linux/drivers/md/dm-stripe.c

// SPDX-License-Identifier: GPL-2.0-only
/*
 * Copyright (C) 2001-2003 Sistina Software (UK) Limited.
 *
 * This file is released under the GPL.
 */

#include "dm.h"
#include <linux/device-mapper.h>

#include <linux/module.h>
#include <linux/init.h>
#include <linux/blkdev.h>
#include <linux/bio.h>
#include <linux/dax.h>
#include <linux/slab.h>
#include <linux/log2.h>

static struct workqueue_struct *dm_stripe_wq;

#define DM_MSG_PREFIX …
#define DM_IO_ERROR_THRESHOLD …

struct stripe { … };

struct stripe_c { … };

/*
 * An event is triggered whenever a drive
 * drops out of a stripe volume.
 */
static void trigger_event(struct work_struct *work)
{ … }

/*
 * Parse a single <dev> <sector> pair
 */
static int get_stripe(struct dm_target *ti, struct stripe_c *sc,
		      unsigned int stripe, char **argv)
{ … }

/*
 * Construct a striped mapping.
 * <number of stripes> <chunk size> [<dev_path> <offset>]+
 */
static int stripe_ctr(struct dm_target *ti, unsigned int argc, char **argv)
{ … }

static void stripe_dtr(struct dm_target *ti)
{ … }

static void stripe_map_sector(struct stripe_c *sc, sector_t sector,
			      uint32_t *stripe, sector_t *result)
{ … }

static void stripe_map_range_sector(struct stripe_c *sc, sector_t sector,
				    uint32_t target_stripe, sector_t *result)
{ … }

static int stripe_map_range(struct stripe_c *sc, struct bio *bio,
			    uint32_t target_stripe)
{ … }

int stripe_map(struct dm_target *ti, struct bio *bio)
{ … }

#if IS_ENABLED(CONFIG_FS_DAX)
static struct dax_device *stripe_dax_pgoff(struct dm_target *ti, pgoff_t *pgoff)
{ … }

static long stripe_dax_direct_access(struct dm_target *ti, pgoff_t pgoff,
		long nr_pages, enum dax_access_mode mode, void **kaddr,
		pfn_t *pfn)
{ … }

static int stripe_dax_zero_page_range(struct dm_target *ti, pgoff_t pgoff,
				      size_t nr_pages)
{ … }

static size_t stripe_dax_recovery_write(struct dm_target *ti, pgoff_t pgoff,
		void *addr, size_t bytes, struct iov_iter *i)
{ … }

#else
#define stripe_dax_direct_access …
#define stripe_dax_zero_page_range …
#define stripe_dax_recovery_write …
#endif

/*
 * Stripe status:
 *
 * INFO
 * #stripes [stripe_name <stripe_name>] [group word count]
 * [error count 'A|D' <error count 'A|D'>]
 *
 * TABLE
 * #stripes [stripe chunk size]
 * [stripe_name physical_start <stripe_name physical_start>]
 *
 */

static void stripe_status(struct dm_target *ti, status_type_t type,
			  unsigned int status_flags, char *result, unsigned int maxlen)
{ … }

static int stripe_end_io(struct dm_target *ti, struct bio *bio,
		blk_status_t *error)
{ … }

static int stripe_iterate_devices(struct dm_target *ti,
				  iterate_devices_callout_fn fn, void *data)
{ … }

static void stripe_io_hints(struct dm_target *ti,
			    struct queue_limits *limits)
{ … }

static struct target_type stripe_target = …;

int __init dm_stripe_init(void)
{ … }

void dm_stripe_exit(void)
{ … }