/* * blk-integrity.c - Block layer data integrity extensions * * Copyright (C) 2007, 2008 Oracle Corporation * Written by: Martin K. Petersen * * This program is free software; you can redistribute it and/or * modify it under the terms of the GNU General Public License version * 2 as published by the Free Software Foundation. * * This program is distributed in the hope that it will be useful, but * WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program; see the file COPYING. If not, write to * the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, * USA. * */ #include #include #include #include #include #include #include "blk.h" static struct kmem_cache *integrity_cachep; static const char *bi_unsupported_name = "unsupported"; /** * 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; unsigned int i = 0; bio_for_each_integrity_vec(iv, bio, i) { if (ivprv) { if (!BIOVEC_PHYS_MERGEABLE(ivprv, iv)) goto new_segment; if (!BIOVEC_SEG_BOUNDARY(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; } 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; unsigned int i = 0; bio_for_each_integrity_vec(iv, bio, i) { if (ivprv) { if (!BIOVEC_PHYS_MERGEABLE(ivprv, iv)) goto new_segment; if (!BIOVEC_SEG_BOUNDARY(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->page_link &= ~0x02; sg = sg_next(sg); } sg_set_page(sg, iv->bv_page, iv->bv_len, iv->bv_offset); segments++; } 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->integrity; struct blk_integrity *b2 = gd2->integrity; if (!b1 && !b2) return 0; if (!b1 || !b2) return -1; if (b1->sector_size != b2->sector_size) { printk(KERN_ERR "%s: %s/%s sector sz %u != %u\n", __func__, gd1->disk_name, gd2->disk_name, b1->sector_size, b2->sector_size); return -1; } if (b1->tuple_size != b2->tuple_size) { printk(KERN_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)) { printk(KERN_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 (strcmp(b1->name, b2->name)) { printk(KERN_ERR "%s: %s/%s type %s != %s\n", __func__, gd1->disk_name, gd2->disk_name, b1->name, b2->name); return -1; } return 0; } EXPORT_SYMBOL(blk_integrity_compare); int blk_integrity_merge_rq(struct request_queue *q, struct request *req, struct request *next) { if (blk_integrity_rq(req) != blk_integrity_rq(next)) return -1; if (req->nr_integrity_segments + next->nr_integrity_segments > q->limits.max_integrity_segments) return -1;