1 // SPDX-License-Identifier: GPL-2.0
3 * bio-integrity.c - bio data integrity extensions
5 * Copyright (C) 2007, 2008, 2009 Oracle Corporation
6 * Written by: Martin K. Petersen <martin.petersen@oracle.com>
9 #include <linux/blkdev.h>
10 #include <linux/mempool.h>
11 #include <linux/export.h>
12 #include <linux/bio.h>
13 #include <linux/workqueue.h>
14 #include <linux/slab.h>
17 #define BIP_INLINE_VECS 4
19 static struct kmem_cache *bip_slab;
20 static struct workqueue_struct *kintegrityd_wq;
22 void blk_flush_integrity(void)
24 flush_workqueue(kintegrityd_wq);
27 static void __bio_integrity_free(struct bio_set *bs,
28 struct bio_integrity_payload *bip)
30 if (bs && mempool_initialized(&bs->bio_integrity_pool)) {
32 bvec_free(&bs->bvec_integrity_pool, bip->bip_vec,
34 mempool_free(bip, &bs->bio_integrity_pool);
41 * bio_integrity_alloc - Allocate integrity payload and attach it to bio
42 * @bio: bio to attach integrity metadata to
43 * @gfp_mask: Memory allocation mask
44 * @nr_vecs: Number of integrity metadata scatter-gather elements
46 * Description: This function prepares a bio for attaching integrity
47 * metadata. nr_vecs specifies the maximum number of pages containing
48 * integrity metadata that can be attached.
50 struct bio_integrity_payload *bio_integrity_alloc(struct bio *bio,
54 struct bio_integrity_payload *bip;
55 struct bio_set *bs = bio->bi_pool;
58 if (WARN_ON_ONCE(bio_has_crypt_ctx(bio)))
59 return ERR_PTR(-EOPNOTSUPP);
61 if (!bs || !mempool_initialized(&bs->bio_integrity_pool)) {
62 bip = kmalloc(struct_size(bip, bip_inline_vecs, nr_vecs), gfp_mask);
63 inline_vecs = nr_vecs;
65 bip = mempool_alloc(&bs->bio_integrity_pool, gfp_mask);
66 inline_vecs = BIP_INLINE_VECS;
70 return ERR_PTR(-ENOMEM);
72 memset(bip, 0, sizeof(*bip));
74 if (nr_vecs > inline_vecs) {
75 unsigned long idx = 0;
77 bip->bip_vec = bvec_alloc(gfp_mask, nr_vecs, &idx,
78 &bs->bvec_integrity_pool);
81 bip->bip_max_vcnt = bvec_nr_vecs(idx);
84 bip->bip_vec = bip->bip_inline_vecs;
85 bip->bip_max_vcnt = inline_vecs;
89 bio->bi_integrity = bip;
90 bio->bi_opf |= REQ_INTEGRITY;
94 __bio_integrity_free(bs, bip);
95 return ERR_PTR(-ENOMEM);
97 EXPORT_SYMBOL(bio_integrity_alloc);
100 * bio_integrity_free - Free bio integrity payload
101 * @bio: bio containing bip to be freed
103 * Description: Used to free the integrity portion of a bio. Usually
104 * called from bio_free().
106 void bio_integrity_free(struct bio *bio)
108 struct bio_integrity_payload *bip = bio_integrity(bio);
109 struct bio_set *bs = bio->bi_pool;
111 if (bip->bip_flags & BIP_BLOCK_INTEGRITY)
112 kfree(page_address(bip->bip_vec->bv_page) +
113 bip->bip_vec->bv_offset);
115 __bio_integrity_free(bs, bip);
116 bio->bi_integrity = NULL;
117 bio->bi_opf &= ~REQ_INTEGRITY;
121 * bio_integrity_add_page - Attach integrity metadata
122 * @bio: bio to update
123 * @page: page containing integrity metadata
124 * @len: number of bytes of integrity metadata in page
125 * @offset: start offset within page
127 * Description: Attach a page containing integrity metadata to bio.
129 int bio_integrity_add_page(struct bio *bio, struct page *page,
130 unsigned int len, unsigned int offset)
132 struct bio_integrity_payload *bip = bio_integrity(bio);
135 if (bip->bip_vcnt >= bip->bip_max_vcnt) {
136 printk(KERN_ERR "%s: bip_vec full\n", __func__);
140 iv = bip->bip_vec + bip->bip_vcnt;
143 bvec_gap_to_prev(bio->bi_disk->queue,
144 &bip->bip_vec[bip->bip_vcnt - 1], offset))
149 iv->bv_offset = offset;
154 EXPORT_SYMBOL(bio_integrity_add_page);
157 * bio_integrity_process - Process integrity metadata for a bio
158 * @bio: bio to generate/verify integrity metadata for
159 * @proc_iter: iterator to process
160 * @proc_fn: Pointer to the relevant processing function
162 static blk_status_t bio_integrity_process(struct bio *bio,
163 struct bvec_iter *proc_iter, integrity_processing_fn *proc_fn)
165 struct blk_integrity *bi = blk_get_integrity(bio->bi_disk);
166 struct blk_integrity_iter iter;
167 struct bvec_iter bviter;
169 struct bio_integrity_payload *bip = bio_integrity(bio);
170 blk_status_t ret = BLK_STS_OK;
171 void *prot_buf = page_address(bip->bip_vec->bv_page) +
172 bip->bip_vec->bv_offset;
174 iter.disk_name = bio->bi_disk->disk_name;
175 iter.interval = 1 << bi->interval_exp;
176 iter.seed = proc_iter->bi_sector;
177 iter.prot_buf = prot_buf;
179 __bio_for_each_segment(bv, bio, bviter, *proc_iter) {
180 void *kaddr = kmap_atomic(bv.bv_page);
182 iter.data_buf = kaddr + bv.bv_offset;
183 iter.data_size = bv.bv_len;
185 ret = proc_fn(&iter);
187 kunmap_atomic(kaddr);
191 kunmap_atomic(kaddr);
197 * bio_integrity_prep - Prepare bio for integrity I/O
198 * @bio: bio to prepare
200 * Description: Checks if the bio already has an integrity payload attached.
201 * If it does, the payload has been generated by another kernel subsystem,
202 * and we just pass it through. Otherwise allocates integrity payload.
203 * The bio must have data direction, target device and start sector set priot
204 * to calling. In the WRITE case, integrity metadata will be generated using
205 * the block device's integrity function. In the READ case, the buffer
206 * will be prepared for DMA and a suitable end_io handler set up.
208 bool bio_integrity_prep(struct bio *bio)
210 struct bio_integrity_payload *bip;
211 struct blk_integrity *bi = blk_get_integrity(bio->bi_disk);
212 struct request_queue *q = bio->bi_disk->queue;
214 unsigned long start, end;
215 unsigned int len, nr_pages;
216 unsigned int bytes, offset, i;
217 unsigned int intervals;
223 if (bio_op(bio) != REQ_OP_READ && bio_op(bio) != REQ_OP_WRITE)
226 if (!bio_sectors(bio))
229 /* Already protected? */
230 if (bio_integrity(bio))
233 if (bio_data_dir(bio) == READ) {
234 if (!bi->profile->verify_fn ||
235 !(bi->flags & BLK_INTEGRITY_VERIFY))
238 if (!bi->profile->generate_fn ||
239 !(bi->flags & BLK_INTEGRITY_GENERATE))
242 intervals = bio_integrity_intervals(bi, bio_sectors(bio));
244 /* Allocate kernel buffer for protection data */
245 len = intervals * bi->tuple_size;
246 buf = kmalloc(len, GFP_NOIO | q->bounce_gfp);
247 status = BLK_STS_RESOURCE;
248 if (unlikely(buf == NULL)) {
249 printk(KERN_ERR "could not allocate integrity buffer\n");
253 end = (((unsigned long) buf) + len + PAGE_SIZE - 1) >> PAGE_SHIFT;
254 start = ((unsigned long) buf) >> PAGE_SHIFT;
255 nr_pages = end - start;
257 /* Allocate bio integrity payload and integrity vectors */
258 bip = bio_integrity_alloc(bio, GFP_NOIO, nr_pages);
260 printk(KERN_ERR "could not allocate data integrity bioset\n");
262 status = BLK_STS_RESOURCE;
266 bip->bip_flags |= BIP_BLOCK_INTEGRITY;
267 bip->bip_iter.bi_size = len;
268 bip_set_seed(bip, bio->bi_iter.bi_sector);
270 if (bi->flags & BLK_INTEGRITY_IP_CHECKSUM)
271 bip->bip_flags |= BIP_IP_CHECKSUM;
274 offset = offset_in_page(buf);
275 for (i = 0 ; i < nr_pages ; i++) {
277 bytes = PAGE_SIZE - offset;
285 ret = bio_integrity_add_page(bio, virt_to_page(buf),
289 printk(KERN_ERR "could not attach integrity payload\n");
290 status = BLK_STS_RESOURCE;
302 /* Auto-generate integrity metadata if this is a write */
303 if (bio_data_dir(bio) == WRITE) {
304 bio_integrity_process(bio, &bio->bi_iter,
305 bi->profile->generate_fn);
307 bip->bio_iter = bio->bi_iter;
312 bio->bi_status = status;
317 EXPORT_SYMBOL(bio_integrity_prep);
320 * bio_integrity_verify_fn - Integrity I/O completion worker
321 * @work: Work struct stored in bio to be verified
323 * Description: This workqueue function is called to complete a READ
324 * request. The function verifies the transferred integrity metadata
325 * and then calls the original bio end_io function.
327 static void bio_integrity_verify_fn(struct work_struct *work)
329 struct bio_integrity_payload *bip =
330 container_of(work, struct bio_integrity_payload, bip_work);
331 struct bio *bio = bip->bip_bio;
332 struct blk_integrity *bi = blk_get_integrity(bio->bi_disk);
335 * At the moment verify is called bio's iterator was advanced
336 * during split and completion, we need to rewind iterator to
337 * it's original position.
339 bio->bi_status = bio_integrity_process(bio, &bip->bio_iter,
340 bi->profile->verify_fn);
341 bio_integrity_free(bio);
346 * __bio_integrity_endio - Integrity I/O completion function
347 * @bio: Protected bio
349 * Description: Completion for integrity I/O
351 * Normally I/O completion is done in interrupt context. However,
352 * verifying I/O integrity is a time-consuming task which must be run
353 * in process context. This function postpones completion
356 bool __bio_integrity_endio(struct bio *bio)
358 struct blk_integrity *bi = blk_get_integrity(bio->bi_disk);
359 struct bio_integrity_payload *bip = bio_integrity(bio);
361 if (bio_op(bio) == REQ_OP_READ && !bio->bi_status &&
362 (bip->bip_flags & BIP_BLOCK_INTEGRITY) && bi->profile->verify_fn) {
363 INIT_WORK(&bip->bip_work, bio_integrity_verify_fn);
364 queue_work(kintegrityd_wq, &bip->bip_work);
368 bio_integrity_free(bio);
373 * bio_integrity_advance - Advance integrity vector
374 * @bio: bio whose integrity vector to update
375 * @bytes_done: number of data bytes that have been completed
377 * Description: This function calculates how many integrity bytes the
378 * number of completed data bytes correspond to and advances the
379 * integrity vector accordingly.
381 void bio_integrity_advance(struct bio *bio, unsigned int bytes_done)
383 struct bio_integrity_payload *bip = bio_integrity(bio);
384 struct blk_integrity *bi = blk_get_integrity(bio->bi_disk);
385 unsigned bytes = bio_integrity_bytes(bi, bytes_done >> 9);
387 bip->bip_iter.bi_sector += bio_integrity_intervals(bi, bytes_done >> 9);
388 bvec_iter_advance(bip->bip_vec, &bip->bip_iter, bytes);
392 * bio_integrity_trim - Trim integrity vector
393 * @bio: bio whose integrity vector to update
395 * Description: Used to trim the integrity vector in a cloned bio.
397 void bio_integrity_trim(struct bio *bio)
399 struct bio_integrity_payload *bip = bio_integrity(bio);
400 struct blk_integrity *bi = blk_get_integrity(bio->bi_disk);
402 bip->bip_iter.bi_size = bio_integrity_bytes(bi, bio_sectors(bio));
404 EXPORT_SYMBOL(bio_integrity_trim);
407 * bio_integrity_clone - Callback for cloning bios with integrity metadata
409 * @bio_src: Original bio
410 * @gfp_mask: Memory allocation mask
412 * Description: Called to allocate a bip when cloning a bio
414 int bio_integrity_clone(struct bio *bio, struct bio *bio_src,
417 struct bio_integrity_payload *bip_src = bio_integrity(bio_src);
418 struct bio_integrity_payload *bip;
420 BUG_ON(bip_src == NULL);
422 bip = bio_integrity_alloc(bio, gfp_mask, bip_src->bip_vcnt);
426 memcpy(bip->bip_vec, bip_src->bip_vec,
427 bip_src->bip_vcnt * sizeof(struct bio_vec));
429 bip->bip_vcnt = bip_src->bip_vcnt;
430 bip->bip_iter = bip_src->bip_iter;
431 bip->bip_flags = bip_src->bip_flags & ~BIP_BLOCK_INTEGRITY;
435 EXPORT_SYMBOL(bio_integrity_clone);
437 int bioset_integrity_create(struct bio_set *bs, int pool_size)
439 if (mempool_initialized(&bs->bio_integrity_pool))
442 if (mempool_init_slab_pool(&bs->bio_integrity_pool,
443 pool_size, bip_slab))
446 if (biovec_init_pool(&bs->bvec_integrity_pool, pool_size)) {
447 mempool_exit(&bs->bio_integrity_pool);
453 EXPORT_SYMBOL(bioset_integrity_create);
455 void bioset_integrity_free(struct bio_set *bs)
457 mempool_exit(&bs->bio_integrity_pool);
458 mempool_exit(&bs->bvec_integrity_pool);
461 void __init bio_integrity_init(void)
464 * kintegrityd won't block much but may burn a lot of CPU cycles.
465 * Make it highpri CPU intensive wq with max concurrency of 1.
467 kintegrityd_wq = alloc_workqueue("kintegrityd", WQ_MEM_RECLAIM |
468 WQ_HIGHPRI | WQ_CPU_INTENSIVE, 1);
470 panic("Failed to create kintegrityd\n");
472 bip_slab = kmem_cache_create("bio_integrity_payload",
473 sizeof(struct bio_integrity_payload) +
474 sizeof(struct bio_vec) * BIP_INLINE_VECS,
475 0, SLAB_HWCACHE_ALIGN|SLAB_PANIC, NULL);