Merge branch 'for-3.16/core' of git://git.kernel.dk/linux-block into next

Pull block core updates from Jens Axboe:
 "It's a big(ish) round this time, lots of development effort has gone
  into blk-mq in the last 3 months.  Generally we're heading to where
  3.16 will be a feature complete and performant blk-mq.  scsi-mq is
  progressing nicely and will hopefully be in 3.17.  A nvme port is in
  progress, and the Micron pci-e flash driver, mtip32xx, is converted
  and will be sent in with the driver pull request for 3.16.

  This pull request contains:

   - Lots of prep and support patches for scsi-mq have been integrated.
     All from Christoph.

   - API and code cleanups for blk-mq from Christoph.

   - Lots of good corner case and error handling cleanup fixes for
     blk-mq from Ming Lei.

   - A flew of blk-mq updates from me:

     * Provide strict mappings so that the driver can rely on the CPU
       to queue mapping.  This enables optimizations in the driver.

     * Provided a bitmap tagging instead of percpu_ida, which never
       really worked well for blk-mq.  percpu_ida relies on the fact
       that we have a lot more tags available than we really need, it
       fails miserably for cases where we exhaust (or are close to
       exhausting) the tag space.

     * Provide sane support for shared tag maps, as utilized by scsi-mq

     * Various fixes for IO timeouts.

     * API cleanups, and lots of perf tweaks and optimizations.

   - Remove 'buffer' from struct request.  This is ancient code, from
     when requests were always virtually mapped.  Kill it, to reclaim
     some space in struct request.  From me.

   - Remove 'magic' from blk_plug.  Since we store these on the stack
     and since we've never caught any actual bugs with this, lets just
     get rid of it.  From me.

   - Only call part_in_flight() once for IO completion, as includes two
     atomic reads.  Hopefully we'll get a better implementation soon, as
     the part IO stats are now one of the more expensive parts of doing
     IO on blk-mq.  From me.

   - File migration of block code from {mm,fs}/ to block/.  This
     includes bio.c, bio-integrity.c, bounce.c, and ioprio.c.  From me,
     from a discussion on lkml.

  That should describe the meat of the pull request.  Also has various
  little fixes and cleanups from Dave Jones, Shaohua Li, Duan Jiong,
  Fengguang Wu, Fabian Frederick, Randy Dunlap, Robert Elliott, and Sam
  Bradshaw"

* 'for-3.16/core' of git://git.kernel.dk/linux-block: (100 commits)
  blk-mq: push IPI or local end_io decision to __blk_mq_complete_request()
  blk-mq: remember to start timeout handler for direct queue
  block: ensure that the timer is always added
  blk-mq: blk_mq_unregister_hctx() can be static
  blk-mq: make the sysfs mq/ layout reflect current mappings
  blk-mq: blk_mq_tag_to_rq should handle flush request
  block: remove dead code in scsi_ioctl:blk_verify_command
  blk-mq: request initialization optimizations
  block: add queue flag for disabling SG merging
  block: remove 'magic' from struct blk_plug
  blk-mq: remove alloc_hctx and free_hctx methods
  blk-mq: add file comments and update copyright notices
  blk-mq: remove blk_mq_alloc_request_pinned
  blk-mq: do not use blk_mq_alloc_request_pinned in blk_mq_map_request
  blk-mq: remove blk_mq_wait_for_tags
  blk-mq: initialize request in __blk_mq_alloc_request
  blk-mq: merge blk_mq_alloc_reserved_request into blk_mq_alloc_request
  blk-mq: add helper to insert requests from irq context
  blk-mq: remove stale comment for blk_mq_complete_request()
  blk-mq: allow non-softirq completions
  ...

4 files changed, 1 insertions, 2937 deletions

diff --git a/fs/Makefile b/fs/Makefile
index f9cb9876e466..4030cbfbc9af 100644
--- a/fs/Makefile
+++ b/fs/Makefile
@@ -14,14 +14,13 @@ obj-y :=	open.o read_write.o file_table.o super.o \
 		stack.o fs_struct.o statfs.o
 
 ifeq ($(CONFIG_BLOCK),y)
-obj-y +=	buffer.o bio.o block_dev.o direct-io.o mpage.o ioprio.o
+obj-y +=	buffer.o block_dev.o direct-io.o mpage.o
 else
 obj-y +=	no-block.o
 endif
 
 obj-$(CONFIG_PROC_FS) += proc_namespace.o
 
-obj-$(CONFIG_BLK_DEV_INTEGRITY) += bio-integrity.o
 obj-y				+= notify/
 obj-$(CONFIG_EPOLL)		+= eventpoll.o
 obj-$(CONFIG_ANON_INODES)	+= anon_inodes.o
diff --git a/fs/bio-integrity.c b/fs/bio-integrity.c
deleted file mode 100644
index 1c2ce0c87711..000000000000
--- a/fs/bio-integrity.c
+++ /dev/null
@@ -1,657 +0,0 @@
-/*
- * 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>
-
-#define BIP_INLINE_VECS	4
-
-static struct kmem_cache *bip_slab;
-static struct workqueue_struct *kintegrityd_wq;
-
-/**
- * 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 long idx = BIO_POOL_NONE;
-	unsigned inline_vecs;
-
-	if (!bs) {
-		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 NULL;
-
-	memset(bip, 0, sizeof(*bip));
-
-	if (nr_vecs > inline_vecs) {
-		bip->bip_vec = bvec_alloc(gfp_mask, nr_vecs, &idx,
-					  bs->bvec_integrity_pool);
-		if (!bip->bip_vec)
-			goto err;
-	} else {
-		bip->bip_vec = bip->bip_inline_vecs;
-	}
-
-	bip->bip_slab = idx;
-	bip->bip_bio = bio;
-	bio->bi_integrity = bip;
-
-	return bip;
-err:
-	mempool_free(bip, bs->bio_integrity_pool);
-	return NULL;
-}
-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->bi_integrity;
-	struct bio_set *bs = bio->bi_pool;
-
-	if (bip->bip_owns_buf)
-		kfree(bip->bip_buf);
-
-	if (bs) {
-		if (bip->bip_slab != BIO_POOL_NONE)
-			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;
-}
-EXPORT_SYMBOL(bio_integrity_free);
-
-static inline unsigned int bip_integrity_vecs(struct bio_integrity_payload *bip)
-{
-	if (bip->bip_slab == BIO_POOL_NONE)
-		return BIP_INLINE_VECS;
-
-	return bvec_nr_vecs(bip->bip_slab);
-}
-
-/**
- * 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 >= bip_integrity_vecs(bip)) {
-		printk(KERN_ERR "%s: bip_vec full\n", __func__);
-		return 0;
-	}
-
-	iv = bip->bip_vec + bip->bip_vcnt;
-
-	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)
-{
-	if (!bio_is_rw(bio))
-		return 0;
-
-	/* 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;
-}
-
-static inline unsigned int bio_integrity_bytes(struct blk_integrity *bi,
-					       unsigned int sectors)
-{
-	return bio_integrity_hw_sectors(bi, sectors) * bi->tuple_size;
-}
-
-/**
- * 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_iter.bi_size == 0);
-
-	return bi->tag_size * (bio->bi_iter.bi_size / bi->sector_size);
-}
-EXPORT_SYMBOL(bio_integrity_tag_size);
-
-static 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_iter.bi_size) {
-		printk(KERN_ERR "%s: tag too big for bio: %u > %u\n", __func__,
-		       nr_sectors * bi->tuple_size, bip->bip_iter.bi_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_verify - Generate/verify integrity metadata for a bio
- * @bio:	bio to generate/verify integrity metadata for
- * @operate:	operate number, 1 for generate, 0 for verify
- */
-static int bio_integrity_generate_verify(struct bio *bio, int operate)
-{
-	struct blk_integrity *bi = bdev_get_integrity(bio->bi_bdev);
-	struct blk_integrity_exchg bix;
-	struct bio_vec *bv;
-	sector_t sector;
-	unsigned int sectors, ret = 0, i;
-	void *prot_buf = bio->bi_integrity->bip_buf;
-
-	if (operate)
-		sector = bio->bi_iter.bi_sector;
-	else
-		sector = bio->bi_integrity->bip_iter.bi_sector;
-
-	bix.disk_name = bio->bi_bdev->bd_disk->disk_name;
-	bix.sector_size = bi->sector_size;
-
-	bio_for_each_segment_all(bv, bio, i) {
-		void *kaddr = kmap_atomic(bv->bv_page);
-		bix.data_buf = kaddr + bv->bv_offset;
-		bix.data_size = bv->bv_len;
-		bix.prot_buf = prot_buf;
-		bix.sector = sector;
-
-		if (operate)
-			bi->generate_fn(&bix);
-		else {
-			ret = bi->verify_fn(&bix);
-			if (ret) {
-				kunmap_atomic(kaddr);
-				return ret;
-			}
-		}
-
-		sectors = bv->bv_len / bi->sector_size;
-		sector += sectors;
-		prot_buf += sectors * bi->tuple_size;
-
-		kunmap_atomic(kaddr);
-	}
-	return ret;
-}
-
-/**
- * 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)
-{
-	bio_integrity_generate_verify(bio, 1);
-}
-
-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_owns_buf = 1;
-	bip->bip_buf = buf;
-	bip->bip_iter.bi_size = len;
-	bip->bip_iter.bi_sector = bio->bi_iter.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)
-{
-	return bio_integrity_generate_verify(bio, 0);
-}
-
-/**
- * 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_nodec(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_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 bytes = bio_integrity_bytes(bi, bytes_done >> 9);
-
-	bvec_iter_advance(bip->bip_vec, &bip->bip_iter, bytes);
-}
-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);
-
-	bio_integrity_advance(bio, offset << 9);
-	bip->bip_iter.bi_size = bio_integrity_bytes(bi, sectors);
-}
-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_src->bi_integrity;
-	struct bio_integrity_payload *bip;
-
-	BUG_ON(bip_src == NULL);
-
-	bip = bio_integrity_alloc(bio, gfp_mask, bip_src->bip_vcnt);
-
-	if (bip == NULL)
-		return -EIO;
-
-	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;
-}
-EXPORT_SYMBOL(bio_integrity_clone);
-
-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(bs, pool_size);
-	if (!bs->bvec_integrity_pool) {
-		mempool_destroy(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);
-
-	if (bs->bvec_integrity_pool)
-		mempool_destroy(bs->bvec_integrity_pool);
-}
-EXPORT_SYMBOL(bioset_integrity_free);
-
-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);
-	if (!bip_slab)
-		panic("Failed to create slab\n");
-}
diff --git a/fs/bio.c b/fs/bio.c
deleted file mode 100644
index 6f0362b77806..000000000000
--- a/fs/bio.c
+++ /dev/null
@@ -1,2037 +0,0 @@
-/*
- * Copyright (C) 2001 Jens Axboe <axboe@kernel.dk>
- *
- * 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 Licens
- * along with this program; if not, write to the Free Software
- * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-
- *
- */
-#include <linux/mm.h>
-#include <linux/swap.h>
-#include <linux/bio.h>
-#include <linux/blkdev.h>
-#include <linux/uio.h>
-#include <linux/iocontext.h>
-#include <linux/slab.h>
-#include <linux/init.h>
-#include <linux/kernel.h>
-#include <linux/export.h>
-#include <linux/mempool.h>
-#include <linux/workqueue.h>
-#include <linux/cgroup.h>
-#include <scsi/sg.h>		/* for struct sg_iovec */
-
-#include <trace/events/block.h>
-
-/*
- * Test patch to inline a certain number of bi_io_vec's inside the bio
- * itself, to shrink a bio data allocation from two mempool calls to one
- */
-#define BIO_INLINE_VECS		4
-
-/*
- * if you change this list, also change bvec_alloc or things will
- * break badly! cannot be bigger than what you can fit into an
- * unsigned short
- */
-#define BV(x) { .nr_vecs = x, .name = "biovec-"__stringify(x) }
-static struct biovec_slab bvec_slabs[BIOVEC_NR_POOLS] __read_mostly = {
-	BV(1), BV(4), BV(16), BV(64), BV(128), BV(BIO_MAX_PAGES),
-};
-#undef BV
-
-/*
- * fs_bio_set is the bio_set containing bio and iovec memory pools used by
- * IO code that does not need private memory pools.
- */
-struct bio_set *fs_bio_set;
-EXPORT_SYMBOL(fs_bio_set);
-
-/*
- * Our slab pool management
- */
-struct bio_slab {
-	struct kmem_cache *slab;
-	unsigned int slab_ref;
-	unsigned int slab_size;
-	char name[8];
-};
-static DEFINE_MUTEX(bio_slab_lock);
-static struct bio_slab *bio_slabs;
-static unsigned int bio_slab_nr, bio_slab_max;
-
-static struct kmem_cache *bio_find_or_create_slab(unsigned int extra_size)
-{
-	unsigned int sz = sizeof(struct bio) + extra_size;
-	struct kmem_cache *slab = NULL;
-	struct bio_slab *bslab, *new_bio_slabs;
-	unsigned int new_bio_slab_max;
-	unsigned int i, entry = -1;
-
-	mutex_lock(&bio_slab_lock);
-
-	i = 0;
-	while (i < bio_slab_nr) {
-		bslab = &bio_slabs[i];
-
-		if (!bslab->slab && entry == -1)
-			entry = i;
-		else if (bslab->slab_size == sz) {
-			slab = bslab->slab;
-			bslab->slab_ref++;
-			break;
-		}
-		i++;
-	}
-
-	if (slab)
-		goto out_unlock;
-
-	if (bio_slab_nr == bio_slab_max && entry == -1) {
-		new_bio_slab_max = bio_slab_max << 1;
-		new_bio_slabs = krealloc(bio_slabs,
-					 new_bio_slab_max * sizeof(struct bio_slab),
-					 GFP_KERNEL);
-		if (!new_bio_slabs)
-			goto out_unlock;
-		bio_slab_max = new_bio_slab_max;
-		bio_slabs = new_bio_slabs;
-	}
-	if (entry == -1)
-		entry = bio_slab_nr++;
-
-	bslab = &bio_slabs[entry];
-
-	snprintf(bslab->name, sizeof(bslab->name), "bio-%d", entry);
-	slab = kmem_cache_create(bslab->name, sz, 0, SLAB_HWCACHE_ALIGN, NULL);
-	if (!slab)
-		goto out_unlock;
-
-	bslab->slab = slab;
-	bslab->slab_ref = 1;
-	bslab->slab_size = sz;
-out_unlock:
-	mutex_unlock(&bio_slab_lock);
-	return slab;
-}
-
-static void bio_put_slab(struct bio_set *bs)
-{
-	struct bio_slab *bslab = NULL;
-	unsigned int i;
-
-	mutex_lock(&bio_slab_lock);
-
-	for (i = 0; i < bio_slab_nr; i++) {
-		if (bs->bio_slab == bio_slabs[i].slab) {
-			bslab = &bio_slabs[i];
-			break;
-		}
-	}
-
-	if (WARN(!bslab, KERN_ERR "bio: unable to find slab!\n"))
-		goto out;
-
-	WARN_ON(!bslab->slab_ref);
-
-	if (--bslab->slab_ref)
-		goto out;
-
-	kmem_cache_destroy(bslab->slab);
-	bslab->slab = NULL;
-
-out:
-	mutex_unlock(&bio_slab_lock);
-}
-
-unsigned int bvec_nr_vecs(unsigned short idx)
-{
-	return bvec_slabs[idx].nr_vecs;
-}
-
-void bvec_free(mempool_t *pool, struct bio_vec *bv, unsigned int idx)
-{
-	BIO_BUG_ON(idx >= BIOVEC_NR_POOLS);
-
-	if (idx == BIOVEC_MAX_IDX)
-		mempool_free(bv, pool);
-	else {
-		struct biovec_slab *bvs = bvec_slabs + idx;
-
-		kmem_cache_free(bvs->slab, bv);
-	}
-}
-
-struct bio_vec *bvec_alloc(gfp_t gfp_mask, int nr, unsigned long *idx,
-			   mempool_t *pool)
-{
-	struct bio_vec *bvl;
-
-	/*
-	 * see comment near bvec_array define!
-	 */
-	switch (nr) {
-	case 1:
-		*idx = 0;
-		break;
-	case 2 ... 4:
-		*idx = 1;
-		break;
-	case 5 ... 16:
-		*idx = 2;
-		break;
-	case 17 ... 64:
-		*idx = 3;
-		break;
-	case 65 ... 128:
-		*idx = 4;
-		break;
-	case 129 ... BIO_MAX_PAGES:
-		*idx = 5;
-		break;
-	default:
-		return NULL;
-	}
-
-	/*
-	 * idx now points to the pool we want to allocate from. only the
-	 * 1-vec entry pool is mempool backed.
-	 */
-	if (*idx == BIOVEC_MAX_IDX) {
-fallback:
-		bvl = mempool_alloc(pool, gfp_mask);
-	} else {
-		struct biovec_slab *bvs = bvec_slabs + *idx;
-		gfp_t __gfp_mask = gfp_mask & ~(__GFP_WAIT | __GFP_IO);
-
-		/*
-		 * Make this allocation restricted and don't dump info on
-		 * allocation failures, since we'll fallback to the mempool
-		 * in case of failure.
-		 */
-		__gfp_mask |= __GFP_NOMEMALLOC | __GFP_NORETRY | __GFP_NOWARN;
-
-		/*
-		 * Try a slab allocation. If this fails and __GFP_WAIT
-		 * is set, retry with the 1-entry mempool
-		 */
-		bvl = kmem_cache_alloc(bvs->slab, __gfp_mask);
-		if (unlikely(!bvl && (gfp_mask & __GFP_WAIT))) {
-			*idx = BIOVEC_MAX_IDX;
-			goto fallback;
-		}
-	}
-
-	return bvl;
-}
-
-static void __bio_free(struct bio *bio)
-{
-	bio_disassociate_task(bio);
-
-	if (bio_integrity(bio))
-		bio_integrity_free(bio);
-}
-
-static void bio_free(struct bio *bio)
-{
-	struct bio_set *bs = bio->bi_pool;
-	void *p;
-
-	__bio_free(bio);
-
-	if (bs) {
-		if (bio_flagged(bio, BIO_OWNS_VEC))
-			bvec_free(bs->bvec_pool, bio->bi_io_vec, BIO_POOL_IDX(bio));
-
-		/*
-		 * If we have front padding, adjust the bio pointer before freeing
-		 */
-		p = bio;
-		p -= bs->front_pad;
-
-		mempool_free(p, bs->bio_pool);
-	} else {
-		/* Bio was allocated by bio_kmalloc() */
-		kfree(bio);
-	}
-}
-
-void bio_init(struct bio *bio)
-{
-	memset(bio, 0, sizeof(*bio));
-	bio->bi_flags = 1 << BIO_UPTODATE;
-	atomic_set(&bio->bi_remaining, 1);
-	atomic_set(&bio->bi_cnt, 1);
-}
-EXPORT_SYMBOL(bio_init);
-
-/**
- * bio_reset - reinitialize a bio
- * @bio:	bio to reset
- *
- * Description:
- *   After calling bio_reset(), @bio will be in the same state as a freshly
- *   allocated bio returned bio bio_alloc_bioset() - the only fields that are
- *   preserved are the ones that are initialized by bio_alloc_bioset(). See
- *   comment in struct bio.
- */
-void bio_reset(struct bio *bio)
-{
-	unsigned long flags = bio->bi_flags & (~0UL << BIO_RESET_BITS);
-
-	__bio_free(bio);
-
-	memset(bio, 0, BIO_RESET_BYTES);
-	bio->bi_flags = flags|(1 << BIO_UPTODATE);
-	atomic_set(&bio->bi_remaining, 1);
-}
-EXPORT_SYMBOL(bio_reset);
-
-static void bio_chain_endio(struct bio *bio, int error)
-{
-	bio_endio(bio->bi_private, error);
-	bio_put(bio);
-}
-
-/**
- * bio_chain - chain bio completions
- *
- * The caller won't have a bi_end_io called when @bio completes - instead,
- * @parent's bi_end_io won't be called until both @parent and @bio have
- * completed; the chained bio will also be freed when it completes.
- *
- * The caller must not set bi_private or bi_end_io in @bio.
- */
-void bio_chain(struct bio *bio, struct bio *parent)
-{
-	BUG_ON(bio->bi_private || bio->bi_end_io);
-
-	bio->bi_private = parent;
-	bio->bi_end_io	= bio_chain_endio;
-	atomic_inc(&parent->bi_remaining);
-}
-EXPORT_SYMBOL(bio_chain);
-
-static void bio_alloc_rescue(struct work_struct *work)
-{
-	struct bio_set *bs = container_of(work, struct bio_set, rescue_work);
-	struct bio *bio;
-
-	while (1) {
-		spin_lock(&bs->rescue_lock);
-		bio = bio_list_pop(&bs->rescue_list);
-		spin_unlock(&bs->rescue_lock);
-
-		if (!bio)
-			break;
-
-		generic_make_request(bio);
-	}
-}
-
-static void punt_bios_to_rescuer(struct bio_set *bs)
-{
-	struct bio_list punt, nopunt;
-	struct bio *bio;
-
-	/*
-	 * In order to guarantee forward progress we must punt only bios that
-	 * were allocated from this bio_set; otherwise, if there was a bio on
-	 * there for a stacking driver higher up in the stack, processing it
-	 * could require allocating bios from this bio_set, and doing that from
-	 * our own rescuer would be bad.
-	 *
-	 * Since bio lists are singly linked, pop them all instead of trying to
-	 * remove from the middle of the list:
-	 */
-
-	bio_list_init(&punt);
-	bio_list_init(&nopunt);
-
-	while ((bio = bio_list_pop(current->bio_list)))
-		bio_list_add(bio->bi_pool == bs ? &punt : &nopunt, bio);
-
-	*current->bio_list = nopunt;
-
-	spin_lock(&bs->rescue_lock);
-	bio_list_merge(&bs->rescue_list, &punt);
-	spin_unlock(&bs->rescue_lock);
-
-	queue_work(bs->rescue_workqueue, &bs->rescue_work);
-}
-
-/**
- * bio_alloc_bioset - allocate a bio for I/O
- * @gfp_mask:   the GFP_ mask given to the slab allocator
- * @nr_iovecs:	number of iovecs to pre-allocate
- * @bs:		the bio_set to allocate from.
- *
- * Description:
- *   If @bs is NULL, uses kmalloc() to allocate the bio; else the allocation is
- *   backed by the @bs's mempool.
- *
- *   When @bs is not NULL, if %__GFP_WAIT is set then bio_alloc will always be
- *   able to allocate a bio. This is due to the mempool guarantees. To make this
- *   work, callers must never allocate more than 1 bio at a time from this pool.
- *   Callers that need to allocate more than 1 bio must always submit the
- *   previously allocated bio for IO before attempting to allocate a new one.
- *   Failure to do so can cause deadlocks under memory pressure.
- *
- *   Note that when running under generic_make_request() (i.e. any block
- *   driver), bios are not submitted until after you return - see the code in
- *   generic_make_request() that converts recursion into iteration, to prevent
- *   stack overflows.
- *
- *   This would normally mean allocating multiple bios under
- *   generic_make_request() would be susceptible to deadlocks, but we have
- *   deadlock avoidance code that resubmits any blocked bios from a rescuer
- *   thread.
- *
- *   However, we do not guarantee forward progress for allocations from other
- *   mempools. Doing multiple allocations from the same mempool under
- *   generic_make_request() should be avoided - instead, use bio_set's front_pad
- *   for per bio allocations.
- *
- *   RETURNS:
- *   Pointer to new bio on success, NULL on failure.
- */
-struct bio *bio_alloc_bioset(gfp_t gfp_mask, int nr_iovecs, struct bio_set *bs)
-{
-	gfp_t saved_gfp = gfp_mask;
-	unsigned front_pad;
-	unsigned inline_vecs;
-	unsigned long idx = BIO_POOL_NONE;
-	struct bio_vec *bvl = NULL;
-	struct bio *bio;
-	void *p;
-
-	if (!bs) {
-		if (nr_iovecs > UIO_MAXIOV)
-			return NULL;
-
-		p = kmalloc(sizeof(struct bio) +
-			    nr_iovecs * sizeof(struct bio_vec),
-			    gfp_mask);
-		front_pad = 0;
-		inline_vecs = nr_iovecs;
-	} else {
-		/*
-		 * generic_make_request() converts recursion to iteration; this
-		 * means if we're running beneath it, any bios we allocate and
-		 * submit will not be submitted (and thus freed) until after we
-		 * return.
-		 *
-		 * This exposes us to a potential deadlock if we allocate
-		 * multiple bios from the same bio_set() while running
-		 * underneath generic_make_request(). If we were to allocate
-		 * multiple bios (say a stacking block driver that was splitting
-		 * bios), we would deadlock if we exhausted the mempool's
-		 * reserve.
-		 *
-		 * We solve this, and guarantee forward progress, with a rescuer
-		 * workqueue per bio_set. If we go to allocate and there are
-		 * bios on current->bio_list, we first try the allocation
-		 * without __GFP_WAIT; if that fails, we punt those bios we
-		 * would be blocking to the rescuer workqueue before we retry
-		 * with the original gfp_flags.
-		 */
-
-		if (current->bio_list && !bio_list_empty(current->bio_list))
-			gfp_mask &= ~__GFP_WAIT;
-
-		p = mempool_alloc(bs->bio_pool, gfp_mask);
-		if (!p && gfp_mask != saved_gfp) {
-			punt_bios_to_rescuer(bs);
-			gfp_mask = saved_gfp;
-			p = mempool_alloc(bs->bio_pool, gfp_mask);
-		}
-
-		front_pad = bs->front_pad;
-		inline_vecs = BIO_INLINE_VECS;
-	}
-
-	if (unlikely(!p))
-		return NULL;
-
-	bio = p + front_pad;
-	bio_init(bio);
-
-	if (nr_iovecs > inline_vecs) {
-		bvl = bvec_alloc(gfp_mask, nr_iovecs, &idx, bs->bvec_pool);
-		if (!bvl && gfp_mask != saved_gfp) {
-			punt_bios_to_rescuer(bs);
-			gfp_mask = saved_gfp;
-			bvl = bvec_alloc(gfp_mask, nr_iovecs, &idx, bs->bvec_pool);
-		}
-
-		if (unlikely(!bvl))
-			goto err_free;
-
-		bio->bi_flags |= 1 << BIO_OWNS_VEC;
-	} else if (nr_iovecs) {
-		bvl = bio->bi_inline_vecs;
-	}
-
-	bio->bi_pool = bs;
-	bio->bi_flags |= idx << BIO_POOL_OFFSET;
-	bio->bi_max_vecs = nr_iovecs;
-	bio->bi_io_vec = bvl;
-	return bio;
-
-err_free:
-	mempool_free(p, bs->bio_pool);
-	return NULL;
-}
-EXPORT_SYMBOL(bio_alloc_bioset);
-
-void zero_fill_bio(struct bio *bio)
-{
-	unsigned long flags;
-	struct bio_vec bv;
-	struct bvec_iter iter;
-
-	bio_for_each_segment(bv, bio, iter) {
-		char *data = bvec_kmap_irq(&bv, &flags);
-		memset(data, 0, bv.bv_len);
-		flush_dcache_page(bv.bv_page);
-		bvec_kunmap_irq(data, &flags);
-	}
-}
-EXPORT_SYMBOL(zero_fill_bio);
-
-/**
- * bio_put - release a reference to a bio
- * @bio:   bio to release reference to
- *
- * Description:
- *   Put a reference to a &struct bio, either one you have gotten with
- *   bio_alloc, bio_get or bio_clone. The last put of a bio will free it.
- **/
-void bio_put(struct bio *bio)
-{
-	BIO_BUG_ON(!atomic_read(&bio->bi_cnt));
-
-	/*
-	 * last put frees it
-	 */
-	if (atomic_dec_and_test(&bio->bi_cnt))
-		bio_free(bio);
-}
-EXPORT_SYMBOL(bio_put);
-
-inline int bio_phys_segments(struct request_queue *q, struct bio *bio)
-{
-	if (unlikely(!bio_flagged(bio, BIO_SEG_VALID)))
-		blk_recount_segments(q, bio);
-
-	return bio->bi_phys_segments;
-}
-EXPORT_SYMBOL(bio_phys_segments);
-
-/**
- * 	__bio_clone_fast - clone a bio that shares the original bio's biovec
- * 	@bio: destination bio
- * 	@bio_src: bio to clone
- *
- *	Clone a &bio. Caller will own the returned bio, but not
- *	the actual data it points to. Reference count of returned
- * 	bio will be one.
- *
- * 	Caller must ensure that @bio_src is not freed before @bio.
- */
-void __bio_clone_fast(struct bio *bio, struct bio *bio_src)
-{
-	BUG_ON(bio->bi_pool && BIO_POOL_IDX(bio) != BIO_POOL_NONE);
-
-	/*
-	 * most users will be overriding ->bi_bdev with a new target,
-	 * so we don't set nor calculate new physical/hw segment counts here
-	 */
-	bio->bi_bdev = bio_src->bi_bdev;
-	bio->bi_flags |= 1 << BIO_CLONED;
-	bio->bi_rw = bio_src->bi_rw;
-	bio->bi_iter = bio_src->bi_iter;
-	bio->bi_io_vec = bio_src->bi_io_vec;
-}
-EXPORT_SYMBOL(__bio_clone_fast);
-
-/**
- *	bio_clone_fast - clone a bio that shares the original bio's biovec
- *	@bio: bio to clone
- *	@gfp_mask: allocation priority
- *	@bs: bio_set to allocate from
- *
- * 	Like __bio_clone_fast, only also allocates the returned bio
- */
-struct bio *bio_clone_fast(struct bio *bio, gfp_t gfp_mask, struct bio_set *bs)
-{
-	struct bio *b;
-
-	b = bio_alloc_bioset(gfp_mask, 0, bs);
-	if (!b)
-		return NULL;
-
-	__bio_clone_fast(b, bio);
-
-	if (bio_integrity(bio)) {
-		int ret;
-
-		ret = bio_integrity_clone(b, bio, gfp_mask);
-
-		if (ret < 0) {
-			bio_put(b);
-			return NULL;
-		}
-	}
-
-	return b;
-}
-EXPORT_SYMBOL(bio_clone_fast);
-
-/**
- * 	bio_clone_bioset - clone a bio
- * 	@bio_src: bio to clone
- *	@gfp_mask: allocation priority
- *	@bs: bio_set to allocate from
- *
- *	Clone bio. Caller will own the returned bio, but not the actual data it
- *	points to. Reference count of returned bio will be one.
- */
-struct bio *bio_clone_bioset(struct bio *bio_src, gfp_t gfp_mask,
-			     struct bio_set *bs)
-{
-	struct bvec_iter iter;
-	struct bio_vec bv;
-	struct bio *bio;
-
-	/*
-	 * Pre immutable biovecs, __bio_clone() used to just do a memcpy from
-	 * bio_src->bi_io_vec to bio->bi_io_vec.
-	 *
-	 * We can't do that anymore, because:
-	 *
-	 *  - The point of cloning the biovec is to produce a bio with a biovec
-	 *    the caller can modify: bi_idx and bi_bvec_done should be 0.
-	 *
-	 *  - The original bio could've had more than BIO_MAX_PAGES biovecs; if
-	 *    we tried to clone the whole thing bio_alloc_bioset() would fail.
-	 *    But the clone should succeed as long as the number of biovecs we
-	 *    actually need to allocate is fewer than BIO_MAX_PAGES.
-	 *
-	 *  - Lastly, bi_vcnt should not be looked at or relied upon by code
-	 *    that does not own the bio - reason being drivers don't use it for
-	 *    iterating over the biovec anymore, so expecting it to be kept up
-	 *    to date (i.e. for clones that share the parent biovec) is just
-	 *    asking for trouble and would force extra work on
-	 *    __bio_clone_fast() anyways.
-	 */
-
-	bio = bio_alloc_bioset(gfp_mask, bio_segments(bio_src), bs);
-	if (!bio)
-		return NULL;
-
-	bio->bi_bdev		= bio_src->bi_bdev;
-	bio->bi_rw		= bio_src->bi_rw;
-	bio->bi_iter.bi_sector	= bio_src->bi_iter.bi_sector;
-	bio->bi_iter.bi_size	= bio_src->bi_iter.bi_size;
-
-	if (bio->bi_rw & REQ_DISCARD)
-		goto integrity_clone;
-
-	if (bio->bi_rw & REQ_WRITE_SAME) {
-		bio->bi_io_vec[bio->bi_vcnt++] = bio_src->bi_io_vec[0];
-		goto integrity_clone;
-	}
-
-	bio_for_each_segment(bv, bio_src, iter)
-		bio->bi_io_vec[bio->bi_vcnt++] = bv;
-
-integrity_clone:
-	if (bio_integrity(bio_src)) {
-		int ret;
-
-		ret = bio_integrity_clone(bio, bio_src, gfp_mask);
-		if (ret < 0) {
-			bio_put(bio);
-			return NULL;
-		}
-	}
-
-	return bio;
-}
-EXPORT_SYMBOL(bio_clone_bioset);
-
-/**
- *	bio_get_nr_vecs		- return approx number of vecs
- *	@bdev:  I/O target
- *
- *	Return the approximate number of pages we can send to this target.
- *	There's no guarantee that you will be able to fit this number of pages
- *	into a bio, it does not account for dynamic restrictions that vary
- *	on offset.
- */
-int bio_get_nr_vecs(struct block_device *bdev)
-{
-	struct request_queue *q = bdev_get_queue(bdev);
-	int nr_pages;
-
-	nr_pages = min_t(unsigned,
-		     queue_max_segments(q),
-		     queue_max_sectors(q) / (PAGE_SIZE >> 9) + 1);
-
-	return min_t(unsigned, nr_pages, BIO_MAX_PAGES);
-
-}
-EXPORT_SYMBOL(bio_get_nr_vecs);
-
-static int __bio_add_page(struct request_queue *q, struct bio *bio, struct page
-			  *page, unsigned int len, unsigned int offset,
-			  unsigned int max_sectors)
-{
-	int retried_segments = 0;
-	struct bio_vec *bvec;
-
-	/*
-	 * cloned bio must not modify vec list
-	 */
-	if (unlikely(bio_flagged(bio, BIO_CLONED)))
-		return 0;
-
-	if (((bio->bi_iter.bi_size + len) >> 9) > max_sectors)
-		return 0;
-
-	/*
-	 * For filesystems with a blocksize smaller than the pagesize
-	 * we will often be called with the same page as last time and
-	 * a consecutive offset.  Optimize this special case.
-	 */
-	if (bio->bi_vcnt > 0) {
-		struct bio_vec *prev = &bio->bi_io_vec[bio->bi_vcnt - 1];
-
-		if (page == prev->bv_page &&
-		    offset == prev->bv_offset + prev->bv_len) {
-			unsigned int prev_bv_len = prev->bv_len;
-			prev->bv_len += len;
-
-			if (q->merge_bvec_fn) {
-				struct bvec_merge_data bvm = {
-					/* prev_bvec is already charged in
-					   bi_size, discharge it in order to
-					   simulate merging updated prev_bvec
-					   as new bvec. */
-					.bi_bdev = bio->bi_bdev,
-					.bi_sector = bio->bi_iter.bi_sector,
-					.bi_size = bio->bi_iter.bi_size -
-						prev_bv_len,
-					.bi_rw = bio->bi_rw,
-				};
-
-				if (q->merge_bvec_fn(q, &bvm, prev) < prev->bv_len) {
-					prev->bv_len -= len;
-					return 0;
-				}
-			}
-
-			goto done;
-		}
-	}
-
-	if (bio->bi_vcnt >= bio->bi_max_vecs)
-		return 0;
-
-	/*
-	 * we might lose a segment or two here, but rather that than
-	 * make this too complex.
-	 */
-
-	while (bio->bi_phys_segments >= queue_max_segments(q)) {
-
-		if (retried_segments)
-			return 0;
-
-		retried_segments = 1;
-		blk_recount_segments(q, bio);
-	}
-
-	/*
-	 * setup the new entry, we might clear it again later if we
-	 * cannot add the page
-	 */
-	bvec = &bio->bi_io_vec[bio->bi_vcnt];
-	bvec->bv_page = page;
-	bvec->bv_len = len;
-	bvec->bv_offset = offset;
-
-	/*
-	 * if queue has other restrictions (eg varying max sector size
-	 * depending on offset), it can specify a merge_bvec_fn in the
-	 * queue to get further control
-	 */
-	if (q->merge_bvec_fn) {
-		struct bvec_merge_data bvm = {
-			.bi_bdev = bio->bi_bdev,
-			.bi_sector = bio->bi_iter.bi_sector,
-			.bi_size = bio->bi_iter.bi_size,
-			.bi_rw = bio->bi_rw,
-		};
-
-		/*
-		 * merge_bvec_fn() returns number of bytes it can accept
-		 * at this offset
-		 */
-		if (q->merge_bvec_fn(q, &bvm, bvec) < bvec->bv_len) {
-			bvec->bv_page = NULL;
-			bvec->bv_len = 0;
-			bvec->bv_offset = 0;
-			return 0;
-		}
-	}
-
-	/* If we may be able to merge these biovecs, force a recount */
-	if (bio->bi_vcnt && (BIOVEC_PHYS_MERGEABLE(bvec-1, bvec)))
-		bio->bi_flags &= ~(1 << BIO_SEG_VALID);
-
-	bio->bi_vcnt++;
-	bio->bi_phys_segments++;
- done:
-	bio->bi_iter.bi_size += len;
-	return len;
-}
-
-/**
- *	bio_add_pc_page	-	attempt to add page to bio
- *	@q: the target queue
- *	@bio: destination bio
- *	@page: page to add
- *	@len: vec entry length
- *	@offset: vec entry offset
- *
- *	Attempt to add a page to the bio_vec maplist. This can fail for a
- *	number of reasons, such as the bio being full or target block device
- *	limitations. The target block device must allow bio's up to PAGE_SIZE,
- *	so it is always possible to add a single page to an empty bio.
- *
- *	This should only be used by REQ_PC bios.
- */
-int bio_add_pc_page(struct request_queue *q, struct bio *bio, struct page *page,
-		    unsigned int len, unsigned int offset)
-{
-	return __bio_add_page(q, bio, page, len, offset,
-			      queue_max_hw_sectors(q));
-}
-EXPORT_SYMBOL(bio_add_pc_page);
-
-/**
- *	bio_add_page	-	attempt to add page to bio
- *	@bio: destination bio
- *	@page: page to add
- *	@len: vec entry length
- *	@offset: vec entry offset
- *
- *	Attempt to add a page to the bio_vec maplist. This can fail for a
- *	number of reasons, such as the bio being full or target block device
- *	limitations. The target block device must allow bio's up to PAGE_SIZE,
- *	so it is always possible to add a single page to an empty bio.
- */
-int bio_add_page(struct bio *bio, struct page *page, unsigned int len,
-		 unsigned int offset)
-{
-	struct request_queue *q = bdev_get_queue(bio->bi_bdev);
-	return __bio_add_page(q, bio, page, len, offset, queue_max_sectors(q));
-}
-EXPORT_SYMBOL(bio_add_page);
-
-struct submit_bio_ret {
-	struct completion event;
-	int error;
-};
-
-static void submit_bio_wait_endio(struct bio *bio, int error)
-{
-	struct submit_bio_ret *ret = bio->bi_private;
-
-	ret->error = error;
-	complete(&ret->event);
-}
-
-/**
- * submit_bio_wait - submit a bio, and wait until it completes
- * @rw: whether to %READ or %WRITE, or maybe to %READA (read ahead)
- * @bio: The &struct bio which describes the I/O
- *
- * Simple wrapper around submit_bio(). Returns 0 on success, or the error from
- * bio_endio() on failure.
- */
-int submit_bio_wait(int rw, struct bio *bio)
-{
-	struct submit_bio_ret ret;
-
-	rw |= REQ_SYNC;
-	init_completion(&ret.event);
-	bio->bi_private = &ret;
-	bio->bi_end_io = submit_bio_wait_endio;
-	submit_bio(rw, bio);
-	wait_for_completion(&ret.event);
-
-	return ret.error;
-}
-EXPORT_SYMBOL(submit_bio_wait);
-
-/**
- * bio_advance - increment/complete a bio by some number of bytes
- * @bio:	bio to advance
- * @bytes:	number of bytes to complete
- *
- * This updates bi_sector, bi_size and bi_idx; if the number of bytes to
- * complete doesn't align with a bvec boundary, then bv_len and bv_offset will
- * be updated on the last bvec as well.
- *
- * @bio will then represent the remaining, uncompleted portion of the io.
- */
-void bio_advance(struct bio *bio, unsigned bytes)
-{
-	if (bio_integrity(bio))
-		bio_integrity_advance(bio, bytes);
-
-	bio_advance_iter(bio, &bio->bi_iter, bytes);
-}
-EXPORT_SYMBOL(bio_advance);
-
-/**
- * bio_alloc_pages - allocates a single page for each bvec in a bio
- * @bio: bio to allocate pages for
- * @gfp_mask: flags for allocation
- *
- * Allocates pages up to @bio->bi_vcnt.
- *
- * Returns 0 on success, -ENOMEM on failure. On failure, any allocated pages are
- * freed.
- */
-int bio_alloc_pages(struct bio *bio, gfp_t gfp_mask)
-{
-	int i;
-	struct bio_vec *bv;
-
-	bio_for_each_segment_all(bv, bio, i) {
-		bv->bv_page = alloc_page(gfp_mask);
-		if (!bv->bv_page) {
-			while (--bv >= bio->bi_io_vec)
-				__free_page(bv->bv_page);
-			return -ENOMEM;
-		}
-	}
-
-	return 0;
-}
-EXPORT_SYMBOL(bio_alloc_pages);
-
-/**
- * bio_copy_data - copy contents of data buffers from one chain of bios to
- * another
- * @src: source bio list
- * @dst: destination bio list
- *
- * If @src and @dst are single bios, bi_next must be NULL - otherwise, treats
- * @src and @dst as linked lists of bios.
- *
- * Stops when it reaches the end of either @src or @dst - that is, copies
- * min(src->bi_size, dst->bi_size) bytes (or the equivalent for lists of bios).
- */
-void bio_copy_data(struct bio *dst, struct bio *src)
-{
-	struct bvec_iter src_iter, dst_iter;
-	struct bio_vec src_bv, dst_bv;
-	void *src_p, *dst_p;
-	unsigned bytes;
-
-	src_iter = src->bi_iter;
-	dst_iter = dst->bi_iter;
-
-	while (1) {
-		if (!src_iter.bi_size) {
-			src = src->bi_next;
-			if (!src)
-				break;
-
-			src_iter = src->bi_iter;
-		}
-
-		if (!dst_iter.bi_size) {
-			dst = dst->bi_next;
-			if (!dst)
-				break;
-
-			dst_iter = dst->bi_iter;
-		}
-
-		src_bv = bio_iter_iovec(src, src_iter);
-		dst_bv = bio_iter_iovec(dst, dst_iter);
-
-		bytes = min(src_bv.bv_len, dst_bv.bv_len);
-
-		src_p = kmap_atomic(src_bv.bv_page);
-		dst_p = kmap_atomic(dst_bv.bv_page);
-
-		memcpy(dst_p + dst_bv.bv_offset,
-		       src_p + src_bv.bv_offset,
-		       bytes);
-
-		kunmap_atomic(dst_p);
-		kunmap_atomic(src_p);
-
-		bio_advance_iter(src, &src_iter, bytes);
-		bio_advance_iter(dst, &dst_iter, bytes);
-	}
-}
-EXPORT_SYMBOL(bio_copy_data);
-
-struct bio_map_data {
-	int nr_sgvecs;
-	int is_our_pages;
-	struct sg_iovec sgvecs[];
-};
-
-static void bio_set_map_data(struct bio_map_data *bmd, struct bio *bio,
-			     const struct sg_iovec *iov, int iov_count,
-			     int is_our_pages)
-{
-	memcpy(bmd->sgvecs, iov, sizeof(struct sg_iovec) * iov_count);
-	bmd->nr_sgvecs = iov_count;
-	bmd->is_our_pages = is_our_pages;
-	bio->bi_private = bmd;
-}
-
-static struct bio_map_data *bio_alloc_map_data(int nr_segs,
-					       unsigned int iov_count,
-					       gfp_t gfp_mask)
-{
-	if (iov_count > UIO_MAXIOV)
-		return NULL;
-
-	return kmalloc(sizeof(struct bio_map_data) +
-		       sizeof(struct sg_iovec) * iov_count, gfp_mask);
-}
-
-static int __bio_copy_iov(struct bio *bio, const struct sg_iovec *iov, int iov_count,
-			  int to_user, int from_user, int do_free_page)
-{
-	int ret = 0, i;
-	struct bio_vec *bvec;
-	int iov_idx = 0;
-	unsigned int iov_off = 0;
-
-	bio_for_each_segment_all(bvec, bio, i) {
-		char *bv_addr = page_address(bvec->bv_page);
-		unsigned int bv_len = bvec->bv_len;
-
-		while (bv_len && iov_idx < iov_count) {
-			unsigned int bytes;
-			char __user *iov_addr;
-
-			bytes = min_t(unsigned int,
-				      iov[iov_idx].iov_len - iov_off, bv_len);
-			iov_addr = iov[iov_idx].iov_base + iov_off;
-
-			if (!ret) {
-				if (to_user)
-					ret = copy_to_user(iov_addr, bv_addr,
-							   bytes);
-
-				if (from_user)
-					ret = copy_from_user(bv_addr, iov_addr,
-							     bytes);
-
-				if (ret)
-					ret = -EFAULT;
-			}
-
-			bv_len -= bytes;
-			bv_addr += bytes;
-			iov_addr += bytes;
-			iov_off += bytes;
-
-			if (iov[iov_idx].iov_len == iov_off) {
-				iov_idx++;
-				iov_off = 0;
-			}
-		}
-
-		if (do_free_page)
-			__free_page(bvec->bv_page);
-	}
-
-	return ret;
-}
-
-/**
- *	bio_uncopy_user	-	finish previously mapped bio
- *	@bio: bio being terminated
- *
- *	Free pages allocated from bio_copy_user() and write back data
- *	to user space in case of a read.
- */
-int bio_uncopy_user(struct bio *bio)
-{
-	struct bio_map_data *bmd = bio->bi_private;
-	struct bio_vec *bvec;
-	int ret = 0, i;
-
-	if (!bio_flagged(bio, BIO_NULL_MAPPED)) {
-		/*
-		 * if we're in a workqueue, the request is orphaned, so
-		 * don't copy into a random user address space, just free.
-		 */
-		if (current->mm)
-			ret = __bio_copy_iov(bio, bmd->sgvecs, bmd->nr_sgvecs,
-					     bio_data_dir(bio) == READ,
-					     0, bmd->is_our_pages);
-		else if (bmd->is_our_pages)
-			bio_for_each_segment_all(bvec, bio, i)
-				__free_page(bvec->bv_page);
-	}
-	kfree(bmd);
-	bio_put(bio);
-	return ret;
-}
-EXPORT_SYMBOL(bio_uncopy_user);
-
-/**
- *	bio_copy_user_iov	-	copy user data to bio
- *	@q: destination block queue
- *	@map_data: pointer to the rq_map_data holding pages (if necessary)
- *	@iov:	the iovec.
- *	@iov_count: number of elements in the iovec
- *	@write_to_vm: bool indicating writing to pages or not
- *	@gfp_mask: memory allocation flags
- *
- *	Prepares and returns a bio for indirect user io, bouncing data
- *	to/from kernel pages as necessary. Must be paired with
- *	call bio_uncopy_user() on io completion.
- */
-struct bio *bio_copy_user_iov(struct request_queue *q,
-			      struct rq_map_data *map_data,
-			      const struct sg_iovec *iov, int iov_count,
-			      int write_to_vm, gfp_t gfp_mask)
-{
-	struct bio_map_data *bmd;
-	struct bio_vec *bvec;
-	struct page *page;
-	struct bio *bio;
-	int i, ret;
-	int nr_pages = 0;
-	unsigned int len = 0;
-	unsigned int offset = map_data ? map_data->offset & ~PAGE_MASK : 0;
-
-	for (i = 0; i < iov_count; i++) {
-		unsigned long uaddr;
-		unsigned long end;
-		unsigned long start;
-
-		uaddr = (unsigned long)iov[i].iov_base;
-		end = (uaddr + iov[i].iov_len + PAGE_SIZE - 1) >> PAGE_SHIFT;
-		start = uaddr >> PAGE_SHIFT;
-
-		/*
-		 * Overflow, abort
-		 */
-		if (end < start)
-			return ERR_PTR(-EINVAL);
-
-		nr_pages += end - start;
-		len += iov[i].iov_len;
-	}
-
-	if (offset)
-		nr_pages++;
-
-	bmd = bio_alloc_map_data(nr_pages, iov_count, gfp_mask);
-	if (!bmd)
-		return ERR_PTR(-ENOMEM);
-
-	ret = -ENOMEM;
-	bio = bio_kmalloc(gfp_mask, nr_pages);
-	if (!bio)
-		goto out_bmd;
-
-	if (!write_to_vm)
-		bio->bi_rw |= REQ_WRITE;
-
-	ret = 0;
-
-	if (map_data) {
-		nr_pages = 1 << map_data->page_order;
-		i = map_data->offset / PAGE_SIZE;
-	}
-	while (len) {
-		unsigned int bytes = PAGE_SIZE;
-
-		bytes -= offset;
-
-		if (bytes > len)
-			bytes = len;
-
-		if (map_data) {
-			if (i == map_data->nr_entries * nr_pages) {
-				ret = -ENOMEM;
-				break;
-			}
-
-			page = map_data->pages[i / nr_pages];
-			page += (i % nr_pages);
-
-			i++;
-		} else {
-			page = alloc_page(q->bounce_gfp | gfp_mask);
-			if (!page) {
-				ret = -ENOMEM;
-				break;
-			}
-		}
-
-		if (bio_add_pc_page(q, bio, page, bytes, offset) < bytes)
-			break;
-
-		len -= bytes;
-		offset = 0;
-	}
-
-	if (ret)
-		goto cleanup;
-
-	/*
-	 * success
-	 */
-	if ((!write_to_vm && (!map_data || !map_data->null_mapped)) ||
-	    (map_data && map_data->from_user)) {
-		ret = __bio_copy_iov(bio, iov, iov_count, 0, 1, 0);
-		if (ret)
-			goto cleanup;
-	}
-
-	bio_set_map_data(bmd, bio, iov, iov_count, map_data ? 0 : 1);
-	return bio;
-cleanup:
-	if (!map_data)
-		bio_for_each_segment_all(bvec, bio, i)
-			__free_page(bvec->bv_page);
-
-	bio_put(bio);
-out_bmd:
-	kfree(bmd);
-	return ERR_PTR(ret);
-}
-
-/**
- *	bio_copy_user	-	copy user data to bio
- *	@q: destination block queue
- *	@map_data: pointer to the rq_map_data holding pages (if necessary)
- *	@uaddr: start of user address
- *	@len: length in bytes
- *	@write_to_vm: bool indicating writing to pages or not
- *	@gfp_mask: memory allocation flags
- *
- *	Prepares and returns a bio for indirect user io, bouncing data
- *	to/from kernel pages as necessary. Must be paired with
- *	call bio_uncopy_user() on io completion.
- */
-struct bio *bio_copy_user(struct request_queue *q, struct rq_map_data *map_data,
-			  unsigned long uaddr, unsigned int len,
-			  int write_to_vm, gfp_t gfp_mask)
-{
-	struct sg_iovec iov;
-
-	iov.iov_base = (void __user *)uaddr;
-	iov.iov_len = len;
-
-	return bio_copy_user_iov(q, map_data, &iov, 1, write_to_vm, gfp_mask);
-}
-EXPORT_SYMBOL(bio_copy_user);
-
-static struct bio *__bio_map_user_iov(struct request_queue *q,
-				      struct block_device *bdev,
-				      const struct sg_iovec *iov, int iov_count,
-				      int write_to_vm, gfp_t gfp_mask)
-{
-	int i, j;
-	int nr_pages = 0;
-	struct page **pages;
-	struct bio *bio;
-	int cur_page = 0;
-	int ret, offset;
-
-	for (i = 0; i < iov_count; i++) {
-		unsigned long uaddr = (unsigned long)iov[i].iov_base;
-		unsigned long len = iov[i].iov_len;
-		unsigned long end = (uaddr + len + PAGE_SIZE - 1) >> PAGE_SHIFT;
-		unsigned long start = uaddr >> PAGE_SHIFT;
-
-		/*
-		 * Overflow, abort
-		 */
-		if (end < start)
-			return ERR_PTR(-EINVAL);
-
-		nr_pages += end - start;
-		/*
-		 * buffer must be aligned to at least hardsector size for now
-		 */
-		if (uaddr & queue_dma_alignment(q))
-			return ERR_PTR(-EINVAL);
-	}
-
-	if (!nr_pages)
-		return ERR_PTR(-EINVAL);
-
-	bio = bio_kmalloc(gfp_mask, nr_pages);
-	if (!bio)
-		return ERR_PTR(-ENOMEM);
-
-	ret = -ENOMEM;
-	pages = kcalloc(nr_pages, sizeof(struct page *), gfp_mask);
-	if (!pages)
-		goto out;
-
-	for (i = 0; i < iov_count; i++) {
-		unsigned long uaddr = (unsigned long)iov[i].iov_base;
-		unsigned long len = iov[i].iov_len;
-		unsigned long end = (uaddr + len + PAGE_SIZE - 1) >> PAGE_SHIFT;
-		unsigned long start = uaddr >> PAGE_SHIFT;
-		const int local_nr_pages = end - start;
-		const int page_limit = cur_page + local_nr_pages;
-
-		ret = get_user_pages_fast(uaddr, local_nr_pages,
-				write_to_vm, &pages[cur_page]);
-		if (ret < local_nr_pages) {
-			ret = -EFAULT;
-			goto out_unmap;
-		}
-
-		offset = uaddr & ~PAGE_MASK;
-		for (j = cur_page; j < page_limit; j++) {
-			unsigned int bytes = PAGE_SIZE - offset;
-
-			if (len <= 0)
-				break;
-			
-			if (bytes > len)
-				bytes = len;
-
-			/*
-			 * sorry...
-			 */
-			if (bio_add_pc_page(q, bio, pages[j], bytes, offset) <
-					    bytes)
-				break;
-
-			len -= bytes;
-			offset = 0;
-		}
-
-		cur_page = j;
-		/*
-		 * release the pages we didn't map into the bio, if any
-		 */
-		while (j < page_limit)
-			page_cache_release(pages[j++]);
-	}
-
-	kfree(pages);
-
-	/*
-	 * set data direction, and check if mapped pages need bouncing
-	 */
-	if (!write_to_vm)
-		bio->bi_rw |= REQ_WRITE;
-
-	bio->bi_bdev = bdev;
-	bio->bi_flags |= (1 << BIO_USER_MAPPED);
-	return bio;
-
- out_unmap:
-	for (i = 0; i < nr_pages; i++) {
-		if(!pages[i])
-			break;
-		page_cache_release(pages[i]);
-	}
- out:
-	kfree(pages);
-	bio_put(bio);
-	return ERR_PTR(ret);
-}
-
-/**
- *	bio_map_user	-	map user address into bio
- *	@q: the struct request_queue for the bio
- *	@bdev: destination block device
- *	@uaddr: start of user address
- *	@len: length in bytes
- *	@write_to_vm: bool indicating writing to pages or not
- *	@gfp_mask: memory allocation flags
- *
- *	Map the user space address into a bio suitable for io to a block
- *	device. Returns an error pointer in case of error.
- */
-struct bio *bio_map_user(struct request_queue *q, struct block_device *bdev,
-			 unsigned long uaddr, unsigned int len, int write_to_vm,
-			 gfp_t gfp_mask)
-{
-	struct sg_iovec iov;
-
-	iov.iov_base = (void __user *)uaddr;
-	iov.iov_len = len;
-
-	return bio_map_user_iov(q, bdev, &iov, 1, write_to_vm, gfp_mask);
-}
-EXPORT_SYMBOL(bio_map_user);
-
-/**
- *	bio_map_user_iov - map user sg_iovec table into bio
- *	@q: the struct request_queue for the bio
- *	@bdev: destination block device
- *	@iov:	the iovec.
- *	@iov_count: number of elements in the iovec
- *	@write_to_vm: bool indicating writing to pages or not
- *	@gfp_mask: memory allocation flags
- *
- *	Map the user space address into a bio suitable for io to a block
- *	device. Returns an error pointer in case of error.
- */
-struct bio *bio_map_user_iov(struct request_queue *q, struct block_device *bdev,
-			     const struct sg_iovec *iov, int iov_count,
-			     int write_to_vm, gfp_t gfp_mask)
-{
-	struct bio *bio;
-
-	bio = __bio_map_user_iov(q, bdev, iov, iov_count, write_to_vm,
-				 gfp_mask);
-	if (IS_ERR(bio))
-		return bio;
-
-	/*
-	 * subtle -- if __bio_map_user() ended up bouncing a bio,
-	 * it would normally disappear when its bi_end_io is run.
-	 * however, we need it for the unmap, so grab an extra
-	 * reference to it
-	 */
-	bio_get(bio);
-
-	return bio;
-}
-
-static void __bio_unmap_user(struct bio *bio)
-{
-	struct bio_vec *bvec;
-	int i;
-
-	/*
-	 * make sure we dirty pages we wrote to
-	 */
-	bio_for_each_segment_all(bvec, bio, i) {
-		if (bio_data_dir(bio) == READ)
-			set_page_dirty_lock(bvec->bv_page);
-
-		page_cache_release(bvec->bv_page);
-	}
-
-	bio_put(bio);
-}
-
-/**
- *	bio_unmap_user	-	unmap a bio
- *	@bio:		the bio being unmapped
- *
- *	Unmap a bio previously mapped by bio_map_user(). Must be called with
- *	a process context.
- *
- *	bio_unmap_user() may sleep.
- */
-void bio_unmap_user(struct bio *bio)
-{
-	__bio_unmap_user(bio);
-	bio_put(bio);
-}
-EXPORT_SYMBOL(bio_unmap_user);
-
-static void bio_map_kern_endio(struct bio *bio, int err)
-{
-	bio_put(bio);
-}
-
-static struct bio *__bio_map_kern(struct request_queue *q, void *data,
-				  unsigned int len, gfp_t gfp_mask)
-{
-	unsigned long kaddr = (unsigned long)data;
-	unsigned long end = (kaddr + len + PAGE_SIZE - 1) >> PAGE_SHIFT;
-	unsigned long start = kaddr >> PAGE_SHIFT;
-	const int nr_pages = end - start;
-	int offset, i;
-	struct bio *bio;
-
-	bio = bio_kmalloc(gfp_mask, nr_pages);
-	if (!bio)
-		return ERR_PTR(-ENOMEM);
-
-	offset = offset_in_page(kaddr);
-	for (i = 0; i < nr_pages; i++) {
-		unsigned int bytes = PAGE_SIZE - offset;
-
-		if (len <= 0)
-			break;
-
-		if (bytes > len)
-			bytes = len;
-
-		if (bio_add_pc_page(q, bio, virt_to_page(data), bytes,
-				    offset) < bytes)
-			break;
-
-		data += bytes;
-		len -= bytes;
-		offset = 0;
-	}
-
-	bio->bi_end_io = bio_map_kern_endio;
-	return bio;
-}
-
-/**
- *	bio_map_kern	-	map kernel address into bio
- *	@q: the struct request_queue for the bio
- *	@data: pointer to buffer to map
- *	@len: length in bytes
- *	@gfp_mask: allocation flags for bio allocation
- *
- *	Map the kernel address into a bio suitable for io to a block
- *	device. Returns an error pointer in case of error.
- */
-struct bio *bio_map_kern(struct request_queue *q, void *data, unsigned int len,
-			 gfp_t gfp_mask)
-{
-	struct bio *bio;
-
-	bio = __bio_map_kern(q, data, len, gfp_mask);
-	if (IS_ERR(bio))
-		return bio;
-
-	if (bio->bi_iter.bi_size == len)
-		return bio;
-
-	/*
-	 * Don't support partial mappings.
-	 */
-	bio_put(bio);
-	return ERR_PTR(-EINVAL);
-}
-EXPORT_SYMBOL(bio_map_kern);
-
-static void bio_copy_kern_endio(struct bio *bio, int err)
-{
-	struct bio_vec *bvec;
-	const int read = bio_data_dir(bio) == READ;
-	struct bio_map_data *bmd = bio->bi_private;
-	int i;
-	char *p = bmd->sgvecs[0].iov_base;
-
-	bio_for_each_segment_all(bvec, bio, i) {
-		char *addr = page_address(bvec->bv_page);
-
-		if (read)
-			memcpy(p, addr, bvec->bv_len);
-
-		__free_page(bvec->bv_page);
-		p += bvec->bv_len;
-	}
-
-	kfree(bmd);
-	bio_put(bio);
-}
-
-/**
- *	bio_copy_kern	-	copy kernel address into bio
- *	@q: the struct request_queue for the bio
- *	@data: pointer to buffer to copy
- *	@len: length in bytes
- *	@gfp_mask: allocation flags for bio and page allocation
- *	@reading: data direction is READ
- *
- *	copy the kernel address into a bio suitable for io to a block
- *	device. Returns an error pointer in case of error.
- */
-struct bio *bio_copy_kern(struct request_queue *q, void *data, unsigned int len,
-			  gfp_t gfp_mask, int reading)
-{
-	struct bio *bio;
-	struct bio_vec *bvec;
-	int i;
-
-	bio = bio_copy_user(q, NULL, (unsigned long)data, len, 1, gfp_mask);
-	if (IS_ERR(bio))
-		return bio;
-
-	if (!reading) {
-		void *p = data;
-
-		bio_for_each_segment_all(bvec, bio, i) {
-			char *addr = page_address(bvec->bv_page);
-
-			memcpy(addr, p, bvec->bv_len);
-			p += bvec->bv_len;
-		}
-	}
-
-	bio->bi_end_io = bio_copy_kern_endio;
-
-	return bio;
-}
-EXPORT_SYMBOL(bio_copy_kern);
-
-/*
- * bio_set_pages_dirty() and bio_check_pages_dirty() are support functions
- * for performing direct-IO in BIOs.
- *
- * The problem is that we cannot run set_page_dirty() from interrupt context
- * because the required locks are not interrupt-safe.  So what we can do is to
- * mark the pages dirty _before_ performing IO.  And in interrupt context,
- * check that the pages are still dirty.   If so, fine.  If not, redirty them
- * in process context.
- *
- * We special-case compound pages here: normally this means reads into hugetlb
- * pages.  The logic in here doesn't really work right for compound pages
- * because the VM does not uniformly chase down the head page in all cases.
- * But dirtiness of compound pages is pretty meaningless anyway: the VM doesn't
- * handle them at all.  So we skip compound pages here at an early stage.
- *
- * Note that this code is very hard to test under normal circumstances because
- * direct-io pins the pages with get_user_pages().  This makes
- * is_page_cache_freeable return false, and the VM will not clean the pages.
- * But other code (eg, flusher threads) could clean the pages if they are mapped
- * pagecache.
- *
- * Simply disabling the call to bio_set_pages_dirty() is a good way to test the
- * deferred bio dirtying paths.
- */
-
-/*
- * bio_set_pages_dirty() will mark all the bio's pages as dirty.
- */
-void bio_set_pages_dirty(struct bio *bio)
-{
-	struct bio_vec *bvec;
-	int i;
-
-	bio_for_each_segment_all(bvec, bio, i) {
-		struct page *page = bvec->bv_page;
-
-		if (page && !PageCompound(page))
-			set_page_dirty_lock(page);
-	}
-}
-
-static void bio_release_pages(struct bio *bio)
-{
-	struct bio_vec *bvec;
-	int i;
-
-	bio_for_each_segment_all(bvec, bio, i) {
-		struct page *page = bvec->bv_page;
-
-		if (page)
-			put_page(page);
-	}
-}
-
-/*
- * bio_check_pages_dirty() will check that all the BIO's pages are still dirty.
- * If they are, then fine.  If, however, some pages are clean then they must
- * have been written out during the direct-IO read.  So we take another ref on
- * the BIO and the offending pages and re-dirty the pages in process context.
- *
- * It is expected that bio_check_pages_dirty() will wholly own the BIO from
- * here on.  It will run one page_cache_release() against each page and will
- * run one bio_put() against the BIO.
- */
-
-static void bio_dirty_fn(struct work_struct *work);
-
-static DECLARE_WORK(bio_dirty_work, bio_dirty_fn);
-static DEFINE_SPINLOCK(bio_dirty_lock);
-static struct bio *bio_dirty_list;
-
-/*
- * This runs in process context
- */
-static void bio_dirty_fn(struct work_struct *work)
-{
-	unsigned long flags;
-	struct bio *bio;
-
-	spin_lock_irqsave(&bio_dirty_lock, flags);
-	bio = bio_dirty_list;
-	bio_dirty_list = NULL;
-	spin_unlock_irqrestore(&bio_dirty_lock, flags);
-
-	while (bio) {
-		struct bio *next = bio->bi_private;
-
-		bio_set_pages_dirty(bio);
-		bio_release_pages(bio);
-		bio_put(bio);
-		bio = next;
-	}
-}
-
-void bio_check_pages_dirty(struct bio *bio)
-{
-	struct bio_vec *bvec;
-	int nr_clean_pages = 0;
-	int i;
-
-	bio_for_each_segment_all(bvec, bio, i) {
-		struct page *page = bvec->bv_page;
-
-		if (PageDirty(page) || PageCompound(page)) {
-			page_cache_release(page);
-			bvec->bv_page = NULL;
-		} else {
-			nr_clean_pages++;
-		}
-	}
-
-	if (nr_clean_pages) {
-		unsigned long flags;
-
-		spin_lock_irqsave(&bio_dirty_lock, flags);
-		bio->bi_private = bio_dirty_list;
-		bio_dirty_list = bio;
-		spin_unlock_irqrestore(&bio_dirty_lock, flags);
-		schedule_work(&bio_dirty_work);
-	} else {
-		bio_put(bio);
-	}
-}
-
-#if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE
-void bio_flush_dcache_pages(struct bio *bi)
-{
-	struct bio_vec bvec;
-	struct bvec_iter iter;
-
-	bio_for_each_segment(bvec, bi, iter)
-		flush_dcache_page(bvec.bv_page);
-}
-EXPORT_SYMBOL(bio_flush_dcache_pages);
-#endif
-
-/**
- * bio_endio - end I/O on a bio
- * @bio:	bio
- * @error:	error, if any
- *
- * Description:
- *   bio_endio() will end I/O on the whole bio. bio_endio() is the
- *   preferred way to end I/O on a bio, it takes care of clearing
- *   BIO_UPTODATE on error. @error is 0 on success, and and one of the
- *   established -Exxxx (-EIO, for instance) error values in case
- *   something went wrong. No one should call bi_end_io() directly on a
- *   bio unless they own it and thus know that it has an end_io
- *   function.
- **/
-void bio_endio(struct bio *bio, int error)
-{
-	while (bio) {
-		BUG_ON(atomic_read(&bio->bi_remaining) <= 0);
-
-		if (error)
-			clear_bit(BIO_UPTODATE, &bio->bi_flags);
-		else if (!test_bit(BIO_UPTODATE, &bio->bi_flags))
-			error = -EIO;
-
-		if (!atomic_dec_and_test(&bio->bi_remaining))
-			return;
-
-		/*
-		 * Need to have a real endio function for chained bios,
-		 * otherwise various corner cases will break (like stacking
-		 * block devices that save/restore bi_end_io) - however, we want
-		 * to avoid unbounded recursion and blowing the stack. Tail call
-		 * optimization would handle this, but compiling with frame
-		 * pointers also disables gcc's sibling call optimization.
-		 */
-		if (bio->bi_end_io == bio_chain_endio) {
-			struct bio *parent = bio->bi_private;
-			bio_put(bio);
-			bio = parent;
-		} else {
-			if (bio->bi_end_io)
-				bio->bi_end_io(bio, error);
-			bio = NULL;
-		}
-	}
-}
-EXPORT_SYMBOL(bio_endio);
-
-/**
- * bio_endio_nodec - end I/O on a bio, without decrementing bi_remaining
- * @bio:	bio
- * @error:	error, if any
- *
- * For code that has saved and restored bi_end_io; thing hard before using this
- * function, probably you should've cloned the entire bio.
- **/
-void bio_endio_nodec(struct bio *bio, int error)
-{
-	atomic_inc(&bio->bi_remaining);
-	bio_endio(bio, error);
-}
-EXPORT_SYMBOL(bio_endio_nodec);
-
-/**
- * bio_split - split a bio
- * @bio:	bio to split
- * @sectors:	number of sectors to split from the front of @bio
- * @gfp:	gfp mask
- * @bs:		bio set to allocate from
- *
- * Allocates and returns a new bio which represents @sectors from the start of
- * @bio, and updates @bio to represent the remaining sectors.
- *
- * The newly allocated bio will point to @bio's bi_io_vec; it is the caller's
- * responsibility to ensure that @bio is not freed before the split.
- */
-struct bio *bio_split(struct bio *bio, int sectors,
-		      gfp_t gfp, struct bio_set *bs)
-{
-	struct bio *split = NULL;
-
-	BUG_ON(sectors <= 0);
-	BUG_ON(sectors >= bio_sectors(bio));
-
-	split = bio_clone_fast(bio, gfp, bs);
-	if (!split)
-		return NULL;
-
-	split->bi_iter.bi_size = sectors << 9;
-
-	if (bio_integrity(split))
-		bio_integrity_trim(split, 0, sectors);
-
-	bio_advance(bio, split->bi_iter.bi_size);
-
-	return split;
-}
-EXPORT_SYMBOL(bio_split);
-
-/**
- * bio_trim - trim a bio
- * @bio:	bio to trim
- * @offset:	number of sectors to trim from the front of @bio
- * @size:	size we want to trim @bio to, in sectors
- */
-void bio_trim(struct bio *bio, int offset, int size)
-{
-	/* 'bio' is a cloned bio which we need to trim to match
-	 * the given offset and size.
-	 */
-
-	size <<= 9;
-	if (offset == 0 && size == bio->bi_iter.bi_size)
-		return;
-
-	clear_bit(BIO_SEG_VALID, &bio->bi_flags);
-
-	bio_advance(bio, offset << 9);
-
-	bio->bi_iter.bi_size = size;
-}
-EXPORT_SYMBOL_GPL(bio_trim);
-
-/*
- * create memory pools for biovec's in a bio_set.
- * use the global biovec slabs created for general use.
- */
-mempool_t *biovec_create_pool(struct bio_set *bs, int pool_entries)
-{
-	struct biovec_slab *bp = bvec_slabs + BIOVEC_MAX_IDX;
-
-	return mempool_create_slab_pool(pool_entries, bp->slab);
-}
-
-void bioset_free(struct bio_set *bs)
-{
-	if (bs->rescue_workqueue)
-		destroy_workqueue(bs->rescue_workqueue);
-
-	if (bs->bio_pool)
-		mempool_destroy(bs->bio_pool);
-
-	if (bs->bvec_pool)
-		mempool_destroy(bs->bvec_pool);
-
-	bioset_integrity_free(bs);
-	bio_put_slab(bs);
-
-	kfree(bs);
-}
-EXPORT_SYMBOL(bioset_free);
-
-/**
- * bioset_create  - Create a bio_set
- * @pool_size:	Number of bio and bio_vecs to cache in the mempool
- * @front_pad:	Number of bytes to allocate in front of the returned bio
- *
- * Description:
- *    Set up a bio_set to be used with @bio_alloc_bioset. Allows the caller
- *    to ask for a number of bytes to be allocated in front of the bio.
- *    Front pad allocation is useful for embedding the bio inside
- *    another structure, to avoid allocating extra data to go with the bio.
- *    Note that the bio must be embedded at the END of that structure always,
- *    or things will break badly.
- */
-struct bio_set *bioset_create(unsigned int pool_size, unsigned int front_pad)
-{
-	unsigned int back_pad = BIO_INLINE_VECS * sizeof(struct bio_vec);
-	struct bio_set *bs;
-
-	bs = kzalloc(sizeof(*bs), GFP_KERNEL);
-	if (!bs)
-		return NULL;
-
-	bs->front_pad = front_pad;
-
-	spin_lock_init(&bs->rescue_lock);
-	bio_list_init(&bs->rescue_list);
-	INIT_WORK(&bs->rescue_work, bio_alloc_rescue);
-
-	bs->bio_slab = bio_find_or_create_slab(front_pad + back_pad);
-	if (!bs->bio_slab) {
-		kfree(bs);
-		return NULL;
-	}
-
-	bs->bio_pool = mempool_create_slab_pool(pool_size, bs->bio_slab);
-	if (!bs->bio_pool)
-		goto bad;
-
-	bs->bvec_pool = biovec_create_pool(bs, pool_size);
-	if (!bs->bvec_pool)
-		goto bad;
-
-	bs->rescue_workqueue = alloc_workqueue("bioset", WQ_MEM_RECLAIM, 0);
-	if (!bs->rescue_workqueue)
-		goto bad;
-
-	return bs;
-bad:
-	bioset_free(bs);
-	return NULL;
-}
-EXPORT_SYMBOL(bioset_create);
-
-#ifdef CONFIG_BLK_CGROUP
-/**
- * bio_associate_current - associate a bio with %current
- * @bio: target bio
- *
- * Associate @bio with %current if it hasn't been associated yet.  Block
- * layer will treat @bio as if it were issued by %current no matter which
- * task actually issues it.
- *
- * This function takes an extra reference of @task's io_context and blkcg
- * which will be put when @bio is released.  The caller must own @bio,
- * ensure %current->io_context exists, and is responsible for synchronizing
- * calls to this function.
- */
-int bio_associate_current(struct bio *bio)
-{
-	struct io_context *ioc;
-	struct cgroup_subsys_state *css;
-
-	if (bio->bi_ioc)
-		return -EBUSY;
-
-	ioc = current->io_context;
-	if (!ioc)
-		return -ENOENT;
-
-	/* acquire active ref on @ioc and associate */
-	get_io_context_active(ioc);
-	bio->bi_ioc = ioc;
-
-	/* associate blkcg if exists */
-	rcu_read_lock();
-	css = task_css(current, blkio_cgrp_id);
-	if (css && css_tryget(css))
-		bio->bi_css = css;
-	rcu_read_unlock();
-
-	return 0;
-}
-
-/**
- * bio_disassociate_task - undo bio_associate_current()
- * @bio: target bio
- */
-void bio_disassociate_task(struct bio *bio)
-{
-	if (bio->bi_ioc) {
-		put_io_context(bio->bi_ioc);
-		bio->bi_ioc = NULL;
-	}
-	if (bio->bi_css) {
-		css_put(bio->bi_css);
-		bio->bi_css = NULL;
-	}
-}
-
-#endif /* CONFIG_BLK_CGROUP */
-
-static void __init biovec_init_slabs(void)
-{
-	int i;
-
-	for (i = 0; i < BIOVEC_NR_POOLS; i++) {
-		int size;
-		struct biovec_slab *bvs = bvec_slabs + i;
-
-		if (bvs->nr_vecs <= BIO_INLINE_VECS) {
-			bvs->slab = NULL;
-			continue;
-		}
-
-		size = bvs->nr_vecs * sizeof(struct bio_vec);
-		bvs->slab = kmem_cache_create(bvs->name, size, 0,
-                                SLAB_HWCACHE_ALIGN|SLAB_PANIC, NULL);
-	}
-}
-
-static int __init init_bio(void)
-{
-	bio_slab_max = 2;
-	bio_slab_nr = 0;
-	bio_slabs = kzalloc(bio_slab_max * sizeof(struct bio_slab), GFP_KERNEL);
-	if (!bio_slabs)
-		panic("bio: can't allocate bios\n");
-
-	bio_integrity_init();
-	biovec_init_slabs();
-
-	fs_bio_set = bioset_create(BIO_POOL_SIZE, 0);
-	if (!fs_bio_set)
-		panic("bio: can't allocate bios\n");
-
-	if (bioset_integrity_create(fs_bio_set, BIO_POOL_SIZE))
-		panic("bio: can't create integrity pool\n");
-
-	return 0;
-}
-subsys_initcall(init_bio);
diff --git a/fs/ioprio.c b/fs/ioprio.c
deleted file mode 100644
index e50170ca7c33..000000000000
--- a/fs/ioprio.c
+++ /dev/null
@@ -1,241 +0,0 @@
-/*
- * fs/ioprio.c
- *
- * Copyright (C) 2004 Jens Axboe <axboe@kernel.dk>
- *
- * Helper functions for setting/querying io priorities of processes. The
- * system calls closely mimmick getpriority/setpriority, see the man page for
- * those. The prio argument is a composite of prio class and prio data, where
- * the data argument has meaning within that class. The standard scheduling
- * classes have 8 distinct prio levels, with 0 being the highest prio and 7
- * being the lowest.
- *
- * IOW, setting BE scheduling class with prio 2 is done ala:
- *
- * unsigned int prio = (IOPRIO_CLASS_BE << IOPRIO_CLASS_SHIFT) | 2;
- *
- * ioprio_set(PRIO_PROCESS, pid, prio);
- *
- * See also Documentation/block/ioprio.txt
- *
- */
-#include <linux/gfp.h>
-#include <linux/kernel.h>
-#include <linux/export.h>
-#include <linux/ioprio.h>
-#include <linux/blkdev.h>
-#include <linux/capability.h>
-#include <linux/syscalls.h>
-#include <linux/security.h>
-#include <linux/pid_namespace.h>
-
-int set_task_ioprio(struct task_struct *task, int ioprio)
-{
-	int err;
-	struct io_context *ioc;
-	const struct cred *cred = current_cred(), *tcred;
-
-	rcu_read_lock();
-	tcred = __task_cred(task);
-	if (!uid_eq(tcred->uid, cred->euid) &&
-	    !uid_eq(tcred->uid, cred->uid) && !capable(CAP_SYS_NICE)) {
-		rcu_read_unlock();
-		return -EPERM;
-	}
-	rcu_read_unlock();
-
-	err = security_task_setioprio(task, ioprio);
-	if (err)
-		return err;
-
-	ioc = get_task_io_context(task, GFP_ATOMIC, NUMA_NO_NODE);
-	if (ioc) {
-		ioc->ioprio = ioprio;
-		put_io_context(ioc);
-	}
-
-	return err;
-}
-EXPORT_SYMBOL_GPL(set_task_ioprio);
-
-SYSCALL_DEFINE3(ioprio_set, int, which, int, who, int, ioprio)
-{
-	int class = IOPRIO_PRIO_CLASS(ioprio);
-	int data = IOPRIO_PRIO_DATA(ioprio);
-	struct task_struct *p, *g;
-	struct user_struct *user;
-	struct pid *pgrp;
-	kuid_t uid;
-	int ret;
-
-	switch (class) {
-		case IOPRIO_CLASS_RT:
-			if (!capable(CAP_SYS_ADMIN))
-				return -EPERM;
-			/* fall through, rt has prio field too */
-		case IOPRIO_CLASS_BE:
-			if (data >= IOPRIO_BE_NR || data < 0)
-				return -EINVAL;
-
-			break;
-		case IOPRIO_CLASS_IDLE:
-			break;
-		case IOPRIO_CLASS_NONE:
-			if (data)
-				return -EINVAL;
-			break;
-		default:
-			return -EINVAL;
-	}
-
-	ret = -ESRCH;
-	rcu_read_lock();
-	switch (which) {
-		case IOPRIO_WHO_PROCESS:
-			if (!who)
-				p = current;
-			else
-				p = find_task_by_vpid(who);
-			if (p)
-				ret = set_task_ioprio(p, ioprio);
-			break;
-		case IOPRIO_WHO_PGRP:
-			if (!who)
-				pgrp = task_pgrp(current);
-			else
-				pgrp = find_vpid(who);
-			do_each_pid_thread(pgrp, PIDTYPE_PGID, p) {
-				ret = set_task_ioprio(p, ioprio);
-				if (ret)
-					break;
-			} while_each_pid_thread(pgrp, PIDTYPE_PGID, p);
-			break;
-		case IOPRIO_WHO_USER:
-			uid = make_kuid(current_user_ns(), who);
-			if (!uid_valid(uid))
-				break;
-			if (!who)
-				user = current_user();
-			else
-				user = find_user(uid);
-
-			if (!user)
-				break;
-
-			do_each_thread(g, p) {
-				if (!uid_eq(task_uid(p), uid))
-					continue;
-				ret = set_task_ioprio(p, ioprio);
-				if (ret)
-					goto free_uid;
-			} while_each_thread(g, p);
-free_uid:
-			if (who)
-				free_uid(user);
-			break;
-		default:
-			ret = -EINVAL;
-	}
-
-	rcu_read_unlock();
-	return ret;
-}
-
-static int get_task_ioprio(struct task_struct *p)
-{
-	int ret;
-
-	ret = security_task_getioprio(p);
-	if (ret)
-		goto out;
-	ret = IOPRIO_PRIO_VALUE(IOPRIO_CLASS_NONE, IOPRIO_NORM);
-	if (p->io_context)
-		ret = p->io_context->ioprio;
-out:
-	return ret;
-}
-
-int ioprio_best(unsigned short aprio, unsigned short bprio)
-{
-	unsigned short aclass = IOPRIO_PRIO_CLASS(aprio);
-	unsigned short bclass = IOPRIO_PRIO_CLASS(bprio);
-
-	if (aclass == IOPRIO_CLASS_NONE)
-		aclass = IOPRIO_CLASS_BE;
-	if (bclass == IOPRIO_CLASS_NONE)
-		bclass = IOPRIO_CLASS_BE;
-
-	if (aclass == bclass)
-		return min(aprio, bprio);
-	if (aclass > bclass)
-		return bprio;
-	else
-		return aprio;
-}
-
-SYSCALL_DEFINE2(ioprio_get, int, which, int, who)
-{
-	struct task_struct *g, *p;
-	struct user_struct *user;
-	struct pid *pgrp;
-	kuid_t uid;
-	int ret = -ESRCH;
-	int tmpio;
-
-	rcu_read_lock();
-	switch (which) {
-		case IOPRIO_WHO_PROCESS:
-			if (!who)
-				p = current;
-			else
-				p = find_task_by_vpid(who);
-			if (p)
-				ret = get_task_ioprio(p);
-			break;
-		case IOPRIO_WHO_PGRP:
-			if (!who)
-				pgrp = task_pgrp(current);
-			else
-				pgrp = find_vpid(who);
-			do_each_pid_thread(pgrp, PIDTYPE_PGID, p) {
-				tmpio = get_task_ioprio(p);
-				if (tmpio < 0)
-					continue;
-				if (ret == -ESRCH)
-					ret = tmpio;
-				else
-					ret = ioprio_best(ret, tmpio);
-			} while_each_pid_thread(pgrp, PIDTYPE_PGID, p);
-			break;
-		case IOPRIO_WHO_USER:
-			uid = make_kuid(current_user_ns(), who);
-			if (!who)
-				user = current_user();
-			else
-				user = find_user(uid);
-
-			if (!user)
-				break;
-
-			do_each_thread(g, p) {
-				if (!uid_eq(task_uid(p), user->uid))
-					continue;
-				tmpio = get_task_ioprio(p);
-				if (tmpio < 0)
-					continue;
-				if (ret == -ESRCH)
-					ret = tmpio;
-				else
-					ret = ioprio_best(ret, tmpio);
-			} while_each_thread(g, p);
-
-			if (who)
-				free_uid(user);
-			break;
-		default:
-			ret = -EINVAL;
-	}
-
-	rcu_read_unlock();
-	return ret;
-}