bcache in userspace; userspace fsck

1 files changed, 156 insertions, 0 deletions

diff --git a/include/linux/blk_types.h b/include/linux/blk_types.h
new file mode 100644
index 00000000..4fc5af31
--- /dev/null
+++ b/include/linux/blk_types.h
@@ -0,0 +1,156 @@
+/*
+ * Block data types and constants.  Directly include this file only to
+ * break include dependency loop.
+ */
+#ifndef __LINUX_BLK_TYPES_H
+#define __LINUX_BLK_TYPES_H
+
+#include <linux/atomic.h>
+#include <linux/types.h>
+#include <linux/bvec.h>
+
+struct bio_set;
+struct bio;
+struct block_device;
+typedef void (bio_end_io_t) (struct bio *);
+typedef void (bio_destructor_t) (struct bio *);
+
+/*
+ * main unit of I/O for the block layer and lower layers (ie drivers and
+ * stacking drivers)
+ */
+struct bio {
+	struct bio		*bi_next;	/* request queue link */
+	struct block_device	*bi_bdev;
+	int			bi_error;
+	unsigned int		bi_opf;		/* bottom bits req flags,
+						 * top bits REQ_OP. Use
+						 * accessors.
+						 */
+	unsigned short		bi_flags;	/* status, command, etc */
+	unsigned short		bi_ioprio;
+
+	struct bvec_iter	bi_iter;
+
+	atomic_t		__bi_remaining;
+
+	bio_end_io_t		*bi_end_io;
+	void			*bi_private;
+
+	unsigned short		bi_vcnt;	/* how many bio_vec's */
+
+	/*
+	 * Everything starting with bi_max_vecs will be preserved by bio_reset()
+	 */
+
+	unsigned short		bi_max_vecs;	/* max bvl_vecs we can hold */
+
+	atomic_t		__bi_cnt;	/* pin count */
+
+	struct bio_vec		*bi_io_vec;	/* the actual vec list */
+
+	struct bio_set		*bi_pool;
+
+	/*
+	 * We can inline a number of vecs at the end of the bio, to avoid
+	 * double allocations for a small number of bio_vecs. This member
+	 * MUST obviously be kept at the very end of the bio.
+	 */
+	struct bio_vec		bi_inline_vecs[0];
+};
+
+#define BIO_OP_SHIFT	(8 * sizeof(unsigned int) - REQ_OP_BITS)
+#define bio_op(bio)	((bio)->bi_opf >> BIO_OP_SHIFT)
+
+#define bio_set_op_attrs(bio, op, op_flags) do {		\
+	WARN_ON(op >= (1 << REQ_OP_BITS));			\
+	(bio)->bi_opf &= ((1 << BIO_OP_SHIFT) - 1);		\
+	(bio)->bi_opf |= ((unsigned int) (op) << BIO_OP_SHIFT);	\
+	(bio)->bi_opf |= op_flags;				\
+} while (0)
+
+#define BIO_RESET_BYTES		offsetof(struct bio, bi_max_vecs)
+
+/*
+ * bio flags
+ */
+#define BIO_SEG_VALID	1	/* bi_phys_segments valid */
+#define BIO_CLONED	2	/* doesn't own data */
+#define BIO_BOUNCED	3	/* bio is a bounce bio */
+#define BIO_USER_MAPPED 4	/* contains user pages */
+#define BIO_NULL_MAPPED 5	/* contains invalid user pages */
+#define BIO_QUIET	6	/* Make BIO Quiet */
+#define BIO_CHAIN	7	/* chained bio, ->bi_remaining in effect */
+#define BIO_REFFED	8	/* bio has elevated ->bi_cnt */
+
+/*
+ * Flags starting here get preserved by bio_reset() - this includes
+ * BVEC_POOL_IDX()
+ */
+#define BIO_RESET_BITS	10
+
+/*
+ * We support 6 different bvec pools, the last one is magic in that it
+ * is backed by a mempool.
+ */
+#define BVEC_POOL_NR		6
+#define BVEC_POOL_MAX		(BVEC_POOL_NR - 1)
+
+/*
+ * Top 4 bits of bio flags indicate the pool the bvecs came from.  We add
+ * 1 to the actual index so that 0 indicates that there are no bvecs to be
+ * freed.
+ */
+#define BVEC_POOL_BITS		(4)
+#define BVEC_POOL_OFFSET	(16 - BVEC_POOL_BITS)
+#define BVEC_POOL_IDX(bio)	((bio)->bi_flags >> BVEC_POOL_OFFSET)
+
+/*
+ * Request flags.  For use in the cmd_flags field of struct request, and in
+ * bi_opf of struct bio.  Note that some flags are only valid in either one.
+ */
+enum rq_flag_bits {
+	__REQ_SYNC,		/* request is sync (sync write or read) */
+	__REQ_META,		/* metadata io request */
+	__REQ_PRIO,		/* boost priority in cfq */
+
+	__REQ_FUA,		/* forced unit access */
+	__REQ_PREFLUSH,		/* request for cache flush */
+};
+
+#define REQ_SYNC		(1ULL << __REQ_SYNC)
+#define REQ_META		(1ULL << __REQ_META)
+#define REQ_PRIO		(1ULL << __REQ_PRIO)
+
+#define REQ_NOMERGE_FLAGS	(REQ_PREFLUSH | REQ_FUA)
+
+#define REQ_RAHEAD		(1ULL << __REQ_RAHEAD)
+#define REQ_THROTTLED		(1ULL << __REQ_THROTTLED)
+
+#define REQ_FUA			(1ULL << __REQ_FUA)
+#define REQ_PREFLUSH		(1ULL << __REQ_PREFLUSH)
+
+#define RW_MASK			REQ_OP_WRITE
+
+#define READ			REQ_OP_READ
+#define WRITE			REQ_OP_WRITE
+
+#define READ_SYNC		REQ_SYNC
+#define WRITE_SYNC		(REQ_SYNC)
+#define WRITE_ODIRECT		REQ_SYNC
+#define WRITE_FLUSH		(REQ_SYNC | REQ_PREFLUSH)
+#define WRITE_FUA		(REQ_SYNC | REQ_FUA)
+#define WRITE_FLUSH_FUA		(REQ_SYNC | REQ_PREFLUSH | REQ_FUA)
+
+enum req_op {
+	REQ_OP_READ,
+	REQ_OP_WRITE,
+	REQ_OP_DISCARD,		/* request to discard sectors */
+	REQ_OP_SECURE_ERASE,	/* request to securely erase sectors */
+	REQ_OP_WRITE_SAME,	/* write same block many times */
+	REQ_OP_FLUSH,		/* request for cache flush */
+};
+
+#define REQ_OP_BITS 3
+
+#endif /* __LINUX_BLK_TYPES_H */