fault-injection: add ability to export fault_attr in arbitrary directory

init_fault_attr_dentries() is used to export fault_attr via debugfs. But it can only export it in debugfs root directory. Per Forlin is working on mmc_fail_request which adds support to inject data errors after a completed host transfer in MMC subsystem. The fault_attr for mmc_fail_request should be defined per mmc host and export it in debugfs directory per mmc host like /sys/kernel/debug/mmc0/mmc_fail_request. init_fault_attr_dentries() doesn't help for mmc_fail_request. So this introduces fault_create_debugfs_attr() which is able to create a directory in the arbitrary directory and replace init_fault_attr_dentries(). [akpm@linux-foundation.org: extraneous semicolon, per Randy] Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com> Tested-by: Per Forlin <per.forlin@linaro.org> Cc: Jens Axboe <axboe@kernel.dk> Cc: Christoph Lameter <cl@linux-foundation.org> Cc: Pekka Enberg <penberg@kernel.org> Cc: Matt Mackall <mpm@selenic.com> Cc: Randy Dunlap <rdunlap@xenotime.net> Cc: Stephen Rothwell <sfr@canb.auug.org.au> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

fault-injection: add ability to export fault_attr in arbitrary directory
init_fault_attr_dentries() is used to export fault_attr via debugfs. But it can only export it in debugfs root directory. Per Forlin is working on mmc_fail_request which adds support to inject data errors after a completed host transfer in MMC subsystem. The fault_attr for mmc_fail_request should be defined per mmc host and export it in debugfs directory per mmc host like /sys/kernel/debug/mmc0/mmc_fail_request. init_fault_attr_dentries() doesn't help for mmc_fail_request. So this introduces fault_create_debugfs_attr() which is able to create a directory in the arbitrary directory and replace init_fault_attr_dentries(). [akpm@linux-foundation.org: extraneous semicolon, per Randy] Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com> Tested-by: Per Forlin <per.forlin@linaro.org> Cc: Jens Axboe <axboe@kernel.dk> Cc: Christoph Lameter <cl@linux-foundation.org> Cc: Pekka Enberg <penberg@kernel.org> Cc: Matt Mackall <mpm@selenic.com> Cc: Randy Dunlap <rdunlap@xenotime.net> Cc: Stephen Rothwell <sfr@canb.auug.org.au> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Akinobu Mita · Linus Torvalds
1 parent f48d1915b8
Showing 7 changed files with 33 additions and 46 deletions Side-by-side Diff
Documentation/fault-injection/fault-injection.txt
block/blk-core.c
block/blk-timeout.c
include/linux/fault-inject.h
lib/fault-inject.c
mm/failslab.c
mm/page_alloc.c
@@ -143,8 +143,7 @@
   failslab, fail_page_alloc, and fail_make_request use this way.
   Helper functions:
  
-	init_fault_attr_dentries(entries, attr, name);
-	void cleanup_fault_attr_dentries(entries);
+	fault_create_debugfs_attr(name, parent, attr);
  
 - module parameters
  
@@ -1368,8 +1368,10 @@
  
 static int __init fail_make_request_debugfs(void)
 {
-	return init_fault_attr_dentries(&fail_make_request,
-					"fail_make_request");
+	struct dentry *dir = fault_create_debugfs_attr("fail_make_request",
+						NULL, &fail_make_request);
+
+	return IS_ERR(dir) ? PTR_ERR(dir) : 0;
 }
  
 late_initcall(fail_make_request_debugfs);
@@ -28,7 +28,10 @@
  
 static int __init fail_io_timeout_debugfs(void)
 {
-	return init_fault_attr_dentries(&fail_io_timeout, "fail_io_timeout");
+	struct dentry *dir = fault_create_debugfs_attr("fail_io_timeout",
+						NULL, &fail_io_timeout);
+
+	return IS_ERR(dir) ? PTR_ERR(dir) : 0;
 }
  
 late_initcall(fail_io_timeout_debugfs);
@@ -25,10 +25,6 @@
 	unsigned long reject_end;
  
 	unsigned long count;
-
-#ifdef CONFIG_FAULT_INJECTION_DEBUG_FS
-	struct dentry *dir;
-#endif
 };
  
 #define FAULT_ATTR_INITIALIZER {				\
  
  
@@ -45,19 +41,15 @@
  
 #ifdef CONFIG_FAULT_INJECTION_DEBUG_FS
  
-int init_fault_attr_dentries(struct fault_attr *attr, const char *name);
-void cleanup_fault_attr_dentries(struct fault_attr *attr);
+struct dentry *fault_create_debugfs_attr(const char *name,
+			struct dentry *parent, struct fault_attr *attr);
  
 #else /* CONFIG_FAULT_INJECTION_DEBUG_FS */
  
-static inline int init_fault_attr_dentries(struct fault_attr *attr,
-					  const char *name)
+static inline struct dentry *fault_create_debugfs_attr(const char *name,
+			struct dentry *parent, struct fault_attr *attr)
 {
-	return -ENODEV;
-}
-
-static inline void cleanup_fault_attr_dentries(struct fault_attr *attr)
-{
+	return ERR_PTR(-ENODEV);
 }
  
 #endif /* CONFIG_FAULT_INJECTION_DEBUG_FS */
@@ -197,22 +197,16 @@
 	return debugfs_create_file(name, mode, parent, value, &fops_atomic_t);
 }
  
-void cleanup_fault_attr_dentries(struct fault_attr *attr)
+struct dentry *fault_create_debugfs_attr(const char *name,
+			struct dentry *parent, struct fault_attr *attr)
 {
-	debugfs_remove_recursive(attr->dir);
-}
-
-int init_fault_attr_dentries(struct fault_attr *attr, const char *name)
-{
 	mode_t mode = S_IFREG | S_IRUSR | S_IWUSR;
 	struct dentry *dir;
  
-	dir = debugfs_create_dir(name, NULL);
+	dir = debugfs_create_dir(name, parent);
 	if (!dir)
-		return -ENOMEM;
+		return ERR_PTR(-ENOMEM);
  
-	attr->dir = dir;
-
 	if (!debugfs_create_ul("probability", mode, dir, &attr->probability))
 		goto fail;
 	if (!debugfs_create_ul("interval", mode, dir, &attr->interval))
  
  
@@ -243,11 +237,11 @@
  
 #endif /* CONFIG_FAULT_INJECTION_STACKTRACE_FILTER */
  
-	return 0;
+	return dir;
 fail:
-	debugfs_remove_recursive(attr->dir);
+	debugfs_remove_recursive(dir);
  
-	return -ENOMEM;
+	return ERR_PTR(-ENOMEM);
 }
  
 #endif /* CONFIG_FAULT_INJECTION_DEBUG_FS */
@@ -34,23 +34,23 @@
 #ifdef CONFIG_FAULT_INJECTION_DEBUG_FS
 static int __init failslab_debugfs_init(void)
 {
+	struct dentry *dir;
 	mode_t mode = S_IFREG | S_IRUSR | S_IWUSR;
-	int err;
  
-	err = init_fault_attr_dentries(&failslab.attr, "failslab");
-	if (err)
-		return err;
+	dir = fault_create_debugfs_attr("failslab", NULL, &failslab.attr);
+	if (IS_ERR(dir))
+		return PTR_ERR(dir);
  
-	if (!debugfs_create_bool("ignore-gfp-wait", mode, failslab.attr.dir,
+	if (!debugfs_create_bool("ignore-gfp-wait", mode, dir,
 				&failslab.ignore_gfp_wait))
 		goto fail;
-	if (!debugfs_create_bool("cache-filter", mode, failslab.attr.dir,
+	if (!debugfs_create_bool("cache-filter", mode, dir,
 				&failslab.cache_filter))
 		goto fail;
  
 	return 0;
 fail:
-	cleanup_fault_attr_dentries(&failslab.attr);
+	debugfs_remove_recursive(dir);
  
 	return -ENOMEM;
 }
@@ -1409,15 +1409,12 @@
 {
 	mode_t mode = S_IFREG | S_IRUSR | S_IWUSR;
 	struct dentry *dir;
-	int err;
  
-	err = init_fault_attr_dentries(&fail_page_alloc.attr,
-				       "fail_page_alloc");
-	if (err)
-		return err;
+	dir = fault_create_debugfs_attr("fail_page_alloc", NULL,
+					&fail_page_alloc.attr);
+	if (IS_ERR(dir))
+		return PTR_ERR(dir);
  
-	dir = fail_page_alloc.attr.dir;
-
 	if (!debugfs_create_bool("ignore-gfp-wait", mode, dir,
 				&fail_page_alloc.ignore_gfp_wait))
 		goto fail;
@@ -1430,7 +1427,7 @@
  
 	return 0;
 fail:
-	cleanup_fault_attr_dentries(&fail_page_alloc.attr);
+	debugfs_remove_recursive(dir);
  
 	return -ENOMEM;
 }
...	...	@@ -143,8 +143,7 @@
143	143	failslab, fail_page_alloc, and fail_make_request use this way.
144	144	Helper functions:
145	145
146		- init_fault_attr_dentries(entries, attr, name);
147		- void cleanup_fault_attr_dentries(entries);
	146	+ fault_create_debugfs_attr(name, parent, attr);
148	147
149	148	- module parameters
150	149
...	...	@@ -1368,8 +1368,10 @@
1368	1368
1369	1369	static int __init fail_make_request_debugfs(void)
1370	1370	{
1371		- return init_fault_attr_dentries(&fail_make_request,
1372		- "fail_make_request");
	1371	+ struct dentry *dir = fault_create_debugfs_attr("fail_make_request",
	1372	+ NULL, &fail_make_request);
	1373	+
	1374	+ return IS_ERR(dir) ? PTR_ERR(dir) : 0;
1373	1375	}
1374	1376
1375	1377	late_initcall(fail_make_request_debugfs);
...	...	@@ -28,7 +28,10 @@
28	28
29	29	static int __init fail_io_timeout_debugfs(void)
30	30	{
31		- return init_fault_attr_dentries(&fail_io_timeout, "fail_io_timeout");
	31	+ struct dentry *dir = fault_create_debugfs_attr("fail_io_timeout",
	32	+ NULL, &fail_io_timeout);
	33	+
	34	+ return IS_ERR(dir) ? PTR_ERR(dir) : 0;
32	35	}
33	36
34	37	late_initcall(fail_io_timeout_debugfs);
...	...	@@ -25,10 +25,6 @@
25	25	unsigned long reject_end;
26	26
27	27	unsigned long count;
28		-
29		-#ifdef CONFIG_FAULT_INJECTION_DEBUG_FS
30		- struct dentry *dir;
31		-#endif
32	28	};
33	29
34	30	#define FAULT_ATTR_INITIALIZER { \
35	31
36	32
...	...	@@ -45,19 +41,15 @@
45	41
46	42	#ifdef CONFIG_FAULT_INJECTION_DEBUG_FS
47	43
48		-int init_fault_attr_dentries(struct fault_attr attr, const char name);
49		-void cleanup_fault_attr_dentries(struct fault_attr *attr);
	44	+struct dentry fault_create_debugfs_attr(const char name,
	45	+ struct dentry parent, struct fault_attr attr);
50	46
51	47	#else /* CONFIG_FAULT_INJECTION_DEBUG_FS */
52	48
53		-static inline int init_fault_attr_dentries(struct fault_attr *attr,
54		- const char *name)
	49	+static inline struct dentry fault_create_debugfs_attr(const char name,
	50	+ struct dentry parent, struct fault_attr attr)
55	51	{
56		- return -ENODEV;
57		-}
58		-
59		-static inline void cleanup_fault_attr_dentries(struct fault_attr *attr)
60		-{
	52	+ return ERR_PTR(-ENODEV);
61	53	}
62	54
63	55	#endif /* CONFIG_FAULT_INJECTION_DEBUG_FS */
...	...	@@ -197,22 +197,16 @@
197	197	return debugfs_create_file(name, mode, parent, value, &fops_atomic_t);
198	198	}
199	199
200		-void cleanup_fault_attr_dentries(struct fault_attr *attr)
	200	+struct dentry fault_create_debugfs_attr(const char name,
	201	+ struct dentry parent, struct fault_attr attr)
201	202	{
202		- debugfs_remove_recursive(attr->dir);
203		-}
204		-
205		-int init_fault_attr_dentries(struct fault_attr attr, const char name)
206		-{
207	203	mode_t mode = S_IFREG \| S_IRUSR \| S_IWUSR;
208	204	struct dentry *dir;
209	205
210		- dir = debugfs_create_dir(name, NULL);
	206	+ dir = debugfs_create_dir(name, parent);
211	207	if (!dir)
212		- return -ENOMEM;
	208	+ return ERR_PTR(-ENOMEM);
213	209
214		- attr->dir = dir;
215		-
216	210	if (!debugfs_create_ul("probability", mode, dir, &attr->probability))
217	211	goto fail;
218	212	if (!debugfs_create_ul("interval", mode, dir, &attr->interval))
219	213
220	214
...	...	@@ -243,11 +237,11 @@
243	237
244	238	#endif /* CONFIG_FAULT_INJECTION_STACKTRACE_FILTER */
245	239
246		- return 0;
	240	+ return dir;
247	241	fail:
248		- debugfs_remove_recursive(attr->dir);
	242	+ debugfs_remove_recursive(dir);
249	243
250		- return -ENOMEM;
	244	+ return ERR_PTR(-ENOMEM);
251	245	}
252	246
253	247	#endif /* CONFIG_FAULT_INJECTION_DEBUG_FS */
...	...	@@ -34,23 +34,23 @@
34	34	#ifdef CONFIG_FAULT_INJECTION_DEBUG_FS
35	35	static int __init failslab_debugfs_init(void)
36	36	{
	37	+ struct dentry *dir;
37	38	mode_t mode = S_IFREG \| S_IRUSR \| S_IWUSR;
38		- int err;
39	39
40		- err = init_fault_attr_dentries(&failslab.attr, "failslab");
41		- if (err)
42		- return err;
	40	+ dir = fault_create_debugfs_attr("failslab", NULL, &failslab.attr);
	41	+ if (IS_ERR(dir))
	42	+ return PTR_ERR(dir);
43	43
44		- if (!debugfs_create_bool("ignore-gfp-wait", mode, failslab.attr.dir,
	44	+ if (!debugfs_create_bool("ignore-gfp-wait", mode, dir,
45	45	&failslab.ignore_gfp_wait))
46	46	goto fail;
47		- if (!debugfs_create_bool("cache-filter", mode, failslab.attr.dir,
	47	+ if (!debugfs_create_bool("cache-filter", mode, dir,
48	48	&failslab.cache_filter))
49	49	goto fail;
50	50
51	51	return 0;
52	52	fail:
53		- cleanup_fault_attr_dentries(&failslab.attr);
	53	+ debugfs_remove_recursive(dir);
54	54
55	55	return -ENOMEM;
56	56	}
...	...	@@ -1409,15 +1409,12 @@
1409	1409	{
1410	1410	mode_t mode = S_IFREG \| S_IRUSR \| S_IWUSR;
1411	1411	struct dentry *dir;
1412		- int err;
1413	1412
1414		- err = init_fault_attr_dentries(&fail_page_alloc.attr,
1415		- "fail_page_alloc");
1416		- if (err)
1417		- return err;
	1413	+ dir = fault_create_debugfs_attr("fail_page_alloc", NULL,
	1414	+ &fail_page_alloc.attr);
	1415	+ if (IS_ERR(dir))
	1416	+ return PTR_ERR(dir);
1418	1417
1419		- dir = fail_page_alloc.attr.dir;
1420		-
1421	1418	if (!debugfs_create_bool("ignore-gfp-wait", mode, dir,
1422	1419	&fail_page_alloc.ignore_gfp_wait))
1423	1420	goto fail;
...	...	@@ -1430,7 +1427,7 @@
1430	1427
1431	1428	return 0;
1432	1429	fail:
1433		- cleanup_fault_attr_dentries(&fail_page_alloc.attr);
	1430	+ debugfs_remove_recursive(dir);
1434	1431
1435	1432	return -ENOMEM;
1436	1433	}