__d_alloc(): treat NULL name as QSTR("/", 1)

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
This commit is contained in:
Al Viro 2016-03-24 20:38:43 -04:00
parent 322ea0bbf3
commit 798434bda3
1 changed files with 7 additions and 6 deletions

View File

@ -1558,7 +1558,11 @@ struct dentry *__d_alloc(struct super_block *sb, const struct qstr *name)
* be overwriting an internal NUL character
*/
dentry->d_iname[DNAME_INLINE_LEN-1] = 0;
if (name->len > DNAME_INLINE_LEN-1) {
if (unlikely(!name)) {
static const struct qstr anon = QSTR_INIT("/", 1);
name = &anon;
dname = dentry->d_iname;
} else if (name->len > DNAME_INLINE_LEN-1) {
size_t size = offsetof(struct external_name, name[1]);
struct external_name *p = kmalloc(size + name->len,
GFP_KERNEL_ACCOUNT);
@ -1812,9 +1816,7 @@ struct dentry *d_make_root(struct inode *root_inode)
struct dentry *res = NULL;
if (root_inode) {
static const struct qstr name = QSTR_INIT("/", 1);
res = __d_alloc(root_inode->i_sb, &name);
res = __d_alloc(root_inode->i_sb, NULL);
if (res)
d_instantiate(res, root_inode);
else
@ -1855,7 +1857,6 @@ EXPORT_SYMBOL(d_find_any_alias);
static struct dentry *__d_obtain_alias(struct inode *inode, int disconnected)
{
static const struct qstr anonstring = QSTR_INIT("/", 1);
struct dentry *tmp;
struct dentry *res;
unsigned add_flags;
@ -1869,7 +1870,7 @@ static struct dentry *__d_obtain_alias(struct inode *inode, int disconnected)
if (res)
goto out_iput;
tmp = __d_alloc(inode->i_sb, &anonstring);
tmp = __d_alloc(inode->i_sb, NULL);
if (!tmp) {
res = ERR_PTR(-ENOMEM);
goto out_iput;