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authorMichael Ernst <mernst@de.ibm.com>2008-07-14 03:57:24 -0400
committerHeiko Carstens <heiko.carstens@de.ibm.com>2008-07-14 04:01:59 -0400
commitb1c02d9110e72ec510ec9b038f9564e3c0d87384 (patch)
tree7c7e75d9230ffbbc29e7424736973f79cbdf50ba /drivers/s390/char
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>
Diffstat (limited to 'drivers/s390/char')
-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 9f37456222e9..005f330ed926 100644
--- a/drivers/s390/char/sclp_cpi_sys.c
+++ b/drivers/s390/char/sclp_cpi_sys.c
@@ -27,6 +27,8 @@
27#define CPI_LENGTH_NAME 8 27#define CPI_LENGTH_NAME 8
28#define CPI_LENGTH_LEVEL 16 28#define CPI_LENGTH_LEVEL 16
29 29
30static DEFINE_MUTEX(sclp_cpi_mutex);
31
30struct cpi_evbuf { 32struct cpi_evbuf {
31 struct evbuf_header header; 33 struct evbuf_header header;
32 u8 id_format; 34 u8 id_format;
@@ -223,7 +225,12 @@ static void set_string(char *attr, const char *value)
223static ssize_t system_name_show(struct kobject *kobj, 225static ssize_t system_name_show(struct kobject *kobj,
224 struct kobj_attribute *attr, char *page) 226 struct kobj_attribute *attr, char *page)
225{ 227{
226 return snprintf(page, PAGE_SIZE, "%s\n", system_name); 228 int rc;
229
230 mutex_lock(&sclp_cpi_mutex);
231 rc = snprintf(page, PAGE_SIZE, "%s\n", system_name);
232 mutex_unlock(&sclp_cpi_mutex);
233 return rc;
227} 234}
228 235
229static ssize_t system_name_store(struct kobject *kobj, 236static ssize_t system_name_store(struct kobject *kobj,
@@ -237,7 +244,9 @@ static ssize_t system_name_store(struct kobject *kobj,
237 if (rc) 244 if (rc)
238 return rc; 245 return rc;
239 246
247 mutex_lock(&sclp_cpi_mutex);
240 set_string(system_name, buf); 248 set_string(system_name, buf);
249 mutex_unlock(&sclp_cpi_mutex);
241 250
242 return len; 251 return len;
243} 252}
@@ -248,7 +257,12 @@ static struct kobj_attribute system_name_attr =
248static ssize_t sysplex_name_show(struct kobject *kobj, 257static ssize_t sysplex_name_show(struct kobject *kobj,
249 struct kobj_attribute *attr, char *page) 258 struct kobj_attribute *attr, char *page)
250{ 259{
251 return snprintf(page, PAGE_SIZE, "%s\n", sysplex_name); 260 int rc;
261
262 mutex_lock(&sclp_cpi_mutex);
263 rc = snprintf(page, PAGE_SIZE, "%s\n", sysplex_name);
264 mutex_unlock(&sclp_cpi_mutex);
265 return rc;
252} 266}
253 267
254static ssize_t sysplex_name_store(struct kobject *kobj, 268static ssize_t sysplex_name_store(struct kobject *kobj,
@@ -262,7 +276,9 @@ static ssize_t sysplex_name_store(struct kobject *kobj,
262 if (rc) 276 if (rc)
263 return rc; 277 return rc;
264 278
279 mutex_lock(&sclp_cpi_mutex);
265 set_string(sysplex_name, buf); 280 set_string(sysplex_name, buf);
281 mutex_unlock(&sclp_cpi_mutex);
266 282
267 return len; 283 return len;
268} 284}
@@ -273,7 +289,12 @@ static struct kobj_attribute sysplex_name_attr =
273static ssize_t system_type_show(struct kobject *kobj, 289static ssize_t system_type_show(struct kobject *kobj,
274 struct kobj_attribute *attr, char *page) 290 struct kobj_attribute *attr, char *page)
275{ 291{
276 return snprintf(page, PAGE_SIZE, "%s\n", system_type); 292 int rc;
293
294 mutex_lock(&sclp_cpi_mutex);
295 rc = snprintf(page, PAGE_SIZE, "%s\n", system_type);
296 mutex_unlock(&sclp_cpi_mutex);
297 return rc;
277} 298}
278 299
279static ssize_t system_type_store(struct kobject *kobj, 300static ssize_t system_type_store(struct kobject *kobj,
@@ -287,7 +308,9 @@ static ssize_t system_type_store(struct kobject *kobj,
287 if (rc) 308 if (rc)
288 return rc; 309 return rc;
289 310
311 mutex_lock(&sclp_cpi_mutex);
290 set_string(system_type, buf); 312 set_string(system_type, buf);
313 mutex_unlock(&sclp_cpi_mutex);
291 314
292 return len; 315 return len;
293} 316}
@@ -298,8 +321,11 @@ static struct kobj_attribute system_type_attr =
298static ssize_t system_level_show(struct kobject *kobj, 321static ssize_t system_level_show(struct kobject *kobj,
299 struct kobj_attribute *attr, char *page) 322 struct kobj_attribute *attr, char *page)
300{ 323{
301 unsigned long long level = system_level; 324 unsigned long long level;
302 325
326 mutex_lock(&sclp_cpi_mutex);
327 level = system_level;
328 mutex_unlock(&sclp_cpi_mutex);
303 return snprintf(page, PAGE_SIZE, "%#018llx\n", level); 329 return snprintf(page, PAGE_SIZE, "%#018llx\n", level);
304} 330}
305 331
@@ -320,8 +346,9 @@ static ssize_t system_level_store(struct kobject *kobj,
320 if (*endp) 346 if (*endp)
321 return -EINVAL; 347 return -EINVAL;
322 348
349 mutex_lock(&sclp_cpi_mutex);
323 system_level = level; 350 system_level = level;
324 351 mutex_unlock(&sclp_cpi_mutex);
325 return len; 352 return len;
326} 353}
327 354
@@ -334,7 +361,9 @@ static ssize_t set_store(struct kobject *kobj,
334{ 361{
335 int rc; 362 int rc;
336 363
364 mutex_lock(&sclp_cpi_mutex);
337 rc = cpi_req(); 365 rc = cpi_req();
366 mutex_unlock(&sclp_cpi_mutex);
338 if (rc) 367 if (rc)
339 return rc; 368 return rc;
340 369
@@ -373,12 +402,16 @@ int sclp_cpi_set_data(const char *system, const char *sysplex, const char *type,
373 if (rc) 402 if (rc)
374 return rc; 403 return rc;
375 404
405 mutex_lock(&sclp_cpi_mutex);
376 set_string(system_name, system); 406 set_string(system_name, system);
377 set_string(sysplex_name, sysplex); 407 set_string(sysplex_name, sysplex);
378 set_string(system_type, type); 408 set_string(system_type, type);
379 system_level = level; 409 system_level = level;
380 410
381 return cpi_req(); 411 rc = cpi_req();
412 mutex_unlock(&sclp_cpi_mutex);
413
414 return rc;
382} 415}
383EXPORT_SYMBOL(sclp_cpi_set_data); 416EXPORT_SYMBOL(sclp_cpi_set_data);
384 417