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>

1 files changed, 12 insertions, 9 deletions

diff --git a/fs/sysfs/dir.c b/fs/sysfs/dir.c
index 048e6054c2fd..83e76b3813c9 100644
--- 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);