/*

 * falloc: ioengine for git://git.kernel.dk/fio.git

 *

 * IO engine that does regular fallocate to simulate data transfer 

 * as fio ioengine.

 * DDIR_READ  does fallocate(,mode = FALLOC_FL_KEEP_SIZE,)

 * DDIR_WRITE does fallocate(,mode = 0) : fallocate with size extension

 * DDIR_TRIM  does fallocate(,mode = FALLOC_FL_KEEP_SIZE | FALLOC_FL_PUNCH_HOLE)

 *

 */

#include <stdio.h>

#include <errno.h>

#include <fcntl.h>

#include "../fio.h"

#include "../filehash.h"

/*

 * generic_open_file is not appropriate because does not allow to perform

 * TRIM in to file

 */

static int open_file(struct thread_data *td, struct fio_file *f)

{

	int from_hash = 0;

	dprint(FD_FILE, "fd open %s\n", f->file_name);

	if (f->filetype != FIO_TYPE_FILE) {

		log_err("fio: only files are supported fallocate \n");

		return 1;

	}

	if (!strcmp(f->file_name, "-")) {

		log_err("fio: can't read/write to stdin/out\n");

		return 1;

	}

open_again:

	from_hash = file_lookup_open(f, O_CREAT|O_RDWR);

	if (f->fd == -1) {

		char buf[FIO_VERROR_SIZE];

		int e = errno;

		snprintf(buf, sizeof(buf), "open(%s)", f->file_name);

		td_verror(td, e, buf);

	}

	if (!from_hash && f->fd != -1) {

		if (add_file_hash(f)) {

			int fio_unused ret;

			/*

			 * OK to ignore, we haven't done anything with it

			 */

			ret = generic_close_file(td, f);

			goto open_again;

		}

	}

	return 0;

}

#ifndef FALLOC_FL_KEEP_SIZE

#define FALLOC_FL_KEEP_SIZE     0x01 /* default is extend size */

#endif

#ifndef FALLOC_FL_PUNCH_HOLE

#define FALLOC_FL_PUNCH_HOLE    0x02 /* de-allocates range */

#endif

static enum fio_q_status fio_fallocate_queue(struct thread_data *td,

					     struct io_u *io_u)

{

	struct fio_file *f = io_u->file;

	int ret;

	int flags = 0;

	fio_ro_check(td, io_u);

	if (io_u->ddir == DDIR_READ)

		flags = FALLOC_FL_KEEP_SIZE;

	else if (io_u->ddir == DDIR_WRITE)

		flags = 0;

	else if (io_u->ddir == DDIR_TRIM)

		flags = FALLOC_FL_PUNCH_HOLE | FALLOC_FL_KEEP_SIZE;

	ret = fallocate(f->fd, flags, io_u->offset, io_u->xfer_buflen);

	if (ret)

		io_u->error = errno;

	return FIO_Q_COMPLETED;

}

static struct ioengine_ops ioengine = {

	.name		= "falloc",

	.version	= FIO_IOOPS_VERSION,

	.queue		= fio_fallocate_queue,

	.open_file	= open_file,

	.close_file	= generic_close_file,

	.get_file_size	= generic_get_file_size,

	.flags		= FIO_SYNCIO

};

static void fio_init fio_syncio_register(void)

{

	register_ioengine(&ioengine);

}

static void fio_exit fio_syncio_unregister(void)

{

	unregister_ioengine(&ioengine);

}