[patch] export, rename fill_kobj_path and get_kobj_path_length

[patch] export, rename fill_kobj_path and get_kobj_path_length

[Robert Love]

Greg,

Per our discussion, the following patch exports fill_kobj_path and
get_kobj_path_length and adds them to kobject.h.

I also renamed them to kobject_get_path_len and kobject_fill_path,
respectively, to match the name space.

I need these for a kobject-based kevent.  Others may find them
fascinating as well.

	Robert Love


Export some internal kobject helpers.
Signed-Off-By: Robert Love <rml@ximian.com>

 include/linux/kobject.h |    3 +++
 lib/kobject.c           |   12 +++++++-----
 2 files changed, 10 insertions(+), 5 deletions(-)

diff -urN linux-2.6.8-rc3-mm1/include/linux/kobject.h linux-rml/include/linux/kobject.h
--- linux-2.6.8-rc3-mm1/include/linux/kobject.h	2004-08-06 14:03:04.882742673 -0400
+++ linux-rml/include/linux/kobject.h	2004-08-06 15:50:32.518075100 -0400
@@ -58,6 +58,9 @@
 
 extern void kobject_hotplug(const char *action, struct kobject *);
 
+extern int kobject_get_path_len(struct kset *, struct kobject *);
+extern void kobject_fill_path(struct kset *, struct kobject *, char *, int);
+
 struct kobj_type {
 	void (*release)(struct kobject *);
 	struct sysfs_ops	* sysfs_ops;
diff -urN linux-2.6.8-rc3-mm1/lib/kobject.c linux-rml/lib/kobject.c
--- linux-2.6.8-rc3-mm1/lib/kobject.c	2004-08-06 14:03:06.229569894 -0400
+++ linux-rml/lib/kobject.c	2004-08-06 16:11:14.450737875 -0400
@@ -66,7 +66,7 @@
 
 
 #ifdef CONFIG_HOTPLUG
-static int get_kobj_path_length(struct kset *kset, struct kobject *kobj)
+int kobject_get_path_len(struct kset *kset, struct kobject *kobj)
 {
 	int length = 1;
 	struct kobject * parent = kobj;
@@ -82,7 +82,8 @@
 	return length;
 }
 
-static void fill_kobj_path(struct kset *kset, struct kobject *kobj, char *path, int length)
+void kobject_fill_path(struct kset *kset, struct kobject *kobj, char *path,
+		       int length)
 {
 	struct kobject * parent;
 
@@ -163,12 +164,12 @@
 	envp [i++] = scratch;
 	scratch += sprintf(scratch, "SEQNUM=%ld", seq) + 1;
 
-	kobj_path_length = get_kobj_path_length (kset, kobj);
+	kobj_path_length = kobject_get_path_len (kset, kobj);
 	kobj_path = kmalloc (kobj_path_length, GFP_KERNEL);
 	if (!kobj_path)
 		goto exit;
 	memset (kobj_path, 0x00, kobj_path_length);
-	fill_kobj_path (kset, kobj, kobj_path, kobj_path_length);
+	kobject_fill_path (kset, kobj, kobj_path, kobj_path_length);
 
 	envp [i++] = scratch;
 	scratch += sprintf (scratch, "DEVPATH=%s", kobj_path) + 1;
@@ -626,7 +627,8 @@
 	}
 }
 
-
+EXPORT_SYMBOL(kobject_get_path_len);
+EXPORT_SYMBOL(kobject_fill_path);
 EXPORT_SYMBOL(kobject_init);
 EXPORT_SYMBOL(kobject_register);
 EXPORT_SYMBOL(kobject_unregister);

[patch] add kobject_get_path

[Robert Love]

Greg -

Hey, here is an alternative to exporting those two functions.

This patch, in lieu, creates a new function that performs the same steps
as in kset_hotplug() and presumably what every single user of the
previously exported functions would do: get the length, allocate memory,
and then build the path.

So just export a single function to do it right.  And use it in
kset_hotplug().  The function is prototyped as

	char * kobject_get_path(struct kset *kset, struct kobject *kobj,
				int gfp_mask)

I like this approach better.

Patch is against 2.6.8-rc3.

	Robert Love


Create a new kobject_get_path() helper function, which is super duper.
Signed-Off-By: Robert Love <rml@novell.com>

 include/linux/kobject.h |    2 ++
 lib/kobject.c           |   31 +++++++++++++++++++++++++------
 2 files changed, 27 insertions(+), 6 deletions(-)

diff -urN linux-2.6.8-rc3-mm1/include/linux/kobject.h linux/include/linux/kobject.h
--- linux-2.6.8-rc3-mm1/include/linux/kobject.h	2004-08-06 14:03:04.882742673 -0400
+++ linux/include/linux/kobject.h	2004-08-06 16:25:02.797522366 -0400
@@ -58,6 +58,8 @@
 
 extern void kobject_hotplug(const char *action, struct kobject *);
 
+extern char * kobject_get_path(struct kset *, struct kobject *, int);
+
 struct kobj_type {
 	void (*release)(struct kobject *);
 	struct sysfs_ops	* sysfs_ops;
diff -urN linux-2.6.8-rc3-mm1/lib/kobject.c linux/lib/kobject.c
--- linux-2.6.8-rc3-mm1/lib/kobject.c	2004-08-06 14:03:06.229569894 -0400
+++ linux/lib/kobject.c	2004-08-06 16:36:03.834757764 -0400
@@ -103,6 +103,29 @@
 static unsigned long sequence_num;
 static spinlock_t sequence_lock = SPIN_LOCK_UNLOCKED;
 
+/**
+ * kobject_get_path - generate and return the path associated with a given kobj
+ * and kset pair.  The result must be freed by the caller with kfree().
+ *
+ * @kset:	kset in question, with which to build the path
+ * @kobj:	kobject in question, with which to build the path
+ * @gfp_mask:	the allocation type used to allocate the path
+ */
+char * kobject_get_path(struct kset *kset, struct kobject *kobj, int gfp_mask)
+{
+	char *path;
+	int len;
+
+	len = get_kobj_path_length (kset, kobj);
+	path = kmalloc (len, gfp_mask);
+	if (!path)
+		return NULL;
+	memset (path, 0x00, len);
+	fill_kobj_path (kset, kobj, path, len);
+
+	return path;
+}
+
 static void kset_hotplug(const char *action, struct kset *kset,
 			 struct kobject *kobj)
 {
@@ -112,7 +135,6 @@
 	char *scratch;
 	int i = 0;
 	int retval;
-	int kobj_path_length;
 	char *kobj_path = NULL;
 	char *name = NULL;
 	unsigned long seq;
@@ -163,12 +185,9 @@
 	envp [i++] = scratch;
 	scratch += sprintf(scratch, "SEQNUM=%ld", seq) + 1;
 
-	kobj_path_length = get_kobj_path_length (kset, kobj);
-	kobj_path = kmalloc (kobj_path_length, GFP_KERNEL);
+	kobj_path = kobject_get_path (kset, kobj, GFP_KERNEL);
 	if (!kobj_path)
 		goto exit;
-	memset (kobj_path, 0x00, kobj_path_length);
-	fill_kobj_path (kset, kobj, kobj_path, kobj_path_length);
 
 	envp [i++] = scratch;
 	scratch += sprintf (scratch, "DEVPATH=%s", kobj_path) + 1;
@@ -626,7 +645,7 @@
 	}
 }
 
-
+EXPORT_SYMBOL(kobject_get_path);
 EXPORT_SYMBOL(kobject_init);
 EXPORT_SYMBOL(kobject_register);
 EXPORT_SYMBOL(kobject_unregister);

Re: [patch] add kobject_get_path

[Greg KH]

On Fri, Aug 06, 2004 at 04:41:43PM -0400, Robert Love wrote:
> Greg -
> 
> Hey, here is an alternative to exporting those two functions.

Ah, good timing, I was just about to apply your other patch :)

> 
> This patch, in lieu, creates a new function that performs the same steps
> as in kset_hotplug() and presumably what every single user of the
> previously exported functions would do: get the length, allocate memory,
> and then build the path.
> 
> So just export a single function to do it right.  And use it in
> kset_hotplug().  The function is prototyped as
> 
> 	char * kobject_get_path(struct kset *kset, struct kobject *kobj,
> 				int gfp_mask)
> 
> I like this approach better.

I do too.  One problem though, get_kobj_path_length and fill_kobj_path
are only built if CONFIG_HOTPLUG is enabled.  Care to respin this patch
by moving the functions outside of that #define?

thanks,

greg k-h

Re: [patch] add kobject_get_path

[Robert Love]

On Fri, 2004-08-06 at 13:50 -0700, Greg KH wrote:

> I do too.  One problem though, get_kobj_path_length and fill_kobj_path
> are only built if CONFIG_HOTPLUG is enabled.  Care to respin this patch
> by moving the functions outside of that #define?

Hrm, did not notice that.  kobject_get_path() was inside there, too.

I presume these functions are still meaningful if !CONFIG_HOTPLUG?

Here we go.  Thanks,

	Robert Love


Add a new kobject helper, kobject_get_path(), which is the greatest
function ever.
Signed-Off-By: Robert Love <rml@ximian.com>

 include/linux/kobject.h |    2 ++
 lib/kobject.c           |   36 +++++++++++++++++++++++++++---------
 2 files changed, 29 insertions(+), 9 deletions(-)

diff -urN linux-2.6.8-rc3-mm1/include/linux/kobject.h linux/include/linux/kobject.h
--- linux-2.6.8-rc3-mm1/include/linux/kobject.h	2004-08-06 14:03:04.882742673 -0400
+++ linux/include/linux/kobject.h	2004-08-06 16:25:02.797522366 -0400
@@ -58,6 +58,8 @@
 
 extern void kobject_hotplug(const char *action, struct kobject *);
 
+extern char * kobject_get_path(struct kset *, struct kobject *, int);
+
 struct kobj_type {
 	void (*release)(struct kobject *);
 	struct sysfs_ops	* sysfs_ops;
diff -urN linux-2.6.8-rc3-mm1/lib/kobject.c linux/lib/kobject.c
--- linux-2.6.8-rc3-mm1/lib/kobject.c	2004-08-06 14:03:06.229569894 -0400
+++ linux/lib/kobject.c	2004-08-06 16:53:24.484278248 -0400
@@ -58,14 +58,11 @@
 	return error;
 }
 
-
 static inline struct kobject * to_kobj(struct list_head * entry)
 {
 	return container_of(entry,struct kobject,entry);
 }
 
-
-#ifdef CONFIG_HOTPLUG
 static int get_kobj_path_length(struct kset *kset, struct kobject *kobj)
 {
 	int length = 1;
@@ -98,6 +95,31 @@
 	pr_debug("%s: path = '%s'\n",__FUNCTION__,path);
 }
 
+/**
+ * kobject_get_path - generate and return the path associated with a given kobj
+ * and kset pair.  The result must be freed by the caller with kfree().
+ *
+ * @kset:	kset in question, with which to build the path
+ * @kobj:	kobject in question, with which to build the path
+ * @gfp_mask:	the allocation type used to allocate the path
+ */
+char * kobject_get_path(struct kset *kset, struct kobject *kobj, int gfp_mask)
+{
+	char *path;
+	int len;
+
+	len = get_kobj_path_length (kset, kobj);
+	path = kmalloc (len, gfp_mask);
+	if (!path)
+		return NULL;
+	memset (path, 0x00, len);
+	fill_kobj_path (kset, kobj, path, len);
+
+	return path;
+}
+
+#ifdef CONFIG_HOTPLUG
+
 #define BUFFER_SIZE	1024	/* should be enough memory for the env */
 #define NUM_ENVP	32	/* number of env pointers */
 static unsigned long sequence_num;
@@ -112,7 +134,6 @@
 	char *scratch;
 	int i = 0;
 	int retval;
-	int kobj_path_length;
 	char *kobj_path = NULL;
 	char *name = NULL;
 	unsigned long seq;
@@ -163,12 +184,9 @@
 	envp [i++] = scratch;
 	scratch += sprintf(scratch, "SEQNUM=%ld", seq) + 1;
 
-	kobj_path_length = get_kobj_path_length (kset, kobj);
-	kobj_path = kmalloc (kobj_path_length, GFP_KERNEL);
+	kobj_path = kobject_get_path (kset, kobj, GFP_KERNEL);
 	if (!kobj_path)
 		goto exit;
-	memset (kobj_path, 0x00, kobj_path_length);
-	fill_kobj_path (kset, kobj, kobj_path, kobj_path_length);
 
 	envp [i++] = scratch;
 	scratch += sprintf (scratch, "DEVPATH=%s", kobj_path) + 1;
@@ -626,7 +644,7 @@
 	}
 }
 
-
+EXPORT_SYMBOL(kobject_get_path);
 EXPORT_SYMBOL(kobject_init);
 EXPORT_SYMBOL(kobject_register);
 EXPORT_SYMBOL(kobject_unregister);

Re: [patch] add kobject_get_path

[Robert Love]

On Fri, 2004-08-06 at 16:56 -0400, Robert Love wrote:

> I presume these functions are still meaningful if !CONFIG_HOTPLUG?

Compiles, at least.  Just tested.

	Robert Love

Re: [patch] add kobject_get_path

[Greg KH]

On Fri, Aug 06, 2004 at 04:56:03PM -0400, Robert Love wrote:
> On Fri, 2004-08-06 at 13:50 -0700, Greg KH wrote:
> 
> > I do too.  One problem though, get_kobj_path_length and fill_kobj_path
> > are only built if CONFIG_HOTPLUG is enabled.  Care to respin this patch
> > by moving the functions outside of that #define?
> 
> Hrm, did not notice that.  kobject_get_path() was inside there, too.
> 
> I presume these functions are still meaningful if !CONFIG_HOTPLUG?

Well, they weren't until your function needed them :)

> Here we go.  Thanks,

Applied, thanks.

greg k-h