UBUNTU: Ubuntu-2.6.38-12.51

[linux-flexiantxendom0-natty.git] / kernel / cgroup.c

diff --git a/kernel/cgroup.c b/kernel/cgroup.c
index 746055b..bcc7336 100644 (file)
--- a/kernel/cgroup.c
+++ b/kernel/cgroup.c
@@ -763,9 +763,8 @@ EXPORT_SYMBOL_GPL(cgroup_unlock);
  * -> cgroup_mkdir.
  */
 
-static struct dentry *cgroup_lookup(struct inode *dir,
-                       struct dentry *dentry, struct nameidata *nd);
 static int cgroup_mkdir(struct inode *dir, struct dentry *dentry, int mode);
+static struct dentry *cgroup_lookup(struct inode *, struct dentry *, struct nameidata *);
 static int cgroup_rmdir(struct inode *unused_dir, struct dentry *dentry);
 static int cgroup_populate_dir(struct cgroup *cgrp);
 static const struct inode_operations cgroup_dir_inode_operations;
@@ -862,6 +861,11 @@ static void cgroup_diput(struct dentry *dentry, struct inode *inode)
        iput(inode);
 }
 
+static int cgroup_delete(const struct dentry *d)
+{
+       return 1;
+}
+
 static void remove_dir(struct dentry *d)
 {
        struct dentry *parent = dget(d->d_parent);
@@ -876,25 +880,29 @@ static void cgroup_clear_directory(struct dentry *dentry)
        struct list_head *node;
 
        BUG_ON(!mutex_is_locked(&dentry->d_inode->i_mutex));
-       spin_lock(&dcache_lock);
+       spin_lock(&dentry->d_lock);
        node = dentry->d_subdirs.next;
        while (node != &dentry->d_subdirs) {
                struct dentry *d = list_entry(node, struct dentry, d_u.d_child);
+
+               spin_lock_nested(&d->d_lock, DENTRY_D_LOCK_NESTED);
                list_del_init(node);
                if (d->d_inode) {
                        /* This should never be called on a cgroup
                         * directory with child cgroups */
                        BUG_ON(d->d_inode->i_mode & S_IFDIR);
-                       d = dget_locked(d);
-                       spin_unlock(&dcache_lock);
+                       dget_dlock(d);
+                       spin_unlock(&d->d_lock);
+                       spin_unlock(&dentry->d_lock);
                        d_delete(d);
                        simple_unlink(dentry->d_inode, d);
                        dput(d);
-                       spin_lock(&dcache_lock);
-               }
+                       spin_lock(&dentry->d_lock);
+               } else
+                       spin_unlock(&d->d_lock);
                node = dentry->d_subdirs.next;
        }
-       spin_unlock(&dcache_lock);
+       spin_unlock(&dentry->d_lock);
 }
 
 /*
@@ -902,11 +910,16 @@ static void cgroup_clear_directory(struct dentry *dentry)
  */
 static void cgroup_d_remove_dir(struct dentry *dentry)
 {
+       struct dentry *parent;
+
        cgroup_clear_directory(dentry);
 
-       spin_lock(&dcache_lock);
+       parent = dentry->d_parent;
+       spin_lock(&parent->d_lock);
+       spin_lock_nested(&dentry->d_lock, DENTRY_D_LOCK_NESTED);
        list_del_init(&dentry->d_u.d_child);
-       spin_unlock(&dcache_lock);
+       spin_unlock(&dentry->d_lock);
+       spin_unlock(&parent->d_lock);
        remove_dir(dentry);
 }
 
@@ -1442,6 +1455,11 @@ static int cgroup_set_super(struct super_block *sb, void *data)
 
 static int cgroup_get_rootdir(struct super_block *sb)
 {
+       static const struct dentry_operations cgroup_dops = {
+               .d_iput = cgroup_diput,
+               .d_delete = cgroup_delete,
+       };
+
        struct inode *inode =
                cgroup_new_inode(S_IFDIR | S_IRUGO | S_IXUGO | S_IWUSR, sb);
        struct dentry *dentry;
@@ -1459,6 +1477,8 @@ static int cgroup_get_rootdir(struct super_block *sb)
                return -ENOMEM;
        }
        sb->s_root = dentry;
+       /* for everything else we want ->d_op set */
+       sb->s_d_op = &cgroup_dops;
        return 0;
 }
 
@@ -1793,10 +1813,8 @@ int cgroup_attach_task(struct cgroup *cgrp, struct task_struct *tsk)
 
        /* Update the css_set linked lists if we're using them */
        write_lock(&css_set_lock);
-       if (!list_empty(&tsk->cg_list)) {
-               list_del(&tsk->cg_list);
-               list_add(&tsk->cg_list, &newcg->tasks);
-       }
+       if (!list_empty(&tsk->cg_list))
+               list_move(&tsk->cg_list, &newcg->tasks);
        write_unlock(&css_set_lock);
 
        for_each_subsys(root, ss) {
@@ -2188,6 +2206,14 @@ static const struct inode_operations cgroup_dir_inode_operations = {
        .rename = cgroup_rename,
 };
 
+static struct dentry *cgroup_lookup(struct inode *dir, struct dentry *dentry, struct nameidata *nd)
+{
+       if (dentry->d_name.len > NAME_MAX)
+               return ERR_PTR(-ENAMETOOLONG);
+       d_add(dentry, NULL);
+       return NULL;
+}
+
 /*
  * Check if a file is a control file
  */
@@ -2198,26 +2224,6 @@ static inline struct cftype *__file_cft(struct file *file)
        return __d_cft(file->f_dentry);
 }
 
-static int cgroup_delete_dentry(const struct dentry *dentry)
-{
-       return 1;
-}
-
-static struct dentry *cgroup_lookup(struct inode *dir,
-                       struct dentry *dentry, struct nameidata *nd)
-{
-       static const struct dentry_operations cgroup_dentry_operations = {
-               .d_delete = cgroup_delete_dentry,
-               .d_iput = cgroup_diput,
-       };
-
-       if (dentry->d_name.len > NAME_MAX)
-               return ERR_PTR(-ENAMETOOLONG);
-       dentry->d_op = &cgroup_dentry_operations;
-       d_add(dentry, NULL);
-       return NULL;
-}
-
 static int cgroup_create_file(struct dentry *dentry, mode_t mode,
                                struct super_block *sb)
 {
@@ -3647,17 +3653,15 @@ again:
        spin_lock(&release_list_lock);
        set_bit(CGRP_REMOVED, &cgrp->flags);
        if (!list_empty(&cgrp->release_list))
-               list_del(&cgrp->release_list);
+               list_del_init(&cgrp->release_list);
        spin_unlock(&release_list_lock);
 
        cgroup_lock_hierarchy(cgrp->root);
        /* delete this cgroup from parent->children */
-       list_del(&cgrp->sibling);
+       list_del_init(&cgrp->sibling);
        cgroup_unlock_hierarchy(cgrp->root);
 
-       spin_lock(&cgrp->dentry->d_lock);
        d = dget(cgrp->dentry);
-       spin_unlock(&d->d_lock);
 
        cgroup_d_remove_dir(d);
        dput(d);
@@ -3873,7 +3877,7 @@ void cgroup_unload_subsys(struct cgroup_subsys *ss)
        subsys[ss->subsys_id] = NULL;
 
        /* remove subsystem from rootnode's list of subsystems */
-       list_del(&ss->sibling);
+       list_del_init(&ss->sibling);
 
        /*
         * disentangle the css from all css_sets attached to the dummytop. as
@@ -4247,7 +4251,7 @@ void cgroup_exit(struct task_struct *tsk, int run_callbacks)
        if (!list_empty(&tsk->cg_list)) {
                write_lock(&css_set_lock);
                if (!list_empty(&tsk->cg_list))
-                       list_del(&tsk->cg_list);
+                       list_del_init(&tsk->cg_list);
                write_unlock(&css_set_lock);
        }