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);
28 * bio_integrity_alloc - Allocate integrity payload and attach it to bio
29 * @bio: bio to attach integrity metadata to
30 * @gfp_mask: Memory allocation mask
31 * @nr_vecs: Number of integrity metadata scatter-gather elements
33 * Description: This function prepares a bio for attaching integrity
34 * metadata. nr_vecs specifies the maximum number of pages containing
35 * integrity metadata that can be attached.
37 struct bio_integrity_payload *bio_integrity_alloc(struct bio *bio,
41 struct bio_integrity_payload *bip;
42 struct bio_set *bs = bio->bi_pool;
45 if (WARN_ON_ONCE(bio_has_crypt_ctx(bio)))
46 return ERR_PTR(-EOPNOTSUPP);
48 if (!bs || !mempool_initialized(&bs->bio_integrity_pool)) {
49 bip = kmalloc(struct_size(bip, bip_inline_vecs, nr_vecs), gfp_mask);
50 inline_vecs = nr_vecs;
52 bip = mempool_alloc(&bs->bio_integrity_pool, gfp_mask);
53 inline_vecs = BIP_INLINE_VECS;
57 return ERR_PTR(-ENOMEM);
59 memset(bip, 0, sizeof(*bip));
61 if (nr_vecs > inline_vecs) {
62 unsigned long idx = 0;
64 bip->bip_vec = bvec_alloc(gfp_mask, nr_vecs, &idx,
65 &bs->bvec_integrity_pool);
68 bip->bip_max_vcnt = bvec_nr_vecs(idx);
71 bip->bip_vec = bip->bip_inline_vecs;
72 bip->bip_max_vcnt = inline_vecs;
76 bio->bi_integrity = bip;
77 bio->bi_opf |= REQ_INTEGRITY;
81 mempool_free(bip, &bs->bio_integrity_pool);
82 return ERR_PTR(-ENOMEM);
84 EXPORT_SYMBOL(bio_integrity_alloc);
87 * bio_integrity_free - Free bio integrity payload
88 * @bio: bio containing bip to be freed
90 * Description: Used to free the integrity portion of a bio. Usually
91 * called from bio_free().
93 void bio_integrity_free(struct bio *bio)
95 struct bio_integrity_payload *bip = bio_integrity(bio);
96 struct bio_set *bs = bio->bi_pool;
98 if (bip->bip_flags & BIP_BLOCK_INTEGRITY)
99 kfree(page_address(bip->bip_vec->bv_page) +
100 bip->bip_vec->bv_offset);
102 if (bs && mempool_initialized(&bs->bio_integrity_pool)) {
103 bvec_free(&bs->bvec_integrity_pool, bip->bip_vec, bip->bip_slab);
105 mempool_free(bip, &bs->bio_integrity_pool);
110 bio->bi_integrity = NULL;
111 bio->bi_opf &= ~REQ_INTEGRITY;
115 * bio_integrity_add_page - Attach integrity metadata
116 * @bio: bio to update
117 * @page: page containing integrity metadata
118 * @len: number of bytes of integrity metadata in page
119 * @offset: start offset within page
121 * Description: Attach a page containing integrity metadata to bio.
123 int bio_integrity_add_page(struct bio *bio, struct page *page,
124 unsigned int len, unsigned int offset)
126 struct bio_integrity_payload *bip = bio_integrity(bio);
129 if (bip->bip_vcnt >= bip->bip_max_vcnt) {
130 printk(KERN_ERR "%s: bip_vec full\n", __func__);
134 iv = bip->bip_vec + bip->bip_vcnt;
137 bvec_gap_to_prev(bio->bi_disk->queue,
138 &bip->bip_vec[bip->bip_vcnt - 1], offset))
143 iv->bv_offset = offset;
148 EXPORT_SYMBOL(bio_integrity_add_page);
151 * bio_integrity_process - Process integrity metadata for a bio
152 * @bio: bio to generate/verify integrity metadata for
153 * @proc_iter: iterator to process
154 * @proc_fn: Pointer to the relevant processing function
156 static blk_status_t bio_integrity_process(struct bio *bio,
157 struct bvec_iter *proc_iter, integrity_processing_fn *proc_fn)
159 struct blk_integrity *bi = blk_get_integrity(bio->bi_disk);
160 struct blk_integrity_iter iter;
161 struct bvec_iter bviter;
163 struct bio_integrity_payload *bip = bio_integrity(bio);
164 blk_status_t ret = BLK_STS_OK;
165 void *prot_buf = page_address(bip->bip_vec->bv_page) +
166 bip->bip_vec->bv_offset;
168 iter.disk_name = bio->bi_disk->disk_name;
169 iter.interval = 1 << bi->interval_exp;
170 iter.seed = proc_iter->bi_sector;
171 iter.prot_buf = prot_buf;
173 __bio_for_each_segment(bv, bio, bviter, *proc_iter) {
174 void *kaddr = kmap_atomic(bv.bv_page);
176 iter.data_buf = kaddr + bv.bv_offset;
177 iter.data_size = bv.bv_len;
179 ret = proc_fn(&iter);
181 kunmap_atomic(kaddr);
185 kunmap_atomic(kaddr);
191 * bio_integrity_prep - Prepare bio for integrity I/O
192 * @bio: bio to prepare
194 * Description: Checks if the bio already has an integrity payload attached.
195 * If it does, the payload has been generated by another kernel subsystem,
196 * and we just pass it through. Otherwise allocates integrity payload.
197 * The bio must have data direction, target device and start sector set priot
198 * to calling. In the WRITE case, integrity metadata will be generated using
199 * the block device's integrity function. In the READ case, the buffer
200 * will be prepared for DMA and a suitable end_io handler set up.
202 bool bio_integrity_prep(struct bio *bio)
204 struct bio_integrity_payload *bip;
205 struct blk_integrity *bi = blk_get_integrity(bio->bi_disk);
206 struct request_queue *q = bio->bi_disk->queue;
208 unsigned long start, end;
209 unsigned int len, nr_pages;
210 unsigned int bytes, offset, i;
211 unsigned int intervals;
217 if (bio_op(bio) != REQ_OP_READ && bio_op(bio) != REQ_OP_WRITE)
220 if (!bio_sectors(bio))
223 /* Already protected? */
224 if (bio_integrity(bio))
227 if (bio_data_dir(bio) == READ) {
228 if (!bi->profile->verify_fn ||
229 !(bi->flags & BLK_INTEGRITY_VERIFY))
232 if (!bi->profile->generate_fn ||
233 !(bi->flags & BLK_INTEGRITY_GENERATE))
236 intervals = bio_integrity_intervals(bi, bio_sectors(bio));
238 /* Allocate kernel buffer for protection data */
239 len = intervals * bi->tuple_size;
240 buf = kmalloc(len, GFP_NOIO | q->bounce_gfp);
241 status = BLK_STS_RESOURCE;
242 if (unlikely(buf == NULL)) {
243 printk(KERN_ERR "could not allocate integrity buffer\n");
247 end = (((unsigned long) buf) + len + PAGE_SIZE - 1) >> PAGE_SHIFT;
248 start = ((unsigned long) buf) >> PAGE_SHIFT;
249 nr_pages = end - start;
251 /* Allocate bio integrity payload and integrity vectors */
252 bip = bio_integrity_alloc(bio, GFP_NOIO, nr_pages);
254 printk(KERN_ERR "could not allocate data integrity bioset\n");
256 status = BLK_STS_RESOURCE;
260 bip->bip_flags |= BIP_BLOCK_INTEGRITY;
261 bip->bip_iter.bi_size = len;
262 bip_set_seed(bip, bio->bi_iter.bi_sector);
264 if (bi->flags & BLK_INTEGRITY_IP_CHECKSUM)
265 bip->bip_flags |= BIP_IP_CHECKSUM;
268 offset = offset_in_page(buf);
269 for (i = 0 ; i < nr_pages ; i++) {
271 bytes = PAGE_SIZE - offset;
279 ret = bio_integrity_add_page(bio, virt_to_page(buf),
283 printk(KERN_ERR "could not attach integrity payload\n");
285 status = BLK_STS_RESOURCE;
297 /* Auto-generate integrity metadata if this is a write */
298 if (bio_data_dir(bio) == WRITE) {
299 bio_integrity_process(bio, &bio->bi_iter,
300 bi->profile->generate_fn);
302 bip->bio_iter = bio->bi_iter;
307 bio->bi_status = status;
312 EXPORT_SYMBOL(bio_integrity_prep);
315 * bio_integrity_verify_fn - Integrity I/O completion worker
316 * @work: Work struct stored in bio to be verified
318 * Description: This workqueue function is called to complete a READ
319 * request. The function verifies the transferred integrity metadata
320 * and then calls the original bio end_io function.
322 static void bio_integrity_verify_fn(struct work_struct *work)
324 struct bio_integrity_payload *bip =
325 container_of(work, struct bio_integrity_payload, bip_work);
326 struct bio *bio = bip->bip_bio;
327 struct blk_integrity *bi = blk_get_integrity(bio->bi_disk);
330 * At the moment verify is called bio's iterator was advanced
331 * during split and completion, we need to rewind iterator to
332 * it's original position.
334 bio->bi_status = bio_integrity_process(bio, &bip->bio_iter,
335 bi->profile->verify_fn);
336 bio_integrity_free(bio);
341 * __bio_integrity_endio - Integrity I/O completion function
342 * @bio: Protected bio
344 * Description: Completion for integrity I/O
346 * Normally I/O completion is done in interrupt context. However,
347 * verifying I/O integrity is a time-consuming task which must be run
348 * in process context. This function postpones completion
351 bool __bio_integrity_endio(struct bio *bio)
353 struct blk_integrity *bi = blk_get_integrity(bio->bi_disk);
354 struct bio_integrity_payload *bip = bio_integrity(bio);
356 if (bio_op(bio) == REQ_OP_READ && !bio->bi_status &&
357 (bip->bip_flags & BIP_BLOCK_INTEGRITY) && bi->profile->verify_fn) {
358 INIT_WORK(&bip->bip_work, bio_integrity_verify_fn);
359 queue_work(kintegrityd_wq, &bip->bip_work);
363 bio_integrity_free(bio);
368 * bio_integrity_advance - Advance integrity vector
369 * @bio: bio whose integrity vector to update
370 * @bytes_done: number of data bytes that have been completed
372 * Description: This function calculates how many integrity bytes the
373 * number of completed data bytes correspond to and advances the
374 * integrity vector accordingly.
376 void bio_integrity_advance(struct bio *bio, unsigned int bytes_done)
378 struct bio_integrity_payload *bip = bio_integrity(bio);
379 struct blk_integrity *bi = blk_get_integrity(bio->bi_disk);
380 unsigned bytes = bio_integrity_bytes(bi, bytes_done >> 9);
382 bip->bip_iter.bi_sector += bytes_done >> 9;
383 bvec_iter_advance(bip->bip_vec, &bip->bip_iter, bytes);
387 * bio_integrity_trim - Trim integrity vector
388 * @bio: bio whose integrity vector to update
390 * Description: Used to trim the integrity vector in a cloned bio.
392 void bio_integrity_trim(struct bio *bio)
394 struct bio_integrity_payload *bip = bio_integrity(bio);
395 struct blk_integrity *bi = blk_get_integrity(bio->bi_disk);
397 bip->bip_iter.bi_size = bio_integrity_bytes(bi, bio_sectors(bio));
399 EXPORT_SYMBOL(bio_integrity_trim);
402 * bio_integrity_clone - Callback for cloning bios with integrity metadata
404 * @bio_src: Original bio
405 * @gfp_mask: Memory allocation mask
407 * Description: Called to allocate a bip when cloning a bio
409 int bio_integrity_clone(struct bio *bio, struct bio *bio_src,
412 struct bio_integrity_payload *bip_src = bio_integrity(bio_src);
413 struct bio_integrity_payload *bip;
415 BUG_ON(bip_src == NULL);
417 bip = bio_integrity_alloc(bio, gfp_mask, bip_src->bip_vcnt);
421 memcpy(bip->bip_vec, bip_src->bip_vec,
422 bip_src->bip_vcnt * sizeof(struct bio_vec));
424 bip->bip_vcnt = bip_src->bip_vcnt;
425 bip->bip_iter = bip_src->bip_iter;
429 EXPORT_SYMBOL(bio_integrity_clone);
431 int bioset_integrity_create(struct bio_set *bs, int pool_size)
433 if (mempool_initialized(&bs->bio_integrity_pool))
436 if (mempool_init_slab_pool(&bs->bio_integrity_pool,
437 pool_size, bip_slab))
440 if (biovec_init_pool(&bs->bvec_integrity_pool, pool_size)) {
441 mempool_exit(&bs->bio_integrity_pool);
447 EXPORT_SYMBOL(bioset_integrity_create);
449 void bioset_integrity_free(struct bio_set *bs)
451 mempool_exit(&bs->bio_integrity_pool);
452 mempool_exit(&bs->bvec_integrity_pool);
455 void __init bio_integrity_init(void)
458 * kintegrityd won't block much but may burn a lot of CPU cycles.
459 * Make it highpri CPU intensive wq with max concurrency of 1.
461 kintegrityd_wq = alloc_workqueue("kintegrityd", WQ_MEM_RECLAIM |
462 WQ_HIGHPRI | WQ_CPU_INTENSIVE, 1);
464 panic("Failed to create kintegrityd\n");
466 bip_slab = kmem_cache_create("bio_integrity_payload",
467 sizeof(struct bio_integrity_payload) +
468 sizeof(struct bio_vec) * BIP_INLINE_VECS,
469 0, SLAB_HWCACHE_ALIGN|SLAB_PANIC, NULL);