/****************************************************************************
 * bfs                                                                      *
 * Copyright (C) 2015-2018 Tavian Barnes <tavianator@tavianator.com>        *
 *                                                                          *
 * Permission to use, copy, modify, and/or distribute this software for any *
 * purpose with or without fee is hereby granted.                           *
 *                                                                          *
 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES *
 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF         *
 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR  *
 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES   *
 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN    *
 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF  *
 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.           *
 ****************************************************************************/

#ifndef BFS_BFTW_H
#define BFS_BFTW_H

#include "stat.h"
#include <stddef.h>

/**
 * Possible file types.
 */
enum bftw_typeflag {
	/** Unknown type. */
	BFTW_UNKNOWN = 0,
	/** Block device. */
	BFTW_BLK     = 1 << 0,
	/** Character device. */
	BFTW_CHR     = 1 << 1,
	/** Directory. */
	BFTW_DIR     = 1 << 2,
	/** Solaris door. */
	BFTW_DOOR    = 1 << 3,
	/** Pipe. */
	BFTW_FIFO    
// SPDX-License-Identifier: GPL-2.0
/*
 * blk-integrity.c - Block layer data integrity extensions
 *
 * Copyright (C) 2007, 2008 Oracle Corporation
 * Written by: Martin K. Petersen <martin.petersen@oracle.com>
 */

#include <linux/blkdev.h>
#include <linux/backing-dev.h>
#include <linux/mempool.h>
#include <linux/bio.h>
#include <linux/scatterlist.h>
#include <linux/export.h>
#include <linux/slab.h>

#include "blk.h"

/**
 * blk_rq_count_integrity_sg - Count number of integrity scatterlist elements
 * @q:		request queue
 * @bio:	bio with integrity metadata attached
 *
 * Description: Returns the number of elements required in a
 * scatterlist corresponding to the integrity metadata in a bio.
 */
int blk_rq_count_integrity_sg(struct request_queue *q, struct bio *bio)
{
	struct bio_vec iv, ivprv = { NULL };
	unsigned int segments = 0;
	unsigned int seg_size = 0;
	struct bvec_iter iter;
	int prev = 0;

	bio_for_each_integrity_vec(iv, bio, iter) {

		if (prev) {
			if (!biovec_phys_mergeable(q, &ivprv, &iv))
				goto new_segment;
			if (seg_size + iv.bv_len > queue_max_segment_size(q))
				goto new_segment;

			seg_size += iv.bv_len;
		} else {
new_segment:
			segments++;
			seg_size = iv.bv_len;
		}

		prev = 1;
		ivprv = iv;
	}

	return segments;
}
EXPORT_SYMBOL(blk_rq_count_integrity_sg);

/**
 * blk_rq_map_integrity_sg - Map integrity metadata into a scatterlist
 * @q:		request queue
 * @bio:	bio with integrity metadata attached
 * @sglist:	target scatterlist
 *
 * Description: Map the integrity vectors in request into a
 * scatterlist.  The scatterlist must be big enough to hold all
 * elements.  I.e. sized using blk_rq_count_integrity_sg().
 */
int blk_rq_map_integrity_sg(struct request_queue *q, struct bio *bio,
			    struct scatterlist *sglist)
{
	struct bio_vec iv, ivprv = { NULL };
	struct scatterlist *sg = NULL;
	unsigned int segments = 0;
	struct bvec_iter iter;
	int prev = 0;

	bio_for_each_integrity_vec(iv, bio, iter) {

		if (prev) {
			if (!biovec_phys_mergeable(q, &ivprv, &iv))
				goto new_segment;
			if (sg->length + iv.bv_len > queue_max_segment_size(q))
				goto new_segment;

			sg->length += iv.bv_len;
		} else {
new_segment:
			if (!sg)
				sg = sglist;
			else {
				sg_unmark_end(sg);
				sg = sg_next(sg);
			}

			sg_set_page(sg, iv.bv_page, iv.bv_len, iv.bv_offset);
			segments++;
		}

		prev = 1;
		ivprv = iv;
	}

	if (sg)
		sg_mark_end(sg);

	return segments;
}
EXPORT_SYMBOL(blk_rq_map_integrity_sg);

/**
 * blk_integrity_compare - Compare integrity profile of two disks
 * @gd1:	Disk to compare
 * @gd2:	Disk to compare
 *
 * Description: Meta-devices like DM and MD need to verify that all
 * sub-devices use the same integrity format before advertising to
 * upper layers that they can send/receive integrity metadata.  This
 * function can be used to check whether two gendisk devices have
 * compatible integrity formats.
 */
int blk_integrity_compare(struct gendisk *gd1, struct gendisk *gd2)
{
	struct blk_integrity *b1 = &gd1->queue->integrity;
	struct blk_integrity *b2 = &gd2->queue->integrity;

	if (!b1->profile && !b2->profile)
		return 0;

	if (!b1->profile || !b2->profile)
		return -1;

	if (b1->interval_exp != b2->interval_exp) {
		pr_err("%s: %s/%s protection interval %u != %u\n",
		       __func__, gd1->disk_name, gd2->disk_name,
		       1 << b1->interval_exp, 1 << b2->interval_exp);
		return -1;
	}

	if (b1->tuple_size != b2->tuple_size) {
		pr_err("%s: %s/%s tuple sz %u != %u\n", __func__,
		       gd1->disk_name, gd2->disk_name,
		       b1->tuple_size, b2->tuple_size);
		return -1;
	}

	if (b1->tag_size && b2->tag_size && (b1->tag_size != b2->tag_size)) {
		pr_err("%s: %s/%s tag sz %u != %u\n", __func__,
		       gd1->disk_name, gd2->disk_name,
		       b1->tag_size, b2->tag_size);
		return -1;
	}

	if (b1->profile != b2->profile) {
		pr_err("%s: %s/%s type %s != %s\n", __func__,
		       gd1->disk_name, gd2->disk_name,
		       b1->profile->name, b2->profile->name);
		return -1;
	}

	return 0;
}
EXPORT_SYMBOL(blk_integrity_compare);

bool blk_integrity_merge_rq(struct request_queue *q, struct request *req,
			    struct request *next)
{
	if (blk_integrity_rq(req) == 0 && blk_integrity_rq(next) == 0)
		return true;

	if (blk_integrity_rq(req) == 0 || blk_integrity_rq(next) == 0)
		return false;

	if (bio_integrity(req->bio)->bip_flags !=
	    bio_integrity(next->bio)->bip_flags)
		return false;

	if (req->nr_integrity_segments + next->nr_integrity_segments >
	    q->limits.max_integrity_segments)
		return false;

	if (integrity_req_gap_back_merge(req, next->bio))
		return false;

	return true;
}
EXPORT_SYMBOL(blk_integrity_merge_rq);

bool blk_integrity_merge_bio(struct request_queue *q, struct request *req,
			     struct bio *bio)
{
	int nr_integrity_segs;
	struct bio *next = bio->bi_next;

	if (blk_integrity_rq(req) == 0 && bio_integrity(bio) == NULL)
		return true;

	if (blk_integrity_rq(req) == 0 || bio_integrity(bio) == NULL)
		return false;

	if (bio_integrity(req->bio)->bip_flags != bio_integrity(bio)->bip_flags)
		return false;

	bio->bi_next = NULL;
	nr_integrity_segs = blk_rq_count_integrity_sg(q, bio);
	bio->bi_next = next;

	if (req->nr_integrity_segments + nr_integrity_segs >
	    q->limits.max_integrity_segments)
		return false;

	req->nr_integrity_segments += nr_integrity_segs;

	return true;
}
EXPORT_SYMBOL(blk_integrity_merge_bio);

struct integrity_sysfs_entry {
	struct attribute attr;
	ssize_t (*show)(struct blk_integrity *, char *);
	ssize_t (*store)(struct blk_integrity *, const char *, size_t);
};

static ssize_t integrity_attr_show(struct kobject *kobj, struct attribute *attr,
				   char *page)
{
	struct gendisk *disk = container_of(kobj, struct gendisk, integrity_kobj);
	struct blk_integrity *bi = &disk->queue->integrity;
	struct integrity_sysfs_entry *entry =
		container_of(attr, struct integrity_sysfs_entry, attr);

	return entry->show(bi, page);
}

static ssize_t integrity_attr_store(struct kobject *kobj,
				    struct attribute *attr, const char *page,
				    size_t count)
{
	struct gendisk *disk = container_of(kobj, struct gendisk, integrity_kobj);
	struct blk_integrity *bi = &disk->queue->integrity;
	struct integrity_sysfs_entry *entry =
		container_of(attr, struct integrity_sysfs_entry, attr);
	ssize_t ret = 0;

	if (entry->store)
		ret = entry->store(bi, page, count