sysfs: Rewrite rename in terms of sysfs dirents

This patch rewrites sysfs_rename_dir to perform it's checks
as much as possible on the underlying sysfs_dirents instead
of the contents of the dcache.  It turns out that this version
is a little simpler, and a little more like the rest of
the sysfs directory modification code.

tj: fixed double locking of sysfs_mutex

Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Tejun Heo <htejun@gmail.com>
Cc: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This commit is contained in:
Eric W. Biederman 2007-08-20 21:36:31 +09:00 committed by Greg Kroah-Hartman
parent 5a26b79c42
commit 9918f9a481

View File

@ -770,7 +770,7 @@ void sysfs_remove_dir(struct kobject * kobj)
int sysfs_rename_dir(struct kobject * kobj, const char *new_name)
{
struct sysfs_dirent *sd;
struct sysfs_dirent *sd = kobj->sd;
struct dentry *parent = NULL;
struct dentry *old_dentry = NULL, *new_dentry = NULL;
const char *dup_name = NULL;
@ -778,63 +778,57 @@ int sysfs_rename_dir(struct kobject * kobj, const char *new_name)
mutex_lock(&sysfs_rename_mutex);
error = 0;
if (strcmp(sd->s_name, new_name) == 0)
goto out; /* nothing to rename */
/* get the original dentry */
sd = kobj->sd;
old_dentry = sysfs_get_dentry(sd);
if (IS_ERR(old_dentry)) {
error = PTR_ERR(old_dentry);
goto out_dput;
goto out;
}
parent = old_dentry->d_parent;
/* lock parent and get dentry for new name */
mutex_lock(&parent->d_inode->i_mutex);
new_dentry = lookup_one_len(new_name, parent, strlen(new_name));
if (IS_ERR(new_dentry)) {
error = PTR_ERR(new_dentry);
goto out_unlock;
}
error = -EINVAL;
if (old_dentry == new_dentry)
goto out_unlock;
mutex_lock(&sysfs_mutex);
error = -EEXIST;
if (new_dentry->d_inode)
if (sysfs_find_dirent(sd->s_parent, new_name))
goto out_unlock;
error = -ENOMEM;
new_dentry = d_alloc_name(parent, new_name);
if (!new_dentry)
goto out_unlock;
/* rename kobject and sysfs_dirent */
error = -ENOMEM;
new_name = dup_name = kstrdup(new_name, GFP_KERNEL);
if (!new_name)
goto out_drop;
goto out_unlock;
error = kobject_set_name(kobj, "%s", new_name);
if (error)
goto out_drop;
goto out_unlock;
mutex_lock(&sysfs_mutex);
dup_name = sd->s_name;
sd->s_name = new_name;
mutex_unlock(&sysfs_mutex);
/* rename */
d_add(new_dentry, NULL);
d_move(old_dentry, new_dentry);
error = 0;
goto out_unlock;
out_drop:
d_drop(new_dentry);
out_unlock:
mutex_unlock(&sysfs_mutex);
mutex_unlock(&parent->d_inode->i_mutex);
out_dput:
kfree(dup_name);
dput(old_dentry);
dput(new_dentry);
out:
mutex_unlock(&sysfs_rename_mutex);
return error;
}