]> git.sesse.net Git - bcachefs-tools-debian/blobdiff - c_src/libbcachefs/bkey.h
move Rust sources to top level, C sources into c_src
[bcachefs-tools-debian] / c_src / libbcachefs / bkey.h
diff --git a/c_src/libbcachefs/bkey.h b/c_src/libbcachefs/bkey.h
new file mode 100644 (file)
index 0000000..831be01
--- /dev/null
@@ -0,0 +1,778 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _BCACHEFS_BKEY_H
+#define _BCACHEFS_BKEY_H
+
+#include <linux/bug.h>
+#include "bcachefs_format.h"
+
+#include "btree_types.h"
+#include "util.h"
+#include "vstructs.h"
+
+enum bkey_invalid_flags {
+       BKEY_INVALID_WRITE              = (1U << 0),
+       BKEY_INVALID_COMMIT             = (1U << 1),
+       BKEY_INVALID_JOURNAL            = (1U << 2),
+};
+
+#if 0
+
+/*
+ * compiled unpack functions are disabled, pending a new interface for
+ * dynamically allocating executable memory:
+ */
+
+#ifdef CONFIG_X86_64
+#define HAVE_BCACHEFS_COMPILED_UNPACK  1
+#endif
+#endif
+
+void bch2_bkey_packed_to_binary_text(struct printbuf *,
+                                    const struct bkey_format *,
+                                    const struct bkey_packed *);
+
+/* bkey with split value, const */
+struct bkey_s_c {
+       const struct bkey       *k;
+       const struct bch_val    *v;
+};
+
+/* bkey with split value */
+struct bkey_s {
+       union {
+       struct {
+               struct bkey     *k;
+               struct bch_val  *v;
+       };
+       struct bkey_s_c         s_c;
+       };
+};
+
+#define bkey_p_next(_k)                vstruct_next(_k)
+
+static inline struct bkey_i *bkey_next(struct bkey_i *k)
+{
+       return (struct bkey_i *) ((u64 *) k->_data + k->k.u64s);
+}
+
+#define bkey_val_u64s(_k)      ((_k)->u64s - BKEY_U64s)
+
+static inline size_t bkey_val_bytes(const struct bkey *k)
+{
+       return bkey_val_u64s(k) * sizeof(u64);
+}
+
+static inline void set_bkey_val_u64s(struct bkey *k, unsigned val_u64s)
+{
+       unsigned u64s = BKEY_U64s + val_u64s;
+
+       BUG_ON(u64s > U8_MAX);
+       k->u64s = u64s;
+}
+
+static inline void set_bkey_val_bytes(struct bkey *k, unsigned bytes)
+{
+       set_bkey_val_u64s(k, DIV_ROUND_UP(bytes, sizeof(u64)));
+}
+
+#define bkey_val_end(_k)       ((void *) (((u64 *) (_k).v) + bkey_val_u64s((_k).k)))
+
+#define bkey_deleted(_k)       ((_k)->type == KEY_TYPE_deleted)
+
+#define bkey_whiteout(_k)                              \
+       ((_k)->type == KEY_TYPE_deleted || (_k)->type == KEY_TYPE_whiteout)
+
+enum bkey_lr_packed {
+       BKEY_PACKED_BOTH,
+       BKEY_PACKED_RIGHT,
+       BKEY_PACKED_LEFT,
+       BKEY_PACKED_NONE,
+};
+
+#define bkey_lr_packed(_l, _r)                                         \
+       ((_l)->format + ((_r)->format << 1))
+
+static inline void bkey_p_copy(struct bkey_packed *dst, const struct bkey_packed *src)
+{
+       memcpy_u64s_small(dst, src, src->u64s);
+}
+
+static inline void bkey_copy(struct bkey_i *dst, const struct bkey_i *src)
+{
+       memcpy_u64s_small(dst, src, src->k.u64s);
+}
+
+struct btree;
+
+__pure
+unsigned bch2_bkey_greatest_differing_bit(const struct btree *,
+                                         const struct bkey_packed *,
+                                         const struct bkey_packed *);
+__pure
+unsigned bch2_bkey_ffs(const struct btree *, const struct bkey_packed *);
+
+__pure
+int __bch2_bkey_cmp_packed_format_checked(const struct bkey_packed *,
+                                    const struct bkey_packed *,
+                                    const struct btree *);
+
+__pure
+int __bch2_bkey_cmp_left_packed_format_checked(const struct btree *,
+                                         const struct bkey_packed *,
+                                         const struct bpos *);
+
+__pure
+int bch2_bkey_cmp_packed(const struct btree *,
+                        const struct bkey_packed *,
+                        const struct bkey_packed *);
+
+__pure
+int __bch2_bkey_cmp_left_packed(const struct btree *,
+                               const struct bkey_packed *,
+                               const struct bpos *);
+
+static inline __pure
+int bkey_cmp_left_packed(const struct btree *b,
+                        const struct bkey_packed *l, const struct bpos *r)
+{
+       return __bch2_bkey_cmp_left_packed(b, l, r);
+}
+
+/*
+ * The compiler generates better code when we pass bpos by ref, but it's often
+ * enough terribly convenient to pass it by val... as much as I hate c++, const
+ * ref would be nice here:
+ */
+__pure __flatten
+static inline int bkey_cmp_left_packed_byval(const struct btree *b,
+                                            const struct bkey_packed *l,
+                                            struct bpos r)
+{
+       return bkey_cmp_left_packed(b, l, &r);
+}
+
+static __always_inline bool bpos_eq(struct bpos l, struct bpos r)
+{
+       return  !((l.inode      ^ r.inode) |
+                 (l.offset     ^ r.offset) |
+                 (l.snapshot   ^ r.snapshot));
+}
+
+static __always_inline bool bpos_lt(struct bpos l, struct bpos r)
+{
+       return  l.inode != r.inode ? l.inode < r.inode :
+               l.offset != r.offset ? l.offset < r.offset :
+               l.snapshot != r.snapshot ? l.snapshot < r.snapshot : false;
+}
+
+static __always_inline bool bpos_le(struct bpos l, struct bpos r)
+{
+       return  l.inode != r.inode ? l.inode < r.inode :
+               l.offset != r.offset ? l.offset < r.offset :
+               l.snapshot != r.snapshot ? l.snapshot < r.snapshot : true;
+}
+
+static __always_inline bool bpos_gt(struct bpos l, struct bpos r)
+{
+       return bpos_lt(r, l);
+}
+
+static __always_inline bool bpos_ge(struct bpos l, struct bpos r)
+{
+       return bpos_le(r, l);
+}
+
+static __always_inline int bpos_cmp(struct bpos l, struct bpos r)
+{
+       return  cmp_int(l.inode,    r.inode) ?:
+               cmp_int(l.offset,   r.offset) ?:
+               cmp_int(l.snapshot, r.snapshot);
+}
+
+static inline struct bpos bpos_min(struct bpos l, struct bpos r)
+{
+       return bpos_lt(l, r) ? l : r;
+}
+
+static inline struct bpos bpos_max(struct bpos l, struct bpos r)
+{
+       return bpos_gt(l, r) ? l : r;
+}
+
+static __always_inline bool bkey_eq(struct bpos l, struct bpos r)
+{
+       return  !((l.inode      ^ r.inode) |
+                 (l.offset     ^ r.offset));
+}
+
+static __always_inline bool bkey_lt(struct bpos l, struct bpos r)
+{
+       return  l.inode != r.inode
+               ? l.inode < r.inode
+               : l.offset < r.offset;
+}
+
+static __always_inline bool bkey_le(struct bpos l, struct bpos r)
+{
+       return  l.inode != r.inode
+               ? l.inode < r.inode
+               : l.offset <= r.offset;
+}
+
+static __always_inline bool bkey_gt(struct bpos l, struct bpos r)
+{
+       return bkey_lt(r, l);
+}
+
+static __always_inline bool bkey_ge(struct bpos l, struct bpos r)
+{
+       return bkey_le(r, l);
+}
+
+static __always_inline int bkey_cmp(struct bpos l, struct bpos r)
+{
+       return  cmp_int(l.inode,    r.inode) ?:
+               cmp_int(l.offset,   r.offset);
+}
+
+static inline struct bpos bkey_min(struct bpos l, struct bpos r)
+{
+       return bkey_lt(l, r) ? l : r;
+}
+
+static inline struct bpos bkey_max(struct bpos l, struct bpos r)
+{
+       return bkey_gt(l, r) ? l : r;
+}
+
+void bch2_bpos_swab(struct bpos *);
+void bch2_bkey_swab_key(const struct bkey_format *, struct bkey_packed *);
+
+static __always_inline int bversion_cmp(struct bversion l, struct bversion r)
+{
+       return  cmp_int(l.hi, r.hi) ?:
+               cmp_int(l.lo, r.lo);
+}
+
+#define ZERO_VERSION   ((struct bversion) { .hi = 0, .lo = 0 })
+#define MAX_VERSION    ((struct bversion) { .hi = ~0, .lo = ~0ULL })
+
+static __always_inline int bversion_zero(struct bversion v)
+{
+       return !bversion_cmp(v, ZERO_VERSION);
+}
+
+#ifdef CONFIG_BCACHEFS_DEBUG
+/* statement expressions confusing unlikely()? */
+#define bkey_packed(_k)                                                        \
+       ({ EBUG_ON((_k)->format > KEY_FORMAT_CURRENT);                  \
+        (_k)->format != KEY_FORMAT_CURRENT; })
+#else
+#define bkey_packed(_k)                ((_k)->format != KEY_FORMAT_CURRENT)
+#endif
+
+/*
+ * It's safe to treat an unpacked bkey as a packed one, but not the reverse
+ */
+static inline struct bkey_packed *bkey_to_packed(struct bkey_i *k)
+{
+       return (struct bkey_packed *) k;
+}
+
+static inline const struct bkey_packed *bkey_to_packed_c(const struct bkey_i *k)
+{
+       return (const struct bkey_packed *) k;
+}
+
+static inline struct bkey_i *packed_to_bkey(struct bkey_packed *k)
+{
+       return bkey_packed(k) ? NULL : (struct bkey_i *) k;
+}
+
+static inline const struct bkey *packed_to_bkey_c(const struct bkey_packed *k)
+{
+       return bkey_packed(k) ? NULL : (const struct bkey *) k;
+}
+
+static inline unsigned bkey_format_key_bits(const struct bkey_format *format)
+{
+       return format->bits_per_field[BKEY_FIELD_INODE] +
+               format->bits_per_field[BKEY_FIELD_OFFSET] +
+               format->bits_per_field[BKEY_FIELD_SNAPSHOT];
+}
+
+static inline struct bpos bpos_successor(struct bpos p)
+{
+       if (!++p.snapshot &&
+           !++p.offset &&
+           !++p.inode)
+               BUG();
+
+       return p;
+}
+
+static inline struct bpos bpos_predecessor(struct bpos p)
+{
+       if (!p.snapshot-- &&
+           !p.offset-- &&
+           !p.inode--)
+               BUG();
+
+       return p;
+}
+
+static inline struct bpos bpos_nosnap_successor(struct bpos p)
+{
+       p.snapshot = 0;
+
+       if (!++p.offset &&
+           !++p.inode)
+               BUG();
+
+       return p;
+}
+
+static inline struct bpos bpos_nosnap_predecessor(struct bpos p)
+{
+       p.snapshot = 0;
+
+       if (!p.offset-- &&
+           !p.inode--)
+               BUG();
+
+       return p;
+}
+
+static inline u64 bkey_start_offset(const struct bkey *k)
+{
+       return k->p.offset - k->size;
+}
+
+static inline struct bpos bkey_start_pos(const struct bkey *k)
+{
+       return (struct bpos) {
+               .inode          = k->p.inode,
+               .offset         = bkey_start_offset(k),
+               .snapshot       = k->p.snapshot,
+       };
+}
+
+/* Packed helpers */
+
+static inline unsigned bkeyp_key_u64s(const struct bkey_format *format,
+                                     const struct bkey_packed *k)
+{
+       unsigned ret = bkey_packed(k) ? format->key_u64s : BKEY_U64s;
+
+       EBUG_ON(k->u64s < ret);
+       return ret;
+}
+
+static inline unsigned bkeyp_key_bytes(const struct bkey_format *format,
+                                      const struct bkey_packed *k)
+{
+       return bkeyp_key_u64s(format, k) * sizeof(u64);
+}
+
+static inline unsigned bkeyp_val_u64s(const struct bkey_format *format,
+                                     const struct bkey_packed *k)
+{
+       return k->u64s - bkeyp_key_u64s(format, k);
+}
+
+static inline size_t bkeyp_val_bytes(const struct bkey_format *format,
+                                    const struct bkey_packed *k)
+{
+       return bkeyp_val_u64s(format, k) * sizeof(u64);
+}
+
+static inline void set_bkeyp_val_u64s(const struct bkey_format *format,
+                                     struct bkey_packed *k, unsigned val_u64s)
+{
+       k->u64s = bkeyp_key_u64s(format, k) + val_u64s;
+}
+
+#define bkeyp_val(_format, _k)                                         \
+        ((struct bch_val *) ((u64 *) (_k)->_data + bkeyp_key_u64s(_format, _k)))
+
+extern const struct bkey_format bch2_bkey_format_current;
+
+bool bch2_bkey_transform(const struct bkey_format *,
+                        struct bkey_packed *,
+                        const struct bkey_format *,
+                        const struct bkey_packed *);
+
+struct bkey __bch2_bkey_unpack_key(const struct bkey_format *,
+                                  const struct bkey_packed *);
+
+#ifndef HAVE_BCACHEFS_COMPILED_UNPACK
+struct bpos __bkey_unpack_pos(const struct bkey_format *,
+                             const struct bkey_packed *);
+#endif
+
+bool bch2_bkey_pack_key(struct bkey_packed *, const struct bkey *,
+                  const struct bkey_format *);
+
+enum bkey_pack_pos_ret {
+       BKEY_PACK_POS_EXACT,
+       BKEY_PACK_POS_SMALLER,
+       BKEY_PACK_POS_FAIL,
+};
+
+enum bkey_pack_pos_ret bch2_bkey_pack_pos_lossy(struct bkey_packed *, struct bpos,
+                                          const struct btree *);
+
+static inline bool bkey_pack_pos(struct bkey_packed *out, struct bpos in,
+                                const struct btree *b)
+{
+       return bch2_bkey_pack_pos_lossy(out, in, b) == BKEY_PACK_POS_EXACT;
+}
+
+void bch2_bkey_unpack(const struct btree *, struct bkey_i *,
+                const struct bkey_packed *);
+bool bch2_bkey_pack(struct bkey_packed *, const struct bkey_i *,
+              const struct bkey_format *);
+
+typedef void (*compiled_unpack_fn)(struct bkey *, const struct bkey_packed *);
+
+static inline void
+__bkey_unpack_key_format_checked(const struct btree *b,
+                              struct bkey *dst,
+                              const struct bkey_packed *src)
+{
+       if (IS_ENABLED(HAVE_BCACHEFS_COMPILED_UNPACK)) {
+               compiled_unpack_fn unpack_fn = b->aux_data;
+               unpack_fn(dst, src);
+
+               if (IS_ENABLED(CONFIG_BCACHEFS_DEBUG) &&
+                   bch2_expensive_debug_checks) {
+                       struct bkey dst2 = __bch2_bkey_unpack_key(&b->format, src);
+
+                       BUG_ON(memcmp(dst, &dst2, sizeof(*dst)));
+               }
+       } else {
+               *dst = __bch2_bkey_unpack_key(&b->format, src);
+       }
+}
+
+static inline struct bkey
+bkey_unpack_key_format_checked(const struct btree *b,
+                              const struct bkey_packed *src)
+{
+       struct bkey dst;
+
+       __bkey_unpack_key_format_checked(b, &dst, src);
+       return dst;
+}
+
+static inline void __bkey_unpack_key(const struct btree *b,
+                                    struct bkey *dst,
+                                    const struct bkey_packed *src)
+{
+       if (likely(bkey_packed(src)))
+               __bkey_unpack_key_format_checked(b, dst, src);
+       else
+               *dst = *packed_to_bkey_c(src);
+}
+
+/**
+ * bkey_unpack_key -- unpack just the key, not the value
+ */
+static inline struct bkey bkey_unpack_key(const struct btree *b,
+                                         const struct bkey_packed *src)
+{
+       return likely(bkey_packed(src))
+               ? bkey_unpack_key_format_checked(b, src)
+               : *packed_to_bkey_c(src);
+}
+
+static inline struct bpos
+bkey_unpack_pos_format_checked(const struct btree *b,
+                              const struct bkey_packed *src)
+{
+#ifdef HAVE_BCACHEFS_COMPILED_UNPACK
+       return bkey_unpack_key_format_checked(b, src).p;
+#else
+       return __bkey_unpack_pos(&b->format, src);
+#endif
+}
+
+static inline struct bpos bkey_unpack_pos(const struct btree *b,
+                                         const struct bkey_packed *src)
+{
+       return likely(bkey_packed(src))
+               ? bkey_unpack_pos_format_checked(b, src)
+               : packed_to_bkey_c(src)->p;
+}
+
+/* Disassembled bkeys */
+
+static inline struct bkey_s_c bkey_disassemble(const struct btree *b,
+                                              const struct bkey_packed *k,
+                                              struct bkey *u)
+{
+       __bkey_unpack_key(b, u, k);
+
+       return (struct bkey_s_c) { u, bkeyp_val(&b->format, k), };
+}
+
+/* non const version: */
+static inline struct bkey_s __bkey_disassemble(const struct btree *b,
+                                              struct bkey_packed *k,
+                                              struct bkey *u)
+{
+       __bkey_unpack_key(b, u, k);
+
+       return (struct bkey_s) { .k = u, .v = bkeyp_val(&b->format, k), };
+}
+
+static inline u64 bkey_field_max(const struct bkey_format *f,
+                                enum bch_bkey_fields nr)
+{
+       return f->bits_per_field[nr] < 64
+               ? (le64_to_cpu(f->field_offset[nr]) +
+                  ~(~0ULL << f->bits_per_field[nr]))
+               : U64_MAX;
+}
+
+#ifdef HAVE_BCACHEFS_COMPILED_UNPACK
+
+int bch2_compile_bkey_format(const struct bkey_format *, void *);
+
+#else
+
+static inline int bch2_compile_bkey_format(const struct bkey_format *format,
+                                         void *out) { return 0; }
+
+#endif
+
+static inline void bkey_reassemble(struct bkey_i *dst,
+                                  struct bkey_s_c src)
+{
+       dst->k = *src.k;
+       memcpy_u64s_small(&dst->v, src.v, bkey_val_u64s(src.k));
+}
+
+#define bkey_s_null            ((struct bkey_s)   { .k = NULL })
+#define bkey_s_c_null          ((struct bkey_s_c) { .k = NULL })
+
+#define bkey_s_err(err)                ((struct bkey_s)   { .k = ERR_PTR(err) })
+#define bkey_s_c_err(err)      ((struct bkey_s_c) { .k = ERR_PTR(err) })
+
+static inline struct bkey_s bkey_to_s(struct bkey *k)
+{
+       return (struct bkey_s) { .k = k, .v = NULL };
+}
+
+static inline struct bkey_s_c bkey_to_s_c(const struct bkey *k)
+{
+       return (struct bkey_s_c) { .k = k, .v = NULL };
+}
+
+static inline struct bkey_s bkey_i_to_s(struct bkey_i *k)
+{
+       return (struct bkey_s) { .k = &k->k, .v = &k->v };
+}
+
+static inline struct bkey_s_c bkey_i_to_s_c(const struct bkey_i *k)
+{
+       return (struct bkey_s_c) { .k = &k->k, .v = &k->v };
+}
+
+/*
+ * For a given type of value (e.g. struct bch_extent), generates the types for
+ * bkey + bch_extent - inline, split, split const - and also all the conversion
+ * functions, which also check that the value is of the correct type.
+ *
+ * We use anonymous unions for upcasting - e.g. converting from e.g. a
+ * bkey_i_extent to a bkey_i - since that's always safe, instead of conversion
+ * functions.
+ */
+#define x(name, ...)                                   \
+struct bkey_i_##name {                                                 \
+       union {                                                         \
+               struct bkey             k;                              \
+               struct bkey_i           k_i;                            \
+       };                                                              \
+       struct bch_##name               v;                              \
+};                                                                     \
+                                                                       \
+struct bkey_s_c_##name {                                               \
+       union {                                                         \
+       struct {                                                        \
+               const struct bkey       *k;                             \
+               const struct bch_##name *v;                             \
+       };                                                              \
+       struct bkey_s_c                 s_c;                            \
+       };                                                              \
+};                                                                     \
+                                                                       \
+struct bkey_s_##name {                                                 \
+       union {                                                         \
+       struct {                                                        \
+               struct bkey             *k;                             \
+               struct bch_##name       *v;                             \
+       };                                                              \
+       struct bkey_s_c_##name          c;                              \
+       struct bkey_s                   s;                              \
+       struct bkey_s_c                 s_c;                            \
+       };                                                              \
+};                                                                     \
+                                                                       \
+static inline struct bkey_i_##name *bkey_i_to_##name(struct bkey_i *k) \
+{                                                                      \
+       EBUG_ON(!IS_ERR_OR_NULL(k) && k->k.type != KEY_TYPE_##name);    \
+       return container_of(&k->k, struct bkey_i_##name, k);            \
+}                                                                      \
+                                                                       \
+static inline const struct bkey_i_##name *                             \
+bkey_i_to_##name##_c(const struct bkey_i *k)                           \
+{                                                                      \
+       EBUG_ON(!IS_ERR_OR_NULL(k) && k->k.type != KEY_TYPE_##name);    \
+       return container_of(&k->k, struct bkey_i_##name, k);            \
+}                                                                      \
+                                                                       \
+static inline struct bkey_s_##name bkey_s_to_##name(struct bkey_s k)   \
+{                                                                      \
+       EBUG_ON(!IS_ERR_OR_NULL(k.k) && k.k->type != KEY_TYPE_##name);  \
+       return (struct bkey_s_##name) {                                 \
+               .k = k.k,                                               \
+               .v = container_of(k.v, struct bch_##name, v),           \
+       };                                                              \
+}                                                                      \
+                                                                       \
+static inline struct bkey_s_c_##name bkey_s_c_to_##name(struct bkey_s_c k)\
+{                                                                      \
+       EBUG_ON(!IS_ERR_OR_NULL(k.k) && k.k->type != KEY_TYPE_##name);  \
+       return (struct bkey_s_c_##name) {                               \
+               .k = k.k,                                               \
+               .v = container_of(k.v, struct bch_##name, v),           \
+       };                                                              \
+}                                                                      \
+                                                                       \
+static inline struct bkey_s_##name name##_i_to_s(struct bkey_i_##name *k)\
+{                                                                      \
+       return (struct bkey_s_##name) {                                 \
+               .k = &k->k,                                             \
+               .v = &k->v,                                             \
+       };                                                              \
+}                                                                      \
+                                                                       \
+static inline struct bkey_s_c_##name                                   \
+name##_i_to_s_c(const struct bkey_i_##name *k)                         \
+{                                                                      \
+       return (struct bkey_s_c_##name) {                               \
+               .k = &k->k,                                             \
+               .v = &k->v,                                             \
+       };                                                              \
+}                                                                      \
+                                                                       \
+static inline struct bkey_s_##name bkey_i_to_s_##name(struct bkey_i *k)        \
+{                                                                      \
+       EBUG_ON(!IS_ERR_OR_NULL(k) && k->k.type != KEY_TYPE_##name);    \
+       return (struct bkey_s_##name) {                                 \
+               .k = &k->k,                                             \
+               .v = container_of(&k->v, struct bch_##name, v),         \
+       };                                                              \
+}                                                                      \
+                                                                       \
+static inline struct bkey_s_c_##name                                   \
+bkey_i_to_s_c_##name(const struct bkey_i *k)                           \
+{                                                                      \
+       EBUG_ON(!IS_ERR_OR_NULL(k) && k->k.type != KEY_TYPE_##name);    \
+       return (struct bkey_s_c_##name) {                               \
+               .k = &k->k,                                             \
+               .v = container_of(&k->v, struct bch_##name, v),         \
+       };                                                              \
+}                                                                      \
+                                                                       \
+static inline struct bkey_i_##name *bkey_##name##_init(struct bkey_i *_k)\
+{                                                                      \
+       struct bkey_i_##name *k =                                       \
+               container_of(&_k->k, struct bkey_i_##name, k);          \
+                                                                       \
+       bkey_init(&k->k);                                               \
+       memset(&k->v, 0, sizeof(k->v));                                 \
+       k->k.type = KEY_TYPE_##name;                                    \
+       set_bkey_val_bytes(&k->k, sizeof(k->v));                        \
+                                                                       \
+       return k;                                                       \
+}
+
+BCH_BKEY_TYPES();
+#undef x
+
+/* byte order helpers */
+
+#if __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__
+
+static inline unsigned high_word_offset(const struct bkey_format *f)
+{
+       return f->key_u64s - 1;
+}
+
+#define high_bit_offset                0
+#define nth_word(p, n)         ((p) - (n))
+
+#elif __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__
+
+static inline unsigned high_word_offset(const struct bkey_format *f)
+{
+       return 0;
+}
+
+#define high_bit_offset                KEY_PACKED_BITS_START
+#define nth_word(p, n)         ((p) + (n))
+
+#else
+#error edit for your odd byteorder.
+#endif
+
+#define high_word(f, k)                ((u64 *) (k)->_data + high_word_offset(f))
+#define next_word(p)           nth_word(p, 1)
+#define prev_word(p)           nth_word(p, -1)
+
+#ifdef CONFIG_BCACHEFS_DEBUG
+void bch2_bkey_pack_test(void);
+#else
+static inline void bch2_bkey_pack_test(void) {}
+#endif
+
+#define bkey_fields()                                                  \
+       x(BKEY_FIELD_INODE,             p.inode)                        \
+       x(BKEY_FIELD_OFFSET,            p.offset)                       \
+       x(BKEY_FIELD_SNAPSHOT,          p.snapshot)                     \
+       x(BKEY_FIELD_SIZE,              size)                           \
+       x(BKEY_FIELD_VERSION_HI,        version.hi)                     \
+       x(BKEY_FIELD_VERSION_LO,        version.lo)
+
+struct bkey_format_state {
+       u64 field_min[BKEY_NR_FIELDS];
+       u64 field_max[BKEY_NR_FIELDS];
+};
+
+void bch2_bkey_format_init(struct bkey_format_state *);
+
+static inline void __bkey_format_add(struct bkey_format_state *s, unsigned field, u64 v)
+{
+       s->field_min[field] = min(s->field_min[field], v);
+       s->field_max[field] = max(s->field_max[field], v);
+}
+
+/*
+ * Changes @format so that @k can be successfully packed with @format
+ */
+static inline void bch2_bkey_format_add_key(struct bkey_format_state *s, const struct bkey *k)
+{
+#define x(id, field) __bkey_format_add(s, id, k->field);
+       bkey_fields()
+#undef x
+}
+
+void bch2_bkey_format_add_pos(struct bkey_format_state *, struct bpos);
+struct bkey_format bch2_bkey_format_done(struct bkey_format_state *);
+int bch2_bkey_format_invalid(struct bch_fs *, struct bkey_format *,
+                            enum bkey_invalid_flags, struct printbuf *);
+void bch2_bkey_format_to_text(struct printbuf *, const struct bkey_format *);
+
+#endif /* _BCACHEFS_BKEY_H */