On Tue, Feb 2, 2021 at 3:25 PM Dmitry Kadashev <dkadashev@xxxxxxxxx> 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().
>
> Cc: Al Viro <viro@xxxxxxxxxxxxxxxxxx>
> Signed-off-by: Dmitry Kadashev <dkadashev@xxxxxxxxx>
> ---
> fs/internal.h | 1 +
> fs/namei.c | 25 +++++++++++++++++++------
> 2 files changed, 20 insertions(+), 6 deletions(-)
>
> diff --git a/fs/internal.h b/fs/internal.h
> index c6c85f6ad598..b10005dfaa48 100644
> --- a/fs/internal.h
> +++ b/fs/internal.h
> @@ -76,6 +76,7 @@ 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 4cae88733a5c..3657bdf1aafc 100644
> --- a/fs/namei.c
> +++ b/fs/namei.c
> @@ -3431,7 +3431,7 @@ struct file *do_file_open_root(struct dentry *dentry, struct vfsmount *mnt,
> return file;
> }
>
> -static struct dentry *filename_create(int dfd, struct filename *name,
> +static struct dentry *__filename_create(int dfd, struct filename *name,
> struct path *path, unsigned int lookup_flags)
> {
> struct dentry *dentry = ERR_PTR(-EEXIST);
> @@ -3487,7 +3487,6 @@ static struct dentry *filename_create(int dfd, struct filename *name,
> error = err2;
> goto fail;
> }
> - putname(name);
> return dentry;
> fail:
> dput(dentry);
> @@ -3502,6 +3501,16 @@ static struct dentry *filename_create(int dfd, struct filename *name,
> return dentry;
> }
>
> +static inline struct dentry *filename_create(int dfd, struct filename *name,
> + struct path *path, unsigned int lookup_flags)
> +{
> + struct dentry *res = __filename_create(dfd, name, path, lookup_flags);
> +
> + if (!IS_ERR(res))
> + putname(name);
> + return res;
> +}
> +
> struct dentry *kern_path_create(int dfd, const char *pathname,
> struct path *path, unsigned int lookup_flags)
> {
> @@ -3654,15 +3663,18 @@ 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);
> + dentry = __filename_create(dfd, name, &path, lookup_flags);
> if (IS_ERR(dentry))
> return PTR_ERR(dentry);
>
> @@ -3676,17 +3688,18 @@ static long do_mkdirat(int dfd, const char __user *pathname, umode_t mode)
> lookup_flags |= LOOKUP_REVAL;
> goto retry;
> }
> + 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)
> --
> 2.30.0
Hi Al,
Are you OK with this version?
--
Dmitry Kadashev
