linux/fs/xfs/xfs_pwork.c

// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * Copyright (C) 2019 Oracle.  All Rights Reserved.
 * Author: Darrick J. Wong <[email protected]>
 */
#include "xfs.h"
#include "xfs_fs.h"
#include "xfs_shared.h"
#include "xfs_format.h"
#include "xfs_log_format.h"
#include "xfs_trans_resv.h"
#include "xfs_mount.h"
#include "xfs_trace.h"
#include "xfs_sysctl.h"
#include "xfs_pwork.h"
#include <linux/nmi.h>

/*
 * Parallel Work Queue
 * ===================
 *
 * Abstract away the details of running a large and "obviously" parallelizable
 * task across multiple CPUs.  Callers initialize the pwork control object with
 * a desired level of parallelization and a work function.  Next, they embed
 * struct xfs_pwork in whatever structure they use to pass work context to a
 * worker thread and queue that pwork.  The work function will be passed the
 * pwork item when it is run (from process context) and any returned error will
 * be recorded in xfs_pwork_ctl.error.  Work functions should check for errors
 * and abort if necessary; the non-zeroness of xfs_pwork_ctl.error does not
 * stop workqueue item processing.
 *
 * This is the rough equivalent of the xfsprogs workqueue code, though we can't
 * reuse that name here.
 */

/* Invoke our caller's function. */
static void
xfs_pwork_work(
	struct work_struct	*work)
{ … }

/*
 * Set up control data for parallel work.  @work_fn is the function that will
 * be called.  @tag will be written into the kernel threads.  @nr_threads is
 * the level of parallelism desired, or 0 for no limit.
 */
int
xfs_pwork_init(
	struct xfs_mount	*mp,
	struct xfs_pwork_ctl	*pctl,
	xfs_pwork_work_fn	work_fn,
	const char		*tag)
{ … }

/* Queue some parallel work. */
void
xfs_pwork_queue(
	struct xfs_pwork_ctl	*pctl,
	struct xfs_pwork	*pwork)
{ … }

/* Wait for the work to finish and tear down the control structure. */
int
xfs_pwork_destroy(
	struct xfs_pwork_ctl	*pctl)
{ … }

/*
 * Wait for the work to finish by polling completion status and touch the soft
 * lockup watchdog.  This is for callers such as mount which hold locks.
 */
void
xfs_pwork_poll(
	struct xfs_pwork_ctl	*pctl)
{ … }