linux-kernel.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
* [PATCH] fs/configfs: allow to create groups on demand
@ 2012-11-29 16:41 Sebastian Andrzej Siewior
  2012-11-30  8:34 ` Andrzej Pietrasiewicz
  2012-12-07 23:20 ` Joel Becker
  0 siblings, 2 replies; 3+ messages in thread
From: Sebastian Andrzej Siewior @ 2012-11-29 16:41 UTC (permalink / raw)
  To: Joel Becker; +Cc: linux-kernel, andrzej.p, linux-usb

This patch adds a function add a group to an existing one and its
counterart. The newly created group behaves as it would be created via
default_groups[] which means the user can't rmdir it.
This should be used by the upcomming USB gadget interface in order to
add the currently available UDCs as a child of the UDC node. The UDC
itself will appear once the hardware driver is loaded and can appear
later.

Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
---
 fs/configfs/dir.c        |   63 ++++++++++++++++++++++++++++++++++------------
 include/linux/configfs.h |    4 +++
 2 files changed, 51 insertions(+), 16 deletions(-)

diff --git a/fs/configfs/dir.c b/fs/configfs/dir.c
index 7414ae2..50ee2bd 100644
--- a/fs/configfs/dir.c
+++ b/fs/configfs/dir.c
@@ -1663,19 +1663,13 @@ const struct file_operations configfs_dir_operations = {
 	.readdir	= configfs_readdir,
 };
 
-int configfs_register_subsystem(struct configfs_subsystem *subsys)
+static int __create_group(struct config_group *group, struct dentry *root)
 {
 	int err;
-	struct config_group *group = &subsys->su_group;
 	struct qstr name;
 	struct dentry *dentry;
-	struct dentry *root;
 	struct configfs_dirent *sd;
 
-	root = configfs_pin_fs();
-	if (IS_ERR(root))
-		return PTR_ERR(root);
-
 	if (!group->cg_item.ci_name)
 		group->cg_item.ci_name = group->cg_item.ci_namebuf;
 
@@ -1708,25 +1702,48 @@ int configfs_register_subsystem(struct configfs_subsystem *subsys)
 
 	mutex_unlock(&root->d_inode->i_mutex);
 
-	if (err) {
+	if (err)
 		unlink_group(group);
-		configfs_release_fs();
+
+	return err;
+}
+
+int configfs_create_group(struct config_group *parent, struct config_group *new)
+{
+	int ret;
+
+	ret = __create_group(new, parent->cg_item.ci_dentry);
+	if (!ret) {
+		struct configfs_dirent *sd = new->cg_item.ci_dentry->d_fsdata;
+
+		sd->s_type |= CONFIGFS_USET_DEFAULT;
 	}
 
+	return ret;
+}
+EXPORT_SYMBOL_GPL(configfs_create_group);
+
+int configfs_register_subsystem(struct configfs_subsystem *subsys)
+{
+	int err;
+	struct dentry *root;
+
+	root = configfs_pin_fs();
+	if (IS_ERR(root))
+		return PTR_ERR(root);
+
+	err = __create_group(&subsys->su_group, root);
+	if (err)
+		configfs_release_fs();
+
 	return err;
 }
 
-void configfs_unregister_subsystem(struct configfs_subsystem *subsys)
+void configfs_remove_group(struct config_group *group)
 {
-	struct config_group *group = &subsys->su_group;
 	struct dentry *dentry = group->cg_item.ci_dentry;
 	struct dentry *root = dentry->d_sb->s_root;
 
-	if (dentry->d_parent != root) {
-		printk(KERN_ERR "configfs: Tried to unregister non-subsystem!\n");
-		return;
-	}
-
 	mutex_lock_nested(&root->d_inode->i_mutex,
 			  I_MUTEX_PARENT);
 	mutex_lock_nested(&dentry->d_inode->i_mutex, I_MUTEX_CHILD);
@@ -1749,6 +1766,20 @@ void configfs_unregister_subsystem(struct configfs_subsystem *subsys)
 	dput(dentry);
 
 	unlink_group(group);
+}
+EXPORT_SYMBOL_GPL(configfs_remove_group);
+
+void configfs_unregister_subsystem(struct configfs_subsystem *subsys)
+{
+	struct config_group *group = &subsys->su_group;
+	struct dentry *dentry = group->cg_item.ci_dentry;
+	struct dentry *root = dentry->d_sb->s_root;
+
+	if (dentry->d_parent != root) {
+		pr_err("configfs: Tried to unregister non-subsystem!\n");
+		return;
+	}
+	configfs_remove_group(group);
 	configfs_release_fs();
 }
 
diff --git a/include/linux/configfs.h b/include/linux/configfs.h
index 34025df..660c25d 100644
--- a/include/linux/configfs.h
+++ b/include/linux/configfs.h
@@ -249,6 +249,10 @@ static inline struct configfs_subsystem *to_configfs_subsystem(struct config_gro
 		NULL;
 }
 
+int configfs_create_group(struct config_group *parent,
+		struct config_group *new);
+void configfs_remove_group(struct config_group *group);
+
 int configfs_register_subsystem(struct configfs_subsystem *subsys);
 void configfs_unregister_subsystem(struct configfs_subsystem *subsys);
 
-- 
1.7.10.4


^ permalink raw reply related	[flat|nested] 3+ messages in thread
* RE: [PATCH] fs/configfs: allow to create groups on demand
  2012-11-29 16:41 [PATCH] fs/configfs: allow to create groups on demand Sebastian Andrzej Siewior
@ 2012-11-30  8:34 ` Andrzej Pietrasiewicz
  2012-12-07 23:20 ` Joel Becker
  1 sibling, 0 replies; 3+ messages in thread
From: Andrzej Pietrasiewicz @ 2012-11-30  8:34 UTC (permalink / raw)
  To: 'Sebastian Andrzej Siewior', 'Joel Becker'
  Cc: linux-kernel, linux-usb, Marek Szyprowski, 'Kyungmin Park'

On Thursday, November 29, 2012 5:41 PM Sebastian Andrzej Siewior wrote:
> Subject: [PATCH] fs/configfs: allow to create groups on demand
> 
> This patch adds a function add a group to an existing one and its
> counterart. The newly created group behaves as it would be created via
> default_groups[] which means the user can't rmdir it.
> This should be used by the upcomming USB gadget interface in order to
> add the currently available UDCs as a child of the UDC node. The UDC
> itself will appear once the hardware driver is loaded and can appear
> later.

Yeah, this mode of operation will be required.

> 
> Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
> ---
>  fs/configfs/dir.c        |   63 ++++++++++++++++++++++++++++++++++-------
> -----
>  include/linux/configfs.h |    4 +++
>  2 files changed, 51 insertions(+), 16 deletions(-)
> 
> diff --git a/fs/configfs/dir.c b/fs/configfs/dir.c
> index 7414ae2..50ee2bd 100644
> --- a/fs/configfs/dir.c
> +++ b/fs/configfs/dir.c
> @@ -1663,19 +1663,13 @@ const struct file_operations
> configfs_dir_operations = {
>  	.readdir	= configfs_readdir,
>  };
> 
> -int configfs_register_subsystem(struct configfs_subsystem *subsys)
> +static int __create_group(struct config_group *group, struct dentry
*root)
>  {

Can __create_group be also used in create_default_group?


Andrzej




^ permalink raw reply	[flat|nested] 3+ messages in thread
* Re: [PATCH] fs/configfs: allow to create groups on demand
  2012-11-29 16:41 [PATCH] fs/configfs: allow to create groups on demand Sebastian Andrzej Siewior
  2012-11-30  8:34 ` Andrzej Pietrasiewicz
@ 2012-12-07 23:20 ` Joel Becker
  1 sibling, 0 replies; 3+ messages in thread
From: Joel Becker @ 2012-12-07 23:20 UTC (permalink / raw)
  To: Sebastian Andrzej Siewior; +Cc: linux-kernel, andrzej.p, linux-usb

On Thu, Nov 29, 2012 at 05:41:23PM +0100, Sebastian Andrzej Siewior wrote:
> This patch adds a function add a group to an existing one and its
> counterart. The newly created group behaves as it would be created via
> default_groups[] which means the user can't rmdir it.
> This should be used by the upcomming USB gadget interface in order to
> add the currently available UDCs as a child of the UDC node. The UDC
> itself will appear once the hardware driver is loaded and can appear
> later.

I've now responded to the original thread.  Sorry I didn't notice last
week.  Please see my thoughts there and comment.

Joel

> 
> Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
> ---
>  fs/configfs/dir.c        |   63 ++++++++++++++++++++++++++++++++++------------
>  include/linux/configfs.h |    4 +++
>  2 files changed, 51 insertions(+), 16 deletions(-)
> 
> diff --git a/fs/configfs/dir.c b/fs/configfs/dir.c
> index 7414ae2..50ee2bd 100644
> --- a/fs/configfs/dir.c
> +++ b/fs/configfs/dir.c
> @@ -1663,19 +1663,13 @@ const struct file_operations configfs_dir_operations = {
>  	.readdir	= configfs_readdir,
>  };
>  
> -int configfs_register_subsystem(struct configfs_subsystem *subsys)
> +static int __create_group(struct config_group *group, struct dentry *root)
>  {
>  	int err;
> -	struct config_group *group = &subsys->su_group;
>  	struct qstr name;
>  	struct dentry *dentry;
> -	struct dentry *root;
>  	struct configfs_dirent *sd;
>  
> -	root = configfs_pin_fs();
> -	if (IS_ERR(root))
> -		return PTR_ERR(root);
> -
>  	if (!group->cg_item.ci_name)
>  		group->cg_item.ci_name = group->cg_item.ci_namebuf;
>  
> @@ -1708,25 +1702,48 @@ int configfs_register_subsystem(struct configfs_subsystem *subsys)
>  
>  	mutex_unlock(&root->d_inode->i_mutex);
>  
> -	if (err) {
> +	if (err)
>  		unlink_group(group);
> -		configfs_release_fs();
> +
> +	return err;
> +}
> +
> +int configfs_create_group(struct config_group *parent, struct config_group *new)
> +{
> +	int ret;
> +
> +	ret = __create_group(new, parent->cg_item.ci_dentry);
> +	if (!ret) {
> +		struct configfs_dirent *sd = new->cg_item.ci_dentry->d_fsdata;
> +
> +		sd->s_type |= CONFIGFS_USET_DEFAULT;
>  	}
>  
> +	return ret;
> +}
> +EXPORT_SYMBOL_GPL(configfs_create_group);
> +
> +int configfs_register_subsystem(struct configfs_subsystem *subsys)
> +{
> +	int err;
> +	struct dentry *root;
> +
> +	root = configfs_pin_fs();
> +	if (IS_ERR(root))
> +		return PTR_ERR(root);
> +
> +	err = __create_group(&subsys->su_group, root);
> +	if (err)
> +		configfs_release_fs();
> +
>  	return err;
>  }
>  
> -void configfs_unregister_subsystem(struct configfs_subsystem *subsys)
> +void configfs_remove_group(struct config_group *group)
>  {
> -	struct config_group *group = &subsys->su_group;
>  	struct dentry *dentry = group->cg_item.ci_dentry;
>  	struct dentry *root = dentry->d_sb->s_root;
>  
> -	if (dentry->d_parent != root) {
> -		printk(KERN_ERR "configfs: Tried to unregister non-subsystem!\n");
> -		return;
> -	}
> -
>  	mutex_lock_nested(&root->d_inode->i_mutex,
>  			  I_MUTEX_PARENT);
>  	mutex_lock_nested(&dentry->d_inode->i_mutex, I_MUTEX_CHILD);
> @@ -1749,6 +1766,20 @@ void configfs_unregister_subsystem(struct configfs_subsystem *subsys)
>  	dput(dentry);
>  
>  	unlink_group(group);
> +}
> +EXPORT_SYMBOL_GPL(configfs_remove_group);
> +
> +void configfs_unregister_subsystem(struct configfs_subsystem *subsys)
> +{
> +	struct config_group *group = &subsys->su_group;
> +	struct dentry *dentry = group->cg_item.ci_dentry;
> +	struct dentry *root = dentry->d_sb->s_root;
> +
> +	if (dentry->d_parent != root) {
> +		pr_err("configfs: Tried to unregister non-subsystem!\n");
> +		return;
> +	}
> +	configfs_remove_group(group);
>  	configfs_release_fs();
>  }
>  
> diff --git a/include/linux/configfs.h b/include/linux/configfs.h
> index 34025df..660c25d 100644
> --- a/include/linux/configfs.h
> +++ b/include/linux/configfs.h
> @@ -249,6 +249,10 @@ static inline struct configfs_subsystem *to_configfs_subsystem(struct config_gro
>  		NULL;
>  }
>  
> +int configfs_create_group(struct config_group *parent,
> +		struct config_group *new);
> +void configfs_remove_group(struct config_group *group);
> +
>  int configfs_register_subsystem(struct configfs_subsystem *subsys);
>  void configfs_unregister_subsystem(struct configfs_subsystem *subsys);
>  
> -- 
> 1.7.10.4
> 
> --
> To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html
> Please read the FAQ at  http://www.tux.org/lkml/

-- 

"Friends may come and go, but enemies accumulate." 
        - Thomas Jones

			http://www.jlbec.org/
			jlbec@evilplan.org

^ permalink raw reply	[flat|nested] 3+ messages in thread
end of thread, other threads:[~2012-12-07 23:20 UTC | newest]

Thread overview: 3+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2012-11-29 16:41 [PATCH] fs/configfs: allow to create groups on demand Sebastian Andrzej Siewior
2012-11-30  8:34 ` Andrzej Pietrasiewicz
2012-12-07 23:20 ` Joel Becker

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).