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authorMichael Ernst <mernst@de.ibm.com>2008-07-14 09:57:24 +0200
committerHeiko Carstens <heiko.carstens@de.ibm.com>2008-07-14 10:01:59 +0200
commitb1c02d9110e72ec510ec9b038f9564e3c0d87384 (patch)
tree7c7e75d9230ffbbc29e7424736973f79cbdf50ba
parent9689b336e193680fc0fcaa33829dc670637e9c98 (diff)
[S390] cio: Use locks when accessing /sys/firmware/cpi data.
Mutex locks are used to avoid problems when /sys/firmware/cpi data are accessed to in parallel. Signed-off-by: Michael Ernst <mernst@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
-rw-r--r--drivers/s390/char/sclp_cpi_sys.c45
1 files changed, 39 insertions, 6 deletions
diff --git a/drivers/s390/char/sclp_cpi_sys.c b/drivers/s390/char/sclp_cpi_sys.c
index 9f37456222e..005f330ed92 100644
--- a/drivers/s390/char/sclp_cpi_sys.c
+++ b/drivers/s390/char/sclp_cpi_sys.c
@@ -27,6 +27,8 @@
#define CPI_LENGTH_NAME 8
#define CPI_LENGTH_LEVEL 16
+static DEFINE_MUTEX(sclp_cpi_mutex);
+
struct cpi_evbuf {
struct evbuf_header header;
u8 id_format;
@@ -223,7 +225,12 @@ static void set_string(char *attr, const char *value)
static ssize_t system_name_show(struct kobject *kobj,
struct kobj_attribute *attr, char *page)
{
- return snprintf(page, PAGE_SIZE, "%s\n", system_name);
+ int rc;
+
+ mutex_lock(&sclp_cpi_mutex);
+ rc = snprintf(page, PAGE_SIZE, "%s\n", system_name);
+ mutex_unlock(&sclp_cpi_mutex);
+ return rc;
}
static ssize_t system_name_store(struct kobject *kobj,
@@ -237,7 +244,9 @@ static ssize_t system_name_store(struct kobject *kobj,
if (rc)
return rc;
+ mutex_lock(&sclp_cpi_mutex);
set_string(system_name, buf);
+ mutex_unlock(&sclp_cpi_mutex);
return len;
}
@@ -248,7 +257,12 @@ static struct kobj_attribute system_name_attr =
static ssize_t sysplex_name_show(struct kobject *kobj,
struct kobj_attribute *attr, char *page)
{
- return snprintf(page, PAGE_SIZE, "%s\n", sysplex_name);
+ int rc;
+
+ mutex_lock(&sclp_cpi_mutex);
+ rc = snprintf(page, PAGE_SIZE, "%s\n", sysplex_name);
+ mutex_unlock(&sclp_cpi_mutex);
+ return rc;
}
static ssize_t sysplex_name_store(struct kobject *kobj,
@@ -262,7 +276,9 @@ static ssize_t sysplex_name_store(struct kobject *kobj,
if (rc)
return rc;
+ mutex_lock(&sclp_cpi_mutex);
set_string(sysplex_name, buf);
+ mutex_unlock(&sclp_cpi_mutex);
return len;
}
@@ -273,7 +289,12 @@ static struct kobj_attribute sysplex_name_attr =
static ssize_t system_type_show(struct kobject *kobj,
struct kobj_attribute *attr, char *page)
{
- return snprintf(page, PAGE_SIZE, "%s\n", system_type);
+ int rc;
+
+ mutex_lock(&sclp_cpi_mutex);
+ rc = snprintf(page, PAGE_SIZE, "%s\n", system_type);
+ mutex_unlock(&sclp_cpi_mutex);
+ return rc;
}
static ssize_t system_type_store(struct kobject *kobj,
@@ -287,7 +308,9 @@ static ssize_t system_type_store(struct kobject *kobj,
if (rc)
return rc;
+ mutex_lock(&sclp_cpi_mutex);
set_string(system_type, buf);
+ mutex_unlock(&sclp_cpi_mutex);
return len;
}
@@ -298,8 +321,11 @@ static struct kobj_attribute system_type_attr =
static ssize_t system_level_show(struct kobject *kobj,
struct kobj_attribute *attr, char *page)
{
- unsigned long long level = system_level;
+ unsigned long long level;
+ mutex_lock(&sclp_cpi_mutex);
+ level = system_level;
+ mutex_unlock(&sclp_cpi_mutex);
return snprintf(page, PAGE_SIZE, "%#018llx\n", level);
}
@@ -320,8 +346,9 @@ static ssize_t system_level_store(struct kobject *kobj,
if (*endp)
return -EINVAL;
+ mutex_lock(&sclp_cpi_mutex);
system_level = level;
-
+ mutex_unlock(&sclp_cpi_mutex);
return len;
}
@@ -334,7 +361,9 @@ static ssize_t set_store(struct kobject *kobj,
{
int rc;
+ mutex_lock(&sclp_cpi_mutex);
rc = cpi_req();
+ mutex_unlock(&sclp_cpi_mutex);
if (rc)
return rc;
@@ -373,12 +402,16 @@ int sclp_cpi_set_data(const char *system, const char *sysplex, const char *type,
if (rc)
return rc;
+ mutex_lock(&sclp_cpi_mutex);
set_string(system_name, system);
set_string(sysplex_name, sysplex);
set_string(system_type, type);
system_level = level;
- return cpi_req();
+ rc = cpi_req();
+ mutex_unlock(&sclp_cpi_mutex);
+
+ return rc;
}
EXPORT_SYMBOL(sclp_cpi_set_data);