Initial import

1 files changed, 777 insertions, 0 deletions

diff --git a/include/linux/bio.h b/include/linux/bio.h
new file mode 100644
index 000000000..bdf6ba5f7
--- /dev/null
+++ b/include/linux/bio.h
@@ -0,0 +1,777 @@
+/*
+ * 2.5 block I/O model
+ *
+ * Copyright (C) 2001 Jens Axboe <axboe@suse.de>
+ *
+ * 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-
+ */
+#ifndef __LINUX_BIO_H
+#define __LINUX_BIO_H
+
+#include <linux/highmem.h>
+#include <linux/mempool.h>
+#include <linux/ioprio.h>
+#include <linux/bug.h>
+
+#ifdef CONFIG_BLOCK
+
+#include <asm/io.h>
+
+/* struct bio, bio_vec and BIO_* flags are defined in blk_types.h */
+#include <linux/blk_types.h>
+
+extern int trap_non_toi_io;
+
+#define BIO_DEBUG
+
+#ifdef BIO_DEBUG
+#define BIO_BUG_ON	BUG_ON
+#else
+#define BIO_BUG_ON
+#endif
+
+#define BIO_MAX_PAGES		256
+#define BIO_MAX_SIZE		(BIO_MAX_PAGES << PAGE_CACHE_SHIFT)
+#define BIO_MAX_SECTORS		(BIO_MAX_SIZE >> 9)
+
+/*
+ * upper 16 bits of bi_rw define the io priority of this bio
+ */
+#define BIO_PRIO_SHIFT	(8 * sizeof(unsigned long) - IOPRIO_BITS)
+#define bio_prio(bio)	((bio)->bi_rw >> BIO_PRIO_SHIFT)
+#define bio_prio_valid(bio)	ioprio_valid(bio_prio(bio))
+
+#define bio_set_prio(bio, prio)		do {			\
+	WARN_ON(prio >= (1 << IOPRIO_BITS));			\
+	(bio)->bi_rw &= ((1UL << BIO_PRIO_SHIFT) - 1);		\
+	(bio)->bi_rw |= ((unsigned long) (prio) << BIO_PRIO_SHIFT);	\
+} while (0)
+
+/*
+ * various member access, note that bio_data should of course not be used
+ * on highmem page vectors
+ */
+#define __bvec_iter_bvec(bvec, iter)	(&(bvec)[(iter).bi_idx])
+
+#define bvec_iter_page(bvec, iter)				\
+	(__bvec_iter_bvec((bvec), (iter))->bv_page)
+
+#define bvec_iter_len(bvec, iter)				\
+	min((iter).bi_size,					\
+	    __bvec_iter_bvec((bvec), (iter))->bv_len - (iter).bi_bvec_done)
+
+#define bvec_iter_offset(bvec, iter)				\
+	(__bvec_iter_bvec((bvec), (iter))->bv_offset + (iter).bi_bvec_done)
+
+#define bvec_iter_bvec(bvec, iter)				\
+((struct bio_vec) {						\
+	.bv_page	= bvec_iter_page((bvec), (iter)),	\
+	.bv_len		= bvec_iter_len((bvec), (iter)),	\
+	.bv_offset	= bvec_iter_offset((bvec), (iter)),	\
+})
+
+#define bio_iter_iovec(bio, iter)				\
+	bvec_iter_bvec((bio)->bi_io_vec, (iter))
+
+#define bio_iter_page(bio, iter)				\
+	bvec_iter_page((bio)->bi_io_vec, (iter))
+#define bio_iter_len(bio, iter)					\
+	bvec_iter_len((bio)->bi_io_vec, (iter))
+#define bio_iter_offset(bio, iter)				\
+	bvec_iter_offset((bio)->bi_io_vec, (iter))
+
+#define bio_page(bio)		bio_iter_page((bio), (bio)->bi_iter)
+#define bio_offset(bio)		bio_iter_offset((bio), (bio)->bi_iter)
+#define bio_iovec(bio)		bio_iter_iovec((bio), (bio)->bi_iter)
+
+#define bio_multiple_segments(bio)				\
+	((bio)->bi_iter.bi_size != bio_iovec(bio).bv_len)
+#define bio_sectors(bio)	((bio)->bi_iter.bi_size >> 9)
+#define bio_end_sector(bio)	((bio)->bi_iter.bi_sector + bio_sectors((bio)))
+
+/*
+ * Check whether this bio carries any data or not. A NULL bio is allowed.
+ */
+static inline bool bio_has_data(struct bio *bio)
+{
+	if (bio &&
+	    bio->bi_iter.bi_size &&
+	    !(bio->bi_rw & REQ_DISCARD))
+		return true;
+
+	return false;
+}
+
+static inline bool bio_is_rw(struct bio *bio)
+{
+	if (!bio_has_data(bio))
+		return false;
+
+	if (bio->bi_rw & BIO_NO_ADVANCE_ITER_MASK)
+		return false;
+
+	return true;
+}
+
+static inline bool bio_mergeable(struct bio *bio)
+{
+	if (bio->bi_rw & REQ_NOMERGE_FLAGS)
+		return false;
+
+	return true;
+}
+
+static inline unsigned int bio_cur_bytes(struct bio *bio)
+{
+	if (bio_has_data(bio))
+		return bio_iovec(bio).bv_len;
+	else /* dataless requests such as discard */
+		return bio->bi_iter.bi_size;
+}
+
+static inline void *bio_data(struct bio *bio)
+{
+	if (bio_has_data(bio))
+		return page_address(bio_page(bio)) + bio_offset(bio);
+
+	return NULL;
+}
+
+/*
+ * will die
+ */
+#define bio_to_phys(bio)	(page_to_phys(bio_page((bio))) + (unsigned long) bio_offset((bio)))
+#define bvec_to_phys(bv)	(page_to_phys((bv)->bv_page) + (unsigned long) (bv)->bv_offset)
+
+/*
+ * queues that have highmem support enabled may still need to revert to
+ * PIO transfers occasionally and thus map high pages temporarily. For
+ * permanent PIO fall back, user is probably better off disabling highmem
+ * I/O completely on that queue (see ide-dma for example)
+ */
+#define __bio_kmap_atomic(bio, iter)				\
+	(kmap_atomic(bio_iter_iovec((bio), (iter)).bv_page) +	\
+		bio_iter_iovec((bio), (iter)).bv_offset)
+
+#define __bio_kunmap_atomic(addr)	kunmap_atomic(addr)
+
+/*
+ * merge helpers etc
+ */
+
+/* Default implementation of BIOVEC_PHYS_MERGEABLE */
+#define __BIOVEC_PHYS_MERGEABLE(vec1, vec2)	\
+	((bvec_to_phys((vec1)) + (vec1)->bv_len) == bvec_to_phys((vec2)))
+
+/*
+ * allow arch override, for eg virtualized architectures (put in asm/io.h)
+ */
+#ifndef BIOVEC_PHYS_MERGEABLE
+#define BIOVEC_PHYS_MERGEABLE(vec1, vec2)	\
+	__BIOVEC_PHYS_MERGEABLE(vec1, vec2)
+#endif
+
+#define __BIO_SEG_BOUNDARY(addr1, addr2, mask) \
+	(((addr1) | (mask)) == (((addr2) - 1) | (mask)))
+#define BIOVEC_SEG_BOUNDARY(q, b1, b2) \
+	__BIO_SEG_BOUNDARY(bvec_to_phys((b1)), bvec_to_phys((b2)) + (b2)->bv_len, queue_segment_boundary((q)))
+
+/*
+ * Check if adding a bio_vec after bprv with offset would create a gap in
+ * the SG list. Most drivers don't care about this, but some do.
+ */
+static inline bool bvec_gap_to_prev(struct bio_vec *bprv, unsigned int offset)
+{
+	return offset || ((bprv->bv_offset + bprv->bv_len) & (PAGE_SIZE - 1));
+}
+
+#define bio_io_error(bio) bio_endio((bio), -EIO)
+
+/*
+ * drivers should _never_ use the all version - the bio may have been split
+ * before it got to the driver and the driver won't own all of it
+ */
+#define bio_for_each_segment_all(bvl, bio, i)				\
+	for (i = 0, bvl = (bio)->bi_io_vec; i < (bio)->bi_vcnt; i++, bvl++)
+
+static inline void bvec_iter_advance(struct bio_vec *bv, struct bvec_iter *iter,
+				     unsigned bytes)
+{
+	WARN_ONCE(bytes > iter->bi_size,
+		  "Attempted to advance past end of bvec iter\n");
+
+	while (bytes) {
+		unsigned len = min(bytes, bvec_iter_len(bv, *iter));
+
+		bytes -= len;
+		iter->bi_size -= len;
+		iter->bi_bvec_done += len;
+
+		if (iter->bi_bvec_done == __bvec_iter_bvec(bv, *iter)->bv_len) {
+			iter->bi_bvec_done = 0;
+			iter->bi_idx++;
+		}
+	}
+}
+
+#define for_each_bvec(bvl, bio_vec, iter, start)			\
+	for (iter = (start);						\
+	     (iter).bi_size &&						\
+		((bvl = bvec_iter_bvec((bio_vec), (iter))), 1);	\
+	     bvec_iter_advance((bio_vec), &(iter), (bvl).bv_len))
+
+
+static inline void bio_advance_iter(struct bio *bio, struct bvec_iter *iter,
+				    unsigned bytes)
+{
+	iter->bi_sector += bytes >> 9;
+
+	if (bio->bi_rw & BIO_NO_ADVANCE_ITER_MASK)
+		iter->bi_size -= bytes;
+	else
+		bvec_iter_advance(bio->bi_io_vec, iter, bytes);
+}
+
+#define __bio_for_each_segment(bvl, bio, iter, start)			\
+	for (iter = (start);						\
+	     (iter).bi_size &&						\
+		((bvl = bio_iter_iovec((bio), (iter))), 1);		\
+	     bio_advance_iter((bio), &(iter), (bvl).bv_len))
+
+#define bio_for_each_segment(bvl, bio, iter)				\
+	__bio_for_each_segment(bvl, bio, iter, (bio)->bi_iter)
+
+#define bio_iter_last(bvec, iter) ((iter).bi_size == (bvec).bv_len)
+
+static inline unsigned bio_segments(struct bio *bio)
+{
+	unsigned segs = 0;
+	struct bio_vec bv;
+	struct bvec_iter iter;
+
+	/*
+	 * We special case discard/write same, because they interpret bi_size
+	 * differently:
+	 */
+
+	if (bio->bi_rw & REQ_DISCARD)
+		return 1;
+
+	if (bio->bi_rw & REQ_WRITE_SAME)
+		return 1;
+
+	bio_for_each_segment(bv, bio, iter)
+		segs++;
+
+	return segs;
+}
+
+/*
+ * get a reference to a bio, so it won't disappear. the intended use is
+ * something like:
+ *
+ * bio_get(bio);
+ * submit_bio(rw, bio);
+ * if (bio->bi_flags ...)
+ *	do_something
+ * bio_put(bio);
+ *
+ * without the bio_get(), it could potentially complete I/O before submit_bio
+ * returns. and then bio would be freed memory when if (bio->bi_flags ...)
+ * runs
+ */
+#define bio_get(bio)	atomic_inc(&(bio)->bi_cnt)
+
+enum bip_flags {
+	BIP_BLOCK_INTEGRITY	= 1 << 0, /* block layer owns integrity data */
+	BIP_MAPPED_INTEGRITY	= 1 << 1, /* ref tag has been remapped */
+	BIP_CTRL_NOCHECK	= 1 << 2, /* disable HBA integrity checking */
+	BIP_DISK_NOCHECK	= 1 << 3, /* disable disk integrity checking */
+	BIP_IP_CHECKSUM		= 1 << 4, /* IP checksum */
+};
+
+#if defined(CONFIG_BLK_DEV_INTEGRITY)
+
+static inline struct bio_integrity_payload *bio_integrity(struct bio *bio)
+{
+	if (bio->bi_rw & REQ_INTEGRITY)
+		return bio->bi_integrity;
+
+	return NULL;
+}
+
+/*
+ * bio integrity payload
+ */
+struct bio_integrity_payload {
+	struct bio		*bip_bio;	/* parent bio */
+
+	struct bvec_iter	bip_iter;
+
+	bio_end_io_t		*bip_end_io;	/* saved I/O completion fn */
+
+	unsigned short		bip_slab;	/* slab the bip came from */
+	unsigned short		bip_vcnt;	/* # of integrity bio_vecs */
+	unsigned short		bip_max_vcnt;	/* integrity bio_vec slots */
+	unsigned short		bip_flags;	/* control flags */
+
+	struct work_struct	bip_work;	/* I/O completion */
+
+	struct bio_vec		*bip_vec;
+	struct bio_vec		bip_inline_vecs[0];/* embedded bvec array */
+};
+
+static inline bool bio_integrity_flagged(struct bio *bio, enum bip_flags flag)
+{
+	struct bio_integrity_payload *bip = bio_integrity(bio);
+
+	if (bip)
+		return bip->bip_flags & flag;
+
+	return false;
+}
+
+static inline sector_t bip_get_seed(struct bio_integrity_payload *bip)
+{
+	return bip->bip_iter.bi_sector;
+}
+
+static inline void bip_set_seed(struct bio_integrity_payload *bip,
+				sector_t seed)
+{
+	bip->bip_iter.bi_sector = seed;
+}
+
+#endif /* CONFIG_BLK_DEV_INTEGRITY */
+
+extern void bio_trim(struct bio *bio, int offset, int size);
+extern struct bio *bio_split(struct bio *bio, int sectors,
+			     gfp_t gfp, struct bio_set *bs);
+
+/**
+ * bio_next_split - get next @sectors from a bio, splitting if necessary
+ * @bio:	bio to split
+ * @sectors:	number of sectors to split from the front of @bio
+ * @gfp:	gfp mask
+ * @bs:		bio set to allocate from
+ *
+ * Returns a bio representing the next @sectors of @bio - if the bio is smaller
+ * than @sectors, returns the original bio unchanged.
+ */
+static inline struct bio *bio_next_split(struct bio *bio, int sectors,
+					 gfp_t gfp, struct bio_set *bs)
+{
+	if (sectors >= bio_sectors(bio))
+		return bio;
+
+	return bio_split(bio, sectors, gfp, bs);
+}
+
+extern struct bio_set *bioset_create(unsigned int, unsigned int);
+extern struct bio_set *bioset_create_nobvec(unsigned int, unsigned int);
+extern void bioset_free(struct bio_set *);
+extern mempool_t *biovec_create_pool(int pool_entries);
+
+extern struct bio *bio_alloc_bioset(gfp_t, int, struct bio_set *);
+extern void bio_put(struct bio *);
+
+extern void __bio_clone_fast(struct bio *, struct bio *);
+extern struct bio *bio_clone_fast(struct bio *, gfp_t, struct bio_set *);
+extern struct bio *bio_clone_bioset(struct bio *, gfp_t, struct bio_set *bs);
+
+extern struct bio_set *fs_bio_set;
+
+static inline struct bio *bio_alloc(gfp_t gfp_mask, unsigned int nr_iovecs)
+{
+	return bio_alloc_bioset(gfp_mask, nr_iovecs, fs_bio_set);
+}
+
+static inline struct bio *bio_clone(struct bio *bio, gfp_t gfp_mask)
+{
+	return bio_clone_bioset(bio, gfp_mask, fs_bio_set);
+}
+
+static inline struct bio *bio_kmalloc(gfp_t gfp_mask, unsigned int nr_iovecs)
+{
+	return bio_alloc_bioset(gfp_mask, nr_iovecs, NULL);
+}
+
+static inline struct bio *bio_clone_kmalloc(struct bio *bio, gfp_t gfp_mask)
+{
+	return bio_clone_bioset(bio, gfp_mask, NULL);
+
+}
+
+extern void bio_endio(struct bio *, int);
+extern void bio_endio_nodec(struct bio *, int);
+struct request_queue;
+extern int bio_phys_segments(struct request_queue *, struct bio *);
+
+extern int submit_bio_wait(int rw, struct bio *bio);
+extern void bio_advance(struct bio *, unsigned);
+
+extern void bio_init(struct bio *);
+extern void bio_reset(struct bio *);
+void bio_chain(struct bio *, struct bio *);
+
+extern int bio_add_page(struct bio *, struct page *, unsigned int,unsigned int);
+extern int bio_add_pc_page(struct request_queue *, struct bio *, struct page *,
+			   unsigned int, unsigned int);
+extern int bio_get_nr_vecs(struct block_device *);
+struct rq_map_data;
+extern struct bio *bio_map_user_iov(struct request_queue *,
+				    const struct iov_iter *, gfp_t);
+extern void bio_unmap_user(struct bio *);
+extern struct bio *bio_map_kern(struct request_queue *, void *, unsigned int,
+				gfp_t);
+extern struct bio *bio_copy_kern(struct request_queue *, void *, unsigned int,
+				 gfp_t, int);
+extern void bio_set_pages_dirty(struct bio *bio);
+extern void bio_check_pages_dirty(struct bio *bio);
+
+void generic_start_io_acct(int rw, unsigned long sectors,
+			   struct hd_struct *part);
+void generic_end_io_acct(int rw, struct hd_struct *part,
+			 unsigned long start_time);
+
+#ifndef ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE
+# error	"You should define ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE for your platform"
+#endif
+#if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE
+extern void bio_flush_dcache_pages(struct bio *bi);
+#else
+static inline void bio_flush_dcache_pages(struct bio *bi)
+{
+}
+#endif
+
+extern void bio_copy_data(struct bio *dst, struct bio *src);
+extern int bio_alloc_pages(struct bio *bio, gfp_t gfp);
+
+extern struct bio *bio_copy_user_iov(struct request_queue *,
+				     struct rq_map_data *,
+				     const struct iov_iter *,
+				     gfp_t);
+extern int bio_uncopy_user(struct bio *);
+void zero_fill_bio(struct bio *bio);
+extern struct bio_vec *bvec_alloc(gfp_t, int, unsigned long *, mempool_t *);
+extern void bvec_free(mempool_t *, struct bio_vec *, unsigned int);
+extern unsigned int bvec_nr_vecs(unsigned short idx);
+
+#ifdef CONFIG_BLK_CGROUP
+int bio_associate_current(struct bio *bio);
+void bio_disassociate_task(struct bio *bio);
+#else	/* CONFIG_BLK_CGROUP */
+static inline int bio_associate_current(struct bio *bio) { return -ENOENT; }
+static inline void bio_disassociate_task(struct bio *bio) { }
+#endif	/* CONFIG_BLK_CGROUP */
+
+#ifdef CONFIG_HIGHMEM
+/*
+ * remember never ever reenable interrupts between a bvec_kmap_irq and
+ * bvec_kunmap_irq!
+ */
+static inline char *bvec_kmap_irq(struct bio_vec *bvec, unsigned long *flags)
+{
+	unsigned long addr;
+
+	/*
+	 * might not be a highmem page, but the preempt/irq count
+	 * balancing is a lot nicer this way
+	 */
+	local_irq_save(*flags);
+	addr = (unsigned long) kmap_atomic(bvec->bv_page);
+
+	BUG_ON(addr & ~PAGE_MASK);
+
+	return (char *) addr + bvec->bv_offset;
+}
+
+static inline void bvec_kunmap_irq(char *buffer, unsigned long *flags)
+{
+	unsigned long ptr = (unsigned long) buffer & PAGE_MASK;
+
+	kunmap_atomic((void *) ptr);
+	local_irq_restore(*flags);
+}
+
+#else
+static inline char *bvec_kmap_irq(struct bio_vec *bvec, unsigned long *flags)
+{
+	return page_address(bvec->bv_page) + bvec->bv_offset;
+}
+
+static inline void bvec_kunmap_irq(char *buffer, unsigned long *flags)
+{
+	*flags = 0;
+}
+#endif
+
+static inline char *__bio_kmap_irq(struct bio *bio, struct bvec_iter iter,
+				   unsigned long *flags)
+{
+	return bvec_kmap_irq(&bio_iter_iovec(bio, iter), flags);
+}
+#define __bio_kunmap_irq(buf, flags)	bvec_kunmap_irq(buf, flags)
+
+#define bio_kmap_irq(bio, flags) \
+	__bio_kmap_irq((bio), (bio)->bi_iter, (flags))
+#define bio_kunmap_irq(buf,flags)	__bio_kunmap_irq(buf, flags)
+
+/*
+ * BIO list management for use by remapping drivers (e.g. DM or MD) and loop.
+ *
+ * A bio_list anchors a singly-linked list of bios chained through the bi_next
+ * member of the bio.  The bio_list also caches the last list member to allow
+ * fast access to the tail.
+ */
+struct bio_list {
+	struct bio *head;
+	struct bio *tail;
+};
+
+static inline int bio_list_empty(const struct bio_list *bl)
+{
+	return bl->head == NULL;
+}
+
+static inline void bio_list_init(struct bio_list *bl)
+{
+	bl->head = bl->tail = NULL;
+}
+
+#define BIO_EMPTY_LIST	{ NULL, NULL }
+
+#define bio_list_for_each(bio, bl) \
+	for (bio = (bl)->head; bio; bio = bio->bi_next)
+
+static inline unsigned bio_list_size(const struct bio_list *bl)
+{
+	unsigned sz = 0;
+	struct bio *bio;
+
+	bio_list_for_each(bio, bl)
+		sz++;
+
+	return sz;
+}
+
+static inline void bio_list_add(struct bio_list *bl, struct bio *bio)
+{
+	bio->bi_next = NULL;
+
+	if (bl->tail)
+		bl->tail->bi_next = bio;
+	else
+		bl->head = bio;
+
+	bl->tail = bio;
+}
+
+static inline void bio_list_add_head(struct bio_list *bl, struct bio *bio)
+{
+	bio->bi_next = bl->head;
+
+	bl->head = bio;
+
+	if (!bl->tail)
+		bl->tail = bio;
+}
+
+static inline void bio_list_merge(struct bio_list *bl, struct bio_list *bl2)
+{
+	if (!bl2->head)
+		return;
+
+	if (bl->tail)
+		bl->tail->bi_next = bl2->head;
+	else
+		bl->head = bl2->head;
+
+	bl->tail = bl2->tail;
+}
+
+static inline void bio_list_merge_head(struct bio_list *bl,
+				       struct bio_list *bl2)
+{
+	if (!bl2->head)
+		return;
+
+	if (bl->head)
+		bl2->tail->bi_next = bl->head;
+	else
+		bl->tail = bl2->tail;
+
+	bl->head = bl2->head;
+}
+
+static inline struct bio *bio_list_peek(struct bio_list *bl)
+{
+	return bl->head;
+}
+
+static inline struct bio *bio_list_pop(struct bio_list *bl)
+{
+	struct bio *bio = bl->head;
+
+	if (bio) {
+		bl->head = bl->head->bi_next;
+		if (!bl->head)
+			bl->tail = NULL;
+
+		bio->bi_next = NULL;
+	}
+
+	return bio;
+}
+
+static inline struct bio *bio_list_get(struct bio_list *bl)
+{
+	struct bio *bio = bl->head;
+
+	bl->head = bl->tail = NULL;
+
+	return bio;
+}
+
+/*
+ * bio_set is used to allow other portions of the IO system to
+ * allocate their own private memory pools for bio and iovec structures.
+ * These memory pools in turn all allocate from the bio_slab
+ * and the bvec_slabs[].
+ */
+#define BIO_POOL_SIZE 2
+#define BIOVEC_NR_POOLS 6
+#define BIOVEC_MAX_IDX	(BIOVEC_NR_POOLS - 1)
+
+struct bio_set {
+	struct kmem_cache *bio_slab;
+	unsigned int front_pad;
+
+	mempool_t *bio_pool;
+	mempool_t *bvec_pool;
+#if defined(CONFIG_BLK_DEV_INTEGRITY)
+	mempool_t *bio_integrity_pool;
+	mempool_t *bvec_integrity_pool;
+#endif
+
+	/*
+	 * Deadlock avoidance for stacking block drivers: see comments in
+	 * bio_alloc_bioset() for details
+	 */
+	spinlock_t		rescue_lock;
+	struct bio_list		rescue_list;
+	struct work_struct	rescue_work;
+	struct workqueue_struct	*rescue_workqueue;
+};
+
+struct biovec_slab {
+	int nr_vecs;
+	char *name;
+	struct kmem_cache *slab;
+};
+
+/*
+ * a small number of entries is fine, not going to be performance critical.
+ * basically we just need to survive
+ */
+#define BIO_SPLIT_ENTRIES 2
+
+#if defined(CONFIG_BLK_DEV_INTEGRITY)
+
+#define bip_for_each_vec(bvl, bip, iter)				\
+	for_each_bvec(bvl, (bip)->bip_vec, iter, (bip)->bip_iter)
+
+#define bio_for_each_integrity_vec(_bvl, _bio, _iter)			\
+	for_each_bio(_bio)						\
+		bip_for_each_vec(_bvl, _bio->bi_integrity, _iter)
+
+extern struct bio_integrity_payload *bio_integrity_alloc(struct bio *, gfp_t, unsigned int);
+extern void bio_integrity_free(struct bio *);
+extern int bio_integrity_add_page(struct bio *, struct page *, unsigned int, unsigned int);
+extern bool bio_integrity_enabled(struct bio *bio);
+extern int bio_integrity_prep(struct bio *);
+extern void bio_integrity_endio(struct bio *, int);
+extern void bio_integrity_advance(struct bio *, unsigned int);
+extern void bio_integrity_trim(struct bio *, unsigned int, unsigned int);
+extern int bio_integrity_clone(struct bio *, struct bio *, gfp_t);
+extern int bioset_integrity_create(struct bio_set *, int);
+extern void bioset_integrity_free(struct bio_set *);
+extern void bio_integrity_init(void);
+
+#else /* CONFIG_BLK_DEV_INTEGRITY */
+
+static inline void *bio_integrity(struct bio *bio)
+{
+	return NULL;
+}
+
+static inline bool bio_integrity_enabled(struct bio *bio)
+{
+	return false;
+}
+
+static inline int bioset_integrity_create(struct bio_set *bs, int pool_size)
+{
+	return 0;
+}
+
+static inline void bioset_integrity_free (struct bio_set *bs)
+{
+	return;
+}
+
+static inline int bio_integrity_prep(struct bio *bio)
+{
+	return 0;
+}
+
+static inline void bio_integrity_free(struct bio *bio)
+{
+	return;
+}
+
+static inline int bio_integrity_clone(struct bio *bio, struct bio *bio_src,
+				      gfp_t gfp_mask)
+{
+	return 0;
+}
+
+static inline void bio_integrity_advance(struct bio *bio,
+					 unsigned int bytes_done)
+{
+	return;
+}
+
+static inline void bio_integrity_trim(struct bio *bio, unsigned int offset,
+				      unsigned int sectors)
+{
+	return;
+}
+
+static inline void bio_integrity_init(void)
+{
+	return;
+}
+
+static inline bool bio_integrity_flagged(struct bio *bio, enum bip_flags flag)
+{
+	return false;
+}
+
+#endif /* CONFIG_BLK_DEV_INTEGRITY */
+
+#endif /* CONFIG_BLOCK */
+#endif /* __LINUX_BIO_H */