sysfs: fix locking in sysfs_lookup() and sysfs_rename_dir()

sd children list walking in sysfs_lookup() and sd renaming in
sysfs_rename_dir() were left out during i_mutex -> sysfs_mutex
conversion.  Fix them.

Signed-off-by: Tejun Heo <htejun@gmail.com>
Acked-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

diff --git a/fs/sysfs/dir.c b/fs/sysfs/dir.c
index 048e6054c2fdb7b60f35945eb87067463eee5896..83e76b3813c9af674fb2c6fda9c2f891c89e0964 100644 (file)
--- a/fs/sysfs/dir.c
+++ b/fs/sysfs/dir.c
@@ -762,12 +762,15 @@ static int sysfs_count_nlink(struct sysfs_dirent *sd)
 static struct dentry * sysfs_lookup(struct inode *dir, struct dentry *dentry,
                                struct nameidata *nd)
 {
+       struct dentry *ret = NULL;
        struct sysfs_dirent * parent_sd = dentry->d_parent->d_fsdata;
        struct sysfs_dirent * sd;
        struct bin_attribute *bin_attr;
        struct inode *inode;
        int found = 0;
 
+       mutex_lock(&sysfs_mutex);
+
        for (sd = parent_sd->s_children; sd; sd = sd->s_sibling) {
                if (sysfs_type(sd) &&
                    !strcmp(sd->s_name, dentry->d_name.name)) {
@@ -778,14 +781,14 @@ static struct dentry * sysfs_lookup(struct inode *dir, struct dentry *dentry,
 
        /* no such entry */
        if (!found)
-               return NULL;
+               goto out_unlock;
 
        /* attach dentry and inode */
        inode = sysfs_get_inode(sd);
-       if (!inode)
-               return ERR_PTR(-ENOMEM);
-
-       mutex_lock(&sysfs_mutex);
+       if (!inode) {
+               ret = ERR_PTR(-ENOMEM);
+               goto out_unlock;
+       }
 
        if (inode->i_state & I_NEW) {
                /* initialize inode according to type */
@@ -815,9 +818,9 @@ static struct dentry * sysfs_lookup(struct inode *dir, struct dentry *dentry,
        sysfs_instantiate(dentry, inode);
        sysfs_attach_dentry(sd, dentry);
 
+ out_unlock:
        mutex_unlock(&sysfs_mutex);
-
-       return NULL;
+       return ret;
 }
 
 const struct inode_operations sysfs_dir_inode_operations = {
@@ -942,6 +945,8 @@ int sysfs_rename_dir(struct kobject *kobj, struct sysfs_dirent *new_parent_sd,
        if (error)
                goto out_drop;
 
+       mutex_lock(&sysfs_mutex);
+
        dup_name = sd->s_name;
        sd->s_name = new_name;
 
@@ -949,8 +954,6 @@ int sysfs_rename_dir(struct kobject *kobj, struct sysfs_dirent *new_parent_sd,
        d_add(new_dentry, NULL);
        d_move(sd->s_dentry, new_dentry);
 
-       mutex_lock(&sysfs_mutex);
-
        sysfs_unlink_sibling(sd);
        sysfs_get(new_parent_sd);
        sysfs_put(sd->s_parent);