From dd48c085c1cdf9446f92826f1fd451167fb6c2fd Mon Sep 17 00:00:00 2001
From: Akinobu Mita <akinobu.mita@gmail.com>
Date: Wed, 3 Aug 2011 16:21:01 -0700
Subject: [PATCH] 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/fault-injection.txt | 3 +--
block/blk-core.c | 6 ++++--
block/blk-timeout.c | 5 ++++-
include/linux/fault-inject.h | 18 +++++------------
lib/fault-inject.c | 20 +++++++------------
mm/failslab.c | 14 ++++++-------
mm/page_alloc.c | 13 +++++-------
7 files changed, 33 insertions(+), 46 deletions(-)
diff --git a/Documentation/fault-injection/fault-injection.txt b/Documentation/fault-injection/fault-injection.txt
index 7be15e44d4816..82a5d250d75e7 100644
--- a/Documentation/fault-injection/fault-injection.txt
+++ b/Documentation/fault-injection/fault-injection.txt
@@ -143,8 +143,7 @@ o provide a way to configure fault attributes
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
diff --git a/block/blk-core.c b/block/blk-core.c
index b850bedad229e..b627558c461fa 100644
--- a/block/blk-core.c
+++ b/block/blk-core.c
@@ -1368,8 +1368,10 @@ static bool should_fail_request(struct hd_struct *part, unsigned int bytes)
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);
diff --git a/block/blk-timeout.c b/block/blk-timeout.c
index 4f0c06c7a3388..780354888958c 100644
--- a/block/blk-timeout.c
+++ b/block/blk-timeout.c
@@ -28,7 +28,10 @@ int blk_should_fake_timeout(struct request_queue *q)
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);
diff --git a/include/linux/fault-inject.h b/include/linux/fault-inject.h
index 3ff060ac78105..c6f996f2abb6c 100644
--- a/include/linux/fault-inject.h
+++ b/include/linux/fault-inject.h
@@ -25,10 +25,6 @@ struct fault_attr {
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 @@ bool should_fail(struct fault_attr *attr, ssize_t size);
#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)
-{
- return -ENODEV;
-}
-
-static inline void cleanup_fault_attr_dentries(struct fault_attr *attr)
+static inline struct dentry *fault_create_debugfs_attr(const char *name,
+ struct dentry *parent, struct fault_attr *attr)
{
+ return ERR_PTR(-ENODEV);
}
#endif /* CONFIG_FAULT_INJECTION_DEBUG_FS */
diff --git a/lib/fault-inject.c b/lib/fault-inject.c
index 2577b121c7c1e..f193b7796449a 100644
--- a/lib/fault-inject.c
+++ b/lib/fault-inject.c
@@ -197,21 +197,15 @@ static struct dentry *debugfs_create_atomic_t(const char *name, mode_t mode,
return debugfs_create_file(name, mode, parent, value, &fops_atomic_t);
}
-void cleanup_fault_attr_dentries(struct fault_attr *attr)
-{
- debugfs_remove_recursive(attr->dir);
-}
-
-int init_fault_attr_dentries(struct fault_attr *attr, const char *name)
+struct dentry *fault_create_debugfs_attr(const char *name,
+ struct dentry *parent, struct fault_attr *attr)
{
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;
-
- attr->dir = dir;
+ return ERR_PTR(-ENOMEM);
if (!debugfs_create_ul("probability", mode, dir, &attr->probability))
goto fail;
@@ -243,11 +237,11 @@ int init_fault_attr_dentries(struct fault_attr *attr, const char *name)
#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 */
diff --git a/mm/failslab.c b/mm/failslab.c
index 1ce58c201dca5..0dd7b8fec71cf 100644
--- a/mm/failslab.c
+++ b/mm/failslab.c
@@ -34,23 +34,23 @@ __setup("failslab=", setup_failslab);
#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;
}
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 1dbcf8888f145..6e8ecb6e021c7 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -1409,14 +1409,11 @@ static int __init fail_page_alloc_debugfs(void)
{
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 = fail_page_alloc.attr.dir;
+ dir = fault_create_debugfs_attr("fail_page_alloc", NULL,
+ &fail_page_alloc.attr);
+ if (IS_ERR(dir))
+ return PTR_ERR(dir);
if (!debugfs_create_bool("ignore-gfp-wait", mode, dir,
&fail_page_alloc.ignore_gfp_wait))
@@ -1430,7 +1427,7 @@ static int __init fail_page_alloc_debugfs(void)
return 0;
fail:
- cleanup_fault_attr_dentries(&fail_page_alloc.attr);
+ debugfs_remove_recursive(dir);
return -ENOMEM;
}
--
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