Subject: [PATCH 7/12] allow proc_dir_entries to have destructor

From: Dmitry Mishin <[email-masked]>
Date: Wed, 17 Jan 2007 19:10:51 +0300

Destructor field added proc_dir_entries,
standard destructor kfree'ing data introduced.

Signed-off-by: Andrey Savochkin <[email-masked]>

---
 fs/proc/generic.c       |   10 ++++++++--
 fs/proc/root.c          |    1 +
 include/linux/proc_fs.h |    4 ++++
 3 files changed, 13 insertions(+), 2 deletions(-)

Index: 2.6.20-rc4-mm1/fs/proc/generic.c
===================================================================
--- 2.6.20-rc4-mm1.orig/fs/proc/generic.c
+++ 2.6.20-rc4-mm1/fs/proc/generic.c
@@ -611,6 +611,11 @@ static struct proc_dir_entry *proc_creat
 	return ent;
 }
 
+void proc_data_destructor(struct proc_dir_entry *ent)
+{
+	kfree(ent->data);
+}
+
 struct proc_dir_entry *proc_symlink(const char *name,
 		struct proc_dir_entry *parent, const char *dest)
 {
@@ -623,6 +628,7 @@ struct proc_dir_entry *proc_symlink(cons
 		ent->data = kmalloc((ent->size=strlen(dest))+1, GFP_KERNEL);
 		if (ent->data) {
 			strcpy((char*)ent->data,dest);
+			ent->destructor = proc_data_destructor;
 			if (proc_register(parent, ent) < 0) {
 				kfree(ent->data);
 				kfree(ent);
@@ -701,8 +707,8 @@ void free_proc_entry(struct proc_dir_ent
 
 	release_inode_number(ino);
 
-	if (S_ISLNK(de->mode) && de->data)
-		kfree(de->data);
+	if (de->destructor)
+		de->destructor(de);
 	kfree(de);
 }
 
Index: 2.6.20-rc4-mm1/fs/proc/root.c
===================================================================
--- 2.6.20-rc4-mm1.orig/fs/proc/root.c
+++ 2.6.20-rc4-mm1/fs/proc/root.c
@@ -167,6 +167,7 @@ EXPORT_SYMBOL(proc_symlink);
 EXPORT_SYMBOL(proc_mkdir);
 EXPORT_SYMBOL(create_proc_entry);
 EXPORT_SYMBOL(remove_proc_entry);
+EXPORT_SYMBOL(proc_data_destructor);
 EXPORT_SYMBOL(proc_root);
 EXPORT_SYMBOL(proc_root_fs);
 EXPORT_SYMBOL(proc_net);
Index: 2.6.20-rc4-mm1/include/linux/proc_fs.h
===================================================================
--- 2.6.20-rc4-mm1.orig/include/linux/proc_fs.h
+++ 2.6.20-rc4-mm1/include/linux/proc_fs.h
@@ -45,6 +45,8 @@ typedef	int (read_proc_t)(char *page, ch
 typedef	int (write_proc_t)(struct file *file, const char __user *buffer,
 			   unsigned long count, void *data);
 typedef int (get_info_t)(char *, char **, off_t, int);
+struct proc_dir_entry;
+typedef void (destroy_proc_t)(struct proc_dir_entry *);
 
 struct proc_dir_entry {
 	unsigned int low_ino;
@@ -64,6 +66,7 @@ struct proc_dir_entry {
 	read_proc_t *read_proc;
 	write_proc_t *write_proc;
 	atomic_t count;		/* use count */
+	destroy_proc_t *destructor;
 	int deleted;		/* delete flag */
 	void *set;
 };
@@ -108,6 +111,7 @@ char *task_mem(struct mm_struct *, char 
 extern struct proc_dir_entry *create_proc_entry(const char *name, mode_t mode,
 						struct proc_dir_entry *parent);
 extern void remove_proc_entry(const char *name, struct proc_dir_entry *parent);
+extern void proc_data_destructor(struct proc_dir_entry *);
 
 extern struct vfsmount *proc_mnt;
 extern int proc_fill_super(struct super_block *,void *,int);