1 files changed, 457 insertions, 0 deletions
diff --git a/block/blk-integrity.c b/block/blk-integrity.c
new file mode 100644
index 000000000..69eed260a
--- /dev/null
+++ b/block/blk-integrity.c
@@ -0,0 +1,457 @@
+// 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;
+}
+
+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);
+
+	return ret;
+}
+
+static ssize_t integrity_format_show(struct blk_integrity *bi, char *page)
+{
+	if (bi->profile && bi->profile->name)
+		return sprintf(page, "%s\n", bi->profile->name);
+	else
+		return sprintf(page, "none\n");
+}
+
+static ssize_t integrity_tag_size_show(struct blk_integrity *bi, char *page)
+{
+	return sprintf(page, "%u\n", bi->tag_size);
+}
+
+static ssize_t integrity_interval_show(struct blk_integrity *bi, char *page)
+{
+	return sprintf(page, "%u\n",
+		       bi->interval_exp ? 1 << bi->interval_exp : 0);
+}
+
+static ssize_t integrity_verify_store(struct blk_integrity *bi,
+				      const char *page, size_t count)
+{
+	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 integrity_verify_show(struct blk_integrity *bi, char *page)
+{
+	return sprintf(page, "%d\n", (bi->flags & BLK_INTEGRITY_VERIFY) != 0);
+}
+
+static ssize_t integrity_generate_store(struct blk_integrity *bi,
+					const char *page, size_t count)
+{
+	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 integrity_generate_show(struct blk_integrity *bi, char *page)
+{
+	return sprintf(page, "%d\n", (bi->flags & BLK_INTEGRITY_GENERATE) != 0);
+}
+
+static ssize_t integrity_device_show(struct blk_integrity *bi, char *page)
+{
+	return sprintf(page, "%u\n",
+		       (bi->flags & BLK_INTEGRITY_DEVICE_CAPABLE) != 0);
+}
+
+static struct integrity_sysfs_entry integrity_format_entry = {
+	.attr = { .name = "format", .mode = 0444 },
+	.show = integrity_format_show,
+};
+
+static struct integrity_sysfs_entry integrity_tag_size_entry = {
+	.attr = { .name = "tag_size", .mode = 0444 },
+	.show = integrity_tag_size_show,
+};
+
+static struct integrity_sysfs_entry integrity_interval_entry = {
+	.attr = { .name = "protection_interval_bytes", .mode = 0444 },
+	.show = integrity_interval_show,
+};
+
+static struct integrity_sysfs_entry integrity_verify_entry = {
+	.attr = { .name = "read_verify", .mode = 0644 },
+	.show = integrity_verify_show,
+	.store = integrity_verify_store,
+};
+
+static struct integrity_sysfs_entry integrity_generate_entry = {
+	.attr = { .name = "write_generate", .mode = 0644 },
+	.show = integrity_generate_show,
+	.store = integrity_generate_store,
+};
+
+static struct integrity_sysfs_entry integrity_device_entry = {
+	.attr = { .name = "device_is_integrity_capable", .mode = 0444 },
+	.show = integrity_device_show,
+};
+
+static struct attribute *integrity_attrs[] = {
+	&integrity_format_entry.attr,
+	&integrity_tag_size_entry.attr,
+	&integrity_interval_entry.attr,
+	&integrity_verify_entry.attr,
+	&integrity_generate_entry.attr,
+	&integrity_device_entry.attr,
+	NULL,
+};
+ATTRIBUTE_GROUPS(integrity);
+
+static const struct sysfs_ops integrity_ops = {
+	.show	= &integrity_attr_show,
+	.store	= &integrity_attr_store,
+};
+
+static struct kobj_type integrity_ktype = {
+	.default_groups = integrity_groups,
+	.sysfs_ops	= &integrity_ops,
+};
+
+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);
+
+int blk_integrity_add(struct gendisk *disk)
+{
+	int ret;
+
+	ret = kobject_init_and_add(&disk->integrity_kobj, &integrity_ktype,
+				   &disk_to_dev(disk)->kobj, "%s", "integrity");
+	if (!ret)
+		kobject_uevent(&disk->integrity_kobj, KOBJ_ADD);
+	return ret;
+}
+
+void blk_integrity_del(struct gendisk *disk)
+{
+	kobject_uevent(&disk->integrity_kobj, KOBJ_REMOVE);
+	kobject_del(&disk->integrity_kobj);
+	kobject_put(&disk->integrity_kobj);
+}