cregit-Linux how code gets into the kernel

Release 4.14 block/bio-integrity.c

Directory: block
 * bio-integrity.c - bio data integrity extensions
 * Copyright (C) 2007, 2008, 2009 Oracle Corporation
 * Written by: Martin K. Petersen <>
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License version
 * 2 as published by the Free Software Foundation.
 * This program is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * General Public License for more details.
 * You should have received a copy of the GNU General Public License
 * along with this program; see the file COPYING.  If not, write to
 * the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139,
 * USA.

#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"


static struct kmem_cache *bip_slab;

static struct workqueue_struct *kintegrityd_wq;

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


Dan J Williams12100.00%1100.00%

/** * 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 (!bs || !bs->bio_integrity_pool) { bip = kmalloc(sizeof(struct bio_integrity_payload) + sizeof(struct bio_vec) * 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: mempool_free(bip, bs->bio_integrity_pool); return ERR_PTR(-ENOMEM); }


Kent Overstreet10143.53%325.00%
Martin K. Petersen8637.07%325.00%
Gu Zheng156.47%18.33%
Christoph Hellwig125.17%18.33%
Keith Busch104.31%18.33%
Mike Snitzer52.16%18.33%
Chuck Ebbert20.86%18.33%
Jens Axboe10.43%18.33%

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(). */
static 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); if (bs && bs->bio_integrity_pool) { bvec_free(bs->bvec_integrity_pool, bip->bip_vec, bip->bip_slab); mempool_free(bip, bs->bio_integrity_pool); } else { kfree(bip); } bio->bi_integrity = NULL; bio->bi_opf &= ~REQ_INTEGRITY; }


Martin K. Petersen7365.77%555.56%
Kent Overstreet2623.42%222.22%
Christoph Hellwig87.21%111.11%
Mike Snitzer43.60%111.11%

/** * 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; }


Martin K. Petersen9271.32%233.33%
Sagi Grimberg2922.48%116.67%
Kent Overstreet32.33%116.67%
Christoph Hellwig32.33%116.67%
Gu Zheng21.55%116.67%

EXPORT_SYMBOL(bio_integrity_add_page); /** * bio_integrity_intervals - Return number of integrity intervals for a bio * @bi: blk_integrity profile for device * @sectors: Size of the bio in 512-byte sectors * * Description: The block layer calculates everything in 512 byte * sectors but integrity metadata is done in terms of the data integrity * interval size of the storage device. Convert the block layer sectors * to the appropriate number of integrity intervals. */
static inline unsigned int bio_integrity_intervals(struct blk_integrity *bi, unsigned int sectors) { return sectors >> (bi->interval_exp - 9); }


Martin K. Petersen28100.00%4100.00%

static inline unsigned int bio_integrity_bytes(struct blk_integrity *bi, unsigned int sectors) { return bio_integrity_intervals(bi, sectors) * bi->tuple_size; }


Kent Overstreet2896.55%150.00%
Martin K. Petersen13.45%150.00%

/** * 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; }


Martin K. Petersen13171.58%650.00%
Gu Zheng2614.21%18.33%
Dmitriy Monakhov116.01%18.33%
Darrick J. Wong84.37%18.33%
Christoph Hellwig63.28%216.67%
Linus Torvalds10.55%18.33%

/** * 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) return false; 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); } return true; err_end_io: bio->bi_status = status; bio_endio(bio); return false; }


Martin K. Petersen32767.01%743.75%
Dmitriy Monakhov13126.84%212.50%
Christoph Hellwig204.10%212.50%
Kent Overstreet81.64%318.75%
Dan Carpenter10.20%16.25%
Fengguang Wu10.20%16.25%

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); struct bvec_iter iter = bio->bi_iter; /* * 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. */ if (bio_rewind_iter(bio, &iter, iter.bi_done)) { bio->bi_status = bio_integrity_process(bio, &iter, bi->profile->verify_fn); } else { bio->bi_status = BLK_STS_IOERR; } bio_integrity_free(bio); bio_endio(bio); }


Martin K. Petersen6357.80%440.00%
Dmitriy Monakhov3733.94%110.00%
Christoph Hellwig87.34%440.00%
Mike Snitzer10.92%110.00%

/** * __bio_integrity_endio - Integrity I/O completion function * @bio: Protected bio * @error: Pointer to errno * * 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; }


Christoph Hellwig3941.94%450.00%
Martin K. Petersen3638.71%225.00%
Milan Broz1819.35%225.00%

/** * 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 += bytes_done >> 9; bvec_iter_advance(bip->bip_vec, &bip->bip_iter, bytes); }


Martin K. Petersen4866.67%240.00%
Kent Overstreet1216.67%120.00%
Dmitriy Monakhov1013.89%120.00%
Christoph Hellwig22.78%120.00%

EXPORT_SYMBOL(bio_integrity_advance); /** * 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)); }


Martin K. Petersen3879.17%240.00%
Kent Overstreet48.33%120.00%
Dmitriy Monakhov48.33%120.00%
Christoph Hellwig24.17%120.00%

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; return 0; }


Martin K. Petersen9387.74%233.33%
Dan Carpenter76.60%116.67%
Kent Overstreet32.83%233.33%
Jun'ichi Nomura32.83%116.67%

int bioset_integrity_create(struct bio_set *bs, int pool_size) { if (bs->bio_integrity_pool) return 0; bs->bio_integrity_pool = mempool_create_slab_pool(pool_size, bip_slab); if (!bs->bio_integrity_pool) return -1; bs->bvec_integrity_pool = biovec_create_pool(pool_size); if (!bs->bvec_integrity_pool) { mempool_destroy(bs->bio_integrity_pool); return -1; } return 0; }


Martin K. Petersen4356.58%360.00%
Gu Zheng1722.37%120.00%
Kent Overstreet1621.05%120.00%

void bioset_integrity_free(struct bio_set *bs) { if (bs->bio_integrity_pool) mempool_destroy(bs->bio_integrity_pool); if (bs->bvec_integrity_pool) mempool_destroy(bs->bvec_integrity_pool); }


Martin K. Petersen2363.89%250.00%
Kent Overstreet1233.33%125.00%
Björn Helgaas12.78%125.00%

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); }


Martin K. Petersen4673.02%360.00%
Tejun Heo1015.87%120.00%
Kent Overstreet711.11%120.00%

Overall Contributors

Martin K. Petersen119662.82%1527.78%
Kent Overstreet22811.97%611.11%
Dmitriy Monakhov19610.29%47.41%
Christoph Hellwig1015.30%712.96%
Gu Zheng603.15%35.56%
Sagi Grimberg291.52%11.85%
Milan Broz180.95%23.70%
Tejun Heo130.68%23.70%
Dan J Williams120.63%11.85%
Keith Busch100.53%11.85%
Mike Snitzer100.53%23.70%
Dan Carpenter80.42%11.85%
Darrick J. Wong80.42%11.85%
Paul Gortmaker30.16%11.85%
Bart Van Assche30.16%11.85%
Jun'ichi Nomura30.16%11.85%
Chuck Ebbert20.11%11.85%
Fengguang Wu10.05%11.85%
Jens Axboe10.05%11.85%
Björn Helgaas10.05%11.85%
Linus Torvalds10.05%11.85%
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