When removing a symlink sysfs_remove_link does not provide enough
information to figure out which shadow directory the symlink falls in.
So I need sysfs_delete_link which is passed the target of the symlink
to delete. 

Further half the time when we are removing a symlink the code is
actually renaming the symlink but not doing so explicitly because we
don't have a symlink rename method.  So I have added sysfs_rename_link
as well.

Both of these functions now have enough information to find a symlink
in a shadow directory.  The only restriction is that they must be
called before the target kobject is renamed or deleted.  If they are
called later I loose track of which tag the target kobject was marked
with and can no longer find the old symlink to remove it.

Signed-off-by: Eric W. Biederman <[EMAIL PROTECTED]>
---
 fs/sysfs/symlink.c    |   31 +++++++++++++++++++++++++++++++
 include/linux/sysfs.h |   18 ++++++++++++++++++
 2 files changed, 49 insertions(+), 0 deletions(-)

diff --git a/fs/sysfs/symlink.c b/fs/sysfs/symlink.c
index 2885ebb..faff190 100644
--- a/fs/sysfs/symlink.c
+++ b/fs/sysfs/symlink.c
@@ -110,6 +110,21 @@ int sysfs_create_link(struct kobject * kobj, struct 
kobject * target, const char
 
 
 /**
+ *     sysfs_delete_link - remove symlink in object's directory.
+ *     @kobj:  object we're acting for.
+ *     @targ:  object we're pointing to.
+ *     @name:  name of the symlink to remove.
+ *
+ *     Unlike sysfs_remove_link sysfs_delete_link has enough information
+ *     to successfully delete symlinks in shadow directories.
+ */
+void sysfs_delete_link(struct kobject *kobj, struct kobject *targ,
+                       const char *name)
+{
+       sysfs_hash_and_remove(targ, kobj->dentry,name);
+}
+
+/**
  *     sysfs_remove_link - remove symlink in object's directory.
  *     @kobj:  object we're acting for.
  *     @name:  name of the symlink to remove.
@@ -120,6 +135,22 @@ void sysfs_remove_link(struct kobject * kobj, const char * 
name)
        sysfs_hash_and_remove(kobj, kobj->dentry,name);
 }
 
+/**
+ *     sysfs_rename_link - rename symlink in object's directory.
+ *     @kobj:  object we're acting for.
+ *     @targ:  object we're pointing to.
+ *     @old:   previous name of the symlink.
+ *     @new:   new name of the symlink.
+ *
+ *     A helper function for the common rename symlink idiom.
+ */
+int sysfs_rename_link(struct kobject *kobj, struct kobject *targ,
+                       const char *old, const char *new)
+{
+       sysfs_delete_link(kobj, targ, old);
+       return sysfs_create_link(kobj, targ, new);
+}
+
 static int sysfs_get_target_path(struct kobject * kobj, struct kobject * 
target,
                                 char *path)
 {
diff --git a/include/linux/sysfs.h b/include/linux/sysfs.h
index cda7b81..c29b38d 100644
--- a/include/linux/sysfs.h
+++ b/include/linux/sysfs.h
@@ -116,6 +116,13 @@ sysfs_create_link(struct kobject * kobj, struct kobject * 
target, const char * n
 extern void
 sysfs_remove_link(struct kobject *, const char * name);
 
+extern int
+sysfs_rename_link(struct kobject *kobj, struct kobject *target,
+                       const char *old_name, const char *new_name);
+
+extern void
+sysfs_delete_link(struct kobject *dir, struct kobject *targ, const char *name);
+
 int __must_check sysfs_create_bin_file(struct kobject *kobj,
                                        struct bin_attribute *attr);
 void sysfs_remove_bin_file(struct kobject *kobj, struct bin_attribute *attr);
@@ -191,6 +198,17 @@ static inline void sysfs_remove_link(struct kobject * k, 
const char * name)
        ;
 }
 
+static inline int
+sysfs_rename_link(struct kobject * k, struct kobject *t,
+                       const char *old_name, const char * new_name)
+{
+       return 0;
+}
+
+static inline void
+sysfs_delete_link(struct kobject *k, struct kobject *t, const char *name)
+{
+}
 
 static inline int sysfs_create_bin_file(struct kobject * k, struct 
bin_attribute * a)
 {
-- 
1.5.0.g53756

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