bcache in userspace; userspace fsck

1 files changed, 461 insertions, 0 deletions

diff --git a/include/linux/bio.h b/include/linux/bio.h
new file mode 100644
index 00000000..94e9048d
--- /dev/null
+++ b/include/linux/bio.h
@@ -0,0 +1,461 @@
+/*
+ * 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/mempool.h>
+#include <linux/bug.h>
+#include <linux/err.h>
+
+#include <linux/blkdev.h>
+#include <linux/blk_types.h>
+#include <linux/workqueue.h>
+
+#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)
+
+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)
+		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;
+}
+
+static inline bool bio_is_rw(struct bio *bio)
+{
+	if (!bio_has_data(bio))
+		return false;
+
+	if (bio_no_advance_iter(bio))
+		return false;
+
+	return true;
+}
+
+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;
+}
+
+#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)
+
+#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;
+	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_op(bio) == REQ_OP_DISCARD)
+		return 1;
+
+	if (bio_op(bio) == REQ_OP_SECURE_ERASE)
+		return 1;
+
+	if (bio_op(bio) == REQ_OP_WRITE_SAME)
+		return 1;
+
+	bio_for_each_segment(bv, bio, iter)
+		segs++;
+
+	return segs;
+}
+
+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 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;
+}
+
+extern struct bio *bio_split(struct bio *bio, int sectors,
+			     gfp_t gfp, struct bio_set *bs);
+
+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);
+}
+
+struct bio_set {
+	unsigned int front_pad;
+};
+
+static inline void bioset_exit(struct bio_set *bs) {}
+
+static inline void bioset_free(struct bio_set *bs)
+{
+	kfree(bs);
+}
+
+static inline int bioset_init(struct bio_set *bs,
+			      unsigned pool_size,
+			      unsigned front_pad)
+{
+	bs->front_pad = front_pad;
+	return 0;
+}
+
+extern struct bio_set *bioset_create(unsigned int, unsigned int);
+extern struct bio_set *bioset_create_nobvec(unsigned int, unsigned int);
+
+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);
+
+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 *);
+extern void bio_endio_nodec(struct bio *);
+
+static inline void bio_io_error(struct bio *bio)
+{
+	bio->bi_error = -EIO;
+	bio_endio(bio);
+}
+
+extern void bio_advance(struct bio *, unsigned);
+
+extern void bio_reset(struct bio *);
+void bio_chain(struct bio *, struct bio *);
+
+static inline void bio_flush_dcache_pages(struct bio *bi)
+{
+}
+
+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 int bio_alloc_pages(struct bio *bio, gfp_t gfp);
+
+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);
+}
+
+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;
+}
+
+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)
+
+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);
+}
+
+static inline struct bio *bio_alloc(gfp_t gfp_mask, unsigned int nr_iovecs)
+{
+	return bio_alloc_bioset(gfp_mask, nr_iovecs, NULL);
+}
+
+static inline struct bio *bio_clone(struct bio *bio, gfp_t gfp_mask)
+{
+	return bio_clone_bioset(bio, gfp_mask, NULL);
+}
+
+static inline void bio_init(struct bio *bio)
+{
+	memset(bio, 0, sizeof(*bio));
+	atomic_set(&bio->__bi_remaining, 1);
+	atomic_set(&bio->__bi_cnt, 1);
+}
+
+#endif /* __LINUX_BIO_H */