DebugFS : more file/directory creation error handling

Correct dentry count to handle creation errors.

This patch puts a dput at the file creation instead of the file removal :
lookup_one_len already returns a dentry with reference count of 1. Then,
the dget() in simple_mknod increments it when the dentry is associated
with a file. In a scenario where simple_create or simple_mkdir returns
an error, this would lead to an unwanted increment of the reference
counter, therefore making file removal impossible.

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

1 files changed, 10 insertions, 4 deletions

diff --git a/fs/debugfs/inode.c b/fs/debugfs/inode.c
index d6c5fb53c74..554f4a9dfaf 100644
--- a/fs/debugfs/inode.c
+++ b/fs/debugfs/inode.c
@@ -162,6 +162,7 @@ static int debugfs_create_by_name(const char *name, mode_t mode,
                         error = debugfs_mkdir(parent->d_inode, *dentry, mode);
                 else 
                         error = debugfs_create(parent->d_inode, *dentry, mode);
+                dput(*dentry);
         } else
                 error = PTR_ERR(*dentry);
         mutex_unlock(&parent->d_inode->i_mutex);
@@ -273,6 +274,7 @@ EXPORT_SYMBOL_GPL(debugfs_create_dir);
 void debugfs_remove(struct dentry *dentry)
 {
         struct dentry *parent;
+        int ret = 0;
         
         if (!dentry)
                 return;
@@ -284,11 +286,15 @@ void debugfs_remove(struct dentry *dentry)
         mutex_lock(&parent->d_inode->i_mutex);
         if (debugfs_positive(dentry)) {
                 if (dentry->d_inode) {
-                        if (S_ISDIR(dentry->d_inode->i_mode))
-                                simple_rmdir(parent->d_inode, dentry);
-                        else
+                        if (S_ISDIR(dentry->d_inode->i_mode)) {
+                                ret = simple_rmdir(parent->d_inode, dentry);
+                                if (ret)
+                                        printk(KERN_ERR
+                                                "DebugFS rmdir on %s failed : "
+                                                "directory not empty.\n",
+                                                dentry->d_name.name);
+                        } else
                                 simple_unlink(parent->d_inode, dentry);
-                dput(dentry);
                 }
         }
         mutex_unlock(&parent->d_inode->i_mutex);