// 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 */ #include #include #include #include #include #include #include #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; } /** * 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() or * rq->nr_integrity_segments. */ int blk_rq_map_integrity_sg(struct request *rq, struct scatterlist *sglist) { struct bio_vec iv, ivprv = { NULL }; struct request_queue *q = rq->q; struct scatterlist *sg = NULL; struct bio *bio = rq->bio; 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); /* * Something must have been wrong if the figured number of segment * is bigger than number of req's physical integrity segments */ BUG_ON(segments > rq->nr_integrity_segments); BUG_ON(segments > queue_max_integrity_segments(q)); return segments; } EXPORT_SYMBOL(blk_rq_map_integrity_sg); int blk_rq_integrity_map_user(struct request *rq, void __user *ubuf, ssize_t bytes, u32 seed) { int ret = bio_integrity_map_user(rq->bio, ubuf, bytes, seed); if (ret) return ret; rq->nr_integrity_segments = blk_rq_count_integrity_sg(rq->q, rq->bio); rq->cmd_flags |= REQ_INTEGRITY; return 0; } EXPORT_SYMBOL_GPL(blk_rq_integrity_map_user); 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; } bool blk_integrity_merge_bio(struct request_queue *q, struct request *req, struct bio *bio) { int nr_integrity_segs; 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; nr_integrity_segs = blk_rq_count_integrity_sg(q, bio); if (req->nr_integrity_segments + nr_integrity_segs > q->limits.max_integrity_segments) return false; return true; } static inline struct blk_integrity *dev_to_bi(struct device *dev) { return &dev_to_disk(dev)->queue->limits.integrity; } const char *blk_integrity_profile_name(struct blk_integrity *bi) { switch (bi->csum_type) { case BLK_INTEGRITY_CSUM_IP: if (bi->flags & BLK_INTEGRITY_REF_TAG) return "T10-DIF-TYPE1-IP"; return "T10-DIF-TYPE3-IP"; case BLK_INTEGRITY_CSUM_CRC: if (bi->flags & BLK_INTEGRITY_REF_TAG) return "T10-DIF-TYPE1-CRC"; return "T10-DIF-TYPE3-CRC"; case BLK_INTEGRITY_CSUM_CRC64: if (bi->flags & BLK_INTEGRITY_REF_TAG) return "EXT-DIF-TYPE1-CRC64"; return "EXT-DIF-TYPE3-CRC64"; case BLK_INTEGRITY_CSUM_NONE: break; } return "nop"; } EXPORT_SYMBOL_GPL(blk_integrity_profile_name); static ssize_t flag_store(struct device *dev, const char *page, size_t count, unsigned char flag) { struct request_queue *q = dev_to_disk(dev)->queue; struct queue_limits lim; unsigned long val; int err; err = kstrtoul(page, 10, &val); if (err) return err; /* note that the flags are inverted vs the values in the sysfs files */ lim = queue_limits_start_update(q); if (val) lim.integrity.flags &= ~flag; else lim.integrity.flags |= flag; blk_mq_freeze_queue(q); err = queue_limits_commit_update(q, &lim); blk_mq_unfreeze_queue(q); if (err) return err; return count; } static ssize_t flag_show(struct device *dev, char *page, unsigned char flag) { struct blk_integrity *bi = dev_to_bi(dev); return sysfs_emit(page, "%d\n", !(bi->flags & flag)); } static ssize_t format_show(struct device *dev, struct device_attribute *attr, char *page) { struct blk_integrity *bi = dev_to_bi(dev); if (!bi->tuple_size) return sysfs_emit(page, "none\n"); return sysfs_emit(page, "%s\n", blk_integrity_profile_name(bi)); } static ssize_t tag_size_show(struct device *dev, struct device_attribute *attr, char *page) { struct blk_integrity *bi = dev_to_bi(dev); return sysfs_emit(page, "%u\n", bi->tag_size); } static ssize_t protection_interval_bytes_show(struct device *dev, struct device_attribute *attr, char *page) { struct blk_integrity *bi = dev_to_bi(dev); return sysfs_emit(page, "%u\n", bi->interval_exp ? 1 << bi->interval_exp : 0); } static ssize_t read_verify_store(struct device *dev, struct device_attribute *attr, const char *page, size_t count) { return flag_store(dev, page, count, BLK_INTEGRITY_NOVERIFY); } static ssize_t read_verify_show(struct device *dev, struct device_attribute *attr, char *page) { return flag_show(dev, page, BLK_INTEGRITY_NOVERIFY); } static ssize_t write_generate_store(struct device *dev, struct device_attribute *attr, const char *page, size_t count) { return flag_store(dev, page, count, BLK_INTEGRITY_NOGENERATE); } static ssize_t write_generate_show(struct device *dev, struct device_attribute *attr, char *page) { return flag_show(dev, page, BLK_INTEGRITY_NOGENERATE); } static ssize_t device_is_integrity_capable_show(struct device *dev, struct device_attribute *attr, char *page) { struct blk_integrity *bi = dev_to_bi(dev); return sysfs_emit(page, "%u\n", !!(bi->flags & BLK_INTEGRITY_DEVICE_CAPABLE)); } static DEVICE_ATTR_RO(format); static DEVICE_ATTR_RO(tag_size); static DEVICE_ATTR_RO(protection_interval_bytes); static DEVICE_ATTR_RW(read_verify); static DEVICE_ATTR_RW(write_generate); static DEVICE_ATTR_RO(device_is_integrity_capable); static struct attribute *integrity_attrs[] = { &dev_attr_format.attr, &dev_attr_tag_size.attr, &dev_attr_protection_interval_bytes.attr, &dev_attr_read_verify.attr, &dev_attr_write_generate.attr, &dev_attr_device_is_integrity_capable.attr, NULL }; const struct attribute_group blk_integrity_attr_group = { .name = "integrity", .attrs = integrity_attrs, };