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Diffstat (limited to '')
| -rw-r--r-- | block/blk-integrity.c | 404 |
1 files changed, 404 insertions, 0 deletions
diff --git a/block/blk-integrity.c b/block/blk-integrity.c new file mode 100644 index 0000000000..d4e9b4556d --- /dev/null +++ b/block/blk-integrity.c @@ -0,0 +1,404 @@ +// 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/blk-integrity.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; +} + +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; +} + +static inline struct blk_integrity *dev_to_bi(struct device *dev) +{ + return &dev_to_disk(dev)->queue->integrity; +} + +static ssize_t format_show(struct device *dev, struct device_attribute *attr, + char *page) +{ + struct blk_integrity *bi = dev_to_bi(dev); + + if (bi->profile && bi->profile->name) + return sysfs_emit(page, "%s\n", bi->profile->name); + return sysfs_emit(page, "none\n"); +} + +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) +{ + struct blk_integrity *bi = dev_to_bi(dev); + char *p = (char *) page; + unsigned long val = simple_strtoul(p, &p, 10); + + if (val) + bi->flags |= BLK_INTEGRITY_VERIFY; + else + bi->flags &= ~BLK_INTEGRITY_VERIFY; + + return count; +} + +static ssize_t read_verify_show(struct device *dev, + struct device_attribute *attr, char *page) +{ + struct blk_integrity *bi = dev_to_bi(dev); + + return sysfs_emit(page, "%d\n", !!(bi->flags & BLK_INTEGRITY_VERIFY)); +} + +static ssize_t write_generate_store(struct device *dev, + struct device_attribute *attr, + const char *page, size_t count) +{ + struct blk_integrity *bi = dev_to_bi(dev); + + char *p = (char *) page; + unsigned long val = simple_strtoul(p, &p, 10); + + if (val) + bi->flags |= BLK_INTEGRITY_GENERATE; + else + bi->flags &= ~BLK_INTEGRITY_GENERATE; + + return count; +} + +static ssize_t write_generate_show(struct device *dev, + struct device_attribute *attr, char *page) +{ + struct blk_integrity *bi = dev_to_bi(dev); + + return sysfs_emit(page, "%d\n", !!(bi->flags & BLK_INTEGRITY_GENERATE)); +} + +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, +}; + +static blk_status_t blk_integrity_nop_fn(struct blk_integrity_iter *iter) +{ + return BLK_STS_OK; +} + +static void blk_integrity_nop_prepare(struct request *rq) +{ +} + +static void blk_integrity_nop_complete(struct request *rq, + unsigned int nr_bytes) +{ +} + +static const struct blk_integrity_profile nop_profile = { + .name = "nop", + .generate_fn = blk_integrity_nop_fn, + .verify_fn = blk_integrity_nop_fn, + .prepare_fn = blk_integrity_nop_prepare, + .complete_fn = blk_integrity_nop_complete, +}; + +/** + * 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.rst. + */ +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; + + blk_queue_flag_set(QUEUE_FLAG_STABLE_WRITES, disk->queue); + +#ifdef CONFIG_BLK_INLINE_ENCRYPTION + if (disk->queue->crypto_profile) { + pr_warn("blk-integrity: Integrity and hardware inline encryption are not supported together. Disabling hardware inline encryption.\n"); + disk->queue->crypto_profile = NULL; + } +#endif +} +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) +{ + struct blk_integrity *bi = &disk->queue->integrity; + + if (!bi->profile) + return; + + /* ensure all bios are off the integrity workqueue */ + blk_flush_integrity(); + blk_queue_flag_clear(QUEUE_FLAG_STABLE_WRITES, disk->queue); + memset(bi, 0, sizeof(*bi)); +} +EXPORT_SYMBOL(blk_integrity_unregister); |