->buffer + *pos, buf, sz);