Fedora kernel-2.6.17-1.2142_FC4 patched with stable patch-2.6.17.4-vs2.0.2-rc26.diff

[linux-2.6.git] / fs / sysfs / symlink.c

diff --git a/fs/sysfs/symlink.c b/fs/sysfs/symlink.c
index 3169fe5..d2eac3c 100644 (file)
--- a/fs/sysfs/symlink.c
+++ b/fs/sysfs/symlink.c
@@ -9,18 +9,6 @@
 
 #include "sysfs.h"
 
-static struct inode_operations sysfs_symlink_inode_operations = {
-       .readlink = generic_readlink,
-       .follow_link = sysfs_follow_link,
-       .put_link = sysfs_put_link,
-};
-
-static int init_symlink(struct inode * inode)
-{
-       inode->i_op = &sysfs_symlink_inode_operations;
-       return 0;
-}
-
 static int object_depth(struct kobject * kobj)
 {
        struct kobject * p = kobj;
@@ -55,31 +43,54 @@ static void fill_object_path(struct kobject * kobj, char * buffer, int length)
        }
 }
 
+static int sysfs_add_link(struct dentry * parent, const char * name, struct kobject * target)
+{
+       struct sysfs_dirent * parent_sd = parent->d_fsdata;
+       struct sysfs_symlink * sl;
+       int error = 0;
+
+       error = -ENOMEM;
+       sl = kmalloc(sizeof(*sl), GFP_KERNEL);
+       if (!sl)
+               goto exit1;
+
+       sl->link_name = kmalloc(strlen(name) + 1, GFP_KERNEL);
+       if (!sl->link_name)
+               goto exit2;
+
+       strcpy(sl->link_name, name);
+       sl->target_kobj = kobject_get(target);
+
+       error = sysfs_make_dirent(parent_sd, NULL, sl, S_IFLNK|S_IRWXUGO,
+                               SYSFS_KOBJ_LINK);
+       if (!error)
+               return 0;
+
+       kobject_put(target);
+       kfree(sl->link_name);
+exit2:
+       kfree(sl);
+exit1:
+       return error;
+}
+
 /**
  *     sysfs_create_link - create symlink between two objects.
  *     @kobj:  object whose directory we're creating the link in.
  *     @target:        object we're pointing to.
  *     @name:          name of the symlink.
  */
-int sysfs_create_link(struct kobject * kobj, struct kobject * target, char * name)
+int sysfs_create_link(struct kobject * kobj, struct kobject * target, const char * name)
 {
        struct dentry * dentry = kobj->dentry;
-       struct dentry * d;
-       int error = 0;
+       int error = -EEXIST;
+
+       BUG_ON(!kobj || !kobj->dentry || !name);
 
-       down(&dentry->d_inode->i_sem);
-       d = sysfs_get_dentry(dentry,name);
-       if (!IS_ERR(d)) {
-               error = sysfs_create(d, S_IFLNK|S_IRWXUGO, init_symlink);
-               if (!error)
-                       /* 
-                        * associate the link dentry with the target kobject 
-                        */
-                       d->d_fsdata = kobject_get(target);
-               dput(d);
-       } else 
-               error = PTR_ERR(d);
-       up(&dentry->d_inode->i_sem);
+       mutex_lock(&dentry->d_inode->i_mutex);
+       if (!sysfs_dirent_exist(dentry->d_fsdata, name))
+               error = sysfs_add_link(dentry, name, target);
+       mutex_unlock(&dentry->d_inode->i_mutex);
        return error;
 }
 
@@ -90,13 +101,13 @@ int sysfs_create_link(struct kobject * kobj, struct kobject * target, char * nam
  *     @name:  name of the symlink to remove.
  */
 
-void sysfs_remove_link(struct kobject * kobj, char * name)
+void sysfs_remove_link(struct kobject * kobj, const char * name)
 {
        sysfs_hash_and_remove(kobj->dentry,name);
 }
 
 static int sysfs_get_target_path(struct kobject * kobj, struct kobject * target,
-                                  char *path)
+                                char *path)
 {
        char * s;
        int depth, size;
@@ -142,23 +153,29 @@ static int sysfs_getlink(struct dentry *dentry, char * path)
 
 }
 
-int sysfs_follow_link(struct dentry *dentry, struct nameidata *nd)
+static void *sysfs_follow_link(struct dentry *dentry, struct nameidata *nd)
 {
        int error = -ENOMEM;
        unsigned long page = get_zeroed_page(GFP_KERNEL);
        if (page)
                error = sysfs_getlink(dentry, (char *) page); 
        nd_set_link(nd, error ? ERR_PTR(error) : (char *)page);
-       return 0;
+       return NULL;
 }
 
-void sysfs_put_link(struct dentry *dentry, struct nameidata *nd)
+static void sysfs_put_link(struct dentry *dentry, struct nameidata *nd, void *cookie)
 {
        char *page = nd_get_link(nd);
        if (!IS_ERR(page))
                free_page((unsigned long)page);
 }
 
-EXPORT_SYMBOL(sysfs_create_link);
-EXPORT_SYMBOL(sysfs_remove_link);
+struct inode_operations sysfs_symlink_inode_operations = {
+       .readlink = generic_readlink,
+       .follow_link = sysfs_follow_link,
+       .put_link = sysfs_put_link,
+};
+
 
+EXPORT_SYMBOL_GPL(sysfs_create_link);
+EXPORT_SYMBOL_GPL(sysfs_remove_link);