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Viewing: liblustreapi_lease.c

// SPDX-License-Identifier: LGPL-2.1+
/*
 * (C) Copyright 2014 Commissariat a l'energie atomique et aux energies
 *     alternatives
 *
 * Copyright (c) 2017, Intel Corporation.
 */
/*
 * This file is part of Lustre, http://www.lustre.org/
 *
 * lustreapi library for file leases
 *
 * Author: Henri Doreau <henri.doreau@cea.fr>
 */

#include <unistd.h>
#include <fcntl.h>
#include <sys/ioctl.h>
#include <errno.h>
#include <lustre/lustreapi.h>
#include "lustreapi_internal.h"

static inline const char *lease_mode2str(enum ll_lease_mode mode)
{
	switch (mode) {
	case LL_LEASE_WRLCK: return "WRITE";
	case LL_LEASE_RDLCK: return "READ";
	case LL_LEASE_UNLCK: return "UNLOCK";
	}
	return "???";
}

#define FMT_STR_LEASE_SET "cannot get %s lease, ext %x"
/**
 * llapi_lease_set() - Extend lease set support.
 * @fd: File to set lease on.
 * @data: ll_ioc_lease data.
 *
 * For setting lease lock, it will return zero for success. For unlock, it will
 * return the lock type it owned for succuess.
 *
 * Return:
 * * %>=0 on success.
 * * %-errno on error
 */
int llapi_lease_set(int fd, const struct ll_ioc_lease *data)
{
	int rc;

	rc = ioctl(fd, LL_IOC_SET_LEASE, data);
	if (rc < 0) {
		struct lu_fid fid;
		int rc2;

		rc = -errno;
		rc2 = llapi_fd2fid(fd, &fid);
		if (rc2 == 0)
			llapi_error(LLAPI_MSG_ERROR, rc,
				    FMT_STR_LEASE_SET" for "DFID,
				    lease_mode2str(data->lil_mode),
				    data->lil_flags, PFID(&fid));
		else
			llapi_error(LLAPI_MSG_ERROR, rc,
				    FMT_STR_LEASE_SET,
				    lease_mode2str(data->lil_mode),
				    data->lil_flags);
	}
	return rc;
}

/**
 * llapi_lease_acquire() - Acquire a lease on an open file.
 * @fd: File to get the lease on.
 * @mode: Lease mode, either LL_LEASE_RDLCK or LL_LEASE_WRLCK.
 *
 * see llapi_lease_release().
 *
 * Return:
 * * %>=0 on success.
 * * %-errno on error
 */
int llapi_lease_acquire(int fd, enum ll_lease_mode mode)
{
	struct ll_ioc_lease data = { .lil_mode = mode };
	int rc;

	if (mode != LL_LEASE_RDLCK && mode != LL_LEASE_WRLCK)
		return -EINVAL;

	rc = llapi_lease_set(fd, &data);
	if (rc == -ENOTTY) {
		rc = ioctl(fd, LL_IOC_SET_LEASE_OLD, mode);
		if (rc < 0)
			rc = -errno;
	}

	return rc;
}

/**
 * llapi_lease_release() - Release a lease.
 * @fd: File to remove the lease from.
 *
 * Return:
 * * %LL_LEASE_READ/%LL_LEASE_WRITE type of the lease that was removed
 * * %0 if no lease was present.
 * * %-errno on error.
 */
int llapi_lease_release(int fd)
{
	struct ll_ioc_lease data = { .lil_mode = LL_LEASE_UNLCK };

	return llapi_lease_set(fd, &data);
}

/**
 * llapi_lease_release_intent() - Release a lease with intent operation
 * @fd: File to remove the lease from.
 * @data: 
 *
 * Release a lease with intent operation. This API will release the lease
 * and execute the intent operation atomically.
 *
 * Return:
 * * %LL_LEASE_READ/%LL_LEASE_WRITE type of the lease that was removed
 * * %0 if no lease was present.
 * * %-EBUSY lease broken, intent operation not executed.
 * * %-errno on error.
 */
int llapi_lease_release_intent(int fd, struct ll_ioc_lease *data)
{
	if (data->lil_mode != LL_LEASE_UNLCK)
		return -EINVAL;

	return llapi_lease_set(fd, data);
}

/**
 * llapi_lease_check() - Check if a lease is still set on a file.
 * @fd: File to check the lease on.
 *
 * Return:
 * * %LL_LEASE_READ/%LL_LEASE_WRITE type of the lease that was removed
 * * %0 if no lease was present.
 * * %-errno on error.
 */
int llapi_lease_check(int fd)
{
	int rc;

	rc = ioctl(fd, LL_IOC_GET_LEASE);
	if (rc < 0) {
		int rc2;
		struct lu_fid fid;

		rc = -errno;
		rc2 = llapi_fd2fid(fd, &fid);
		if (rc2 == 0)
			llapi_error(LLAPI_MSG_ERROR, rc,
				    "cannot check lease for "DFID, PFID(&fid));
		else
			llapi_error(LLAPI_MSG_ERROR, rc, "cannot check lease");
	}
	return rc;
}

/*
 * XXX: This is an obsoleted API - do not use it any more.
 */
int llapi_lease_get(int fd, int mode)
{
	int rc;

	if (mode != LL_LEASE_RDLCK && mode != LL_LEASE_WRLCK)
		return -EINVAL;

	rc = ioctl(fd, LL_IOC_SET_LEASE_OLD, mode);
	if (rc < 0)
		rc = -errno;

	return rc;
}

/*
 * XXX: This is an obsoleted API - do not use it any more.
 */
int llapi_lease_put(int fd)
{
	int rc;

	rc = ioctl(fd, LL_IOC_SET_LEASE_OLD, LL_LEASE_UNLCK);
	if (rc < 0)
		rc = -errno;

	return rc;
}