cregit-Linux how code gets into the kernel

Release 4.12 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(). */
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; }


Martin K. Petersen7370.87%562.50%
Kent Overstreet2625.24%225.00%
Mike Snitzer43.88%112.50%

EXPORT_SYMBOL(bio_integrity_free); /** * 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(bdev_get_queue(bio->bi_bdev), &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. Petersen9270.77%240.00%
Sagi Grimberg3325.38%120.00%
Kent Overstreet32.31%120.00%
Gu Zheng21.54%120.00%

EXPORT_SYMBOL(bio_integrity_add_page); /** * bio_integrity_enabled - Check whether integrity can be passed * @bio: bio to check * * Description: Determines whether bio_integrity_prep() can be called * on this bio or not. bio data direction and target device must be * set prior to calling. The functions honors the write_generate and * read_verify flags in sysfs. */
bool bio_integrity_enabled(struct bio *bio) { struct blk_integrity *bi = bdev_get_integrity(bio->bi_bdev); if (bio_op(bio) != REQ_OP_READ && bio_op(bio) != REQ_OP_WRITE) return false; if (!bio_sectors(bio)) return false; /* Already protected? */ if (bio_integrity(bio)) return false; if (bi == NULL) return false; if (bio_data_dir(bio) == READ && bi->profile->verify_fn != NULL && (bi->flags & BLK_INTEGRITY_VERIFY)) return true; if (bio_data_dir(bio) == WRITE && bi->profile->generate_fn != NULL && (bi->flags & BLK_INTEGRITY_GENERATE)) return true; return false; }


Jens Axboe6348.09%114.29%
Martin K. Petersen4735.88%457.14%
Dmitriy Monakhov118.40%114.29%
Christoph Hellwig107.63%114.29%

EXPORT_SYMBOL(bio_integrity_enabled); /** * 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_fn: Pointer to the relevant processing function */
static int bio_integrity_process(struct bio *bio, integrity_processing_fn *proc_fn) { struct blk_integrity *bi = bdev_get_integrity(bio->bi_bdev); struct blk_integrity_iter iter; struct bvec_iter bviter; struct bio_vec bv; struct bio_integrity_payload *bip = bio_integrity(bio); unsigned int ret = 0; void *prot_buf = page_address(bip->bip_vec->bv_page) + bip->bip_vec->bv_offset; iter.disk_name = bio->bi_bdev->bd_disk->disk_name; iter.interval = 1 << bi->interval_exp; iter.seed = bip_get_seed(bip); iter.prot_buf = prot_buf; bio_for_each_segment(bv, bio, bviter) { 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. Petersen14278.89%666.67%
Gu Zheng2715.00%111.11%
Darrick J. Wong95.00%111.11%
Linus Torvalds21.11%111.11%

/** * bio_integrity_prep - Prepare bio for integrity I/O * @bio: bio to prepare * * Description: Allocates a buffer for integrity metadata, maps the * pages and attaches them to a bio. 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. */
int bio_integrity_prep(struct bio *bio) { struct bio_integrity_payload *bip; struct blk_integrity *bi; struct request_queue *q; void *buf; unsigned long start, end; unsigned int len, nr_pages; unsigned int bytes, offset, i; unsigned int intervals; bi = bdev_get_integrity(bio->bi_bdev); q = bdev_get_queue(bio->bi_bdev); BUG_ON(bi == NULL); BUG_ON(bio_integrity(bio)); 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); if (unlikely(buf == NULL)) { printk(KERN_ERR "could not allocate integrity buffer\n"); return -ENOMEM; } 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); return PTR_ERR(bip); } 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 0; if (ret < bytes) break; buf += bytes; len -= bytes; offset = 0; } /* Install custom I/O completion handler if read verify is enabled */ if (bio_data_dir(bio) == READ) { bip->bip_end_io = bio->bi_end_io; bio->bi_end_io = bio_integrity_endio; } /* Auto-generate integrity metadata if this is a write */ if (bio_data_dir(bio) == WRITE) bio_integrity_process(bio, bi->profile->generate_fn); return 0; }


Martin K. Petersen38596.49%758.33%
Kent Overstreet82.01%325.00%
Dan Carpenter51.25%18.33%
Andrew Morton10.25%18.33%

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 = bdev_get_integrity(bio->bi_bdev); bio->bi_error = bio_integrity_process(bio, bi->profile->verify_fn); /* Restore original bio completion handler */ bio->bi_end_io = bip->bip_end_io; bio_endio(bio); }


Martin K. Petersen7294.74%466.67%
Christoph Hellwig33.95%116.67%
Mike Snitzer11.32%116.67%

/** * 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. */
void bio_integrity_endio(struct bio *bio) { struct bio_integrity_payload *bip = bio_integrity(bio); BUG_ON(bip->bip_bio != bio); /* In case of an I/O error there is no point in verifying the * integrity metadata. Restore original bio end_io handler * and run it. */ if (bio->bi_error) { bio->bi_end_io = bip->bip_end_io; bio_endio(bio); return; } INIT_WORK(&bip->bip_work, bio_integrity_verify_fn); queue_work(kintegrityd_wq, &bip->bip_work); }


Martin K. Petersen6894.44%360.00%
Christoph Hellwig34.17%120.00%
Mike Snitzer11.39%120.00%

EXPORT_SYMBOL(bio_integrity_endio); /** * 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 = bdev_get_integrity(bio->bi_bdev); unsigned bytes = bio_integrity_bytes(bi, bytes_done >> 9); bvec_iter_advance(bip->bip_vec, &bip->bip_iter, bytes); }


Martin K. Petersen5080.65%266.67%
Kent Overstreet1219.35%133.33%

EXPORT_SYMBOL(bio_integrity_advance); /** * bio_integrity_trim - Trim integrity vector * @bio: bio whose integrity vector to update * @offset: offset to first data sector * @sectors: number of data sectors * * Description: Used to trim the integrity vector in a cloned bio. * The ivec will be advanced corresponding to 'offset' data sectors * and the length will be truncated corresponding to 'len' data * sectors. */
void bio_integrity_trim(struct bio *bio, unsigned int offset, unsigned int sectors) { struct bio_integrity_payload *bip = bio_integrity(bio); struct blk_integrity *bi = bdev_get_integrity(bio->bi_bdev); bio_integrity_advance(bio, offset << 9); bip->bip_iter.bi_size = bio_integrity_bytes(bi, sectors); }


Martin K. Petersen5487.10%266.67%
Kent Overstreet812.90%133.33%

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. Petersen139173.13%1735.42%
Kent Overstreet23212.20%612.50%
Jens Axboe643.36%24.17%
Gu Zheng613.21%36.25%
Sagi Grimberg331.74%12.08%
Christoph Hellwig281.47%36.25%
Tejun Heo130.68%24.17%
Dan Carpenter120.63%12.08%
Dan J Williams120.63%12.08%
Dmitriy Monakhov110.58%12.08%
Mike Snitzer110.58%24.17%
Keith Busch100.53%12.08%
Darrick J. Wong90.47%12.08%
Bart Van Assche30.16%12.08%
Jun'ichi Nomura30.16%12.08%
Paul Gortmaker30.16%12.08%
Linus Torvalds20.11%12.08%
Chuck Ebbert20.11%12.08%
Andrew Morton10.05%12.08%
Björn Helgaas10.05%12.08%
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