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-rw-r--r--block/bio-integrity.c476
1 files changed, 476 insertions, 0 deletions
diff --git a/block/bio-integrity.c b/block/bio-integrity.c
new file mode 100644
index 000000000..a4cfc9727
--- /dev/null
+++ b/block/bio-integrity.c
@@ -0,0 +1,476 @@
+// 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/blkdev.h>
+#include <linux/mempool.h>
+#include <linux/export.h>
+#include <linux/bio.h>
+#include <linux/workqueue.h>
+#include <linux/slab.h>
+#include "blk.h"
+
+#define BIP_INLINE_VECS 4
+
+static struct kmem_cache *bip_slab;
+static struct workqueue_struct *kintegrityd_wq;
+
+void blk_flush_integrity(void)
+{
+ flush_workqueue(kintegrityd_wq);
+}
+
+static void __bio_integrity_free(struct bio_set *bs,
+ struct bio_integrity_payload *bip)
+{
+ if (bs && mempool_initialized(&bs->bio_integrity_pool)) {
+ if (bip->bip_vec)
+ bvec_free(&bs->bvec_integrity_pool, bip->bip_vec,
+ bip->bip_slab);
+ mempool_free(bip, &bs->bio_integrity_pool);
+ } else {
+ kfree(bip);
+ }
+}
+
+/**
+ * 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 = BIP_INLINE_VECS;
+ }
+
+ if (unlikely(!bip))
+ return ERR_PTR(-ENOMEM);
+
+ memset(bip, 0, sizeof(*bip));
+
+ if (nr_vecs > inline_vecs) {
+ unsigned long idx = 0;
+
+ bip->bip_vec = bvec_alloc(gfp_mask, nr_vecs, &idx,
+ &bs->bvec_integrity_pool);
+ if (!bip->bip_vec)
+ goto err;
+ bip->bip_max_vcnt = bvec_nr_vecs(idx);
+ bip->bip_slab = idx;
+ } else {
+ bip->bip_vec = bip->bip_inline_vecs;
+ bip->bip_max_vcnt = inline_vecs;
+ }
+
+ bip->bip_bio = bio;
+ bio->bi_integrity = bip;
+ bio->bi_opf |= REQ_INTEGRITY;
+
+ return bip;
+err:
+ __bio_integrity_free(bs, bip);
+ return ERR_PTR(-ENOMEM);
+}
+EXPORT_SYMBOL(bio_integrity_alloc);
+
+/**
+ * bio_integrity_free - Free bio integrity payload
+ * @bio: bio containing bip to be freed
+ *
+ * Description: Used to free the integrity portion of a bio. Usually
+ * called from bio_free().
+ */
+void bio_integrity_free(struct bio *bio)
+{
+ struct bio_integrity_payload *bip = bio_integrity(bio);
+ struct bio_set *bs = bio->bi_pool;
+
+ if (bip->bip_flags & BIP_BLOCK_INTEGRITY)
+ kfree(page_address(bip->bip_vec->bv_page) +
+ bip->bip_vec->bv_offset);
+
+ __bio_integrity_free(bs, bip);
+ bio->bi_integrity = NULL;
+ bio->bi_opf &= ~REQ_INTEGRITY;
+}
+
+/**
+ * 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 bio_integrity_payload *bip = bio_integrity(bio);
+ struct bio_vec *iv;
+
+ if (bip->bip_vcnt >= bip->bip_max_vcnt) {
+ printk(KERN_ERR "%s: bip_vec full\n", __func__);
+ return 0;
+ }
+
+ iv = bip->bip_vec + bip->bip_vcnt;
+
+ if (bip->bip_vcnt &&
+ bvec_gap_to_prev(bio->bi_disk->queue,
+ &bip->bip_vec[bip->bip_vcnt - 1], offset))
+ return 0;
+
+ iv->bv_page = page;
+ iv->bv_len = len;
+ iv->bv_offset = offset;
+ bip->bip_vcnt++;
+
+ return len;
+}
+EXPORT_SYMBOL(bio_integrity_add_page);
+
+/**
+ * bio_integrity_process - Process integrity metadata for a bio
+ * @bio: bio to generate/verify integrity metadata for
+ * @proc_iter: iterator to process
+ * @proc_fn: Pointer to the relevant processing function
+ */
+static blk_status_t bio_integrity_process(struct bio *bio,
+ struct bvec_iter *proc_iter, integrity_processing_fn *proc_fn)
+{
+ struct blk_integrity *bi = blk_get_integrity(bio->bi_disk);
+ struct blk_integrity_iter iter;
+ struct bvec_iter bviter;
+ struct bio_vec bv;
+ struct bio_integrity_payload *bip = bio_integrity(bio);
+ blk_status_t ret = BLK_STS_OK;
+ void *prot_buf = page_address(bip->bip_vec->bv_page) +
+ bip->bip_vec->bv_offset;
+
+ iter.disk_name = bio->bi_disk->disk_name;
+ iter.interval = 1 << bi->interval_exp;
+ iter.seed = proc_iter->bi_sector;
+ iter.prot_buf = prot_buf;
+
+ __bio_for_each_segment(bv, bio, bviter, *proc_iter) {
+ void *kaddr = kmap_atomic(bv.bv_page);
+
+ iter.data_buf = kaddr + bv.bv_offset;
+ iter.data_size = bv.bv_len;
+
+ ret = proc_fn(&iter);
+ if (ret) {
+ kunmap_atomic(kaddr);
+ return ret;
+ }
+
+ kunmap_atomic(kaddr);
+ }
+ return ret;
+}
+
+/**
+ * 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_disk);
+ struct request_queue *q = bio->bi_disk->queue;
+ void *buf;
+ unsigned long start, end;
+ unsigned int len, nr_pages;
+ unsigned int bytes, offset, i;
+ unsigned int intervals;
+ blk_status_t status;
+
+ if (!bi)
+ return true;
+
+ if (bio_op(bio) != REQ_OP_READ && bio_op(bio) != REQ_OP_WRITE)
+ return true;
+
+ if (!bio_sectors(bio))
+ return true;
+
+ /* Already protected? */
+ if (bio_integrity(bio))
+ return true;
+
+ if (bio_data_dir(bio) == READ) {
+ if (!bi->profile->verify_fn ||
+ !(bi->flags & BLK_INTEGRITY_VERIFY))
+ return true;
+ } else {
+ if (!bi->profile->generate_fn ||
+ !(bi->flags & BLK_INTEGRITY_GENERATE))
+ return true;
+ }
+ intervals = bio_integrity_intervals(bi, bio_sectors(bio));
+
+ /* Allocate kernel buffer for protection data */
+ len = intervals * bi->tuple_size;
+ buf = kmalloc(len, GFP_NOIO | q->bounce_gfp);
+ status = BLK_STS_RESOURCE;
+ if (unlikely(buf == NULL)) {
+ printk(KERN_ERR "could not allocate integrity buffer\n");
+ goto err_end_io;
+ }
+
+ end = (((unsigned long) buf) + len + PAGE_SIZE - 1) >> PAGE_SHIFT;
+ start = ((unsigned long) buf) >> PAGE_SHIFT;
+ nr_pages = end - start;
+
+ /* Allocate bio integrity payload and integrity vectors */
+ bip = bio_integrity_alloc(bio, GFP_NOIO, nr_pages);
+ if (IS_ERR(bip)) {
+ printk(KERN_ERR "could not allocate data integrity bioset\n");
+ kfree(buf);
+ status = BLK_STS_RESOURCE;
+ goto err_end_io;
+ }
+
+ bip->bip_flags |= BIP_BLOCK_INTEGRITY;
+ bip->bip_iter.bi_size = len;
+ bip_set_seed(bip, bio->bi_iter.bi_sector);
+
+ if (bi->flags & BLK_INTEGRITY_IP_CHECKSUM)
+ bip->bip_flags |= BIP_IP_CHECKSUM;
+
+ /* Map it */
+ offset = offset_in_page(buf);
+ for (i = 0 ; i < nr_pages ; i++) {
+ int ret;
+ bytes = PAGE_SIZE - offset;
+
+ if (len <= 0)
+ break;
+
+ if (bytes > len)
+ bytes = len;
+
+ ret = bio_integrity_add_page(bio, virt_to_page(buf),
+ bytes, offset);
+
+ if (ret == 0) {
+ printk(KERN_ERR "could not attach integrity payload\n");
+ status = BLK_STS_RESOURCE;
+ goto err_end_io;
+ }
+
+ if (ret < bytes)
+ break;
+
+ buf += bytes;
+ len -= bytes;
+ offset = 0;
+ }
+
+ /* Auto-generate integrity metadata if this is a write */
+ if (bio_data_dir(bio) == WRITE) {
+ bio_integrity_process(bio, &bio->bi_iter,
+ bi->profile->generate_fn);
+ } else {
+ bip->bio_iter = bio->bi_iter;
+ }
+ return true;
+
+err_end_io:
+ bio->bi_status = status;
+ 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;
+ struct blk_integrity *bi = blk_get_integrity(bio->bi_disk);
+
+ /*
+ * At the moment verify is called bio's iterator was advanced
+ * during split and completion, we need to rewind iterator to
+ * it's original position.
+ */
+ bio->bi_status = bio_integrity_process(bio, &bip->bio_iter,
+ bi->profile->verify_fn);
+ 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_disk);
+ struct bio_integrity_payload *bip = bio_integrity(bio);
+
+ if (bio_op(bio) == REQ_OP_READ && !bio->bi_status &&
+ (bip->bip_flags & BIP_BLOCK_INTEGRITY) && bi->profile->verify_fn) {
+ INIT_WORK(&bip->bip_work, bio_integrity_verify_fn);
+ queue_work(kintegrityd_wq, &bip->bip_work);
+ return false;
+ }
+
+ 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_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_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, bip_src->bip_vcnt);
+ if (IS_ERR(bip))
+ return PTR_ERR(bip);
+
+ memcpy(bip->bip_vec, bip_src->bip_vec,
+ bip_src->bip_vcnt * sizeof(struct bio_vec));
+
+ bip->bip_vcnt = bip_src->bip_vcnt;
+ bip->bip_iter = bip_src->bip_iter;
+ bip->bip_flags = bip_src->bip_flags & ~BIP_BLOCK_INTEGRITY;
+
+ return 0;
+}
+EXPORT_SYMBOL(bio_integrity_clone);
+
+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) * BIP_INLINE_VECS,
+ 0, SLAB_HWCACHE_ALIGN|SLAB_PANIC, NULL);
+}