// SPDX-License-Identifier: GPL-2.0
#include <linux/kernel.h>
#include <linux/errno.h>
#include <linux/fs.h>
#include <linux/file.h>
#include <linux/mm.h>
#include <linux/slab.h>
#include <linux/namei.h>
#include <linux/io_uring.h>
#include <linux/xattr.h>

#include <uapi/linux/io_uring.h>

#include "../fs/internal.h"

#include "io_uring.h"
#include "xattr.h"

struct io_xattr {
        struct file                     *file;
        struct kernel_xattr_ctx         ctx;
        struct delayed_filename         filename;
};

void io_xattr_cleanup(struct io_kiocb *req)
{
        struct io_xattr *ix = io_kiocb_to_cmd(req, struct io_xattr);

        dismiss_delayed_filename(&ix->filename);
        kfree(ix->ctx.kname);
        kvfree(ix->ctx.kvalue);
}

static void io_xattr_finish(struct io_kiocb *req, int ret)
{
        req->flags &= ~REQ_F_NEED_CLEANUP;

        io_xattr_cleanup(req);
        io_req_set_res(req, ret, 0);
}

static int __io_getxattr_prep(struct io_kiocb *req,
                              const struct io_uring_sqe *sqe)
{
        struct io_xattr *ix = io_kiocb_to_cmd(req, struct io_xattr);
        const char __user *name;
        int ret;

        INIT_DELAYED_FILENAME(&ix->filename);
        ix->ctx.kvalue = NULL;
        name = u64_to_user_ptr(READ_ONCE(sqe->addr));
        ix->ctx.value = u64_to_user_ptr(READ_ONCE(sqe->addr2));
        ix->ctx.size = READ_ONCE(sqe->len);
        ix->ctx.flags = READ_ONCE(sqe->xattr_flags);

        if (ix->ctx.flags)
                return -EINVAL;

        ix->ctx.kname = kmalloc_obj(*ix->ctx.kname);
        if (!ix->ctx.kname)
                return -ENOMEM;

        ret = import_xattr_name(ix->ctx.kname, name);
        if (ret) {
                kfree(ix->ctx.kname);
                return ret;
        }

        req->flags |= REQ_F_NEED_CLEANUP;
        req->flags |= REQ_F_FORCE_ASYNC;
        return 0;
}

int io_fgetxattr_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
{
        return __io_getxattr_prep(req, sqe);
}

int io_getxattr_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
{
        struct io_xattr *ix = io_kiocb_to_cmd(req, struct io_xattr);
        const char __user *path;
        int ret;

        if (unlikely(req->flags & REQ_F_FIXED_FILE))
                return -EBADF;

        ret = __io_getxattr_prep(req, sqe);
        if (ret)
                return ret;

        path = u64_to_user_ptr(READ_ONCE(sqe->addr3));

        return delayed_getname(&ix->filename, path);
}

int io_fgetxattr(struct io_kiocb *req, unsigned int issue_flags)
{
        struct io_xattr *ix = io_kiocb_to_cmd(req, struct io_xattr);
        int ret;

        WARN_ON_ONCE(issue_flags & IO_URING_F_NONBLOCK);

        ret = file_getxattr(req->file, &ix->ctx);
        io_xattr_finish(req, ret);
        return IOU_COMPLETE;
}

int io_getxattr(struct io_kiocb *req, unsigned int issue_flags)
{
        struct io_xattr *ix = io_kiocb_to_cmd(req, struct io_xattr);
        CLASS(filename_complete_delayed, name)(&ix->filename);
        int ret;

        WARN_ON_ONCE(issue_flags & IO_URING_F_NONBLOCK);

        ret = filename_getxattr(AT_FDCWD, name, LOOKUP_FOLLOW, &ix->ctx);
        io_xattr_finish(req, ret);
        return IOU_COMPLETE;
}

static int __io_setxattr_prep(struct io_kiocb *req,
                        const struct io_uring_sqe *sqe)
{
        struct io_xattr *ix = io_kiocb_to_cmd(req, struct io_xattr);
        const char __user *name;
        int ret;

        INIT_DELAYED_FILENAME(&ix->filename);
        name = u64_to_user_ptr(READ_ONCE(sqe->addr));
        ix->ctx.cvalue = u64_to_user_ptr(READ_ONCE(sqe->addr2));
        ix->ctx.kvalue = NULL;
        ix->ctx.size = READ_ONCE(sqe->len);
        ix->ctx.flags = READ_ONCE(sqe->xattr_flags);

        ix->ctx.kname = kmalloc_obj(*ix->ctx.kname);
        if (!ix->ctx.kname)
                return -ENOMEM;

        ret = setxattr_copy(name, &ix->ctx);
        if (ret) {
                kfree(ix->ctx.kname);
                return ret;
        }

        req->flags |= REQ_F_NEED_CLEANUP;
        req->flags |= REQ_F_FORCE_ASYNC;
        return 0;
}

int io_setxattr_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
{
        struct io_xattr *ix = io_kiocb_to_cmd(req, struct io_xattr);
        const char __user *path;
        int ret;

        if (unlikely(req->flags & REQ_F_FIXED_FILE))
                return -EBADF;

        ret = __io_setxattr_prep(req, sqe);
        if (ret)
                return ret;

        path = u64_to_user_ptr(READ_ONCE(sqe->addr3));

        return delayed_getname(&ix->filename, path);
}

int io_fsetxattr_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
{
        return __io_setxattr_prep(req, sqe);
}

int io_fsetxattr(struct io_kiocb *req, unsigned int issue_flags)
{
        struct io_xattr *ix = io_kiocb_to_cmd(req, struct io_xattr);
        int ret;

        WARN_ON_ONCE(issue_flags & IO_URING_F_NONBLOCK);

        ret = file_setxattr(req->file, &ix->ctx);
        io_xattr_finish(req, ret);
        return IOU_COMPLETE;
}

int io_setxattr(struct io_kiocb *req, unsigned int issue_flags)
{
        struct io_xattr *ix = io_kiocb_to_cmd(req, struct io_xattr);
        CLASS(filename_complete_delayed, name)(&ix->filename);
        int ret;

        WARN_ON_ONCE(issue_flags & IO_URING_F_NONBLOCK);

        ret = filename_setxattr(AT_FDCWD, name, LOOKUP_FOLLOW, &ix->ctx);
        io_xattr_finish(req, ret);
        return IOU_COMPLETE;
}