v4.19.13 snapshot.
diff --git a/include/linux/bio.h b/include/linux/bio.h
new file mode 100644
index 0000000..5137174
--- /dev/null
+++ b/include/linux/bio.h
@@ -0,0 +1,866 @@
+/*
+ * 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>
+
+#define BIO_DEBUG
+
+#ifdef BIO_DEBUG
+#define BIO_BUG_ON BUG_ON
+#else
+#define BIO_BUG_ON
+#endif
+
+#ifdef CONFIG_THP_SWAP
+#if HPAGE_PMD_NR > 256
+#define BIO_MAX_PAGES HPAGE_PMD_NR
+#else
+#define BIO_MAX_PAGES 256
+#endif
+#else
+#define BIO_MAX_PAGES 256
+#endif
+
+#define bio_prio(bio) (bio)->bi_ioprio
+#define bio_set_prio(bio, prio) ((bio)->bi_ioprio = prio)
+
+#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 bvec_iter_sectors(iter) ((iter).bi_size >> 9)
+#define bvec_iter_end_sector(iter) ((iter).bi_sector + bvec_iter_sectors((iter)))
+
+#define bio_sectors(bio) bvec_iter_sectors((bio)->bi_iter)
+#define bio_end_sector(bio) bvec_iter_end_sector((bio)->bi_iter)
+
+/*
+ * Return the data direction, READ or WRITE.
+ */
+#define bio_data_dir(bio) \
+ (op_is_write(bio_op(bio)) ? WRITE : READ)
+
+/*
+ * 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_op(bio) != REQ_OP_DISCARD &&
+ bio_op(bio) != REQ_OP_SECURE_ERASE &&
+ bio_op(bio) != REQ_OP_WRITE_ZEROES)
+ return true;
+
+ return false;
+}
+
+static inline bool bio_no_advance_iter(struct bio *bio)
+{
+ return bio_op(bio) == REQ_OP_DISCARD ||
+ bio_op(bio) == REQ_OP_SECURE_ERASE ||
+ bio_op(bio) == REQ_OP_WRITE_SAME ||
+ bio_op(bio) == REQ_OP_WRITE_ZEROES;
+}
+
+static inline bool bio_mergeable(struct bio *bio)
+{
+ if (bio->bi_opf & 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;
+}
+
+static inline bool bio_full(struct bio *bio)
+{
+ return bio->bi_vcnt >= bio->bi_max_vecs;
+}
+
+/*
+ * will die
+ */
+#define bvec_to_phys(bv) (page_to_phys((bv)->bv_page) + (unsigned long) (bv)->bv_offset)
+
+/*
+ * 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)))
+
+/*
+ * 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 bio_advance_iter(struct bio *bio, struct bvec_iter *iter,
+ unsigned bytes)
+{
+ iter->bi_sector += bytes >> 9;
+
+ if (bio_no_advance_iter(bio)) {
+ iter->bi_size -= bytes;
+ iter->bi_done += bytes;
+ } else {
+ bvec_iter_advance(bio->bi_io_vec, iter, bytes);
+ /* TODO: It is reasonable to complete bio with error here. */
+ }
+}
+
+static inline bool bio_rewind_iter(struct bio *bio, struct bvec_iter *iter,
+ unsigned int bytes)
+{
+ iter->bi_sector -= bytes >> 9;
+
+ if (bio_no_advance_iter(bio)) {
+ iter->bi_size += bytes;
+ iter->bi_done -= bytes;
+ return true;
+ }
+
+ return bvec_iter_rewind(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/write zeroes, because they
+ * interpret bi_size differently:
+ */
+
+ switch (bio_op(bio)) {
+ case REQ_OP_DISCARD:
+ case REQ_OP_SECURE_ERASE:
+ case REQ_OP_WRITE_ZEROES:
+ return 0;
+ case REQ_OP_WRITE_SAME:
+ return 1;
+ default:
+ break;
+ }
+
+ 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
+ */
+static inline void bio_get(struct bio *bio)
+{
+ bio->bi_flags |= (1 << BIO_REFFED);
+ smp_mb__before_atomic();
+ atomic_inc(&bio->__bi_cnt);
+}
+
+static inline void bio_cnt_set(struct bio *bio, unsigned int count)
+{
+ if (count != 1) {
+ bio->bi_flags |= (1 << BIO_REFFED);
+ smp_mb__before_atomic();
+ }
+ atomic_set(&bio->__bi_cnt, count);
+}
+
+static inline bool bio_flagged(struct bio *bio, unsigned int bit)
+{
+ return (bio->bi_flags & (1U << bit)) != 0;
+}
+
+static inline void bio_set_flag(struct bio *bio, unsigned int bit)
+{
+ bio->bi_flags |= (1U << bit);
+}
+
+static inline void bio_clear_flag(struct bio *bio, unsigned int bit)
+{
+ bio->bi_flags &= ~(1U << bit);
+}
+
+static inline void bio_get_first_bvec(struct bio *bio, struct bio_vec *bv)
+{
+ *bv = bio_iovec(bio);
+}
+
+static inline void bio_get_last_bvec(struct bio *bio, struct bio_vec *bv)
+{
+ struct bvec_iter iter = bio->bi_iter;
+ int idx;
+
+ if (unlikely(!bio_multiple_segments(bio))) {
+ *bv = bio_iovec(bio);
+ return;
+ }
+
+ bio_advance_iter(bio, &iter, iter.bi_size);
+
+ if (!iter.bi_bvec_done)
+ idx = iter.bi_idx - 1;
+ else /* in the middle of bvec */
+ idx = iter.bi_idx;
+
+ *bv = bio->bi_io_vec[idx];
+
+ /*
+ * iter.bi_bvec_done records actual length of the last bvec
+ * if this bio ends in the middle of one io vector
+ */
+ if (iter.bi_bvec_done)
+ bv->bv_len = iter.bi_bvec_done;
+}
+
+static inline unsigned bio_pages_all(struct bio *bio)
+{
+ WARN_ON_ONCE(bio_flagged(bio, BIO_CLONED));
+ return bio->bi_vcnt;
+}
+
+static inline struct bio_vec *bio_first_bvec_all(struct bio *bio)
+{
+ WARN_ON_ONCE(bio_flagged(bio, BIO_CLONED));
+ return bio->bi_io_vec;
+}
+
+static inline struct page *bio_first_page_all(struct bio *bio)
+{
+ return bio_first_bvec_all(bio)->bv_page;
+}
+
+static inline struct bio_vec *bio_last_bvec_all(struct bio *bio)
+{
+ WARN_ON_ONCE(bio_flagged(bio, BIO_CLONED));
+ return &bio->bi_io_vec[bio->bi_vcnt - 1];
+}
+
+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 */
+};
+
+/*
+ * bio integrity payload
+ */
+struct bio_integrity_payload {
+ struct bio *bip_bio; /* parent bio */
+
+ struct bvec_iter bip_iter;
+
+ 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 */
+};
+
+#if defined(CONFIG_BLK_DEV_INTEGRITY)
+
+static inline struct bio_integrity_payload *bio_integrity(struct bio *bio)
+{
+ if (bio->bi_opf & REQ_INTEGRITY)
+ return bio->bi_integrity;
+
+ return NULL;
+}
+
+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);
+}
+
+enum {
+ BIOSET_NEED_BVECS = BIT(0),
+ BIOSET_NEED_RESCUER = BIT(1),
+};
+extern int bioset_init(struct bio_set *, unsigned int, unsigned int, int flags);
+extern void bioset_exit(struct bio_set *);
+extern int biovec_init_pool(mempool_t *pool, int pool_entries);
+extern int bioset_init_from_src(struct bio_set *bs, struct bio_set *src);
+
+extern struct bio *bio_alloc_bioset(gfp_t, unsigned 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_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_kmalloc(gfp_t gfp_mask, unsigned int nr_iovecs)
+{
+ return bio_alloc_bioset(gfp_mask, nr_iovecs, NULL);
+}
+
+extern blk_qc_t submit_bio(struct bio *);
+
+extern void bio_endio(struct bio *);
+
+static inline void bio_io_error(struct bio *bio)
+{
+ bio->bi_status = BLK_STS_IOERR;
+ bio_endio(bio);
+}
+
+static inline void bio_wouldblock_error(struct bio *bio)
+{
+ bio->bi_status = BLK_STS_AGAIN;
+ bio_endio(bio);
+}
+
+struct request_queue;
+extern int bio_phys_segments(struct request_queue *, struct bio *);
+
+extern int submit_bio_wait(struct bio *bio);
+extern void bio_advance(struct bio *, unsigned);
+
+extern void bio_init(struct bio *bio, struct bio_vec *table,
+ unsigned short max_vecs);
+extern void bio_uninit(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);
+bool __bio_try_merge_page(struct bio *bio, struct page *page,
+ unsigned int len, unsigned int off);
+void __bio_add_page(struct bio *bio, struct page *page,
+ unsigned int len, unsigned int off);
+int bio_iov_iter_get_pages(struct bio *bio, struct iov_iter *iter);
+struct rq_map_data;
+extern struct bio *bio_map_user_iov(struct request_queue *,
+ 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(struct request_queue *q, int op,
+ unsigned long sectors, struct hd_struct *part);
+void generic_end_io_acct(struct request_queue *q, int op,
+ 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_iter(struct bio *dst, struct bvec_iter *dst_iter,
+ struct bio *src, struct bvec_iter *src_iter);
+extern void bio_copy_data(struct bio *dst, struct bio *src);
+extern void bio_list_copy_data(struct bio *dst, struct bio *src);
+extern void bio_free_pages(struct bio *bio);
+
+extern struct bio *bio_copy_user_iov(struct request_queue *,
+ struct rq_map_data *,
+ struct iov_iter *,
+ gfp_t);
+extern int bio_uncopy_user(struct bio *);
+void zero_fill_bio_iter(struct bio *bio, struct bvec_iter iter);
+
+static inline void zero_fill_bio(struct bio *bio)
+{
+ zero_fill_bio_iter(bio, bio->bi_iter);
+}
+
+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);
+extern const char *bio_devname(struct bio *bio, char *buffer);
+
+#define bio_set_dev(bio, bdev) \
+do { \
+ if ((bio)->bi_disk != (bdev)->bd_disk) \
+ bio_clear_flag(bio, BIO_THROTTLED);\
+ (bio)->bi_disk = (bdev)->bd_disk; \
+ (bio)->bi_partno = (bdev)->bd_partno; \
+} while (0)
+
+#define bio_copy_dev(dst, src) \
+do { \
+ (dst)->bi_disk = (src)->bi_disk; \
+ (dst)->bi_partno = (src)->bi_partno; \
+} while (0)
+
+#define bio_dev(bio) \
+ disk_devt((bio)->bi_disk)
+
+#if defined(CONFIG_MEMCG) && defined(CONFIG_BLK_CGROUP)
+int bio_associate_blkcg_from_page(struct bio *bio, struct page *page);
+#else
+static inline int bio_associate_blkcg_from_page(struct bio *bio,
+ struct page *page) { return 0; }
+#endif
+
+#ifdef CONFIG_BLK_CGROUP
+int bio_associate_blkcg(struct bio *bio, struct cgroup_subsys_state *blkcg_css);
+int bio_associate_blkg(struct bio *bio, struct blkcg_gq *blkg);
+void bio_disassociate_task(struct bio *bio);
+void bio_clone_blkcg_association(struct bio *dst, struct bio *src);
+#else /* CONFIG_BLK_CGROUP */
+static inline int bio_associate_blkcg(struct bio *bio,
+ struct cgroup_subsys_state *blkcg_css) { return 0; }
+static inline void bio_disassociate_task(struct bio *bio) { }
+static inline void bio_clone_blkcg_association(struct bio *dst,
+ struct bio *src) { }
+#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
+
+/*
+ * 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;
+}
+
+/*
+ * Increment chain count for the bio. Make sure the CHAIN flag update
+ * is visible before the raised count.
+ */
+static inline void bio_inc_remaining(struct bio *bio)
+{
+ bio_set_flag(bio, BIO_CHAIN);
+ smp_mb__before_atomic();
+ atomic_inc(&bio->__bi_remaining);
+}
+
+/*
+ * 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
+
+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;
+};
+
+static inline bool bioset_initialized(struct bio_set *bs)
+{
+ return bs->bio_slab != NULL;
+}
+
+/*
+ * 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 int bio_integrity_add_page(struct bio *, struct page *, unsigned int, unsigned int);
+extern bool bio_integrity_prep(struct bio *);
+extern void bio_integrity_advance(struct bio *, unsigned int);
+extern void bio_integrity_trim(struct bio *);
+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 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 bool bio_integrity_prep(struct bio *bio)
+{
+ return true;
+}
+
+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)
+{
+ return;
+}
+
+static inline void bio_integrity_init(void)
+{
+ return;
+}
+
+static inline bool bio_integrity_flagged(struct bio *bio, enum bip_flags flag)
+{
+ return false;
+}
+
+static inline void *bio_integrity_alloc(struct bio * bio, gfp_t gfp,
+ unsigned int nr)
+{
+ return ERR_PTR(-EINVAL);
+}
+
+static inline int bio_integrity_add_page(struct bio *bio, struct page *page,
+ unsigned int len, unsigned int offset)
+{
+ return 0;
+}
+
+#endif /* CONFIG_BLK_DEV_INTEGRITY */
+
+#endif /* CONFIG_BLOCK */
+#endif /* __LINUX_BIO_H */