On 11/15/20 9:45 PM, Dmitry Kadashev wrote:
> Pass in the struct filename pointers instead of the user string, and
> update the three callers to do the same. This is heavily based on
> commit dbea8d345177 ("fs: make do_renameat2() take struct filename").
>
> This behaves like do_unlinkat() and do_renameat2().
Al, are you OK with this patch? Leaving it quoted, though you should
have the original too.
>
> Signed-off-by: Dmitry Kadashev <dkadashev@xxxxxxxxx>
> ---
> fs/internal.h | 1 +
> fs/namei.c | 20 ++++++++++++++------
> 2 files changed, 15 insertions(+), 6 deletions(-)
>
> diff --git a/fs/internal.h b/fs/internal.h
> index 6fd14ea213c3..23b8b427dbd2 100644
> --- a/fs/internal.h
> +++ b/fs/internal.h
> @@ -80,6 +80,7 @@ long do_unlinkat(int dfd, struct filename *name);
> int may_linkat(struct path *link);
> int do_renameat2(int olddfd, struct filename *oldname, int newdfd,
> struct filename *newname, unsigned int flags);
> +long do_mkdirat(int dfd, struct filename *name, umode_t mode);
>
> /*
> * namespace.c
> diff --git a/fs/namei.c b/fs/namei.c
> index 03d0e11e4f36..9d26a51f3f54 100644
> --- a/fs/namei.c
> +++ b/fs/namei.c
> @@ -3654,17 +3654,23 @@ int vfs_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode)
> }
> EXPORT_SYMBOL(vfs_mkdir);
>
> -static long do_mkdirat(int dfd, const char __user *pathname, umode_t mode)
> +long do_mkdirat(int dfd, struct filename *name, umode_t mode)
> {
> struct dentry *dentry;
> struct path path;
> int error;
> unsigned int lookup_flags = LOOKUP_DIRECTORY;
>
> + if (IS_ERR(name))
> + return PTR_ERR(name);
> +
> retry:
> - dentry = user_path_create(dfd, pathname, &path, lookup_flags);
> - if (IS_ERR(dentry))
> - return PTR_ERR(dentry);
> + name->refcnt++; /* filename_create() drops our ref */
> + dentry = filename_create(dfd, name, &path, lookup_flags);
> + if (IS_ERR(dentry)) {
> + error = PTR_ERR(dentry);
> + goto out;
> + }
>
> if (!IS_POSIXACL(path.dentry->d_inode))
> mode &= ~current_umask();
> @@ -3676,17 +3682,19 @@ static long do_mkdirat(int dfd, const char __user *pathname, umode_t mode)
> lookup_flags |= LOOKUP_REVAL;
> goto retry;
> }
> +out:
> + putname(name);
> return error;
> }
>
> SYSCALL_DEFINE3(mkdirat, int, dfd, const char __user *, pathname, umode_t, mode)
> {
> - return do_mkdirat(dfd, pathname, mode);
> + return do_mkdirat(dfd, getname(pathname), mode);
> }
>
> SYSCALL_DEFINE2(mkdir, const char __user *, pathname, umode_t, mode)
> {
> - return do_mkdirat(AT_FDCWD, pathname, mode);
> + return do_mkdirat(AT_FDCWD, getname(pathname), mode);
> }
>
> int vfs_rmdir(struct inode *dir, struct dentry *dentry)
>
--
Jens Axboe
