linux-hardened/fs/bio-integrity.c
Paul Gortmaker afeacc8c1f fs: add export.h to files using EXPORT_SYMBOL/THIS_MODULE macros
These files were getting <linux/module.h> via an implicit include
path, but we want to crush those out of existence since they cost
time during compiles of processing thousands of lines of headers
for no reason.  Give them the lightweight header that just contains
the EXPORT_SYMBOL infrastructure.

Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
2011-10-31 19:30:31 -04:00

808 lines
21 KiB
C

/*
* bio-integrity.c - bio data integrity extensions
*
* Copyright (C) 2007, 2008, 2009 Oracle Corporation
* Written by: Martin K. Petersen <martin.petersen@oracle.com>
*
* 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
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* 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>
struct integrity_slab {
struct kmem_cache *slab;
unsigned short nr_vecs;
char name[8];
};
#define IS(x) { .nr_vecs = x, .name = "bip-"__stringify(x) }
struct integrity_slab bip_slab[BIOVEC_NR_POOLS] __read_mostly = {
IS(1), IS(4), IS(16), IS(64), IS(128), IS(BIO_MAX_PAGES),
};
#undef IS
static struct workqueue_struct *kintegrityd_wq;
static inline unsigned int vecs_to_idx(unsigned int nr)
{
switch (nr) {
case 1:
return 0;
case 2 ... 4:
return 1;
case 5 ... 16:
return 2;
case 17 ... 64:
return 3;
case 65 ... 128:
return 4;
case 129 ... BIO_MAX_PAGES:
return 5;
default:
BUG();
}
}
static inline int use_bip_pool(unsigned int idx)
{
if (idx == BIOVEC_MAX_IDX)
return 1;
return 0;
}
/**
* bio_integrity_alloc_bioset - 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
* @bs: bio_set to allocate from
*
* 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_bioset(struct bio *bio,
gfp_t gfp_mask,
unsigned int nr_vecs,
struct bio_set *bs)
{
struct bio_integrity_payload *bip;
unsigned int idx = vecs_to_idx(nr_vecs);
BUG_ON(bio == NULL);
bip = NULL;
/* Lower order allocations come straight from slab */
if (!use_bip_pool(idx))
bip = kmem_cache_alloc(bip_slab[idx].slab, gfp_mask);
/* Use mempool if lower order alloc failed or max vecs were requested */
if (bip == NULL) {
idx = BIOVEC_MAX_IDX; /* so we free the payload properly later */
bip = mempool_alloc(bs->bio_integrity_pool, gfp_mask);
if (unlikely(bip == NULL)) {
printk(KERN_ERR "%s: could not alloc bip\n", __func__);
return NULL;
}
}
memset(bip, 0, sizeof(*bip));
bip->bip_slab = idx;
bip->bip_bio = bio;
bio->bi_integrity = bip;
return bip;
}
EXPORT_SYMBOL(bio_integrity_alloc_bioset);
/**
* 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)
{
return bio_integrity_alloc_bioset(bio, gfp_mask, nr_vecs, fs_bio_set);
}
EXPORT_SYMBOL(bio_integrity_alloc);
/**
* bio_integrity_free - Free bio integrity payload
* @bio: bio containing bip to be freed
* @bs: bio_set this bio was allocated from
*
* Description: Used to free the integrity portion of a bio. Usually
* called from bio_free().
*/
void bio_integrity_free(struct bio *bio, struct bio_set *bs)
{
struct bio_integrity_payload *bip = bio->bi_integrity;
BUG_ON(bip == NULL);
/* A cloned bio doesn't own the integrity metadata */
if (!bio_flagged(bio, BIO_CLONED) && !bio_flagged(bio, BIO_FS_INTEGRITY)
&& bip->bip_buf != NULL)
kfree(bip->bip_buf);
if (use_bip_pool(bip->bip_slab))
mempool_free(bip, bs->bio_integrity_pool);
else
kmem_cache_free(bip_slab[bip->bip_slab].slab, bip);
bio->bi_integrity = NULL;
}
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->bi_integrity;
struct bio_vec *iv;
if (bip->bip_vcnt >= bvec_nr_vecs(bip->bip_slab)) {
printk(KERN_ERR "%s: bip_vec full\n", __func__);
return 0;
}
iv = bip_vec_idx(bip, bip->bip_vcnt);
BUG_ON(iv == NULL);
iv->bv_page = page;
iv->bv_len = len;
iv->bv_offset = offset;
bip->bip_vcnt++;
return len;
}
EXPORT_SYMBOL(bio_integrity_add_page);
static int bdev_integrity_enabled(struct block_device *bdev, int rw)
{
struct blk_integrity *bi = bdev_get_integrity(bdev);
if (bi == NULL)
return 0;
if (rw == READ && bi->verify_fn != NULL &&
(bi->flags & INTEGRITY_FLAG_READ))
return 1;
if (rw == WRITE && bi->generate_fn != NULL &&
(bi->flags & INTEGRITY_FLAG_WRITE))
return 1;
return 0;
}
/**
* 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.
*/
int bio_integrity_enabled(struct bio *bio)
{
/* Already protected? */
if (bio_integrity(bio))
return 0;
return bdev_integrity_enabled(bio->bi_bdev, bio_data_dir(bio));
}
EXPORT_SYMBOL(bio_integrity_enabled);
/**
* bio_integrity_hw_sectors - Convert 512b sectors to hardware ditto
* @bi: blk_integrity profile for device
* @sectors: Number of 512 sectors to convert
*
* Description: The block layer calculates everything in 512 byte
* sectors but integrity metadata is done in terms of the hardware
* sector size of the storage device. Convert the block layer sectors
* to physical sectors.
*/
static inline unsigned int bio_integrity_hw_sectors(struct blk_integrity *bi,
unsigned int sectors)
{
/* At this point there are only 512b or 4096b DIF/EPP devices */
if (bi->sector_size == 4096)
return sectors >>= 3;
return sectors;
}
/**
* bio_integrity_tag_size - Retrieve integrity tag space
* @bio: bio to inspect
*
* Description: Returns the maximum number of tag bytes that can be
* attached to this bio. Filesystems can use this to determine how
* much metadata to attach to an I/O.
*/
unsigned int bio_integrity_tag_size(struct bio *bio)
{
struct blk_integrity *bi = bdev_get_integrity(bio->bi_bdev);
BUG_ON(bio->bi_size == 0);
return bi->tag_size * (bio->bi_size / bi->sector_size);
}
EXPORT_SYMBOL(bio_integrity_tag_size);
int bio_integrity_tag(struct bio *bio, void *tag_buf, unsigned int len, int set)
{
struct bio_integrity_payload *bip = bio->bi_integrity;
struct blk_integrity *bi = bdev_get_integrity(bio->bi_bdev);
unsigned int nr_sectors;
BUG_ON(bip->bip_buf == NULL);
if (bi->tag_size == 0)
return -1;
nr_sectors = bio_integrity_hw_sectors(bi,
DIV_ROUND_UP(len, bi->tag_size));
if (nr_sectors * bi->tuple_size > bip->bip_size) {
printk(KERN_ERR "%s: tag too big for bio: %u > %u\n",
__func__, nr_sectors * bi->tuple_size, bip->bip_size);
return -1;
}
if (set)
bi->set_tag_fn(bip->bip_buf, tag_buf, nr_sectors);
else
bi->get_tag_fn(bip->bip_buf, tag_buf, nr_sectors);
return 0;
}
/**
* bio_integrity_set_tag - Attach a tag buffer to a bio
* @bio: bio to attach buffer to
* @tag_buf: Pointer to a buffer containing tag data
* @len: Length of the included buffer
*
* Description: Use this function to tag a bio by leveraging the extra
* space provided by devices formatted with integrity protection. The
* size of the integrity buffer must be <= to the size reported by
* bio_integrity_tag_size().
*/
int bio_integrity_set_tag(struct bio *bio, void *tag_buf, unsigned int len)
{
BUG_ON(bio_data_dir(bio) != WRITE);
return bio_integrity_tag(bio, tag_buf, len, 1);
}
EXPORT_SYMBOL(bio_integrity_set_tag);
/**
* bio_integrity_get_tag - Retrieve a tag buffer from a bio
* @bio: bio to retrieve buffer from
* @tag_buf: Pointer to a buffer for the tag data
* @len: Length of the target buffer
*
* Description: Use this function to retrieve the tag buffer from a
* completed I/O. The size of the integrity buffer must be <= to the
* size reported by bio_integrity_tag_size().
*/
int bio_integrity_get_tag(struct bio *bio, void *tag_buf, unsigned int len)
{
BUG_ON(bio_data_dir(bio) != READ);
return bio_integrity_tag(bio, tag_buf, len, 0);
}
EXPORT_SYMBOL(bio_integrity_get_tag);
/**
* bio_integrity_generate - Generate integrity metadata for a bio
* @bio: bio to generate integrity metadata for
*
* Description: Generates integrity metadata for a bio by calling the
* block device's generation callback function. The bio must have a
* bip attached with enough room to accommodate the generated
* integrity metadata.
*/
static void bio_integrity_generate(struct bio *bio)
{
struct blk_integrity *bi = bdev_get_integrity(bio->bi_bdev);
struct blk_integrity_exchg bix;
struct bio_vec *bv;
sector_t sector = bio->bi_sector;
unsigned int i, sectors, total;
void *prot_buf = bio->bi_integrity->bip_buf;
total = 0;
bix.disk_name = bio->bi_bdev->bd_disk->disk_name;
bix.sector_size = bi->sector_size;
bio_for_each_segment(bv, bio, i) {
void *kaddr = kmap_atomic(bv->bv_page, KM_USER0);
bix.data_buf = kaddr + bv->bv_offset;
bix.data_size = bv->bv_len;
bix.prot_buf = prot_buf;
bix.sector = sector;
bi->generate_fn(&bix);
sectors = bv->bv_len / bi->sector_size;
sector += sectors;
prot_buf += sectors * bi->tuple_size;
total += sectors * bi->tuple_size;
BUG_ON(total > bio->bi_integrity->bip_size);
kunmap_atomic(kaddr, KM_USER0);
}
}
static inline unsigned short blk_integrity_tuple_size(struct blk_integrity *bi)
{
if (bi)
return bi->tuple_size;
return 0;
}
/**
* 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 sectors;
bi = bdev_get_integrity(bio->bi_bdev);
q = bdev_get_queue(bio->bi_bdev);
BUG_ON(bi == NULL);
BUG_ON(bio_integrity(bio));
sectors = bio_integrity_hw_sectors(bi, bio_sectors(bio));
/* Allocate kernel buffer for protection data */
len = sectors * blk_integrity_tuple_size(bi);
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 (unlikely(bip == NULL)) {
printk(KERN_ERR "could not allocate data integrity bioset\n");
kfree(buf);
return -EIO;
}
bip->bip_buf = buf;
bip->bip_size = len;
bip->bip_sector = bio->bi_sector;
/* 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_generate(bio);
return 0;
}
EXPORT_SYMBOL(bio_integrity_prep);
/**
* bio_integrity_verify - Verify integrity metadata for a bio
* @bio: bio to verify
*
* Description: This function is called to verify the integrity of a
* bio. The data in the bio io_vec is compared to the integrity
* metadata returned by the HBA.
*/
static int bio_integrity_verify(struct bio *bio)
{
struct blk_integrity *bi = bdev_get_integrity(bio->bi_bdev);
struct blk_integrity_exchg bix;
struct bio_vec *bv;
sector_t sector = bio->bi_integrity->bip_sector;
unsigned int i, sectors, total, ret;
void *prot_buf = bio->bi_integrity->bip_buf;
ret = total = 0;
bix.disk_name = bio->bi_bdev->bd_disk->disk_name;
bix.sector_size = bi->sector_size;
bio_for_each_segment(bv, bio, i) {
void *kaddr = kmap_atomic(bv->bv_page, KM_USER0);
bix.data_buf = kaddr + bv->bv_offset;
bix.data_size = bv->bv_len;
bix.prot_buf = prot_buf;
bix.sector = sector;
ret = bi->verify_fn(&bix);
if (ret) {
kunmap_atomic(kaddr, KM_USER0);
return ret;
}
sectors = bv->bv_len / bi->sector_size;
sector += sectors;
prot_buf += sectors * bi->tuple_size;
total += sectors * bi->tuple_size;
BUG_ON(total > bio->bi_integrity->bip_size);
kunmap_atomic(kaddr, KM_USER0);
}
return ret;
}
/**
* 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;
int error;
error = bio_integrity_verify(bio);
/* Restore original bio completion handler */
bio->bi_end_io = bip->bip_end_io;
bio_endio(bio, error);
}
/**
* 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, int error)
{
struct bio_integrity_payload *bip = bio->bi_integrity;
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 (error) {
bio->bi_end_io = bip->bip_end_io;
bio_endio(bio, error);
return;
}
INIT_WORK(&bip->bip_work, bio_integrity_verify_fn);
queue_work(kintegrityd_wq, &bip->bip_work);
}
EXPORT_SYMBOL(bio_integrity_endio);
/**
* bio_integrity_mark_head - Advance bip_vec skip bytes
* @bip: Integrity vector to advance
* @skip: Number of bytes to advance it
*/
void bio_integrity_mark_head(struct bio_integrity_payload *bip,
unsigned int skip)
{
struct bio_vec *iv;
unsigned int i;
bip_for_each_vec(iv, bip, i) {
if (skip == 0) {
bip->bip_idx = i;
return;
} else if (skip >= iv->bv_len) {
skip -= iv->bv_len;
} else { /* skip < iv->bv_len) */
iv->bv_offset += skip;
iv->bv_len -= skip;
bip->bip_idx = i;
return;
}
}
}
/**
* bio_integrity_mark_tail - Truncate bip_vec to be len bytes long
* @bip: Integrity vector to truncate
* @len: New length of integrity vector
*/
void bio_integrity_mark_tail(struct bio_integrity_payload *bip,
unsigned int len)
{
struct bio_vec *iv;
unsigned int i;
bip_for_each_vec(iv, bip, i) {
if (len == 0) {
bip->bip_vcnt = i;
return;
} else if (len >= iv->bv_len) {
len -= iv->bv_len;
} else { /* len < iv->bv_len) */
iv->bv_len = len;
len = 0;
}
}
}
/**
* 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->bi_integrity;
struct blk_integrity *bi = bdev_get_integrity(bio->bi_bdev);
unsigned int nr_sectors;
BUG_ON(bip == NULL);
BUG_ON(bi == NULL);
nr_sectors = bio_integrity_hw_sectors(bi, bytes_done >> 9);
bio_integrity_mark_head(bip, nr_sectors * bi->tuple_size);
}
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->bi_integrity;
struct blk_integrity *bi = bdev_get_integrity(bio->bi_bdev);
unsigned int nr_sectors;
BUG_ON(bip == NULL);
BUG_ON(bi == NULL);
BUG_ON(!bio_flagged(bio, BIO_CLONED));
nr_sectors = bio_integrity_hw_sectors(bi, sectors);
bip->bip_sector = bip->bip_sector + offset;
bio_integrity_mark_head(bip, offset * bi->tuple_size);
bio_integrity_mark_tail(bip, sectors * bi->tuple_size);
}
EXPORT_SYMBOL(bio_integrity_trim);
/**
* bio_integrity_split - Split integrity metadata
* @bio: Protected bio
* @bp: Resulting bio_pair
* @sectors: Offset
*
* Description: Splits an integrity page into a bio_pair.
*/
void bio_integrity_split(struct bio *bio, struct bio_pair *bp, int sectors)
{
struct blk_integrity *bi;
struct bio_integrity_payload *bip = bio->bi_integrity;
unsigned int nr_sectors;
if (bio_integrity(bio) == 0)
return;
bi = bdev_get_integrity(bio->bi_bdev);
BUG_ON(bi == NULL);
BUG_ON(bip->bip_vcnt != 1);
nr_sectors = bio_integrity_hw_sectors(bi, sectors);
bp->bio1.bi_integrity = &bp->bip1;
bp->bio2.bi_integrity = &bp->bip2;
bp->iv1 = bip->bip_vec[0];
bp->iv2 = bip->bip_vec[0];
bp->bip1.bip_vec[0] = bp->iv1;
bp->bip2.bip_vec[0] = bp->iv2;
bp->iv1.bv_len = sectors * bi->tuple_size;
bp->iv2.bv_offset += sectors * bi->tuple_size;
bp->iv2.bv_len -= sectors * bi->tuple_size;
bp->bip1.bip_sector = bio->bi_integrity->bip_sector;
bp->bip2.bip_sector = bio->bi_integrity->bip_sector + nr_sectors;
bp->bip1.bip_vcnt = bp->bip2.bip_vcnt = 1;
bp->bip1.bip_idx = bp->bip2.bip_idx = 0;
}
EXPORT_SYMBOL(bio_integrity_split);
/**
* bio_integrity_clone - Callback for cloning bios with integrity metadata
* @bio: New bio
* @bio_src: Original bio
* @gfp_mask: Memory allocation mask
* @bs: bio_set to allocate bip from
*
* 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_set *bs)
{
struct bio_integrity_payload *bip_src = bio_src->bi_integrity;
struct bio_integrity_payload *bip;
BUG_ON(bip_src == NULL);
bip = bio_integrity_alloc_bioset(bio, gfp_mask, bip_src->bip_vcnt, bs);
if (bip == NULL)
return -EIO;
memcpy(bip->bip_vec, bip_src->bip_vec,
bip_src->bip_vcnt * sizeof(struct bio_vec));
bip->bip_sector = bip_src->bip_sector;
bip->bip_vcnt = bip_src->bip_vcnt;
bip->bip_idx = bip_src->bip_idx;
return 0;
}
EXPORT_SYMBOL(bio_integrity_clone);
int bioset_integrity_create(struct bio_set *bs, int pool_size)
{
unsigned int max_slab = vecs_to_idx(BIO_MAX_PAGES);
if (bs->bio_integrity_pool)
return 0;
bs->bio_integrity_pool =
mempool_create_slab_pool(pool_size, bip_slab[max_slab].slab);
if (!bs->bio_integrity_pool)
return -1;
return 0;
}
EXPORT_SYMBOL(bioset_integrity_create);
void bioset_integrity_free(struct bio_set *bs)
{
if (bs->bio_integrity_pool)
mempool_destroy(bs->bio_integrity_pool);
}
EXPORT_SYMBOL(bioset_integrity_free);
void __init bio_integrity_init(void)
{
unsigned int i;
/*
* 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");
for (i = 0 ; i < BIOVEC_NR_POOLS ; i++) {
unsigned int size;
size = sizeof(struct bio_integrity_payload)
+ bip_slab[i].nr_vecs * sizeof(struct bio_vec);
bip_slab[i].slab =
kmem_cache_create(bip_slab[i].name, size, 0,
SLAB_HWCACHE_ALIGN|SLAB_PANIC, NULL);
}
}