-
-/**
- * sysfs_make_shadowed_dir - Setup so a directory can be shadowed
- * @kobj: object we're creating shadow of.
- */
-
-int sysfs_make_shadowed_dir(struct kobject *kobj,
- void * (*follow_link)(struct dentry *, struct nameidata *))
-{
- struct dentry *dentry;
- struct inode *inode;
- struct inode_operations *i_op;
-
- /* get dentry for @kobj->sd, dentry of a shadowed dir is pinned */
- dentry = sysfs_get_dentry(kobj->sd);
- if (IS_ERR(dentry))
- return PTR_ERR(dentry);
-
- inode = dentry->d_inode;
- if (inode->i_op != &sysfs_dir_inode_operations) {
- dput(dentry);
- return -EINVAL;
- }
-
- i_op = kmalloc(sizeof(*i_op), GFP_KERNEL);
- if (!i_op)
- return -ENOMEM;
-
- memcpy(i_op, &sysfs_dir_inode_operations, sizeof(*i_op));
- i_op->follow_link = follow_link;
-
- /* Locking of inode->i_op?
- * Since setting i_op is a single word write and they
- * are atomic we should be ok here.
- */
- inode->i_op = i_op;
- return 0;
-}
-
-/**
- * sysfs_create_shadow_dir - create a shadow directory for an object.
- * @kobj: object we're creating directory for.
- *
- * sysfs_make_shadowed_dir must already have been called on this
- * directory.
- */
-
-struct sysfs_dirent *sysfs_create_shadow_dir(struct kobject *kobj)
-{
- struct sysfs_dirent *parent_sd = kobj->sd->s_parent;
- struct dentry *dir, *parent, *shadow;
- struct inode *inode;
- struct sysfs_dirent *sd;
- struct sysfs_addrm_cxt acxt;
-
- dir = sysfs_get_dentry(kobj->sd);
- if (IS_ERR(dir)) {
- sd = (void *)dir;
- goto out;
- }
- parent = dir->d_parent;
-
- inode = dir->d_inode;
- sd = ERR_PTR(-EINVAL);
- if (!sysfs_is_shadowed_inode(inode))
- goto out_dput;
-
- shadow = d_alloc(parent, &dir->d_name);
- if (!shadow)
- goto nomem;
-
- sd = sysfs_new_dirent("_SHADOW_", inode->i_mode, SYSFS_DIR);
- if (!sd)
- goto nomem;
- sd->s_elem.dir.kobj = kobj;
-
- sysfs_addrm_start(&acxt, parent_sd);
-
- /* add but don't link into children list */
- sysfs_add_one(&acxt, sd);
-
- /* attach and instantiate dentry */
- sysfs_attach_dentry(sd, shadow);
- d_instantiate(shadow, igrab(inode));
- inc_nlink(inode); /* tj: synchronization? */
-
- sysfs_addrm_finish(&acxt);
-
- dget(shadow); /* Extra count - pin the dentry in core */
-
- goto out_dput;
-
- nomem:
- dput(shadow);
- sd = ERR_PTR(-ENOMEM);
- out_dput:
- dput(dir);
- out:
- return sd;
-}
-
-/**
- * sysfs_remove_shadow_dir - remove an object's directory.
- * @shadow_sd: sysfs_dirent of shadow directory
- *
- * The only thing special about this is that we remove any files in
- * the directory before we remove the directory, and we've inlined
- * what used to be sysfs_rmdir() below, instead of calling separately.
- */
-
-void sysfs_remove_shadow_dir(struct sysfs_dirent *shadow_sd)
-{
- __sysfs_remove_dir(shadow_sd);
-}
-