From htejun@gmail.com Mon Aug 20 05:36:58 2007 From: Eric W. Biederman Date: Mon, 20 Aug 2007 21:36:31 +0900 Subject: [PATCH 13/14] sysfs: Rewrite rename in terms of sysfs dirents To: ebiederm@xmission.com, cornelia.huck@de.ibm.com, greg@kroah.com, linux-kernel@vger.kernel.org, satyam@infradead.org, stern@rowland.harvard.edu, containers@lists.osdl.org, htejun@gmail.com Cc: Eric W. Biederman , Tejun Heo Message-ID: <11876133911357-git-send-email-htejun@gmail.com> From: Eric W. Biederman 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 Signed-off-by: Tejun Heo Cc: Cornelia Huck Signed-off-by: Greg Kroah-Hartman --- fs/sysfs/dir.c | 38 ++++++++++++++++---------------------- 1 file changed, 16 insertions(+), 22 deletions(-) --- a/fs/sysfs/dir.c +++ b/fs/sysfs/dir.c @@ -770,7 +770,7 @@ void sysfs_remove_dir(struct kobject * k 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 * ko 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); + mutex_lock(&sysfs_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) + error = -EEXIST; + if (sysfs_find_dirent(sd->s_parent, new_name)) goto out_unlock; - error = -EEXIST; - if (new_dentry->d_inode) + 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; }