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 static struct kmem_cache *bip_slab;
18 static struct workqueue_struct *kintegrityd_wq;
20 void blk_flush_integrity(void)
22 flush_workqueue(kintegrityd_wq);
25 static void __bio_integrity_free(struct bio_set *bs,
26 struct bio_integrity_payload *bip)
28 if (bs && mempool_initialized(&bs->bio_integrity_pool)) {
30 bvec_free(&bs->bvec_integrity_pool, bip->bip_vec,
32 mempool_free(bip, &bs->bio_integrity_pool);
39 * bio_integrity_alloc - Allocate integrity payload and attach it to bio
40 * @bio: bio to attach integrity metadata to
41 * @gfp_mask: Memory allocation mask
42 * @nr_vecs: Number of integrity metadata scatter-gather elements
44 * Description: This function prepares a bio for attaching integrity
45 * metadata. nr_vecs specifies the maximum number of pages containing
46 * integrity metadata that can be attached.
48 struct bio_integrity_payload *bio_integrity_alloc(struct bio *bio,
52 struct bio_integrity_payload *bip;
53 struct bio_set *bs = bio->bi_pool;
56 if (WARN_ON_ONCE(bio_has_crypt_ctx(bio)))
57 return ERR_PTR(-EOPNOTSUPP);
59 if (!bs || !mempool_initialized(&bs->bio_integrity_pool)) {
60 bip = kmalloc(struct_size(bip, bip_inline_vecs, nr_vecs), gfp_mask);
61 inline_vecs = nr_vecs;
63 bip = mempool_alloc(&bs->bio_integrity_pool, gfp_mask);
64 inline_vecs = BIO_INLINE_VECS;
68 return ERR_PTR(-ENOMEM);
70 memset(bip, 0, sizeof(*bip));
72 if (nr_vecs > inline_vecs) {
73 bip->bip_max_vcnt = nr_vecs;
74 bip->bip_vec = bvec_alloc(&bs->bvec_integrity_pool,
75 &bip->bip_max_vcnt, gfp_mask);
79 bip->bip_vec = bip->bip_inline_vecs;
80 bip->bip_max_vcnt = inline_vecs;
84 bio->bi_integrity = bip;
85 bio->bi_opf |= REQ_INTEGRITY;
89 __bio_integrity_free(bs, bip);
90 return ERR_PTR(-ENOMEM);
92 EXPORT_SYMBOL(bio_integrity_alloc);
95 * bio_integrity_free - Free bio integrity payload
96 * @bio: bio containing bip to be freed
98 * Description: Used to free the integrity portion of a bio. Usually
99 * called from bio_free().
101 void bio_integrity_free(struct bio *bio)
103 struct bio_integrity_payload *bip = bio_integrity(bio);
104 struct bio_set *bs = bio->bi_pool;
106 if (bip->bip_flags & BIP_BLOCK_INTEGRITY)
107 kfree(page_address(bip->bip_vec->bv_page) +
108 bip->bip_vec->bv_offset);
110 __bio_integrity_free(bs, bip);
111 bio->bi_integrity = NULL;
112 bio->bi_opf &= ~REQ_INTEGRITY;
116 * bio_integrity_add_page - Attach integrity metadata
117 * @bio: bio to update
118 * @page: page containing integrity metadata
119 * @len: number of bytes of integrity metadata in page
120 * @offset: start offset within page
122 * Description: Attach a page containing integrity metadata to bio.
124 int bio_integrity_add_page(struct bio *bio, struct page *page,
125 unsigned int len, unsigned int offset)
127 struct bio_integrity_payload *bip = bio_integrity(bio);
130 if (bip->bip_vcnt >= bip->bip_max_vcnt) {
131 printk(KERN_ERR "%s: bip_vec full\n", __func__);
135 iv = bip->bip_vec + bip->bip_vcnt;
138 bvec_gap_to_prev(bio->bi_bdev->bd_disk->queue,
139 &bip->bip_vec[bip->bip_vcnt - 1], offset))
144 iv->bv_offset = offset;
149 EXPORT_SYMBOL(bio_integrity_add_page);
152 * bio_integrity_process - Process integrity metadata for a bio
153 * @bio: bio to generate/verify integrity metadata for
154 * @proc_iter: iterator to process
155 * @proc_fn: Pointer to the relevant processing function
157 static blk_status_t bio_integrity_process(struct bio *bio,
158 struct bvec_iter *proc_iter, integrity_processing_fn *proc_fn)
160 struct blk_integrity *bi = blk_get_integrity(bio->bi_bdev->bd_disk);
161 struct blk_integrity_iter iter;
162 struct bvec_iter bviter;
164 struct bio_integrity_payload *bip = bio_integrity(bio);
165 blk_status_t ret = BLK_STS_OK;
166 void *prot_buf = page_address(bip->bip_vec->bv_page) +
167 bip->bip_vec->bv_offset;
169 iter.disk_name = bio->bi_bdev->bd_disk->disk_name;
170 iter.interval = 1 << bi->interval_exp;
171 iter.seed = proc_iter->bi_sector;
172 iter.prot_buf = prot_buf;
174 __bio_for_each_segment(bv, bio, bviter, *proc_iter) {
175 void *kaddr = kmap_atomic(bv.bv_page);
177 iter.data_buf = kaddr + bv.bv_offset;
178 iter.data_size = bv.bv_len;
180 ret = proc_fn(&iter);
182 kunmap_atomic(kaddr);
186 kunmap_atomic(kaddr);
192 * bio_integrity_prep - Prepare bio for integrity I/O
193 * @bio: bio to prepare
195 * Description: Checks if the bio already has an integrity payload attached.
196 * If it does, the payload has been generated by another kernel subsystem,
197 * and we just pass it through. Otherwise allocates integrity payload.
198 * The bio must have data direction, target device and start sector set priot
199 * to calling. In the WRITE case, integrity metadata will be generated using
200 * the block device's integrity function. In the READ case, the buffer
201 * will be prepared for DMA and a suitable end_io handler set up.
203 bool bio_integrity_prep(struct bio *bio)
205 struct bio_integrity_payload *bip;
206 struct blk_integrity *bi = blk_get_integrity(bio->bi_bdev->bd_disk);
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);
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");
284 status = BLK_STS_RESOURCE;
296 /* Auto-generate integrity metadata if this is a write */
297 if (bio_data_dir(bio) == WRITE) {
298 bio_integrity_process(bio, &bio->bi_iter,
299 bi->profile->generate_fn);
301 bip->bio_iter = bio->bi_iter;
306 bio->bi_status = status;
311 EXPORT_SYMBOL(bio_integrity_prep);
314 * bio_integrity_verify_fn - Integrity I/O completion worker
315 * @work: Work struct stored in bio to be verified
317 * Description: This workqueue function is called to complete a READ
318 * request. The function verifies the transferred integrity metadata
319 * and then calls the original bio end_io function.
321 static void bio_integrity_verify_fn(struct work_struct *work)
323 struct bio_integrity_payload *bip =
324 container_of(work, struct bio_integrity_payload, bip_work);
325 struct bio *bio = bip->bip_bio;
326 struct blk_integrity *bi = blk_get_integrity(bio->bi_bdev->bd_disk);
329 * At the moment verify is called bio's iterator was advanced
330 * during split and completion, we need to rewind iterator to
331 * it's original position.
333 bio->bi_status = bio_integrity_process(bio, &bip->bio_iter,
334 bi->profile->verify_fn);
335 bio_integrity_free(bio);
340 * __bio_integrity_endio - Integrity I/O completion function
341 * @bio: Protected bio
343 * Description: Completion for integrity I/O
345 * Normally I/O completion is done in interrupt context. However,
346 * verifying I/O integrity is a time-consuming task which must be run
347 * in process context. This function postpones completion
350 bool __bio_integrity_endio(struct bio *bio)
352 struct blk_integrity *bi = blk_get_integrity(bio->bi_bdev->bd_disk);
353 struct bio_integrity_payload *bip = bio_integrity(bio);
355 if (bio_op(bio) == REQ_OP_READ && !bio->bi_status &&
356 (bip->bip_flags & BIP_BLOCK_INTEGRITY) && bi->profile->verify_fn) {
357 INIT_WORK(&bip->bip_work, bio_integrity_verify_fn);
358 queue_work(kintegrityd_wq, &bip->bip_work);
362 bio_integrity_free(bio);
367 * bio_integrity_advance - Advance integrity vector
368 * @bio: bio whose integrity vector to update
369 * @bytes_done: number of data bytes that have been completed
371 * Description: This function calculates how many integrity bytes the
372 * number of completed data bytes correspond to and advances the
373 * integrity vector accordingly.
375 void bio_integrity_advance(struct bio *bio, unsigned int bytes_done)
377 struct bio_integrity_payload *bip = bio_integrity(bio);
378 struct blk_integrity *bi = blk_get_integrity(bio->bi_bdev->bd_disk);
379 unsigned bytes = bio_integrity_bytes(bi, bytes_done >> 9);
381 bip->bip_iter.bi_sector += bytes_done >> 9;
382 bvec_iter_advance(bip->bip_vec, &bip->bip_iter, bytes);
386 * bio_integrity_trim - Trim integrity vector
387 * @bio: bio whose integrity vector to update
389 * Description: Used to trim the integrity vector in a cloned bio.
391 void bio_integrity_trim(struct bio *bio)
393 struct bio_integrity_payload *bip = bio_integrity(bio);
394 struct blk_integrity *bi = blk_get_integrity(bio->bi_bdev->bd_disk);
396 bip->bip_iter.bi_size = bio_integrity_bytes(bi, bio_sectors(bio));
398 EXPORT_SYMBOL(bio_integrity_trim);
401 * bio_integrity_clone - Callback for cloning bios with integrity metadata
403 * @bio_src: Original bio
404 * @gfp_mask: Memory allocation mask
406 * Description: Called to allocate a bip when cloning a bio
408 int bio_integrity_clone(struct bio *bio, struct bio *bio_src,
411 struct bio_integrity_payload *bip_src = bio_integrity(bio_src);
412 struct bio_integrity_payload *bip;
414 BUG_ON(bip_src == NULL);
416 bip = bio_integrity_alloc(bio, gfp_mask, bip_src->bip_vcnt);
420 memcpy(bip->bip_vec, bip_src->bip_vec,
421 bip_src->bip_vcnt * sizeof(struct bio_vec));
423 bip->bip_vcnt = bip_src->bip_vcnt;
424 bip->bip_iter = bip_src->bip_iter;
428 EXPORT_SYMBOL(bio_integrity_clone);
430 int bioset_integrity_create(struct bio_set *bs, int pool_size)
432 if (mempool_initialized(&bs->bio_integrity_pool))
435 if (mempool_init_slab_pool(&bs->bio_integrity_pool,
436 pool_size, bip_slab))
439 if (biovec_init_pool(&bs->bvec_integrity_pool, pool_size)) {
440 mempool_exit(&bs->bio_integrity_pool);
446 EXPORT_SYMBOL(bioset_integrity_create);
448 void bioset_integrity_free(struct bio_set *bs)
450 mempool_exit(&bs->bio_integrity_pool);
451 mempool_exit(&bs->bvec_integrity_pool);
454 void __init bio_integrity_init(void)
457 * kintegrityd won't block much but may burn a lot of CPU cycles.
458 * Make it highpri CPU intensive wq with max concurrency of 1.
460 kintegrityd_wq = alloc_workqueue("kintegrityd", WQ_MEM_RECLAIM |
461 WQ_HIGHPRI | WQ_CPU_INTENSIVE, 1);
463 panic("Failed to create kintegrityd\n");
465 bip_slab = kmem_cache_create("bio_integrity_payload",
466 sizeof(struct bio_integrity_payload) +
467 sizeof(struct bio_vec) * BIO_INLINE_VECS,
468 0, SLAB_HWCACHE_ALIGN|SLAB_PANIC, NULL);