454 lines
12 KiB
C
454 lines
12 KiB
C
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/*
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* blk-integrity.c - Block layer data integrity extensions
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*
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* Copyright (C) 2007, 2008 Oracle Corporation
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* Written by: Martin K. Petersen <martin.petersen@oracle.com>
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License version
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* 2 as published by the Free Software Foundation.
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*
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* This program is distributed in the hope that it will be useful, but
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* WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; see the file COPYING. If not, write to
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* the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139,
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* USA.
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*
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*/
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#include <linux/blkdev.h>
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#include <linux/backing-dev.h>
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#include <linux/mempool.h>
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#include <linux/bio.h>
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#include <linux/scatterlist.h>
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#include <linux/export.h>
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#include <linux/slab.h>
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#include "blk.h"
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/**
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* blk_rq_count_integrity_sg - Count number of integrity scatterlist elements
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* @q: request queue
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* @bio: bio with integrity metadata attached
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*
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* Description: Returns the number of elements required in a
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* scatterlist corresponding to the integrity metadata in a bio.
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*/
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int blk_rq_count_integrity_sg(struct request_queue *q, struct bio *bio)
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{
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struct bio_vec iv, ivprv = { NULL };
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unsigned int segments = 0;
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unsigned int seg_size = 0;
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struct bvec_iter iter;
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int prev = 0;
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bio_for_each_integrity_vec(iv, bio, iter) {
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if (prev) {
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if (!BIOVEC_PHYS_MERGEABLE(&ivprv, &iv))
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goto new_segment;
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if (!BIOVEC_SEG_BOUNDARY(q, &ivprv, &iv))
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goto new_segment;
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if (seg_size + iv.bv_len > queue_max_segment_size(q))
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goto new_segment;
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seg_size += iv.bv_len;
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} else {
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new_segment:
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segments++;
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seg_size = iv.bv_len;
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}
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prev = 1;
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ivprv = iv;
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}
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return segments;
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}
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EXPORT_SYMBOL(blk_rq_count_integrity_sg);
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/**
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* blk_rq_map_integrity_sg - Map integrity metadata into a scatterlist
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* @q: request queue
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* @bio: bio with integrity metadata attached
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* @sglist: target scatterlist
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*
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* Description: Map the integrity vectors in request into a
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* scatterlist. The scatterlist must be big enough to hold all
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* elements. I.e. sized using blk_rq_count_integrity_sg().
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*/
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int blk_rq_map_integrity_sg(struct request_queue *q, struct bio *bio,
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struct scatterlist *sglist)
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{
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struct bio_vec iv, ivprv = { NULL };
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struct scatterlist *sg = NULL;
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unsigned int segments = 0;
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struct bvec_iter iter;
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int prev = 0;
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bio_for_each_integrity_vec(iv, bio, iter) {
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if (prev) {
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if (!BIOVEC_PHYS_MERGEABLE(&ivprv, &iv))
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goto new_segment;
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if (!BIOVEC_SEG_BOUNDARY(q, &ivprv, &iv))
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goto new_segment;
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if (sg->length + iv.bv_len > queue_max_segment_size(q))
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goto new_segment;
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sg->length += iv.bv_len;
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} else {
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new_segment:
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if (!sg)
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sg = sglist;
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else {
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sg_unmark_end(sg);
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sg = sg_next(sg);
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}
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sg_set_page(sg, iv.bv_page, iv.bv_len, iv.bv_offset);
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segments++;
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}
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prev = 1;
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ivprv = iv;
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}
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if (sg)
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sg_mark_end(sg);
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return segments;
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}
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EXPORT_SYMBOL(blk_rq_map_integrity_sg);
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/**
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* blk_integrity_compare - Compare integrity profile of two disks
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* @gd1: Disk to compare
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* @gd2: Disk to compare
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*
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* Description: Meta-devices like DM and MD need to verify that all
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* sub-devices use the same integrity format before advertising to
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* upper layers that they can send/receive integrity metadata. This
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* function can be used to check whether two gendisk devices have
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* compatible integrity formats.
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*/
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int blk_integrity_compare(struct gendisk *gd1, struct gendisk *gd2)
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{
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struct blk_integrity *b1 = &gd1->queue->integrity;
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struct blk_integrity *b2 = &gd2->queue->integrity;
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if (!b1->profile && !b2->profile)
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return 0;
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if (!b1->profile || !b2->profile)
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return -1;
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if (b1->interval_exp != b2->interval_exp) {
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pr_err("%s: %s/%s protection interval %u != %u\n",
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__func__, gd1->disk_name, gd2->disk_name,
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1 << b1->interval_exp, 1 << b2->interval_exp);
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return -1;
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}
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if (b1->tuple_size != b2->tuple_size) {
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pr_err("%s: %s/%s tuple sz %u != %u\n", __func__,
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gd1->disk_name, gd2->disk_name,
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b1->tuple_size, b2->tuple_size);
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return -1;
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}
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if (b1->tag_size && b2->tag_size && (b1->tag_size != b2->tag_size)) {
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pr_err("%s: %s/%s tag sz %u != %u\n", __func__,
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gd1->disk_name, gd2->disk_name,
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b1->tag_size, b2->tag_size);
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return -1;
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}
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if (b1->profile != b2->profile) {
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pr_err("%s: %s/%s type %s != %s\n", __func__,
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gd1->disk_name, gd2->disk_name,
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b1->profile->name, b2->profile->name);
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return -1;
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}
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return 0;
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}
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EXPORT_SYMBOL(blk_integrity_compare);
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bool blk_integrity_merge_rq(struct request_queue *q, struct request *req,
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struct request *next)
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{
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if (blk_integrity_rq(req) == 0 && blk_integrity_rq(next) == 0)
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return true;
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if (blk_integrity_rq(req) == 0 || blk_integrity_rq(next) == 0)
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return false;
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if (bio_integrity(req->bio)->bip_flags !=
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bio_integrity(next->bio)->bip_flags)
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return false;
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if (req->nr_integrity_segments + next->nr_integrity_segments >
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q->limits.max_integrity_segments)
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return false;
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if (integrity_req_gap_back_merge(req, next->bio))
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return false;
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return true;
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}
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EXPORT_SYMBOL(blk_integrity_merge_rq);
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bool blk_integrity_merge_bio(struct request_queue *q, struct request *req,
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struct bio *bio)
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{
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int nr_integrity_segs;
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struct bio *next = bio->bi_next;
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if (blk_integrity_rq(req) == 0 && bio_integrity(bio) == NULL)
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return true;
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if (blk_integrity_rq(req) == 0 || bio_integrity(bio) == NULL)
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return false;
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if (bio_integrity(req->bio)->bip_flags != bio_integrity(bio)->bip_flags)
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return false;
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bio->bi_next = NULL;
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nr_integrity_segs = blk_rq_count_integrity_sg(q, bio);
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bio->bi_next = next;
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if (req->nr_integrity_segments + nr_integrity_segs >
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q->limits.max_integrity_segments)
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return false;
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req->nr_integrity_segments += nr_integrity_segs;
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return true;
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}
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EXPORT_SYMBOL(blk_integrity_merge_bio);
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struct integrity_sysfs_entry {
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struct attribute attr;
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ssize_t (*show)(struct blk_integrity *, char *);
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ssize_t (*store)(struct blk_integrity *, const char *, size_t);
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};
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static ssize_t integrity_attr_show(struct kobject *kobj, struct attribute *attr,
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char *page)
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{
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struct gendisk *disk = container_of(kobj, struct gendisk, integrity_kobj);
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struct blk_integrity *bi = &disk->queue->integrity;
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struct integrity_sysfs_entry *entry =
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container_of(attr, struct integrity_sysfs_entry, attr);
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return entry->show(bi, page);
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}
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static ssize_t integrity_attr_store(struct kobject *kobj,
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struct attribute *attr, const char *page,
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size_t count)
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{
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struct gendisk *disk = container_of(kobj, struct gendisk, integrity_kobj);
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struct blk_integrity *bi = &disk->queue->integrity;
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struct integrity_sysfs_entry *entry =
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container_of(attr, struct integrity_sysfs_entry, attr);
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ssize_t ret = 0;
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if (entry->store)
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ret = entry->store(bi, page, count);
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return ret;
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}
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static ssize_t integrity_format_show(struct blk_integrity *bi, char *page)
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{
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if (bi->profile && bi->profile->name)
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return sprintf(page, "%s\n", bi->profile->name);
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else
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return sprintf(page, "none\n");
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}
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static ssize_t integrity_tag_size_show(struct blk_integrity *bi, char *page)
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{
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return sprintf(page, "%u\n", bi->tag_size);
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}
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static ssize_t integrity_interval_show(struct blk_integrity *bi, char *page)
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{
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return sprintf(page, "%u\n",
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bi->interval_exp ? 1 << bi->interval_exp : 0);
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}
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static ssize_t integrity_verify_store(struct blk_integrity *bi,
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const char *page, size_t count)
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{
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char *p = (char *) page;
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unsigned long val = simple_strtoul(p, &p, 10);
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if (val)
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bi->flags |= BLK_INTEGRITY_VERIFY;
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else
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bi->flags &= ~BLK_INTEGRITY_VERIFY;
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return count;
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}
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static ssize_t integrity_verify_show(struct blk_integrity *bi, char *page)
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{
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return sprintf(page, "%d\n", (bi->flags & BLK_INTEGRITY_VERIFY) != 0);
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}
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static ssize_t integrity_generate_store(struct blk_integrity *bi,
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const char *page, size_t count)
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{
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char *p = (char *) page;
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unsigned long val = simple_strtoul(p, &p, 10);
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if (val)
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bi->flags |= BLK_INTEGRITY_GENERATE;
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else
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bi->flags &= ~BLK_INTEGRITY_GENERATE;
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return count;
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}
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static ssize_t integrity_generate_show(struct blk_integrity *bi, char *page)
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{
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return sprintf(page, "%d\n", (bi->flags & BLK_INTEGRITY_GENERATE) != 0);
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}
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static ssize_t integrity_device_show(struct blk_integrity *bi, char *page)
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{
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return sprintf(page, "%u\n",
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(bi->flags & BLK_INTEGRITY_DEVICE_CAPABLE) != 0);
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}
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static struct integrity_sysfs_entry integrity_format_entry = {
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.attr = { .name = "format", .mode = S_IRUGO },
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.show = integrity_format_show,
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};
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static struct integrity_sysfs_entry integrity_tag_size_entry = {
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.attr = { .name = "tag_size", .mode = S_IRUGO },
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.show = integrity_tag_size_show,
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};
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static struct integrity_sysfs_entry integrity_interval_entry = {
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.attr = { .name = "protection_interval_bytes", .mode = S_IRUGO },
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.show = integrity_interval_show,
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};
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static struct integrity_sysfs_entry integrity_verify_entry = {
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.attr = { .name = "read_verify", .mode = S_IRUGO | S_IWUSR },
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.show = integrity_verify_show,
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.store = integrity_verify_store,
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};
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static struct integrity_sysfs_entry integrity_generate_entry = {
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.attr = { .name = "write_generate", .mode = S_IRUGO | S_IWUSR },
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.show = integrity_generate_show,
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.store = integrity_generate_store,
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};
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static struct integrity_sysfs_entry integrity_device_entry = {
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.attr = { .name = "device_is_integrity_capable", .mode = S_IRUGO },
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.show = integrity_device_show,
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};
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static struct attribute *integrity_attrs[] = {
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&integrity_format_entry.attr,
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&integrity_tag_size_entry.attr,
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&integrity_interval_entry.attr,
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&integrity_verify_entry.attr,
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&integrity_generate_entry.attr,
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|
|
&integrity_device_entry.attr,
|
||
|
|
NULL,
|
||
|
|
};
|
||
|
|
|
||
|
|
static const struct sysfs_ops integrity_ops = {
|
||
|
|
.show = &integrity_attr_show,
|
||
|
|
.store = &integrity_attr_store,
|
||
|
|
};
|
||
|
|
|
||
|
|
static struct kobj_type integrity_ktype = {
|
||
|
|
.default_attrs = integrity_attrs,
|
||
|
|
.sysfs_ops = &integrity_ops,
|
||
|
|
};
|
||
|
|
|
||
|
|
static blk_status_t blk_integrity_nop_fn(struct blk_integrity_iter *iter)
|
||
|
|
{
|
||
|
|
return BLK_STS_OK;
|
||
|
|
}
|
||
|
|
|
||
|
|
static const struct blk_integrity_profile nop_profile = {
|
||
|
|
.name = "nop",
|
||
|
|
.generate_fn = blk_integrity_nop_fn,
|
||
|
|
.verify_fn = blk_integrity_nop_fn,
|
||
|
|
};
|
||
|
|
|
||
|
|
/**
|
||
|
|
* blk_integrity_register - Register a gendisk as being integrity-capable
|
||
|
|
* @disk: struct gendisk pointer to make integrity-aware
|
||
|
|
* @template: block integrity profile to register
|
||
|
|
*
|
||
|
|
* Description: When a device needs to advertise itself as being able to
|
||
|
|
* send/receive integrity metadata it must use this function to register
|
||
|
|
* the capability with the block layer. The template is a blk_integrity
|
||
|
|
* struct with values appropriate for the underlying hardware. See
|
||
|
|
* Documentation/block/data-integrity.txt.
|
||
|
|
*/
|
||
|
|
void blk_integrity_register(struct gendisk *disk, struct blk_integrity *template)
|
||
|
|
{
|
||
|
|
struct blk_integrity *bi = &disk->queue->integrity;
|
||
|
|
|
||
|
|
bi->flags = BLK_INTEGRITY_VERIFY | BLK_INTEGRITY_GENERATE |
|
||
|
|
template->flags;
|
||
|
|
bi->interval_exp = template->interval_exp ? :
|
||
|
|
ilog2(queue_logical_block_size(disk->queue));
|
||
|
|
bi->profile = template->profile ? template->profile : &nop_profile;
|
||
|
|
bi->tuple_size = template->tuple_size;
|
||
|
|
bi->tag_size = template->tag_size;
|
||
|
|
|
||
|
|
disk->queue->backing_dev_info->capabilities |= BDI_CAP_STABLE_WRITES;
|
||
|
|
}
|
||
|
|
EXPORT_SYMBOL(blk_integrity_register);
|
||
|
|
|
||
|
|
/**
|
||
|
|
* blk_integrity_unregister - Unregister block integrity profile
|
||
|
|
* @disk: disk whose integrity profile to unregister
|
||
|
|
*
|
||
|
|
* Description: This function unregisters the integrity capability from
|
||
|
|
* a block device.
|
||
|
|
*/
|
||
|
|
void blk_integrity_unregister(struct gendisk *disk)
|
||
|
|
{
|
||
|
|
disk->queue->backing_dev_info->capabilities &= ~BDI_CAP_STABLE_WRITES;
|
||
|
|
memset(&disk->queue->integrity, 0, sizeof(struct blk_integrity));
|
||
|
|
}
|
||
|
|
EXPORT_SYMBOL(blk_integrity_unregister);
|
||
|
|
|
||
|
|
void blk_integrity_add(struct gendisk *disk)
|
||
|
|
{
|
||
|
|
if (kobject_init_and_add(&disk->integrity_kobj, &integrity_ktype,
|
||
|
|
&disk_to_dev(disk)->kobj, "%s", "integrity"))
|
||
|
|
return;
|
||
|
|
|
||
|
|
kobject_uevent(&disk->integrity_kobj, KOBJ_ADD);
|
||
|
|
}
|
||
|
|
|
||
|
|
void blk_integrity_del(struct gendisk *disk)
|
||
|
|
{
|
||
|
|
kobject_uevent(&disk->integrity_kobj, KOBJ_REMOVE);
|
||
|
|
kobject_del(&disk->integrity_kobj);
|
||
|
|
kobject_put(&disk->integrity_kobj);
|
||
|
|
}
|