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authorFrederic Weisbecker <fweisbec@gmail.com>2009-03-22 23:10:44 +0100
committerIngo Molnar <mingo@elte.hu>2009-03-23 16:25:46 +0100
commitc0f92ba99bdeaf35f9c580291b4e1a657c67fbd4 (patch)
treee3e102f83c9a7fe44935ff7cd57540f4b6dce9e4
parentb8b94265337f83b7db9c5f429b1769d463d7da8c (diff)
debugfs: function to know if debugfs is initialized
Impact: add new debugfs API With ftrace, some tracers are registered in early initcalls and attempt to create files on the debugfs filesystem. Depending on when they are activated, they can try to create their file at any time. Some checks can be done on the tracing area but providing a helper to know if debugfs is registered make it really more easy. Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Acked-by: Greg Kroah-Hartman <gregkh@suse.de> Cc: Steven Rostedt <rostedt@goodmis.org> LKML-Reference: <1237759847-21025-2-git-send-email-fweisbec@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
-rw-r--r--fs/debugfs/inode.c16
-rw-r--r--include/linux/debugfs.h8
2 files changed, 24 insertions, 0 deletions
diff --git a/fs/debugfs/inode.c b/fs/debugfs/inode.c
index 81ae9ea3c6e..0662ba6de85 100644
--- a/fs/debugfs/inode.c
+++ b/fs/debugfs/inode.c
@@ -30,6 +30,7 @@
static struct vfsmount *debugfs_mount;
static int debugfs_mount_count;
+static bool debugfs_registered;
static struct inode *debugfs_get_inode(struct super_block *sb, int mode, dev_t dev)
{
@@ -496,6 +497,16 @@ exit:
}
EXPORT_SYMBOL_GPL(debugfs_rename);
+/**
+ * debugfs_initialized - Tells whether debugfs has been registered
+ */
+bool debugfs_initialized(void)
+{
+ return debugfs_registered;
+}
+EXPORT_SYMBOL_GPL(debugfs_initialized);
+
+
static struct kobject *debug_kobj;
static int __init debugfs_init(void)
@@ -509,11 +520,16 @@ static int __init debugfs_init(void)
retval = register_filesystem(&debug_fs_type);
if (retval)
kobject_put(debug_kobj);
+ else
+ debugfs_registered = true;
+
return retval;
}
static void __exit debugfs_exit(void)
{
+ debugfs_registered = false;
+
simple_release_fs(&debugfs_mount, &debugfs_mount_count);
unregister_filesystem(&debug_fs_type);
kobject_put(debug_kobj);
diff --git a/include/linux/debugfs.h b/include/linux/debugfs.h
index af0e01d4c66..eb5c2ba2f81 100644
--- a/include/linux/debugfs.h
+++ b/include/linux/debugfs.h
@@ -71,6 +71,9 @@ struct dentry *debugfs_create_bool(const char *name, mode_t mode,
struct dentry *debugfs_create_blob(const char *name, mode_t mode,
struct dentry *parent,
struct debugfs_blob_wrapper *blob);
+
+bool debugfs_initialized(void);
+
#else
#include <linux/err.h>
@@ -183,6 +186,11 @@ static inline struct dentry *debugfs_create_blob(const char *name, mode_t mode,
return ERR_PTR(-ENODEV);
}
+static inline bool debugfs_initialized(void)
+{
+ return false;
+}
+
#endif
#endif