From b1c02d9110e72ec510ec9b038f9564e3c0d87384 Mon Sep 17 00:00:00 2001 From: Michael Ernst Date: Mon, 14 Jul 2008 09:57:24 +0200 Subject: [PATCH] [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 Signed-off-by: Martin Schwidefsky Signed-off-by: Heiko Carstens --- drivers/s390/char/sclp_cpi_sys.c | 45 +++++++++++++++++++++++++++----- 1 file changed, 39 insertions(+), 6 deletions(-) diff --git a/drivers/s390/char/sclp_cpi_sys.c b/drivers/s390/char/sclp_cpi_sys.c index 9f37456222..005f330ed9 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); -- 2.39.5