[S390] cio: add lock to struct channel_path
Serialize access to members of struct channel_path with a mutex.
Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
diff --git a/drivers/s390/cio/chp.c b/drivers/s390/cio/chp.c
index 6c9fa15..b1addd7 100644
--- a/drivers/s390/cio/chp.c
+++ b/drivers/s390/cio/chp.c
@@ -1,7 +1,7 @@
/*
* drivers/s390/cio/chp.c
*
- * Copyright IBM Corp. 1999,2007
+ * Copyright IBM Corp. 1999,2010
* Author(s): Cornelia Huck (cornelia.huck@de.ibm.com)
* Arnd Bergmann (arndb@de.ibm.com)
* Peter Oberparleiter <peter.oberparleiter@de.ibm.com>
@@ -241,11 +241,13 @@
struct device_attribute *attr, char *buf)
{
struct channel_path *chp = to_channelpath(dev);
+ int status;
- if (!chp)
- return 0;
- return (chp_get_status(chp->chpid) ? sprintf(buf, "online\n") :
- sprintf(buf, "offline\n"));
+ mutex_lock(&chp->lock);
+ status = chp->state;
+ mutex_unlock(&chp->lock);
+
+ return status ? sprintf(buf, "online\n") : sprintf(buf, "offline\n");
}
static ssize_t chp_status_write(struct device *dev,
@@ -261,15 +263,18 @@
if (!num_args)
return count;
- if (!strnicmp(cmd, "on", 2) || !strcmp(cmd, "1"))
+ if (!strnicmp(cmd, "on", 2) || !strcmp(cmd, "1")) {
+ mutex_lock(&cp->lock);
error = s390_vary_chpid(cp->chpid, 1);
- else if (!strnicmp(cmd, "off", 3) || !strcmp(cmd, "0"))
+ mutex_unlock(&cp->lock);
+ } else if (!strnicmp(cmd, "off", 3) || !strcmp(cmd, "0")) {
+ mutex_lock(&cp->lock);
error = s390_vary_chpid(cp->chpid, 0);
- else
+ mutex_unlock(&cp->lock);
+ } else
error = -EINVAL;
return error < 0 ? error : count;
-
}
static DEVICE_ATTR(status, 0644, chp_status_show, chp_status_write);
@@ -315,10 +320,12 @@
char *buf)
{
struct channel_path *chp = to_channelpath(dev);
+ u8 type;
- if (!chp)
- return 0;
- return sprintf(buf, "%x\n", chp->desc.desc);
+ mutex_lock(&chp->lock);
+ type = chp->desc.desc;
+ mutex_unlock(&chp->lock);
+ return sprintf(buf, "%x\n", type);
}
static DEVICE_ATTR(type, 0444, chp_type_show, NULL);
@@ -395,6 +402,7 @@
chp->state = 1;
chp->dev.parent = &channel_subsystems[chpid.cssid]->device;
chp->dev.release = chp_release;
+ mutex_init(&chp->lock);
/* Obtain channel path description and fill it in. */
ret = chsc_determine_base_channel_path_desc(chpid, &chp->desc);
@@ -464,7 +472,10 @@
desc = kmalloc(sizeof(struct channel_path_desc), GFP_KERNEL);
if (!desc)
return NULL;
+
+ mutex_lock(&chp->lock);
memcpy(desc, &chp->desc, sizeof(struct channel_path_desc));
+ mutex_unlock(&chp->lock);
return desc;
}