// 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/fsnotify.h>

#include <uapi/linux/io_uring.h>

#include "io_uring.h"
#include "sync.h"

struct io_sync {
        struct file                     *file;
        loff_t                          len;
        loff_t                          off;
        int                             flags;
        int                             mode;
};

int io_sfr_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
{
        struct io_sync *sync = io_kiocb_to_cmd(req, struct io_sync);

        if (unlikely(sqe->addr || sqe->buf_index || sqe->splice_fd_in))
                return -EINVAL;

        sync->off = READ_ONCE(sqe->off);
        sync->len = READ_ONCE(sqe->len);
        sync->flags = READ_ONCE(sqe->sync_range_flags);
        req->flags |= REQ_F_FORCE_ASYNC;

        return 0;
}

int io_sync_file_range(struct io_kiocb *req, unsigned int issue_flags)
{
        struct io_sync *sync = io_kiocb_to_cmd(req, struct io_sync);
        int ret;

        /* sync_file_range always requires a blocking context */
        WARN_ON_ONCE(issue_flags & IO_URING_F_NONBLOCK);

        ret = sync_file_range(req->file, sync->off, sync->len, sync->flags);
        io_req_set_res(req, ret, 0);
        return IOU_COMPLETE;
}

int io_fsync_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
{
        struct io_sync *sync = io_kiocb_to_cmd(req, struct io_sync);

        if (unlikely(sqe->addr || sqe->buf_index || sqe->splice_fd_in))
                return -EINVAL;

        sync->flags = READ_ONCE(sqe->fsync_flags);
        if (unlikely(sync->flags & ~IORING_FSYNC_DATASYNC))
                return -EINVAL;

        sync->off = READ_ONCE(sqe->off);
        if (sync->off < 0)
                return -EINVAL;
        sync->len = READ_ONCE(sqe->len);
        req->flags |= REQ_F_FORCE_ASYNC;
        return 0;
}

int io_fsync(struct io_kiocb *req, unsigned int issue_flags)
{
        struct io_sync *sync = io_kiocb_to_cmd(req, struct io_sync);
        loff_t end = sync->off + sync->len;
        int ret;

        /* fsync always requires a blocking context */
        WARN_ON_ONCE(issue_flags & IO_URING_F_NONBLOCK);

        ret = vfs_fsync_range(req->file, sync->off, end > 0 ? end : LLONG_MAX,
                                sync->flags & IORING_FSYNC_DATASYNC);
        io_req_set_res(req, ret, 0);
        return IOU_COMPLETE;
}

int io_fallocate_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
{
        struct io_sync *sync = io_kiocb_to_cmd(req, struct io_sync);

        if (sqe->buf_index || sqe->rw_flags || sqe->splice_fd_in)
                return -EINVAL;

        sync->off = READ_ONCE(sqe->off);
        sync->len = READ_ONCE(sqe->addr);
        sync->mode = READ_ONCE(sqe->len);
        req->flags |= REQ_F_FORCE_ASYNC;
        return 0;
}

int io_fallocate(struct io_kiocb *req, unsigned int issue_flags)
{
        struct io_sync *sync = io_kiocb_to_cmd(req, struct io_sync);
        int ret;

        /* fallocate always requiring blocking context */
        WARN_ON_ONCE(issue_flags & IO_URING_F_NONBLOCK);

        ret = vfs_fallocate(req->file, sync->mode, sync->off, sync->len);
        if (ret >= 0)
                fsnotify_modify(req->file);
        io_req_set_res(req, ret, 0);
        return IOU_COMPLETE;
}