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Commit 65c33336 authored by Mathieu Desnoyers's avatar Mathieu Desnoyers Committed by Greg Kroah-Hartman
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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: default avatarMathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@suse.de>
parent 63223a06

fs/debugfs/inode.c

+10 −4
Original line number Diff line number Diff line
@@ -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);