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[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>
This commit is contained in:
Michael Ernst 2008-07-14 09:57:24 +02:00 committed by Heiko Carstens
parent 9689b336e1
commit b1c02d9110
1 changed files with 39 additions and 6 deletions
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45
drivers/s390/char/sclp_cpi_sys.c
View File

@ -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);