block/bio-integrity.c - linux - Git at Google

 // SPDX-License-Identifier: GPL-2.0
 /*
  * bio-integrity.c - bio data integrity extensions
  *
  * Copyright (C) 2007, 2008, 2009 Oracle Corporation
  * Written by: Martin K. Petersen <martin.petersen@oracle.com>
  */

 #include <linux/blk-integrity.h>
 #include <linux/mempool.h>
 #include <linux/export.h>
 #include <linux/bio.h>
 #include <linux/workqueue.h>
 #include <linux/slab.h>
 #include "blk.h"

 static struct kmem_cache *bip_slab;
 static struct workqueue_struct *kintegrityd_wq;

 void blk_flush_integrity(void)
 {
 	flush_workqueue(kintegrityd_wq);
 }

 /**
  * bio_integrity_free - Free bio integrity payload
  * @bio:	bio containing bip to be freed
  *
  * Description: Free the integrity portion of a bio.
  */
 void bio_integrity_free(struct bio *bio)
 {
 	struct bio_integrity_payload *bip = bio_integrity(bio);
 	struct bio_set *bs = bio->bi_pool;

 	if (bs && mempool_initialized(&bs->bio_integrity_pool)) {
 		if (bip->bip_vec)
 			bvec_free(&bs->bvec_integrity_pool, bip->bip_vec,
 				  bip->bip_max_vcnt);
 		mempool_free(bip, &bs->bio_integrity_pool);
 	} else {
 		kfree(bip);
 	}
 	bio->bi_integrity = NULL;
 	bio->bi_opf &= ~REQ_INTEGRITY;
 }

 /**
  * bio_integrity_alloc - Allocate integrity payload and attach it to bio
  * @bio:	bio to attach integrity metadata to
  * @gfp_mask:	Memory allocation mask
  * @nr_vecs:	Number of integrity metadata scatter-gather elements
  *
  * Description: This function prepares a bio for attaching integrity
  * metadata.  nr_vecs specifies the maximum number of pages containing
  * integrity metadata that can be attached.
  */
 struct bio_integrity_payload *bio_integrity_alloc(struct bio *bio,
 						  gfp_t gfp_mask,
 						  unsigned int nr_vecs)
 {
 	struct bio_integrity_payload *bip;
 	struct bio_set *bs = bio->bi_pool;
 	unsigned inline_vecs;

 	if (WARN_ON_ONCE(bio_has_crypt_ctx(bio)))
 		return ERR_PTR(-EOPNOTSUPP);

 	if (!bs || !mempool_initialized(&bs->bio_integrity_pool)) {
 		bip = kmalloc(struct_size(bip, bip_inline_vecs, nr_vecs), gfp_mask);
 		inline_vecs = nr_vecs;
 	} else {
 		bip = mempool_alloc(&bs->bio_integrity_pool, gfp_mask);
 		inline_vecs = BIO_INLINE_VECS;
 	}

 	if (unlikely(!bip))
 		return ERR_PTR(-ENOMEM);

 	memset(bip, 0, sizeof(*bip));

 	/* always report as many vecs as asked explicitly, not inline vecs */
 	bip->bip_max_vcnt = nr_vecs;
 	if (nr_vecs > inline_vecs) {
 		bip->bip_vec = bvec_alloc(&bs->bvec_integrity_pool,
 					  &bip->bip_max_vcnt, gfp_mask);
 		if (!bip->bip_vec)
 			goto err;
 	} else if (nr_vecs) {
 		bip->bip_vec = bip->bip_inline_vecs;
 	}

 	bip->bip_bio = bio;
 	bio->bi_integrity = bip;
 	bio->bi_opf |= REQ_INTEGRITY;

 	return bip;
 err:
 	if (bs && mempool_initialized(&bs->bio_integrity_pool))
 		mempool_free(bip, &bs->bio_integrity_pool);
 	else
 		kfree(bip);
 	return ERR_PTR(-ENOMEM);
 }
 EXPORT_SYMBOL(bio_integrity_alloc);

 static void bio_integrity_unpin_bvec(struct bio_vec *bv, int nr_vecs,
 				     bool dirty)
 {
 	int i;

 	for (i = 0; i < nr_vecs; i++) {
 		if (dirty && !PageCompound(bv[i].bv_page))
 			set_page_dirty_lock(bv[i].bv_page);
 		unpin_user_page(bv[i].bv_page);
 	}
 }

 static void bio_integrity_uncopy_user(struct bio_integrity_payload *bip)
 {
 	unsigned short nr_vecs = bip->bip_max_vcnt - 1;
 	struct bio_vec *copy = &bip->bip_vec[1];
 	size_t bytes = bip->bip_iter.bi_size;
 	struct iov_iter iter;
 	int ret;

 	iov_iter_bvec(&iter, ITER_DEST, copy, nr_vecs, bytes);
 	ret = copy_to_iter(bvec_virt(bip->bip_vec), bytes, &iter);
 	WARN_ON_ONCE(ret != bytes);

 	bio_integrity_unpin_bvec(copy, nr_vecs, true);
 }

 /**
  * bio_integrity_unmap_user - Unmap user integrity payload
  * @bio:	bio containing bip to be unmapped
  *
  * Unmap the user mapped integrity portion of a bio.
  */
 void bio_integrity_unmap_user(struct bio *bio)
 {
 	struct bio_integrity_payload *bip = bio_integrity(bio);

 	if (bip->bip_flags & BIP_COPY_USER) {
 		if (bio_data_dir(bio) == READ)
 			bio_integrity_uncopy_user(bip);
 		kfree(bvec_virt(bip->bip_vec));
 		return;
 	}

 	bio_integrity_unpin_bvec(bip->bip_vec, bip->bip_max_vcnt,
 			bio_data_dir(bio) == READ);
 }

 /**
  * bio_integrity_add_page - Attach integrity metadata
  * @bio:	bio to update
  * @page:	page containing integrity metadata
  * @len:	number of bytes of integrity metadata in page
  * @offset:	start offset within page
  *
  * Description: Attach a page containing integrity metadata to bio.
  */
 int bio_integrity_add_page(struct bio *bio, struct page *page,
 			   unsigned int len, unsigned int offset)
 {
 	struct request_queue *q = bdev_get_queue(bio->bi_bdev);
 	struct bio_integrity_payload *bip = bio_integrity(bio);

 	if (((bip->bip_iter.bi_size + len) >> SECTOR_SHIFT) >
 	    queue_max_hw_sectors(q))
 		return 0;

 	if (bip->bip_vcnt > 0) {
 		struct bio_vec *bv = &bip->bip_vec[bip->bip_vcnt - 1];
 		bool same_page = false;

 		if (bvec_try_merge_hw_page(q, bv, page, len, offset,
 					   &same_page)) {
 			bip->bip_iter.bi_size += len;
 			return len;
 		}

 		if (bip->bip_vcnt >=
 		    min(bip->bip_max_vcnt, queue_max_integrity_segments(q)))
 			return 0;

 		/*
 		 * If the queue doesn't support SG gaps and adding this segment
 		 * would create a gap, disallow it.
 		 */
 		if (bvec_gap_to_prev(&q->limits, bv, offset))
 			return 0;
 	}

 	bvec_set_page(&bip->bip_vec[bip->bip_vcnt], page, len, offset);
 	bip->bip_vcnt++;
 	bip->bip_iter.bi_size += len;

 	return len;
 }
 EXPORT_SYMBOL(bio_integrity_add_page);

 static int bio_integrity_copy_user(struct bio *bio, struct bio_vec *bvec,
 				   int nr_vecs, unsigned int len,
 				   unsigned int direction, u32 seed)
 {
 	bool write = direction == ITER_SOURCE;
 	struct bio_integrity_payload *bip;
 	struct iov_iter iter;
 	void *buf;
 	int ret;

 	buf = kmalloc(len, GFP_KERNEL);
 	if (!buf)
 		return -ENOMEM;

 	if (write) {
 		iov_iter_bvec(&iter, direction, bvec, nr_vecs, len);
 		if (!copy_from_iter_full(buf, len, &iter)) {
 			ret = -EFAULT;
 			goto free_buf;
 		}

 		bip = bio_integrity_alloc(bio, GFP_KERNEL, 1);
 	} else {
 		memset(buf, 0, len);

 		/*
 		 * We need to preserve the original bvec and the number of vecs
 		 * in it for completion handling
 		 */
 		bip = bio_integrity_alloc(bio, GFP_KERNEL, nr_vecs + 1);
 	}

 	if (IS_ERR(bip)) {
 		ret = PTR_ERR(bip);
 		goto free_buf;
 	}

 	if (write)
 		bio_integrity_unpin_bvec(bvec, nr_vecs, false);
 	else
 		memcpy(&bip->bip_vec[1], bvec, nr_vecs * sizeof(*bvec));

 	ret = bio_integrity_add_page(bio, virt_to_page(buf), len,
 				     offset_in_page(buf));
 	if (ret != len) {
 		ret = -ENOMEM;
 		goto free_bip;
 	}

 	bip->bip_flags |= BIP_COPY_USER;
 	bip->bip_iter.bi_sector = seed;
 	bip->bip_vcnt = nr_vecs;
 	return 0;
 free_bip:
 	bio_integrity_free(bio);
 free_buf:
 	kfree(buf);
 	return ret;
 }

 static int bio_integrity_init_user(struct bio *bio, struct bio_vec *bvec,
 				   int nr_vecs, unsigned int len, u32 seed)
 {
 	struct bio_integrity_payload *bip;

 	bip = bio_integrity_alloc(bio, GFP_KERNEL, nr_vecs);
 	if (IS_ERR(bip))
 		return PTR_ERR(bip);

 	memcpy(bip->bip_vec, bvec, nr_vecs * sizeof(*bvec));
 	bip->bip_iter.bi_sector = seed;
 	bip->bip_iter.bi_size = len;
 	bip->bip_vcnt = nr_vecs;
 	return 0;
 }

 static unsigned int bvec_from_pages(struct bio_vec *bvec, struct page **pages,
 				    int nr_vecs, ssize_t bytes, ssize_t offset)
 {
 	unsigned int nr_bvecs = 0;
 	int i, j;

 	for (i = 0; i < nr_vecs; i = j) {
 		size_t size = min_t(size_t, bytes, PAGE_SIZE - offset);
 		struct folio *folio = page_folio(pages[i]);

 		bytes -= size;
 		for (j = i + 1; j < nr_vecs; j++) {
 			size_t next = min_t(size_t, PAGE_SIZE, bytes);

 			if (page_folio(pages[j]) != folio ||
 			    pages[j] != pages[j - 1] + 1)
 				break;
 			unpin_user_page(pages[j]);
 			size += next;
 			bytes -= next;
 		}

 		bvec_set_page(&bvec[nr_bvecs], pages[i], size, offset);
 		offset = 0;
 		nr_bvecs++;
 	}

 	return nr_bvecs;
 }

 int bio_integrity_map_user(struct bio *bio, void __user *ubuf, ssize_t bytes,
 			   u32 seed)
 {
 	struct request_queue *q = bdev_get_queue(bio->bi_bdev);
 	unsigned int align = blk_lim_dma_alignment_and_pad(&q->limits);
 	struct page *stack_pages[UIO_FASTIOV], **pages = stack_pages;
 	struct bio_vec stack_vec[UIO_FASTIOV], *bvec = stack_vec;
 	unsigned int direction, nr_bvecs;
 	struct iov_iter iter;
 	int ret, nr_vecs;
 	size_t offset;
 	bool copy;

 	if (bio_integrity(bio))
 		return -EINVAL;
 	if (bytes >> SECTOR_SHIFT > queue_max_hw_sectors(q))
 		return -E2BIG;

 	if (bio_data_dir(bio) == READ)
 		direction = ITER_DEST;
 	else
 		direction = ITER_SOURCE;

 	iov_iter_ubuf(&iter, direction, ubuf, bytes);
 	nr_vecs = iov_iter_npages(&iter, BIO_MAX_VECS + 1);
 	if (nr_vecs > BIO_MAX_VECS)
 		return -E2BIG;
 	if (nr_vecs > UIO_FASTIOV) {
 		bvec = kcalloc(nr_vecs, sizeof(*bvec), GFP_KERNEL);
 		if (!bvec)
 			return -ENOMEM;
 		pages = NULL;
 	}

 	copy = !iov_iter_is_aligned(&iter, align, align);
 	ret = iov_iter_extract_pages(&iter, &pages, bytes, nr_vecs, 0, &offset);
 	if (unlikely(ret < 0))
 		goto free_bvec;

 	nr_bvecs = bvec_from_pages(bvec, pages, nr_vecs, bytes, offset);
 	if (pages != stack_pages)
 		kvfree(pages);
 	if (nr_bvecs > queue_max_integrity_segments(q))
 		copy = true;

 	if (copy)
 		ret = bio_integrity_copy_user(bio, bvec, nr_bvecs, bytes,
 					      direction, seed);
 	else
 		ret = bio_integrity_init_user(bio, bvec, nr_bvecs, bytes, seed);
 	if (ret)
 		goto release_pages;
 	if (bvec != stack_vec)
 		kfree(bvec);

 	return 0;

 release_pages:
 	bio_integrity_unpin_bvec(bvec, nr_bvecs, false);
 free_bvec:
 	if (bvec != stack_vec)
 		kfree(bvec);
 	return ret;
 }
 EXPORT_SYMBOL_GPL(bio_integrity_map_user);

 /**
  * bio_integrity_prep - Prepare bio for integrity I/O
  * @bio:	bio to prepare
  *
  * Description:  Checks if the bio already has an integrity payload attached.
  * If it does, the payload has been generated by another kernel subsystem,
  * and we just pass it through. Otherwise allocates integrity payload.
  * The bio must have data direction, target device and start sector set priot
  * to calling.  In the WRITE case, integrity metadata will be generated using
  * the block device's integrity function.  In the READ case, the buffer
  * will be prepared for DMA and a suitable end_io handler set up.
  */
 bool bio_integrity_prep(struct bio *bio)
 {
 	struct bio_integrity_payload *bip;
 	struct blk_integrity *bi = blk_get_integrity(bio->bi_bdev->bd_disk);
 	unsigned int len;
 	void *buf;
 	gfp_t gfp = GFP_NOIO;

 	if (!bi)
 		return true;

 	if (!bio_sectors(bio))
 		return true;

 	/* Already protected? */
 	if (bio_integrity(bio))
 		return true;

 	switch (bio_op(bio)) {
 	case REQ_OP_READ:
 		if (bi->flags & BLK_INTEGRITY_NOVERIFY)
 			return true;
 		break;
 	case REQ_OP_WRITE:
 		if (bi->flags & BLK_INTEGRITY_NOGENERATE)
 			return true;

 		/*
 		 * Zero the memory allocated to not leak uninitialized kernel
 		 * memory to disk for non-integrity metadata where nothing else
 		 * initializes the memory.
 		 */
 		if (bi->csum_type == BLK_INTEGRITY_CSUM_NONE)
 			gfp |= __GFP_ZERO;
 		break;
 	default:
 		return true;
 	}

 	/* Allocate kernel buffer for protection data */
 	len = bio_integrity_bytes(bi, bio_sectors(bio));
 	buf = kmalloc(len, gfp);
 	if (unlikely(buf == NULL)) {
 		goto err_end_io;
 	}

 	bip = bio_integrity_alloc(bio, GFP_NOIO, 1);
 	if (IS_ERR(bip)) {
 		kfree(buf);
 		goto err_end_io;
 	}

 	bip->bip_flags |= BIP_BLOCK_INTEGRITY;
 	bip_set_seed(bip, bio->bi_iter.bi_sector);

 	if (bi->csum_type == BLK_INTEGRITY_CSUM_IP)
 		bip->bip_flags |= BIP_IP_CHECKSUM;

 	if (bio_integrity_add_page(bio, virt_to_page(buf), len,
 			offset_in_page(buf)) < len) {
 		printk(KERN_ERR "could not attach integrity payload\n");
 		goto err_end_io;
 	}

 	/* Auto-generate integrity metadata if this is a write */
 	if (bio_data_dir(bio) == WRITE)
 		blk_integrity_generate(bio);
 	else
 		bip->bio_iter = bio->bi_iter;
 	return true;

 err_end_io:
 	bio->bi_status = BLK_STS_RESOURCE;
 	bio_endio(bio);
 	return false;
 }
 EXPORT_SYMBOL(bio_integrity_prep);

 /**
  * bio_integrity_verify_fn - Integrity I/O completion worker
  * @work:	Work struct stored in bio to be verified
  *
  * Description: This workqueue function is called to complete a READ
  * request.  The function verifies the transferred integrity metadata
  * and then calls the original bio end_io function.
  */
 static void bio_integrity_verify_fn(struct work_struct *work)
 {
 	struct bio_integrity_payload *bip =
 		container_of(work, struct bio_integrity_payload, bip_work);
 	struct bio *bio = bip->bip_bio;

 	blk_integrity_verify(bio);

 	kfree(bvec_virt(bip->bip_vec));
 	bio_integrity_free(bio);
 	bio_endio(bio);
 }

 /**
  * __bio_integrity_endio - Integrity I/O completion function
  * @bio:	Protected bio
  *
  * Description: Completion for integrity I/O
  *
  * Normally I/O completion is done in interrupt context.  However,
  * verifying I/O integrity is a time-consuming task which must be run
  * in process context.	This function postpones completion
  * accordingly.
  */
 bool __bio_integrity_endio(struct bio *bio)
 {
 	struct blk_integrity *bi = blk_get_integrity(bio->bi_bdev->bd_disk);
 	struct bio_integrity_payload *bip = bio_integrity(bio);

 	if (bio_op(bio) == REQ_OP_READ && !bio->bi_status && bi->csum_type) {
 		INIT_WORK(&bip->bip_work, bio_integrity_verify_fn);
 		queue_work(kintegrityd_wq, &bip->bip_work);
 		return false;
 	}

 	kfree(bvec_virt(bip->bip_vec));
 	bio_integrity_free(bio);
 	return true;
 }

 /**
  * bio_integrity_advance - Advance integrity vector
  * @bio:	bio whose integrity vector to update
  * @bytes_done:	number of data bytes that have been completed
  *
  * Description: This function calculates how many integrity bytes the
  * number of completed data bytes correspond to and advances the
  * integrity vector accordingly.
  */
 void bio_integrity_advance(struct bio *bio, unsigned int bytes_done)
 {
 	struct bio_integrity_payload *bip = bio_integrity(bio);
 	struct blk_integrity *bi = blk_get_integrity(bio->bi_bdev->bd_disk);
 	unsigned bytes = bio_integrity_bytes(bi, bytes_done >> 9);

 	bip->bip_iter.bi_sector += bio_integrity_intervals(bi, bytes_done >> 9);
 	bvec_iter_advance(bip->bip_vec, &bip->bip_iter, bytes);
 }

 /**
  * bio_integrity_trim - Trim integrity vector
  * @bio:	bio whose integrity vector to update
  *
  * Description: Used to trim the integrity vector in a cloned bio.
  */
 void bio_integrity_trim(struct bio *bio)
 {
 	struct bio_integrity_payload *bip = bio_integrity(bio);
 	struct blk_integrity *bi = blk_get_integrity(bio->bi_bdev->bd_disk);

 	bip->bip_iter.bi_size = bio_integrity_bytes(bi, bio_sectors(bio));
 }
 EXPORT_SYMBOL(bio_integrity_trim);

 /**
  * bio_integrity_clone - Callback for cloning bios with integrity metadata
  * @bio:	New bio
  * @bio_src:	Original bio
  * @gfp_mask:	Memory allocation mask
  *
  * Description:	Called to allocate a bip when cloning a bio
  */
 int bio_integrity_clone(struct bio *bio, struct bio *bio_src,
 			gfp_t gfp_mask)
 {
 	struct bio_integrity_payload *bip_src = bio_integrity(bio_src);
 	struct bio_integrity_payload *bip;

 	BUG_ON(bip_src == NULL);

 	bip = bio_integrity_alloc(bio, gfp_mask, 0);
 	if (IS_ERR(bip))
 		return PTR_ERR(bip);

 	bip->bip_vec = bip_src->bip_vec;
 	bip->bip_iter = bip_src->bip_iter;
 	bip->bip_flags = bip_src->bip_flags & ~BIP_BLOCK_INTEGRITY;

 	return 0;
 }

 int bioset_integrity_create(struct bio_set *bs, int pool_size)
 {
 	if (mempool_initialized(&bs->bio_integrity_pool))
 		return 0;

 	if (mempool_init_slab_pool(&bs->bio_integrity_pool,
 				   pool_size, bip_slab))
 		return -1;

 	if (biovec_init_pool(&bs->bvec_integrity_pool, pool_size)) {
 		mempool_exit(&bs->bio_integrity_pool);
 		return -1;
 	}

 	return 0;
 }
 EXPORT_SYMBOL(bioset_integrity_create);

 void bioset_integrity_free(struct bio_set *bs)
 {
 	mempool_exit(&bs->bio_integrity_pool);
 	mempool_exit(&bs->bvec_integrity_pool);
 }

 void __init bio_integrity_init(void)
 {
 	/*
 	 * kintegrityd won't block much but may burn a lot of CPU cycles.
 	 * Make it highpri CPU intensive wq with max concurrency of 1.
 	 */
 	kintegrityd_wq = alloc_workqueue("kintegrityd", WQ_MEM_RECLAIM |
 					 WQ_HIGHPRI | WQ_CPU_INTENSIVE, 1);
 	if (!kintegrityd_wq)
 		panic("Failed to create kintegrityd\n");

 	bip_slab = kmem_cache_create("bio_integrity_payload",
 				     sizeof(struct bio_integrity_payload) +
 				     sizeof(struct bio_vec) * BIO_INLINE_VECS,
 				     0, SLAB_HWCACHE_ALIGN|SLAB_PANIC, NULL);
 }
	// SPDX-License-Identifier: GPL-2.0
	/*
	* bio-integrity.c - bio data integrity extensions
	*
	* Copyright (C) 2007, 2008, 2009 Oracle Corporation
	* Written by: Martin K. Petersen <martin.petersen@oracle.com>
	*/

	#include <linux/blk-integrity.h>
	#include <linux/mempool.h>
	#include <linux/export.h>
	#include <linux/bio.h>
	#include <linux/workqueue.h>
	#include <linux/slab.h>
	#include "blk.h"

	static struct kmem_cache *bip_slab;
	static struct workqueue_struct *kintegrityd_wq;

	void blk_flush_integrity(void)
	{
	flush_workqueue(kintegrityd_wq);
	}

	/**
	* bio_integrity_free - Free bio integrity payload
	* @bio: bio containing bip to be freed
	*
	* Description: Free the integrity portion of a bio.
	*/
	void bio_integrity_free(struct bio *bio)
	{
	struct bio_integrity_payload *bip = bio_integrity(bio);
	struct bio_set *bs = bio->bi_pool;

	if (bs && mempool_initialized(&bs->bio_integrity_pool)) {
	if (bip->bip_vec)
	bvec_free(&bs->bvec_integrity_pool, bip->bip_vec,
	bip->bip_max_vcnt);
	mempool_free(bip, &bs->bio_integrity_pool);
	} else {
	kfree(bip);
	}
	bio->bi_integrity = NULL;
	bio->bi_opf &= ~REQ_INTEGRITY;
	}

	/**
	* bio_integrity_alloc - Allocate integrity payload and attach it to bio
	* @bio: bio to attach integrity metadata to
	* @gfp_mask: Memory allocation mask
	* @nr_vecs: Number of integrity metadata scatter-gather elements
	*
	* Description: This function prepares a bio for attaching integrity
	* metadata. nr_vecs specifies the maximum number of pages containing
	* integrity metadata that can be attached.
	*/
	struct bio_integrity_payload bio_integrity_alloc(struct bio bio,
	gfp_t gfp_mask,
	unsigned int nr_vecs)
	{
	struct bio_integrity_payload *bip;
	struct bio_set *bs = bio->bi_pool;
	unsigned inline_vecs;

	if (WARN_ON_ONCE(bio_has_crypt_ctx(bio)))
	return ERR_PTR(-EOPNOTSUPP);

	if (!bs \|\| !mempool_initialized(&bs->bio_integrity_pool)) {
	bip = kmalloc(struct_size(bip, bip_inline_vecs, nr_vecs), gfp_mask);
	inline_vecs = nr_vecs;
	} else {
	bip = mempool_alloc(&bs->bio_integrity_pool, gfp_mask);
	inline_vecs = BIO_INLINE_VECS;
	}

	if (unlikely(!bip))
	return ERR_PTR(-ENOMEM);

	memset(bip, 0, sizeof(*bip));

	/* always report as many vecs as asked explicitly, not inline vecs */
	bip->bip_max_vcnt = nr_vecs;
	if (nr_vecs > inline_vecs) {
	bip->bip_vec = bvec_alloc(&bs->bvec_integrity_pool,
	&bip->bip_max_vcnt, gfp_mask);
	if (!bip->bip_vec)
	goto err;
	} else if (nr_vecs) {
	bip->bip_vec = bip->bip_inline_vecs;
	}

	bip->bip_bio = bio;
	bio->bi_integrity = bip;
	bio->bi_opf \|= REQ_INTEGRITY;

	return bip;
	err:
	if (bs && mempool_initialized(&bs->bio_integrity_pool))
	mempool_free(bip, &bs->bio_integrity_pool);
	else
	kfree(bip);
	return ERR_PTR(-ENOMEM);
	}
	EXPORT_SYMBOL(bio_integrity_alloc);

	static void bio_integrity_unpin_bvec(struct bio_vec *bv, int nr_vecs,
	bool dirty)
	{
	int i;

	for (i = 0; i < nr_vecs; i++) {
	if (dirty && !PageCompound(bv[i].bv_page))
	set_page_dirty_lock(bv[i].bv_page);
	unpin_user_page(bv[i].bv_page);
	}
	}

	static void bio_integrity_uncopy_user(struct bio_integrity_payload *bip)
	{
	unsigned short nr_vecs = bip->bip_max_vcnt - 1;
	struct bio_vec *copy = &bip->bip_vec[1];
	size_t bytes = bip->bip_iter.bi_size;
	struct iov_iter iter;
	int ret;

	iov_iter_bvec(&iter, ITER_DEST, copy, nr_vecs, bytes);
	ret = copy_to_iter(bvec_virt(bip->bip_vec), bytes, &iter);
	WARN_ON_ONCE(ret != bytes);

	bio_integrity_unpin_bvec(copy, nr_vecs, true);
	}

	/**
	* bio_integrity_unmap_user - Unmap user integrity payload
	* @bio: bio containing bip to be unmapped
	*
	* Unmap the user mapped integrity portion of a bio.
	*/
	void bio_integrity_unmap_user(struct bio *bio)
	{
	struct bio_integrity_payload *bip = bio_integrity(bio);

	if (bip->bip_flags & BIP_COPY_USER) {
	if (bio_data_dir(bio) == READ)
	bio_integrity_uncopy_user(bip);
	kfree(bvec_virt(bip->bip_vec));
	return;
	}

	bio_integrity_unpin_bvec(bip->bip_vec, bip->bip_max_vcnt,
	bio_data_dir(bio) == READ);
	}

	/**
	* bio_integrity_add_page - Attach integrity metadata
	* @bio: bio to update
	* @page: page containing integrity metadata
	* @len: number of bytes of integrity metadata in page
	* @offset: start offset within page
	*
	* Description: Attach a page containing integrity metadata to bio.
	*/
	int bio_integrity_add_page(struct bio bio, struct page page,
	unsigned int len, unsigned int offset)
	{
	struct request_queue *q = bdev_get_queue(bio->bi_bdev);
	struct bio_integrity_payload *bip = bio_integrity(bio);

	if (((bip->bip_iter.bi_size + len) >> SECTOR_SHIFT) >
	queue_max_hw_sectors(q))
	return 0;

	if (bip->bip_vcnt > 0) {
	struct bio_vec *bv = &bip->bip_vec[bip->bip_vcnt - 1];
	bool same_page = false;

	if (bvec_try_merge_hw_page(q, bv, page, len, offset,
	&same_page)) {
	bip->bip_iter.bi_size += len;
	return len;
	}

	if (bip->bip_vcnt >=
	min(bip->bip_max_vcnt, queue_max_integrity_segments(q)))
	return 0;

	/*
	* If the queue doesn't support SG gaps and adding this segment
	* would create a gap, disallow it.
	*/
	if (bvec_gap_to_prev(&q->limits, bv, offset))
	return 0;
	}

	bvec_set_page(&bip->bip_vec[bip->bip_vcnt], page, len, offset);
	bip->bip_vcnt++;
	bip->bip_iter.bi_size += len;

	return len;
	}
	EXPORT_SYMBOL(bio_integrity_add_page);

	static int bio_integrity_copy_user(struct bio bio, struct bio_vec bvec,
	int nr_vecs, unsigned int len,
	unsigned int direction, u32 seed)
	{
	bool write = direction == ITER_SOURCE;
	struct bio_integrity_payload *bip;
	struct iov_iter iter;
	void *buf;
	int ret;

	buf = kmalloc(len, GFP_KERNEL);
	if (!buf)
	return -ENOMEM;

	if (write) {
	iov_iter_bvec(&iter, direction, bvec, nr_vecs, len);
	if (!copy_from_iter_full(buf, len, &iter)) {
	ret = -EFAULT;
	goto free_buf;
	}

	bip = bio_integrity_alloc(bio, GFP_KERNEL, 1);
	} else {
	memset(buf, 0, len);

	/*
	* We need to preserve the original bvec and the number of vecs
	* in it for completion handling
	*/
	bip = bio_integrity_alloc(bio, GFP_KERNEL, nr_vecs + 1);
	}

	if (IS_ERR(bip)) {
	ret = PTR_ERR(bip);
	goto free_buf;
	}

	if (write)
	bio_integrity_unpin_bvec(bvec, nr_vecs, false);
	else
	memcpy(&bip->bip_vec[1], bvec, nr_vecs * sizeof(*bvec));

	ret = bio_integrity_add_page(bio, virt_to_page(buf), len,
	offset_in_page(buf));
	if (ret != len) {
	ret = -ENOMEM;
	goto free_bip;
	}

	bip->bip_flags \|= BIP_COPY_USER;
	bip->bip_iter.bi_sector = seed;
	bip->bip_vcnt = nr_vecs;
	return 0;
	free_bip:
	bio_integrity_free(bio);
	free_buf:
	kfree(buf);
	return ret;
	}

	static int bio_integrity_init_user(struct bio bio, struct bio_vec bvec,
	int nr_vecs, unsigned int len, u32 seed)
	{
	struct bio_integrity_payload *bip;

	bip = bio_integrity_alloc(bio, GFP_KERNEL, nr_vecs);
	if (IS_ERR(bip))
	return PTR_ERR(bip);

	memcpy(bip->bip_vec, bvec, nr_vecs * sizeof(*bvec));
	bip->bip_iter.bi_sector = seed;
	bip->bip_iter.bi_size = len;
	bip->bip_vcnt = nr_vecs;
	return 0;
	}

	static unsigned int bvec_from_pages(struct bio_vec bvec, struct page *pages,
	int nr_vecs, ssize_t bytes, ssize_t offset)
	{
	unsigned int nr_bvecs = 0;
	int i, j;

	for (i = 0; i < nr_vecs; i = j) {
	size_t size = min_t(size_t, bytes, PAGE_SIZE - offset);
	struct folio *folio = page_folio(pages[i]);

	bytes -= size;
	for (j = i + 1; j < nr_vecs; j++) {
	size_t next = min_t(size_t, PAGE_SIZE, bytes);

	if (page_folio(pages[j]) != folio \|\|
	pages[j] != pages[j - 1] + 1)
	break;
	unpin_user_page(pages[j]);
	size += next;
	bytes -= next;
	}

	bvec_set_page(&bvec[nr_bvecs], pages[i], size, offset);
	offset = 0;
	nr_bvecs++;
	}

	return nr_bvecs;
	}

	int bio_integrity_map_user(struct bio bio, void __user ubuf, ssize_t bytes,
	u32 seed)
	{
	struct request_queue *q = bdev_get_queue(bio->bi_bdev);
	unsigned int align = blk_lim_dma_alignment_and_pad(&q->limits);
	struct page stack_pages[UIO_FASTIOV], *pages = stack_pages;
	struct bio_vec stack_vec[UIO_FASTIOV], *bvec = stack_vec;
	unsigned int direction, nr_bvecs;
	struct iov_iter iter;
	int ret, nr_vecs;
	size_t offset;
	bool copy;

	if (bio_integrity(bio))
	return -EINVAL;
	if (bytes >> SECTOR_SHIFT > queue_max_hw_sectors(q))
	return -E2BIG;

	if (bio_data_dir(bio) == READ)
	direction = ITER_DEST;
	else
	direction = ITER_SOURCE;

	iov_iter_ubuf(&iter, direction, ubuf, bytes);
	nr_vecs = iov_iter_npages(&iter, BIO_MAX_VECS + 1);
	if (nr_vecs > BIO_MAX_VECS)
	return -E2BIG;
	if (nr_vecs > UIO_FASTIOV) {
	bvec = kcalloc(nr_vecs, sizeof(*bvec), GFP_KERNEL);
	if (!bvec)
	return -ENOMEM;
	pages = NULL;
	}

	copy = !iov_iter_is_aligned(&iter, align, align);
	ret = iov_iter_extract_pages(&iter, &pages, bytes, nr_vecs, 0, &offset);
	if (unlikely(ret < 0))
	goto free_bvec;

	nr_bvecs = bvec_from_pages(bvec, pages, nr_vecs, bytes, offset);
	if (pages != stack_pages)
	kvfree(pages);
	if (nr_bvecs > queue_max_integrity_segments(q))
	copy = true;

	if (copy)
	ret = bio_integrity_copy_user(bio, bvec, nr_bvecs, bytes,
	direction, seed);
	else
	ret = bio_integrity_init_user(bio, bvec, nr_bvecs, bytes, seed);
	if (ret)
	goto release_pages;
	if (bvec != stack_vec)
	kfree(bvec);

	return 0;

	release_pages:
	bio_integrity_unpin_bvec(bvec, nr_bvecs, false);
	free_bvec:
	if (bvec != stack_vec)
	kfree(bvec);
	return ret;
	}
	EXPORT_SYMBOL_GPL(bio_integrity_map_user);

	/**
	* bio_integrity_prep - Prepare bio for integrity I/O
	* @bio: bio to prepare
	*
	* Description: Checks if the bio already has an integrity payload attached.
	* If it does, the payload has been generated by another kernel subsystem,
	* and we just pass it through. Otherwise allocates integrity payload.
	* The bio must have data direction, target device and start sector set priot
	* to calling. In the WRITE case, integrity metadata will be generated using
	* the block device's integrity function. In the READ case, the buffer
	* will be prepared for DMA and a suitable end_io handler set up.
	*/
	bool bio_integrity_prep(struct bio *bio)
	{
	struct bio_integrity_payload *bip;
	struct blk_integrity *bi = blk_get_integrity(bio->bi_bdev->bd_disk);
	unsigned int len;
	void *buf;
	gfp_t gfp = GFP_NOIO;

	if (!bi)
	return true;

	if (!bio_sectors(bio))
	return true;

	/* Already protected? */
	if (bio_integrity(bio))
	return true;

	switch (bio_op(bio)) {
	case REQ_OP_READ:
	if (bi->flags & BLK_INTEGRITY_NOVERIFY)
	return true;
	break;
	case REQ_OP_WRITE:
	if (bi->flags & BLK_INTEGRITY_NOGENERATE)
	return true;

	/*
	* Zero the memory allocated to not leak uninitialized kernel
	* memory to disk for non-integrity metadata where nothing else
	* initializes the memory.
	*/
	if (bi->csum_type == BLK_INTEGRITY_CSUM_NONE)
	gfp \|= __GFP_ZERO;
	break;
	default:
	return true;
	}

	/* Allocate kernel buffer for protection data */
	len = bio_integrity_bytes(bi, bio_sectors(bio));
	buf = kmalloc(len, gfp);
	if (unlikely(buf == NULL)) {
	goto err_end_io;
	}

	bip = bio_integrity_alloc(bio, GFP_NOIO, 1);
	if (IS_ERR(bip)) {
	kfree(buf);
	goto err_end_io;
	}

	bip->bip_flags \|= BIP_BLOCK_INTEGRITY;
	bip_set_seed(bip, bio->bi_iter.bi_sector);

	if (bi->csum_type == BLK_INTEGRITY_CSUM_IP)
	bip->bip_flags \|= BIP_IP_CHECKSUM;

	if (bio_integrity_add_page(bio, virt_to_page(buf), len,
	offset_in_page(buf)) < len) {
	printk(KERN_ERR "could not attach integrity payload\n");
	goto err_end_io;
	}

	/* Auto-generate integrity metadata if this is a write */
	if (bio_data_dir(bio) == WRITE)
	blk_integrity_generate(bio);
	else
	bip->bio_iter = bio->bi_iter;
	return true;

	err_end_io:
	bio->bi_status = BLK_STS_RESOURCE;
	bio_endio(bio);
	return false;
	}
	EXPORT_SYMBOL(bio_integrity_prep);

	/**
	* bio_integrity_verify_fn - Integrity I/O completion worker
	* @work: Work struct stored in bio to be verified
	*
	* Description: This workqueue function is called to complete a READ
	* request. The function verifies the transferred integrity metadata
	* and then calls the original bio end_io function.
	*/
	static void bio_integrity_verify_fn(struct work_struct *work)
	{
	struct bio_integrity_payload *bip =
	container_of(work, struct bio_integrity_payload, bip_work);
	struct bio *bio = bip->bip_bio;

	blk_integrity_verify(bio);

	kfree(bvec_virt(bip->bip_vec));
	bio_integrity_free(bio);
	bio_endio(bio);
	}

	/**
	* __bio_integrity_endio - Integrity I/O completion function
	* @bio: Protected bio
	*
	* Description: Completion for integrity I/O
	*
	* Normally I/O completion is done in interrupt context. However,
	* verifying I/O integrity is a time-consuming task which must be run
	* in process context. This function postpones completion
	* accordingly.
	*/
	bool __bio_integrity_endio(struct bio *bio)
	{
	struct blk_integrity *bi = blk_get_integrity(bio->bi_bdev->bd_disk);
	struct bio_integrity_payload *bip = bio_integrity(bio);

	if (bio_op(bio) == REQ_OP_READ && !bio->bi_status && bi->csum_type) {
	INIT_WORK(&bip->bip_work, bio_integrity_verify_fn);
	queue_work(kintegrityd_wq, &bip->bip_work);
	return false;
	}

	kfree(bvec_virt(bip->bip_vec));
	bio_integrity_free(bio);
	return true;
	}

	/**
	* bio_integrity_advance - Advance integrity vector
	* @bio: bio whose integrity vector to update
	* @bytes_done: number of data bytes that have been completed
	*
	* Description: This function calculates how many integrity bytes the
	* number of completed data bytes correspond to and advances the
	* integrity vector accordingly.
	*/
	void bio_integrity_advance(struct bio *bio, unsigned int bytes_done)
	{
	struct bio_integrity_payload *bip = bio_integrity(bio);
	struct blk_integrity *bi = blk_get_integrity(bio->bi_bdev->bd_disk);
	unsigned bytes = bio_integrity_bytes(bi, bytes_done >> 9);

	bip->bip_iter.bi_sector += bio_integrity_intervals(bi, bytes_done >> 9);
	bvec_iter_advance(bip->bip_vec, &bip->bip_iter, bytes);
	}

	/**
	* bio_integrity_trim - Trim integrity vector
	* @bio: bio whose integrity vector to update
	*
	* Description: Used to trim the integrity vector in a cloned bio.
	*/
	void bio_integrity_trim(struct bio *bio)
	{
	struct bio_integrity_payload *bip = bio_integrity(bio);
	struct blk_integrity *bi = blk_get_integrity(bio->bi_bdev->bd_disk);

	bip->bip_iter.bi_size = bio_integrity_bytes(bi, bio_sectors(bio));
	}
	EXPORT_SYMBOL(bio_integrity_trim);

	/**
	* bio_integrity_clone - Callback for cloning bios with integrity metadata
	* @bio: New bio
	* @bio_src: Original bio
	* @gfp_mask: Memory allocation mask
	*
	* Description: Called to allocate a bip when cloning a bio
	*/
	int bio_integrity_clone(struct bio bio, struct bio bio_src,
	gfp_t gfp_mask)
	{
	struct bio_integrity_payload *bip_src = bio_integrity(bio_src);
	struct bio_integrity_payload *bip;

	BUG_ON(bip_src == NULL);

	bip = bio_integrity_alloc(bio, gfp_mask, 0);
	if (IS_ERR(bip))
	return PTR_ERR(bip);

	bip->bip_vec = bip_src->bip_vec;
	bip->bip_iter = bip_src->bip_iter;
	bip->bip_flags = bip_src->bip_flags & ~BIP_BLOCK_INTEGRITY;

	return 0;
	}

	int bioset_integrity_create(struct bio_set *bs, int pool_size)
	{
	if (mempool_initialized(&bs->bio_integrity_pool))
	return 0;

	if (mempool_init_slab_pool(&bs->bio_integrity_pool,
	pool_size, bip_slab))
	return -1;

	if (biovec_init_pool(&bs->bvec_integrity_pool, pool_size)) {
	mempool_exit(&bs->bio_integrity_pool);
	return -1;
	}

	return 0;
	}
	EXPORT_SYMBOL(bioset_integrity_create);

	void bioset_integrity_free(struct bio_set *bs)
	{
	mempool_exit(&bs->bio_integrity_pool);
	mempool_exit(&bs->bvec_integrity_pool);
	}

	void __init bio_integrity_init(void)
	{
	/*
	* kintegrityd won't block much but may burn a lot of CPU cycles.
	* Make it highpri CPU intensive wq with max concurrency of 1.
	*/
	kintegrityd_wq = alloc_workqueue("kintegrityd", WQ_MEM_RECLAIM \|
	WQ_HIGHPRI \| WQ_CPU_INTENSIVE, 1);
	if (!kintegrityd_wq)
	panic("Failed to create kintegrityd\n");

	bip_slab = kmem_cache_create("bio_integrity_payload",
	sizeof(struct bio_integrity_payload) +
	sizeof(struct bio_vec) * BIO_INLINE_VECS,
	0, SLAB_HWCACHE_ALIGN\|SLAB_PANIC, NULL);
	}