Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit ed413ae6 authored by Kay Sievers's avatar Kay Sievers Committed by Greg Kroah-Hartman
Browse files

Driver core: devtmpfs: prevent concurrent subdirectory creation and removal 



Signed-off-by: default avatarKay Sievers <kay.sievers@vrfy.org>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@suse.de>
parent 00926996

drivers/base/devtmpfs.c

+16 −10
Original line number Diff line number Diff line
@@ -32,6 +32,8 @@ static int dev_mount = 1; 
static int dev_mount;

#endif



static rwlock_t dirlock;



static int __init mount_param(char *str)

{

	dev_mount = simple_strtoul(str, NULL, 0);
@@ -86,16 +88,12 @@ static int dev_mkdir(const char *name, mode_t mode) 


static int create_path(const char *nodepath)

{

	char *path;

	struct nameidata nd;

	int err = 0;



	path = kstrdup(nodepath, GFP_KERNEL);

	if (!path)

		return -ENOMEM;



	read_lock(&dirlock);

	err = vfs_path_lookup(dev_mnt->mnt_root, dev_mnt,

			      path, LOOKUP_PARENT, &nd);

			      nodepath, LOOKUP_PARENT, &nd);

	if (err == 0) {

		struct dentry *dentry;
@@ -107,14 +105,17 @@ static int create_path(const char *nodepath) 
			dput(dentry);

		}

		mutex_unlock(&nd.path.dentry->d_inode->i_mutex);



		path_put(&nd.path);

	} else if (err == -ENOENT) {

		char *path;

		char *s;



		/* parent directories do not exist, create them */

		path = kstrdup(nodepath, GFP_KERNEL);

		if (!path)

			return -ENOMEM;

		s = path;

		while (1) {

		for (;;) {

			s = strchr(s, '/');

			if (!s)

				break;
@@ -125,9 +126,10 @@ static int create_path(const char *nodepath) 
			s[0] = '/';

			s++;

		}

		kfree(path);

	}

	read_unlock(&dirlock);



	kfree(path);

	return err;

}
@@ -234,7 +236,8 @@ static int delete_path(const char *nodepath) 
	if (!path)

		return -ENOMEM;



	while (1) {

	write_lock(&dirlock);

	for (;;) {

		char *base;



		base = strrchr(path, '/');
@@ -245,6 +248,7 @@ static int delete_path(const char *nodepath) 
		if (err)

			break;

	}

	write_unlock(&dirlock);



	kfree(path);

	return err;
@@ -360,6 +364,8 @@ int __init devtmpfs_init(void) 
	int err;

	struct vfsmount *mnt;



	rwlock_init(&dirlock);



	err = register_filesystem(&dev_fs_type);

	if (err) {

		printk(KERN_ERR "devtmpfs: unable to register devtmpfs "