Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs

Pull vfs fixes from Al Viro:
 "A nasty bug in fs/namespace.c caught by Andrey + a couple of less
  serious unpleasantness - ecryptfs misc device playing hopeless games
  with try_module_get() and palinfo procfs support being...  not quite
  correctly done, to be polite."

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  mnt: release locks on error path in do_loopback
  palinfo fixes
  procfs: add proc_remove_subtree()
  ecryptfs: close rmmod race

3 files changed, 92 insertions, 43 deletions

diff --git a/fs/ecryptfs/miscdev.c b/fs/ecryptfs/miscdev.c
index 412e6eda25f..e4141f25749 100644
--- a/fs/ecryptfs/miscdev.c
+++ b/fs/ecryptfs/miscdev.c
@@ -80,13 +80,6 @@ ecryptfs_miscdev_open(struct inode *inode, struct file *file)
 	int rc;
 
 	mutex_lock(&ecryptfs_daemon_hash_mux);
-	rc = try_module_get(THIS_MODULE);
-	if (rc == 0) {
-		rc = -EIO;
-		printk(KERN_ERR "%s: Error attempting to increment module use "
-		       "count; rc = [%d]\n", __func__, rc);
-		goto out_unlock_daemon_list;
-	}
 	rc = ecryptfs_find_daemon_by_euid(&daemon);
 	if (!rc) {
 		rc = -EINVAL;
@@ -96,7 +89,7 @@ ecryptfs_miscdev_open(struct inode *inode, struct file *file)
 	if (rc) {
 		printk(KERN_ERR "%s: Error attempting to spawn daemon; "
 		       "rc = [%d]\n", __func__, rc);
-		goto out_module_put_unlock_daemon_list;
+		goto out_unlock_daemon_list;
 	}
 	mutex_lock(&daemon->mux);
 	if (daemon->flags & ECRYPTFS_DAEMON_MISCDEV_OPEN) {
@@ -108,9 +101,6 @@ ecryptfs_miscdev_open(struct inode *inode, struct file *file)
 	atomic_inc(&ecryptfs_num_miscdev_opens);
 out_unlock_daemon:
 	mutex_unlock(&daemon->mux);
-out_module_put_unlock_daemon_list:
-	if (rc)
-		module_put(THIS_MODULE);
 out_unlock_daemon_list:
 	mutex_unlock(&ecryptfs_daemon_hash_mux);
 	return rc;
@@ -147,7 +137,6 @@ ecryptfs_miscdev_release(struct inode *inode, struct file *file)
 		       "bug.\n", __func__, rc);
 		BUG();
 	}
-	module_put(THIS_MODULE);
 	return rc;
 }
 
@@ -471,6 +460,7 @@ out_free:
 
 
 static const struct file_operations ecryptfs_miscdev_fops = {
+	.owner   = THIS_MODULE,
 	.open    = ecryptfs_miscdev_open,
 	.poll    = ecryptfs_miscdev_poll,
 	.read    = ecryptfs_miscdev_read,
diff --git a/fs/namespace.c b/fs/namespace.c
index d581e45c0a9..341d3f56408 100644
--- a/fs/namespace.c
+++ b/fs/namespace.c
@@ -1690,7 +1690,7 @@ static int do_loopback(struct path *path, const char *old_name,
 
 	if (IS_ERR(mnt)) {
 		err = PTR_ERR(mnt);
-		goto out;
+		goto out2;
 	}
 
 	err = graft_tree(mnt, path);
diff --git a/fs/proc/generic.c b/fs/proc/generic.c
index 4b3b3ffb52f..21e1a8f1659 100644
--- a/fs/proc/generic.c
+++ b/fs/proc/generic.c
@@ -755,37 +755,8 @@ void pde_put(struct proc_dir_entry *pde)
 		free_proc_entry(pde);
 }
 
-/*
- * Remove a /proc entry and free it if it's not currently in use.
- */
-void remove_proc_entry(const char *name, struct proc_dir_entry *parent)
+static void entry_rundown(struct proc_dir_entry *de)
 {
-	struct proc_dir_entry **p;
-	struct proc_dir_entry *de = NULL;
-	const char *fn = name;
-	unsigned int len;
-
-	spin_lock(&proc_subdir_lock);
-	if (__xlate_proc_name(name, &parent, &fn) != 0) {
-		spin_unlock(&proc_subdir_lock);
-		return;
-	}
-	len = strlen(fn);
-
-	for (p = &parent->subdir; *p; p=&(*p)->next ) {
-		if (proc_match(len, fn, *p)) {
-			de = *p;
-			*p = de->next;
-			de->next = NULL;
-			break;
-		}
-	}
-	spin_unlock(&proc_subdir_lock);
-	if (!de) {
-		WARN(1, "name '%s'\n", name);
-		return;
-	}
-
 	spin_lock(&de->pde_unload_lock);
 	/*
 	 * Stop accepting new callers into module. If you're
@@ -817,6 +788,40 @@ void remove_proc_entry(const char *name, struct proc_dir_entry *parent)
 		spin_lock(&de->pde_unload_lock);
 	}
 	spin_unlock(&de->pde_unload_lock);
+}
+
+/*
+ * Remove a /proc entry and free it if it's not currently in use.
+ */
+void remove_proc_entry(const char *name, struct proc_dir_entry *parent)
+{
+	struct proc_dir_entry **p;
+	struct proc_dir_entry *de = NULL;
+	const char *fn = name;
+	unsigned int len;
+
+	spin_lock(&proc_subdir_lock);
+	if (__xlate_proc_name(name, &parent, &fn) != 0) {
+		spin_unlock(&proc_subdir_lock);
+		return;
+	}
+	len = strlen(fn);
+
+	for (p = &parent->subdir; *p; p=&(*p)->next ) {
+		if (proc_match(len, fn, *p)) {
+			de = *p;
+			*p = de->next;
+			de->next = NULL;
+			break;
+		}
+	}
+	spin_unlock(&proc_subdir_lock);
+	if (!de) {
+		WARN(1, "name '%s'\n", name);
+		return;
+	}
+
+	entry_rundown(de);
 
 	if (S_ISDIR(de->mode))
 		parent->nlink--;
@@ -827,3 +832,57 @@ void remove_proc_entry(const char *name, struct proc_dir_entry *parent)
 	pde_put(de);
 }
 EXPORT_SYMBOL(remove_proc_entry);
+
+int remove_proc_subtree(const char *name, struct proc_dir_entry *parent)
+{
+	struct proc_dir_entry **p;
+	struct proc_dir_entry *root = NULL, *de, *next;
+	const char *fn = name;
+	unsigned int len;
+
+	spin_lock(&proc_subdir_lock);
+	if (__xlate_proc_name(name, &parent, &fn) != 0) {
+		spin_unlock(&proc_subdir_lock);
+		return -ENOENT;
+	}
+	len = strlen(fn);
+
+	for (p = &parent->subdir; *p; p=&(*p)->next ) {
+		if (proc_match(len, fn, *p)) {
+			root = *p;
+			*p = root->next;
+			root->next = NULL;
+			break;
+		}
+	}
+	if (!root) {
+		spin_unlock(&proc_subdir_lock);
+		return -ENOENT;
+	}
+	de = root;
+	while (1) {
+		next = de->subdir;
+		if (next) {
+			de->subdir = next->next;
+			next->next = NULL;
+			de = next;
+			continue;
+		}
+		spin_unlock(&proc_subdir_lock);
+
+		entry_rundown(de);
+		next = de->parent;
+		if (S_ISDIR(de->mode))
+			next->nlink--;
+		de->nlink = 0;
+		if (de == root)
+			break;
+		pde_put(de);
+
+		spin_lock(&proc_subdir_lock);
+		de = next;
+	}
+	pde_put(root);
+	return 0;
+}
+EXPORT_SYMBOL(remove_proc_subtree);