bb8b9d095c
sysfs assumed 0755 for all newly created directories and kernfs inherited it. This assumption is unnecessarily restrictive and inconsistent with kernfs_create_file[_ns](). This patch adds @mode parameter to kernfs_create_dir[_ns]() and update uses in sysfs accordingly. Among others, this will be useful for implementations of the planned ->mkdir() method. This patch doesn't introduce any behavior differences. Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
141 lines
3.6 KiB
C
141 lines
3.6 KiB
C
/*
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* fs/sysfs/dir.c - sysfs core and dir operation implementation
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*
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* Copyright (c) 2001-3 Patrick Mochel
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* Copyright (c) 2007 SUSE Linux Products GmbH
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* Copyright (c) 2007 Tejun Heo <teheo@suse.de>
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*
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* This file is released under the GPLv2.
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*
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* Please see Documentation/filesystems/sysfs.txt for more information.
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*/
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#undef DEBUG
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#include <linux/fs.h>
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#include <linux/kobject.h>
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#include <linux/slab.h>
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#include "sysfs.h"
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DEFINE_SPINLOCK(sysfs_symlink_target_lock);
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/**
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* sysfs_pathname - return full path to sysfs dirent
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* @kn: kernfs_node whose path we want
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* @path: caller allocated buffer of size PATH_MAX
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*
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* Gives the name "/" to the sysfs_root entry; any path returned
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* is relative to wherever sysfs is mounted.
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*/
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static char *sysfs_pathname(struct kernfs_node *kn, char *path)
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{
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if (kn->parent) {
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sysfs_pathname(kn->parent, path);
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strlcat(path, "/", PATH_MAX);
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}
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strlcat(path, kn->name, PATH_MAX);
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return path;
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}
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void sysfs_warn_dup(struct kernfs_node *parent, const char *name)
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{
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char *path;
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path = kzalloc(PATH_MAX, GFP_KERNEL);
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if (path) {
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sysfs_pathname(parent, path);
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strlcat(path, "/", PATH_MAX);
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strlcat(path, name, PATH_MAX);
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}
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WARN(1, KERN_WARNING "sysfs: cannot create duplicate filename '%s'\n",
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path ? path : name);
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kfree(path);
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}
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/**
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* sysfs_create_dir_ns - create a directory for an object with a namespace tag
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* @kobj: object we're creating directory for
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* @ns: the namespace tag to use
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*/
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int sysfs_create_dir_ns(struct kobject *kobj, const void *ns)
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{
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struct kernfs_node *parent, *kn;
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BUG_ON(!kobj);
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if (kobj->parent)
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parent = kobj->parent->sd;
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else
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parent = sysfs_root_kn;
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if (!parent)
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return -ENOENT;
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kn = kernfs_create_dir_ns(parent, kobject_name(kobj),
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S_IRWXU | S_IRUGO | S_IXUGO, kobj, ns);
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if (IS_ERR(kn)) {
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if (PTR_ERR(kn) == -EEXIST)
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sysfs_warn_dup(parent, kobject_name(kobj));
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return PTR_ERR(kn);
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}
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kobj->sd = kn;
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return 0;
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}
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/**
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* sysfs_remove_dir - remove an object's directory.
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* @kobj: object.
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*
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* The only thing special about this is that we remove any files in
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* the directory before we remove the directory, and we've inlined
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* what used to be sysfs_rmdir() below, instead of calling separately.
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*/
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void sysfs_remove_dir(struct kobject *kobj)
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{
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struct kernfs_node *kn = kobj->sd;
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/*
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* In general, kboject owner is responsible for ensuring removal
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* doesn't race with other operations and sysfs doesn't provide any
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* protection; however, when @kobj is used as a symlink target, the
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* symlinking entity usually doesn't own @kobj and thus has no
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* control over removal. @kobj->sd may be removed anytime
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* and symlink code may end up dereferencing an already freed node.
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*
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* sysfs_symlink_target_lock synchronizes @kobj->sd
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* disassociation against symlink operations so that symlink code
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* can safely dereference @kobj->sd.
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*/
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spin_lock(&sysfs_symlink_target_lock);
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kobj->sd = NULL;
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spin_unlock(&sysfs_symlink_target_lock);
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if (kn) {
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WARN_ON_ONCE(kernfs_type(kn) != KERNFS_DIR);
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kernfs_remove(kn);
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}
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}
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int sysfs_rename_dir_ns(struct kobject *kobj, const char *new_name,
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const void *new_ns)
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{
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struct kernfs_node *parent = kobj->sd->parent;
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return kernfs_rename_ns(kobj->sd, parent, new_name, new_ns);
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}
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int sysfs_move_dir_ns(struct kobject *kobj, struct kobject *new_parent_kobj,
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const void *new_ns)
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{
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struct kernfs_node *kn = kobj->sd;
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struct kernfs_node *new_parent;
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BUG_ON(!kn->parent);
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new_parent = new_parent_kobj && new_parent_kobj->sd ?
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new_parent_kobj->sd : sysfs_root_kn;
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return kernfs_rename_ns(kn, new_parent, kn->name, new_ns);
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}
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