]> git.sesse.net Git - bcachefs-tools-debian/blobdiff - libbcachefs/bcachefs_format.h
Update bcachefs sources to 7c0fe6f104 bcachefs: Fix bch2_fsck_ask_yn()
[bcachefs-tools-debian] / libbcachefs / bcachefs_format.h
index 2dc9a7e0719c7f27a0eeae5265a745ebb31cbbdf..4d142b2e3bf6691dc136b10d22ed1f61f7b47f51 100644 (file)
@@ -1,13 +1,97 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 #ifndef _BCACHEFS_FORMAT_H
 #define _BCACHEFS_FORMAT_H
 
 /*
  * bcachefs on disk data structures
+ *
+ * OVERVIEW:
+ *
+ * There are three main types of on disk data structures in bcachefs (this is
+ * reduced from 5 in bcache)
+ *
+ *  - superblock
+ *  - journal
+ *  - btree
+ *
+ * The btree is the primary structure; most metadata exists as keys in the
+ * various btrees. There are only a small number of btrees, they're not
+ * sharded - we have one btree for extents, another for inodes, et cetera.
+ *
+ * SUPERBLOCK:
+ *
+ * The superblock contains the location of the journal, the list of devices in
+ * the filesystem, and in general any metadata we need in order to decide
+ * whether we can start a filesystem or prior to reading the journal/btree
+ * roots.
+ *
+ * The superblock is extensible, and most of the contents of the superblock are
+ * in variable length, type tagged fields; see struct bch_sb_field.
+ *
+ * Backup superblocks do not reside in a fixed location; also, superblocks do
+ * not have a fixed size. To locate backup superblocks we have struct
+ * bch_sb_layout; we store a copy of this inside every superblock, and also
+ * before the first superblock.
+ *
+ * JOURNAL:
+ *
+ * The journal primarily records btree updates in the order they occurred;
+ * journal replay consists of just iterating over all the keys in the open
+ * journal entries and re-inserting them into the btrees.
+ *
+ * The journal also contains entry types for the btree roots, and blacklisted
+ * journal sequence numbers (see journal_seq_blacklist.c).
+ *
+ * BTREE:
+ *
+ * bcachefs btrees are copy on write b+ trees, where nodes are big (typically
+ * 128k-256k) and log structured. We use struct btree_node for writing the first
+ * entry in a given node (offset 0), and struct btree_node_entry for all
+ * subsequent writes.
+ *
+ * After the header, btree node entries contain a list of keys in sorted order.
+ * Values are stored inline with the keys; since values are variable length (and
+ * keys effectively are variable length too, due to packing) we can't do random
+ * access without building up additional in memory tables in the btree node read
+ * path.
+ *
+ * BTREE KEYS (struct bkey):
+ *
+ * The various btrees share a common format for the key - so as to avoid
+ * switching in fastpath lookup/comparison code - but define their own
+ * structures for the key values.
+ *
+ * The size of a key/value pair is stored as a u8 in units of u64s, so the max
+ * size is just under 2k. The common part also contains a type tag for the
+ * value, and a format field indicating whether the key is packed or not (and
+ * also meant to allow adding new key fields in the future, if desired).
+ *
+ * bkeys, when stored within a btree node, may also be packed. In that case, the
+ * bkey_format in that node is used to unpack it. Packed bkeys mean that we can
+ * be generous with field sizes in the common part of the key format (64 bit
+ * inode number, 64 bit offset, 96 bit version field, etc.) for negligible cost.
  */
 
 #include <asm/types.h>
 #include <asm/byteorder.h>
+#include <linux/kernel.h>
 #include <linux/uuid.h>
+#include "vstructs.h"
+
+#define BITMASK(name, type, field, offset, end)                                \
+static const unsigned  name##_OFFSET = offset;                         \
+static const unsigned  name##_BITS = (end - offset);                   \
+                                                                       \
+static inline __u64 name(const type *k)                                        \
+{                                                                      \
+       return (k->field >> offset) & ~(~0ULL << (end - offset));       \
+}                                                                      \
+                                                                       \
+static inline void SET_##name(type *k, __u64 v)                                \
+{                                                                      \
+       k->field &= ~(~(~0ULL << (end - offset)) << offset);            \
+       k->field |= (v & ~(~0ULL << (end - offset))) << offset;         \
+}
 
 #define LE_BITMASK(_bits, name, type, field, offset, end)              \
 static const unsigned  name##_OFFSET = offset;                         \
@@ -44,38 +128,45 @@ struct bkey_format {
 /* Btree keys - all units are in sectors */
 
 struct bpos {
-       /* Word order matches machine byte order */
-#if defined(__LITTLE_ENDIAN)
+       /*
+        * Word order matches machine byte order - btree code treats a bpos as a
+        * single large integer, for search/comparison purposes
+        *
+        * Note that wherever a bpos is embedded in another on disk data
+        * structure, it has to be byte swabbed when reading in metadata that
+        * wasn't written in native endian order:
+        */
+#if __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__
        __u32           snapshot;
        __u64           offset;
        __u64           inode;
-#elif defined(__BIG_ENDIAN)
+#elif __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__
        __u64           inode;
        __u64           offset;         /* Points to end of extent - sectors */
        __u32           snapshot;
 #else
 #error edit for your odd byteorder.
 #endif
-} __attribute__((packed, aligned(4)));
+} __packed __aligned(4);
 
 #define KEY_INODE_MAX                  ((__u64)~0ULL)
 #define KEY_OFFSET_MAX                 ((__u64)~0ULL)
 #define KEY_SNAPSHOT_MAX               ((__u32)~0U)
 #define KEY_SIZE_MAX                   ((__u32)~0U)
 
-static inline struct bpos POS(__u64 inode, __u64 offset)
+static inline struct bpos SPOS(__u64 inode, __u64 offset, __u32 snapshot)
 {
-       struct bpos ret;
-
-       ret.inode       = inode;
-       ret.offset      = offset;
-       ret.snapshot    = 0;
-
-       return ret;
+       return (struct bpos) {
+               .inode          = inode,
+               .offset         = offset,
+               .snapshot       = snapshot,
+       };
 }
 
-#define POS_MIN                                POS(0, 0)
-#define POS_MAX                                POS(KEY_INODE_MAX, KEY_OFFSET_MAX)
+#define POS_MIN                                SPOS(0, 0, 0)
+#define POS_MAX                                SPOS(KEY_INODE_MAX, KEY_OFFSET_MAX, 0)
+#define SPOS_MAX                       SPOS(KEY_INODE_MAX, KEY_OFFSET_MAX, KEY_SNAPSHOT_MAX)
+#define POS(_inode, _offset)           SPOS(_inode, _offset, 0)
 
 /* Empty placeholder struct, for container_of() */
 struct bch_val {
@@ -83,14 +174,14 @@ struct bch_val {
 };
 
 struct bversion {
-#if defined(__LITTLE_ENDIAN)
+#if __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__
        __u64           lo;
        __u32           hi;
-#elif defined(__BIG_ENDIAN)
+#elif __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__
        __u32           hi;
        __u64           lo;
 #endif
-} __attribute__((packed, aligned(4)));
+} __packed __aligned(4);
 
 struct bkey {
        /* Size of combined key and value, in u64s */
@@ -110,20 +201,20 @@ struct bkey {
        /* Type of the value */
        __u8            type;
 
-#if defined(__LITTLE_ENDIAN)
+#if __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__
        __u8            pad[1];
 
        struct bversion version;
        __u32           size;           /* extent size, in sectors */
        struct bpos     p;
-#elif defined(__BIG_ENDIAN)
+#elif __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__
        struct bpos     p;
        __u32           size;           /* extent size, in sectors */
        struct bversion version;
 
        __u8            pad[1];
 #endif
-} __attribute__((packed, aligned(8)));
+} __packed __aligned(8);
 
 struct bkey_packed {
        __u64           _data[0];
@@ -157,9 +248,17 @@ struct bkey_packed {
         * to the same size as struct bkey should hopefully be safest.
         */
        __u8            pad[sizeof(struct bkey) - 3];
-} __attribute__((packed, aligned(8)));
+} __packed __aligned(8);
+
+typedef struct {
+       __le64                  lo;
+       __le64                  hi;
+} bch_le128;
 
 #define BKEY_U64s                      (sizeof(struct bkey) / sizeof(__u64))
+#define BKEY_U64s_MAX                  U8_MAX
+#define BKEY_VAL_U64s_MAX              (BKEY_U64s_MAX - BKEY_U64s)
+
 #define KEY_PACKED_BITS_START          24
 
 #define KEY_FORMAT_LOCAL_BTREE         0
@@ -196,16 +295,8 @@ enum bch_bkey_fields {
 struct bkey_i {
        __u64                   _data[0];
 
-       union {
-       struct {
-               /* Size of combined key and value, in u64s */
-               __u8            u64s;
-       };
-       struct {
-               struct bkey     k;
-               struct bch_val  v;
-       };
-       };
+       struct bkey     k;
+       struct bch_val  v;
 };
 
 #define KEY(_inode, _offset, _size)                                    \
@@ -224,16 +315,7 @@ static inline void bkey_init(struct bkey *k)
 #define bkey_bytes(_k)         ((_k)->u64s * sizeof(__u64))
 
 #define __BKEY_PADDED(key, pad)                                        \
-       struct { struct bkey_i key; __u64 key ## _pad[pad]; }
-
-#define BKEY_VAL_TYPE(name, nr)                                                \
-struct bkey_i_##name {                                                 \
-       union {                                                         \
-               struct bkey             k;                              \
-               struct bkey_i           k_i;                            \
-       };                                                              \
-       struct bch_##name               v;                              \
-}
+       struct bkey_i key; __u64 key ## _pad[pad]
 
 /*
  * - DELETED keys are used internally to mark keys that should be ignored but
@@ -249,19 +331,74 @@ struct bkey_i_##name {                                                    \
  *   by new writes or cluster-wide GC. Node repair can also overwrite them with
  *   the same or a more recent version number, but not with an older version
  *   number.
-*/
-#define KEY_TYPE_DELETED               0
-#define KEY_TYPE_DISCARD               1
-#define KEY_TYPE_ERROR                 2
-#define KEY_TYPE_COOKIE                        3
-#define KEY_TYPE_PERSISTENT_DISCARD    4
-#define KEY_TYPE_GENERIC_NR            128
+ *
+ * - WHITEOUT: for hash table btrees
+ */
+#define BCH_BKEY_TYPES()                               \
+       x(deleted,              0)                      \
+       x(whiteout,             1)                      \
+       x(error,                2)                      \
+       x(cookie,               3)                      \
+       x(hash_whiteout,        4)                      \
+       x(btree_ptr,            5)                      \
+       x(extent,               6)                      \
+       x(reservation,          7)                      \
+       x(inode,                8)                      \
+       x(inode_generation,     9)                      \
+       x(dirent,               10)                     \
+       x(xattr,                11)                     \
+       x(alloc,                12)                     \
+       x(quota,                13)                     \
+       x(stripe,               14)                     \
+       x(reflink_p,            15)                     \
+       x(reflink_v,            16)                     \
+       x(inline_data,          17)                     \
+       x(btree_ptr_v2,         18)                     \
+       x(indirect_inline_data, 19)                     \
+       x(alloc_v2,             20)                     \
+       x(subvolume,            21)                     \
+       x(snapshot,             22)                     \
+       x(inode_v2,             23)                     \
+       x(alloc_v3,             24)                     \
+       x(set,                  25)                     \
+       x(lru,                  26)                     \
+       x(alloc_v4,             27)                     \
+       x(backpointer,          28)                     \
+       x(inode_v3,             29)                     \
+       x(bucket_gens,          30)                     \
+       x(snapshot_tree,        31)
+
+enum bch_bkey_type {
+#define x(name, nr) KEY_TYPE_##name    = nr,
+       BCH_BKEY_TYPES()
+#undef x
+       KEY_TYPE_MAX,
+};
+
+struct bch_deleted {
+       struct bch_val          v;
+};
+
+struct bch_whiteout {
+       struct bch_val          v;
+};
+
+struct bch_error {
+       struct bch_val          v;
+};
 
 struct bch_cookie {
        struct bch_val          v;
        __le64                  cookie;
 };
-BKEY_VAL_TYPE(cookie,          KEY_TYPE_COOKIE);
+
+struct bch_hash_whiteout {
+       struct bch_val          v;
+};
+
+struct bch_set {
+       struct bch_val          v;
+};
 
 /* Extents */
 
@@ -275,10 +412,10 @@ BKEY_VAL_TYPE(cookie,             KEY_TYPE_COOKIE);
  *
  * If an extent is not checksummed or compressed, when the extent is trimmed we
  * don't have to remember the extent we originally allocated and wrote: we can
- * merely adjust ptr->offset to point to the start of the start of the data that
- * is currently live. The size field in struct bkey records the current (live)
- * size of the extent, and is also used to mean "size of region on disk that we
- * point to" in this case.
+ * merely adjust ptr->offset to point to the start of the data that is currently
+ * live. The size field in struct bkey records the current (live) size of the
+ * extent, and is also used to mean "size of region on disk that we point to" in
+ * this case.
  *
  * Thus an extent that is not checksummed or compressed will consist only of a
  * list of bch_extent_ptrs, with none of the fields in
@@ -340,47 +477,22 @@ BKEY_VAL_TYPE(cookie,             KEY_TYPE_COOKIE);
 struct bch_csum {
        __le64                  lo;
        __le64                  hi;
-} __attribute__((packed, aligned(8)));
-
-enum bch_csum_type {
-       BCH_CSUM_NONE                   = 0,
-       BCH_CSUM_CRC32C_NONZERO         = 1,
-       BCH_CSUM_CRC64_NONZERO          = 2,
-       BCH_CSUM_CHACHA20_POLY1305_80   = 3,
-       BCH_CSUM_CHACHA20_POLY1305_128  = 4,
-       BCH_CSUM_CRC32C                 = 5,
-       BCH_CSUM_CRC64                  = 6,
-       BCH_CSUM_NR                     = 7,
-};
-
-static inline _Bool bch2_csum_type_is_encryption(enum bch_csum_type type)
-{
-       switch (type) {
-       case BCH_CSUM_CHACHA20_POLY1305_80:
-       case BCH_CSUM_CHACHA20_POLY1305_128:
-               return true;
-       default:
-               return false;
-       }
-}
+} __packed __aligned(8);
 
-enum bch_compression_type {
-       BCH_COMPRESSION_NONE            = 0,
-       BCH_COMPRESSION_LZ4_OLD         = 1,
-       BCH_COMPRESSION_GZIP            = 2,
-       BCH_COMPRESSION_LZ4             = 3,
-       BCH_COMPRESSION_NR              = 4,
-};
+#define BCH_EXTENT_ENTRY_TYPES()               \
+       x(ptr,                  0)              \
+       x(crc32,                1)              \
+       x(crc64,                2)              \
+       x(crc128,               3)              \
+       x(stripe_ptr,           4)
+#define BCH_EXTENT_ENTRY_MAX   5
 
 enum bch_extent_entry_type {
-       BCH_EXTENT_ENTRY_ptr            = 0,
-       BCH_EXTENT_ENTRY_crc32          = 1,
-       BCH_EXTENT_ENTRY_crc64          = 2,
-       BCH_EXTENT_ENTRY_crc128         = 3,
+#define x(f, n) BCH_EXTENT_ENTRY_##f = n,
+       BCH_EXTENT_ENTRY_TYPES()
+#undef x
 };
 
-#define BCH_EXTENT_ENTRY_MAX           4
-
 /* Compressed/uncompressed size are stored biased by 1: */
 struct bch_extent_crc32 {
 #if defined(__LITTLE_ENDIAN_BITFIELD)
@@ -402,7 +514,7 @@ struct bch_extent_crc32 {
                                _compressed_size:7,
                                type:2;
 #endif
-} __attribute__((packed, aligned(8)));
+} __packed __aligned(8);
 
 #define CRC32_SIZE_MAX         (1U << 7)
 #define CRC32_NONCE_MAX                0
@@ -428,7 +540,7 @@ struct bch_extent_crc64 {
                                type:3;
 #endif
        __u64                   csum_lo;
-} __attribute__((packed, aligned(8)));
+} __packed __aligned(8);
 
 #define CRC64_SIZE_MAX         (1U << 9)
 #define CRC64_NONCE_MAX                ((1U << 10) - 1)
@@ -445,14 +557,14 @@ struct bch_extent_crc128 {
 #elif defined (__BIG_ENDIAN_BITFIELD)
        __u64                   compression_type:4,
                                csum_type:4,
-                               nonce:14,
+                               nonce:13,
                                offset:13,
                                _uncompressed_size:13,
                                _compressed_size:13,
-                               type:3;
+                               type:4;
 #endif
        struct bch_csum         csum;
-} __attribute__((packed, aligned(8)));
+} __packed __aligned(8);
 
 #define CRC128_SIZE_MAX                (1U << 13)
 #define CRC128_NONCE_MAX       ((1U << 13) - 1)
@@ -464,8 +576,8 @@ struct bch_extent_ptr {
 #if defined(__LITTLE_ENDIAN_BITFIELD)
        __u64                   type:1,
                                cached:1,
-                               erasure_coded:1,
-                               reservation:1,
+                               unused:1,
+                               unwritten:1,
                                offset:44, /* 8 petabytes */
                                dev:8,
                                gen:8;
@@ -473,29 +585,43 @@ struct bch_extent_ptr {
        __u64                   gen:8,
                                dev:8,
                                offset:44,
-                               reservation:1,
-                               erasure_coded:1,
+                               unwritten:1,
+                               unused:1,
                                cached:1,
                                type:1;
 #endif
-} __attribute__((packed, aligned(8)));
+} __packed __aligned(8);
 
-struct bch_extent_reservation {
+struct bch_extent_stripe_ptr {
 #if defined(__LITTLE_ENDIAN_BITFIELD)
        __u64                   type:5,
-                               unused:23,
+                               block:8,
+                               redundancy:4,
+                               idx:47;
+#elif defined (__BIG_ENDIAN_BITFIELD)
+       __u64                   idx:47,
+                               redundancy:4,
+                               block:8,
+                               type:5;
+#endif
+};
+
+struct bch_extent_reservation {
+#if defined(__LITTLE_ENDIAN_BITFIELD)
+       __u64                   type:6,
+                               unused:22,
                                replicas:4,
                                generation:32;
 #elif defined (__BIG_ENDIAN_BITFIELD)
        __u64                   generation:32,
                                replicas:4,
-                               unused:23,
-                               type:5;
+                               unused:22,
+                               type:6;
 #endif
 };
 
 union bch_extent_entry {
-#if defined(__LITTLE_ENDIAN) ||  __BITS_PER_LONG == 64
+#if __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__ ||  __BITS_PER_LONG == 64
        unsigned long                   type;
 #elif __BITS_PER_LONG == 32
        struct {
@@ -505,35 +631,39 @@ union bch_extent_entry {
 #else
 #error edit for your odd byteorder.
 #endif
-       struct bch_extent_crc32         crc32;
-       struct bch_extent_crc64         crc64;
-       struct bch_extent_crc128        crc128;
-       struct bch_extent_ptr           ptr;
+
+#define x(f, n) struct bch_extent_##f  f;
+       BCH_EXTENT_ENTRY_TYPES()
+#undef x
 };
 
-enum {
-       BCH_EXTENT              = 128,
+struct bch_btree_ptr {
+       struct bch_val          v;
 
-       /*
-        * This is kind of a hack, we're overloading the type for a boolean that
-        * really should be part of the value - BCH_EXTENT and BCH_EXTENT_CACHED
-        * have the same value type:
-        */
-       BCH_EXTENT_CACHED       = 129,
+       __u64                   _data[0];
+       struct bch_extent_ptr   start[];
+} __packed __aligned(8);
 
-       /*
-        * Persistent reservation:
-        */
-       BCH_RESERVATION         = 130,
-};
+struct bch_btree_ptr_v2 {
+       struct bch_val          v;
+
+       __u64                   mem_ptr;
+       __le64                  seq;
+       __le16                  sectors_written;
+       __le16                  flags;
+       struct bpos             min_key;
+       __u64                   _data[0];
+       struct bch_extent_ptr   start[];
+} __packed __aligned(8);
+
+LE16_BITMASK(BTREE_PTR_RANGE_UPDATED,  struct bch_btree_ptr_v2, flags, 0, 1);
 
 struct bch_extent {
        struct bch_val          v;
 
-       union bch_extent_entry  start[0];
        __u64                   _data[0];
-} __attribute__((packed, aligned(8)));
-BKEY_VAL_TYPE(extent,          BCH_EXTENT);
+       union bch_extent_entry  start[];
+} __packed __aligned(8);
 
 struct bch_reservation {
        struct bch_val          v;
@@ -541,8 +671,7 @@ struct bch_reservation {
        __le32                  generation;
        __u8                    nr_replicas;
        __u8                    pad[3];
-} __attribute__((packed, aligned(8)));
-BKEY_VAL_TYPE(reservation,     BCH_RESERVATION);
+} __packed __aligned(8);
 
 /* Maximum size (in u64s) a single pointer could be: */
 #define BKEY_EXTENT_PTR_U64s_MAX\
@@ -550,16 +679,16 @@ BKEY_VAL_TYPE(reservation,        BCH_RESERVATION);
          sizeof(struct bch_extent_ptr)) / sizeof(u64))
 
 /* Maximum possible size of an entire extent value: */
-/* There's a hack in the keylist code that needs to be fixed.. */
 #define BKEY_EXTENT_VAL_U64s_MAX                               \
-       (BKEY_EXTENT_PTR_U64s_MAX * (BCH_REPLICAS_MAX + 1))
+       (1 + BKEY_EXTENT_PTR_U64s_MAX * (BCH_REPLICAS_MAX + 1))
 
 /* * Maximum possible size of an entire extent, key + value: */
 #define BKEY_EXTENT_U64s_MAX           (BKEY_U64s + BKEY_EXTENT_VAL_U64s_MAX)
 
 /* Btree pointers don't carry around checksums: */
 #define BKEY_BTREE_PTR_VAL_U64s_MAX                            \
-       ((sizeof(struct bch_extent_ptr)) / sizeof(u64) * BCH_REPLICAS_MAX)
+       ((sizeof(struct bch_btree_ptr_v2) +                     \
+         sizeof(struct bch_extent_ptr) * BCH_REPLICAS_MAX) / sizeof(u64))
 #define BKEY_BTREE_PTR_U64s_MAX                                        \
        (BKEY_U64s + BKEY_BTREE_PTR_VAL_U64s_MAX)
 
@@ -569,12 +698,6 @@ BKEY_VAL_TYPE(reservation, BCH_RESERVATION);
 
 #define BCACHEFS_ROOT_INO      4096
 
-enum bch_inode_types {
-       BCH_INODE_FS            = 128,
-       BCH_INODE_BLOCKDEV      = 129,
-       BCH_INODE_GENERATION    = 130,
-};
-
 struct bch_inode {
        struct bch_val          v;
 
@@ -582,46 +705,133 @@ struct bch_inode {
        __le32                  bi_flags;
        __le16                  bi_mode;
        __u8                    fields[0];
-} __attribute__((packed, aligned(8)));
-BKEY_VAL_TYPE(inode,           BCH_INODE_FS);
+} __packed __aligned(8);
+
+struct bch_inode_v2 {
+       struct bch_val          v;
+
+       __le64                  bi_journal_seq;
+       __le64                  bi_hash_seed;
+       __le64                  bi_flags;
+       __le16                  bi_mode;
+       __u8                    fields[0];
+} __packed __aligned(8);
+
+struct bch_inode_v3 {
+       struct bch_val          v;
+
+       __le64                  bi_journal_seq;
+       __le64                  bi_hash_seed;
+       __le64                  bi_flags;
+       __le64                  bi_sectors;
+       __le64                  bi_size;
+       __le64                  bi_version;
+       __u8                    fields[0];
+} __packed __aligned(8);
+
+#define INODEv3_FIELDS_START_INITIAL   6
+#define INODEv3_FIELDS_START_CUR       (offsetof(struct bch_inode_v3, fields) / sizeof(u64))
 
 struct bch_inode_generation {
        struct bch_val          v;
 
        __le32                  bi_generation;
        __le32                  pad;
-} __attribute__((packed, aligned(8)));
-BKEY_VAL_TYPE(inode_generation,        BCH_INODE_GENERATION);
-
-#define BCH_INODE_FIELDS()                             \
-       BCH_INODE_FIELD(bi_atime,       64)             \
-       BCH_INODE_FIELD(bi_ctime,       64)             \
-       BCH_INODE_FIELD(bi_mtime,       64)             \
-       BCH_INODE_FIELD(bi_otime,       64)             \
-       BCH_INODE_FIELD(bi_size,        64)             \
-       BCH_INODE_FIELD(bi_sectors,     64)             \
-       BCH_INODE_FIELD(bi_uid,         32)             \
-       BCH_INODE_FIELD(bi_gid,         32)             \
-       BCH_INODE_FIELD(bi_nlink,       32)             \
-       BCH_INODE_FIELD(bi_generation,  32)             \
-       BCH_INODE_FIELD(bi_dev,         32)
+} __packed __aligned(8);
+
+/*
+ * bi_subvol and bi_parent_subvol are only set for subvolume roots:
+ */
+
+#define BCH_INODE_FIELDS_v2()                  \
+       x(bi_atime,                     96)     \
+       x(bi_ctime,                     96)     \
+       x(bi_mtime,                     96)     \
+       x(bi_otime,                     96)     \
+       x(bi_size,                      64)     \
+       x(bi_sectors,                   64)     \
+       x(bi_uid,                       32)     \
+       x(bi_gid,                       32)     \
+       x(bi_nlink,                     32)     \
+       x(bi_generation,                32)     \
+       x(bi_dev,                       32)     \
+       x(bi_data_checksum,             8)      \
+       x(bi_compression,               8)      \
+       x(bi_project,                   32)     \
+       x(bi_background_compression,    8)      \
+       x(bi_data_replicas,             8)      \
+       x(bi_promote_target,            16)     \
+       x(bi_foreground_target,         16)     \
+       x(bi_background_target,         16)     \
+       x(bi_erasure_code,              16)     \
+       x(bi_fields_set,                16)     \
+       x(bi_dir,                       64)     \
+       x(bi_dir_offset,                64)     \
+       x(bi_subvol,                    32)     \
+       x(bi_parent_subvol,             32)
+
+#define BCH_INODE_FIELDS_v3()                  \
+       x(bi_atime,                     96)     \
+       x(bi_ctime,                     96)     \
+       x(bi_mtime,                     96)     \
+       x(bi_otime,                     96)     \
+       x(bi_uid,                       32)     \
+       x(bi_gid,                       32)     \
+       x(bi_nlink,                     32)     \
+       x(bi_generation,                32)     \
+       x(bi_dev,                       32)     \
+       x(bi_data_checksum,             8)      \
+       x(bi_compression,               8)      \
+       x(bi_project,                   32)     \
+       x(bi_background_compression,    8)      \
+       x(bi_data_replicas,             8)      \
+       x(bi_promote_target,            16)     \
+       x(bi_foreground_target,         16)     \
+       x(bi_background_target,         16)     \
+       x(bi_erasure_code,              16)     \
+       x(bi_fields_set,                16)     \
+       x(bi_dir,                       64)     \
+       x(bi_dir_offset,                64)     \
+       x(bi_subvol,                    32)     \
+       x(bi_parent_subvol,             32)     \
+       x(bi_nocow,                     8)
+
+/* subset of BCH_INODE_FIELDS */
+#define BCH_INODE_OPTS()                       \
+       x(data_checksum,                8)      \
+       x(compression,                  8)      \
+       x(project,                      32)     \
+       x(background_compression,       8)      \
+       x(data_replicas,                8)      \
+       x(promote_target,               16)     \
+       x(foreground_target,            16)     \
+       x(background_target,            16)     \
+       x(erasure_code,                 16)     \
+       x(nocow,                        8)
+
+enum inode_opt_id {
+#define x(name, ...)                           \
+       Inode_opt_##name,
+       BCH_INODE_OPTS()
+#undef  x
+       Inode_opt_nr,
+};
 
 enum {
        /*
         * User flags (get/settable with FS_IOC_*FLAGS, correspond to FS_*_FL
         * flags)
         */
-       __BCH_INODE_SYNC        = 0,
-       __BCH_INODE_IMMUTABLE   = 1,
-       __BCH_INODE_APPEND      = 2,
-       __BCH_INODE_NODUMP      = 3,
-       __BCH_INODE_NOATIME     = 4,
-
-       __BCH_INODE_I_SIZE_DIRTY= 5,
-       __BCH_INODE_I_SECTORS_DIRTY= 6,
+       __BCH_INODE_SYNC                = 0,
+       __BCH_INODE_IMMUTABLE           = 1,
+       __BCH_INODE_APPEND              = 2,
+       __BCH_INODE_NODUMP              = 3,
+       __BCH_INODE_NOATIME             = 4,
 
-       /* not implemented yet: */
-       __BCH_INODE_HAS_XATTRS  = 7, /* has xattrs in xattr btree */
+       __BCH_INODE_I_SIZE_DIRTY        = 5,
+       __BCH_INODE_I_SECTORS_DIRTY     = 6,
+       __BCH_INODE_UNLINKED            = 7,
+       __BCH_INODE_BACKPTR_UNTRUSTED   = 8,
 
        /* bits 20+ reserved for packed fields below: */
 };
@@ -633,28 +843,22 @@ enum {
 #define BCH_INODE_NOATIME      (1 << __BCH_INODE_NOATIME)
 #define BCH_INODE_I_SIZE_DIRTY (1 << __BCH_INODE_I_SIZE_DIRTY)
 #define BCH_INODE_I_SECTORS_DIRTY (1 << __BCH_INODE_I_SECTORS_DIRTY)
-#define BCH_INODE_HAS_XATTRS   (1 << __BCH_INODE_HAS_XATTRS)
+#define BCH_INODE_UNLINKED     (1 << __BCH_INODE_UNLINKED)
+#define BCH_INODE_BACKPTR_UNTRUSTED (1 << __BCH_INODE_BACKPTR_UNTRUSTED)
 
 LE32_BITMASK(INODE_STR_HASH,   struct bch_inode, bi_flags, 20, 24);
-LE32_BITMASK(INODE_NR_FIELDS,  struct bch_inode, bi_flags, 24, 32);
-
-struct bch_inode_blockdev {
-       struct bch_val          v;
-
-       __le64                  i_size;
-       __le64                  i_flags;
+LE32_BITMASK(INODE_NR_FIELDS,  struct bch_inode, bi_flags, 24, 31);
+LE32_BITMASK(INODE_NEW_VARINT, struct bch_inode, bi_flags, 31, 32);
 
-       /* Seconds: */
-       __le64                  i_ctime;
-       __le64                  i_mtime;
+LE64_BITMASK(INODEv2_STR_HASH, struct bch_inode_v2, bi_flags, 20, 24);
+LE64_BITMASK(INODEv2_NR_FIELDS,        struct bch_inode_v2, bi_flags, 24, 31);
 
-       uuid_le                 i_uuid;
-       __u8                    i_label[32];
-} __attribute__((packed, aligned(8)));
-BKEY_VAL_TYPE(inode_blockdev,  BCH_INODE_BLOCKDEV);
+LE64_BITMASK(INODEv3_STR_HASH, struct bch_inode_v3, bi_flags, 20, 24);
+LE64_BITMASK(INODEv3_NR_FIELDS,        struct bch_inode_v3, bi_flags, 24, 31);
 
-/* Thin provisioned volume, or cache for another block device? */
-LE64_BITMASK(CACHED_DEV,       struct bch_inode_blockdev, i_flags, 0,  1)
+LE64_BITMASK(INODEv3_FIELDS_START,
+                               struct bch_inode_v3, bi_flags, 31, 36);
+LE64_BITMASK(INODEv3_MODE,     struct bch_inode_v3, bi_flags, 36, 52);
 
 /* Dirents */
 
@@ -669,16 +873,17 @@ LE64_BITMASK(CACHED_DEV,  struct bch_inode_blockdev, i_flags, 0,  1)
  * collision:
  */
 
-enum {
-       BCH_DIRENT              = 128,
-       BCH_DIRENT_WHITEOUT     = 129,
-};
-
 struct bch_dirent {
        struct bch_val          v;
 
        /* Target inode number: */
+       union {
        __le64                  d_inum;
+       struct {                /* DT_SUBVOL */
+       __le32                  d_child_subvol;
+       __le32                  d_parent_subvol;
+       };
+       };
 
        /*
         * Copy of mode bits 12-15 from the target inode - so userspace can get
@@ -687,21 +892,22 @@ struct bch_dirent {
        __u8                    d_type;
 
        __u8                    d_name[];
-} __attribute__((packed, aligned(8)));
-BKEY_VAL_TYPE(dirent,          BCH_DIRENT);
+} __packed __aligned(8);
 
-/* Xattrs */
+#define DT_SUBVOL      16
+#define BCH_DT_MAX     17
 
-enum {
-       BCH_XATTR               = 128,
-       BCH_XATTR_WHITEOUT      = 129,
-};
+#define BCH_NAME_MAX   ((unsigned) (U8_MAX * sizeof(u64) -             \
+                        sizeof(struct bkey) -                          \
+                        offsetof(struct bch_dirent, d_name)))
+
+/* Xattrs */
 
-#define BCH_XATTR_INDEX_USER                   0
-#define BCH_XATTR_INDEX_POSIX_ACL_ACCESS       1
-#define BCH_XATTR_INDEX_POSIX_ACL_DEFAULT      2
-#define BCH_XATTR_INDEX_TRUSTED                        3
-#define BCH_XATTR_INDEX_SECURITY               4
+#define KEY_TYPE_XATTR_INDEX_USER                      0
+#define KEY_TYPE_XATTR_INDEX_POSIX_ACL_ACCESS  1
+#define KEY_TYPE_XATTR_INDEX_POSIX_ACL_DEFAULT 2
+#define KEY_TYPE_XATTR_INDEX_TRUSTED                   3
+#define KEY_TYPE_XATTR_INDEX_SECURITY          4
 
 struct bch_xattr {
        struct bch_val          v;
@@ -709,95 +915,250 @@ struct bch_xattr {
        __u8                    x_name_len;
        __le16                  x_val_len;
        __u8                    x_name[];
-} __attribute__((packed, aligned(8)));
-BKEY_VAL_TYPE(xattr,           BCH_XATTR);
+} __packed __aligned(8);
 
 /* Bucket/allocation information: */
 
-enum {
-       BCH_ALLOC               = 128,
-};
+struct bch_alloc {
+       struct bch_val          v;
+       __u8                    fields;
+       __u8                    gen;
+       __u8                    data[];
+} __packed __aligned(8);
+
+#define BCH_ALLOC_FIELDS_V1()                  \
+       x(read_time,            16)             \
+       x(write_time,           16)             \
+       x(data_type,            8)              \
+       x(dirty_sectors,        16)             \
+       x(cached_sectors,       16)             \
+       x(oldest_gen,           8)              \
+       x(stripe,               32)             \
+       x(stripe_redundancy,    8)
 
 enum {
-       BCH_ALLOC_FIELD_READ_TIME       = 0,
-       BCH_ALLOC_FIELD_WRITE_TIME      = 1,
+#define x(name, _bits) BCH_ALLOC_FIELD_V1_##name,
+       BCH_ALLOC_FIELDS_V1()
+#undef x
 };
 
-struct bch_alloc {
+struct bch_alloc_v2 {
        struct bch_val          v;
-       __u8                    fields;
+       __u8                    nr_fields;
        __u8                    gen;
+       __u8                    oldest_gen;
+       __u8                    data_type;
        __u8                    data[];
-} __attribute__((packed, aligned(8)));
-BKEY_VAL_TYPE(alloc,   BCH_ALLOC);
+} __packed __aligned(8);
 
-/* Superblock */
+#define BCH_ALLOC_FIELDS_V2()                  \
+       x(read_time,            64)             \
+       x(write_time,           64)             \
+       x(dirty_sectors,        32)             \
+       x(cached_sectors,       32)             \
+       x(stripe,               32)             \
+       x(stripe_redundancy,    8)
 
-/*
- * Version 8:  BCH_SB_ENCODED_EXTENT_MAX_BITS
- *             BCH_MEMBER_DATA_ALLOWED
- * Version 9:  incompatible extent nonce change
- */
+struct bch_alloc_v3 {
+       struct bch_val          v;
+       __le64                  journal_seq;
+       __le32                  flags;
+       __u8                    nr_fields;
+       __u8                    gen;
+       __u8                    oldest_gen;
+       __u8                    data_type;
+       __u8                    data[];
+} __packed __aligned(8);
 
-#define BCH_SB_VERSION_MIN             7
-#define BCH_SB_VERSION_EXTENT_MAX      8
-#define BCH_SB_VERSION_EXTENT_NONCE_V1 9
-#define BCH_SB_VERSION_MAX             9
+LE32_BITMASK(BCH_ALLOC_V3_NEED_DISCARD,struct bch_alloc_v3, flags,  0,  1)
+LE32_BITMASK(BCH_ALLOC_V3_NEED_INC_GEN,struct bch_alloc_v3, flags,  1,  2)
 
-#define BCH_SB_SECTOR                  8
-#define BCH_SB_LABEL_SIZE              32
-#define BCH_SB_MEMBERS_MAX             64 /* XXX kill */
+struct bch_alloc_v4 {
+       struct bch_val          v;
+       __u64                   journal_seq;
+       __u32                   flags;
+       __u8                    gen;
+       __u8                    oldest_gen;
+       __u8                    data_type;
+       __u8                    stripe_redundancy;
+       __u32                   dirty_sectors;
+       __u32                   cached_sectors;
+       __u64                   io_time[2];
+       __u32                   stripe;
+       __u32                   nr_external_backpointers;
+       __u64                   fragmentation_lru;
+} __packed __aligned(8);
+
+#define BCH_ALLOC_V4_U64s_V0   6
+#define BCH_ALLOC_V4_U64s      (sizeof(struct bch_alloc_v4) / sizeof(u64))
+
+BITMASK(BCH_ALLOC_V4_NEED_DISCARD,     struct bch_alloc_v4, flags,  0,  1)
+BITMASK(BCH_ALLOC_V4_NEED_INC_GEN,     struct bch_alloc_v4, flags,  1,  2)
+BITMASK(BCH_ALLOC_V4_BACKPOINTERS_START,struct bch_alloc_v4, flags,  2,  8)
+BITMASK(BCH_ALLOC_V4_NR_BACKPOINTERS,  struct bch_alloc_v4, flags,  8,  14)
+
+#define BCH_ALLOC_V4_NR_BACKPOINTERS_MAX       40
+
+struct bch_backpointer {
+       struct bch_val          v;
+       __u8                    btree_id;
+       __u8                    level;
+       __u8                    data_type;
+       __u64                   bucket_offset:40;
+       __u32                   bucket_len;
+       struct bpos             pos;
+} __packed __aligned(8);
 
-struct bch_member {
-       uuid_le                 uuid;
-       __le64                  nbuckets;       /* device size */
-       __le16                  first_bucket;   /* index of first bucket used */
-       __le16                  bucket_size;    /* sectors */
-       __le32                  pad;
-       __le64                  last_mount;     /* time_t */
+#define KEY_TYPE_BUCKET_GENS_BITS      8
+#define KEY_TYPE_BUCKET_GENS_NR                (1U << KEY_TYPE_BUCKET_GENS_BITS)
+#define KEY_TYPE_BUCKET_GENS_MASK      (KEY_TYPE_BUCKET_GENS_NR - 1)
 
-       __le64                  flags[2];
+struct bch_bucket_gens {
+       struct bch_val          v;
+       u8                      gens[KEY_TYPE_BUCKET_GENS_NR];
+} __packed __aligned(8);
+
+/* Quotas: */
+
+enum quota_types {
+       QTYP_USR                = 0,
+       QTYP_GRP                = 1,
+       QTYP_PRJ                = 2,
+       QTYP_NR                 = 3,
 };
 
-LE64_BITMASK(BCH_MEMBER_STATE,         struct bch_member, flags[0],  0,  4)
-LE64_BITMASK(BCH_MEMBER_TIER,          struct bch_member, flags[0],  4,  8)
-/* 8-10 unused, was HAS_(META)DATA */
-LE64_BITMASK(BCH_MEMBER_REPLACEMENT,   struct bch_member, flags[0], 10, 14)
-LE64_BITMASK(BCH_MEMBER_DISCARD,       struct bch_member, flags[0], 14, 15);
-LE64_BITMASK(BCH_MEMBER_DATA_ALLOWED,  struct bch_member, flags[0], 15, 20);
+enum quota_counters {
+       Q_SPC                   = 0,
+       Q_INO                   = 1,
+       Q_COUNTERS              = 2,
+};
 
-#if 0
-LE64_BITMASK(BCH_MEMBER_NR_READ_ERRORS,        struct bch_member, flags[1], 0,  20);
-LE64_BITMASK(BCH_MEMBER_NR_WRITE_ERRORS,struct bch_member, flags[1], 20, 40);
-#endif
+struct bch_quota_counter {
+       __le64                  hardlimit;
+       __le64                  softlimit;
+};
 
-enum bch_member_state {
-       BCH_MEMBER_STATE_RW             = 0,
-       BCH_MEMBER_STATE_RO             = 1,
-       BCH_MEMBER_STATE_FAILED         = 2,
-       BCH_MEMBER_STATE_SPARE          = 3,
-       BCH_MEMBER_STATE_NR             = 4,
+struct bch_quota {
+       struct bch_val          v;
+       struct bch_quota_counter c[Q_COUNTERS];
+} __packed __aligned(8);
+
+/* Erasure coding */
+
+struct bch_stripe {
+       struct bch_val          v;
+       __le16                  sectors;
+       __u8                    algorithm;
+       __u8                    nr_blocks;
+       __u8                    nr_redundant;
+
+       __u8                    csum_granularity_bits;
+       __u8                    csum_type;
+       __u8                    pad;
+
+       struct bch_extent_ptr   ptrs[];
+} __packed __aligned(8);
+
+/* Reflink: */
+
+struct bch_reflink_p {
+       struct bch_val          v;
+       __le64                  idx;
+       /*
+        * A reflink pointer might point to an indirect extent which is then
+        * later split (by copygc or rebalance). If we only pointed to part of
+        * the original indirect extent, and then one of the fragments is
+        * outside the range we point to, we'd leak a refcount: so when creating
+        * reflink pointers, we need to store pad values to remember the full
+        * range we were taking a reference on.
+        */
+       __le32                  front_pad;
+       __le32                  back_pad;
+} __packed __aligned(8);
+
+struct bch_reflink_v {
+       struct bch_val          v;
+       __le64                  refcount;
+       union bch_extent_entry  start[0];
+       __u64                   _data[0];
+} __packed __aligned(8);
+
+struct bch_indirect_inline_data {
+       struct bch_val          v;
+       __le64                  refcount;
+       u8                      data[0];
 };
 
-#define BCH_TIER_MAX                   4U
+/* Inline data */
 
-enum cache_replacement {
-       CACHE_REPLACEMENT_LRU           = 0,
-       CACHE_REPLACEMENT_FIFO          = 1,
-       CACHE_REPLACEMENT_RANDOM        = 2,
-       CACHE_REPLACEMENT_NR            = 3,
+struct bch_inline_data {
+       struct bch_val          v;
+       u8                      data[0];
 };
 
-struct bch_sb_layout {
-       uuid_le                 magic;  /* bcachefs superblock UUID */
-       __u8                    layout_type;
-       __u8                    sb_max_size_bits; /* base 2 of 512 byte sectors */
-       __u8                    nr_superblocks;
-       __u8                    pad[5];
-       __u64                   sb_offset[61];
-} __attribute__((packed, aligned(8)));
+/* Subvolumes: */
 
-#define BCH_SB_LAYOUT_SECTOR   7
+#define SUBVOL_POS_MIN         POS(0, 1)
+#define SUBVOL_POS_MAX         POS(0, S32_MAX)
+#define BCACHEFS_ROOT_SUBVOL   1
+
+struct bch_subvolume {
+       struct bch_val          v;
+       __le32                  flags;
+       __le32                  snapshot;
+       __le64                  inode;
+       __le32                  parent;
+       __le32                  pad;
+       bch_le128               otime;
+};
+
+LE32_BITMASK(BCH_SUBVOLUME_RO,         struct bch_subvolume, flags,  0,  1)
+/*
+ * We need to know whether a subvolume is a snapshot so we can know whether we
+ * can delete it (or whether it should just be rm -rf'd)
+ */
+LE32_BITMASK(BCH_SUBVOLUME_SNAP,       struct bch_subvolume, flags,  1,  2)
+LE32_BITMASK(BCH_SUBVOLUME_UNLINKED,   struct bch_subvolume, flags,  2,  3)
+
+/* Snapshots */
+
+struct bch_snapshot {
+       struct bch_val          v;
+       __le32                  flags;
+       __le32                  parent;
+       __le32                  children[2];
+       __le32                  subvol;
+       __le32                  tree;
+};
+
+LE32_BITMASK(BCH_SNAPSHOT_DELETED,     struct bch_snapshot, flags,  0,  1)
+
+/* True if a subvolume points to this snapshot node: */
+LE32_BITMASK(BCH_SNAPSHOT_SUBVOL,      struct bch_snapshot, flags,  1,  2)
+
+/*
+ * Snapshot trees:
+ *
+ * The snapshot_trees btree gives us persistent indentifier for each tree of
+ * bch_snapshot nodes, and allow us to record and easily find the root/master
+ * subvolume that other snapshots were created from:
+ */
+struct bch_snapshot_tree {
+       struct bch_val          v;
+       __le32                  master_subvol;
+       __le32                  root_snapshot;
+};
+
+/* LRU btree: */
+
+struct bch_lru {
+       struct bch_val          v;
+       __le64                  idx;
+} __packed __aligned(8);
+
+#define LRU_ID_STRIPES         (1U << 16)
+
+/* Optional/variable size superblock sections: */
 
 struct bch_sb_field {
        __u64                   _data[0];
@@ -805,25 +1166,98 @@ struct bch_sb_field {
        __le32                  type;
 };
 
+#define BCH_SB_FIELDS()                                \
+       x(journal,      0)                      \
+       x(members,      1)                      \
+       x(crypt,        2)                      \
+       x(replicas_v0,  3)                      \
+       x(quota,        4)                      \
+       x(disk_groups,  5)                      \
+       x(clean,        6)                      \
+       x(replicas,     7)                      \
+       x(journal_seq_blacklist, 8)             \
+       x(journal_v2,   9)                      \
+       x(counters,     10)
+
 enum bch_sb_field_type {
-       BCH_SB_FIELD_journal    = 0,
-       BCH_SB_FIELD_members    = 1,
-       BCH_SB_FIELD_crypt      = 2,
-       BCH_SB_FIELD_replicas   = 3,
-       BCH_SB_FIELD_NR         = 4,
+#define x(f, nr)       BCH_SB_FIELD_##f = nr,
+       BCH_SB_FIELDS()
+#undef x
+       BCH_SB_FIELD_NR
 };
 
+/*
+ * Most superblock fields are replicated in all device's superblocks - a few are
+ * not:
+ */
+#define BCH_SINGLE_DEVICE_SB_FIELDS            \
+       ((1U << BCH_SB_FIELD_journal)|          \
+        (1U << BCH_SB_FIELD_journal_v2))
+
+/* BCH_SB_FIELD_journal: */
+
 struct bch_sb_field_journal {
        struct bch_sb_field     field;
        __le64                  buckets[0];
 };
 
+struct bch_sb_field_journal_v2 {
+       struct bch_sb_field     field;
+
+       struct bch_sb_field_journal_v2_entry {
+               __le64          start;
+               __le64          nr;
+       }                       d[0];
+};
+
+/* BCH_SB_FIELD_members: */
+
+#define BCH_MIN_NR_NBUCKETS    (1 << 6)
+
+struct bch_member {
+       uuid_le                 uuid;
+       __le64                  nbuckets;       /* device size */
+       __le16                  first_bucket;   /* index of first bucket used */
+       __le16                  bucket_size;    /* sectors */
+       __le32                  pad;
+       __le64                  last_mount;     /* time_t */
+
+       __le64                  flags[2];
+};
+
+LE64_BITMASK(BCH_MEMBER_STATE,         struct bch_member, flags[0],  0,  4)
+/* 4-14 unused, was TIER, HAS_(META)DATA, REPLACEMENT */
+LE64_BITMASK(BCH_MEMBER_DISCARD,       struct bch_member, flags[0], 14, 15)
+LE64_BITMASK(BCH_MEMBER_DATA_ALLOWED,  struct bch_member, flags[0], 15, 20)
+LE64_BITMASK(BCH_MEMBER_GROUP,         struct bch_member, flags[0], 20, 28)
+LE64_BITMASK(BCH_MEMBER_DURABILITY,    struct bch_member, flags[0], 28, 30)
+LE64_BITMASK(BCH_MEMBER_FREESPACE_INITIALIZED,
+                                       struct bch_member, flags[0], 30, 31)
+
+#if 0
+LE64_BITMASK(BCH_MEMBER_NR_READ_ERRORS,        struct bch_member, flags[1], 0,  20);
+LE64_BITMASK(BCH_MEMBER_NR_WRITE_ERRORS,struct bch_member, flags[1], 20, 40);
+#endif
+
+#define BCH_MEMBER_STATES()                    \
+       x(rw,           0)                      \
+       x(ro,           1)                      \
+       x(failed,       2)                      \
+       x(spare,        3)
+
+enum bch_member_state {
+#define x(t, n) BCH_MEMBER_STATE_##t = n,
+       BCH_MEMBER_STATES()
+#undef x
+       BCH_MEMBER_STATE_NR
+};
+
 struct bch_sb_field_members {
        struct bch_sb_field     field;
        struct bch_member       members[0];
 };
 
-/* Crypto: */
+/* BCH_SB_FIELD_crypt: */
 
 struct nonce {
        __le32                  d[4];
@@ -871,30 +1305,314 @@ LE64_BITMASK(BCH_KDF_SCRYPT_N,  struct bch_sb_field_crypt, kdf_flags,  0, 16);
 LE64_BITMASK(BCH_KDF_SCRYPT_R, struct bch_sb_field_crypt, kdf_flags, 16, 32);
 LE64_BITMASK(BCH_KDF_SCRYPT_P, struct bch_sb_field_crypt, kdf_flags, 32, 48);
 
+/* BCH_SB_FIELD_replicas: */
+
+#define BCH_DATA_TYPES()               \
+       x(free,         0)              \
+       x(sb,           1)              \
+       x(journal,      2)              \
+       x(btree,        3)              \
+       x(user,         4)              \
+       x(cached,       5)              \
+       x(parity,       6)              \
+       x(stripe,       7)              \
+       x(need_gc_gens, 8)              \
+       x(need_discard, 9)
+
 enum bch_data_type {
-       BCH_DATA_NONE           = 0,
-       BCH_DATA_SB             = 1,
-       BCH_DATA_JOURNAL        = 2,
-       BCH_DATA_BTREE          = 3,
-       BCH_DATA_USER           = 4,
-       BCH_DATA_NR             = 5,
+#define x(t, n) BCH_DATA_##t,
+       BCH_DATA_TYPES()
+#undef x
+       BCH_DATA_NR
 };
 
+static inline bool data_type_is_empty(enum bch_data_type type)
+{
+       switch (type) {
+       case BCH_DATA_free:
+       case BCH_DATA_need_gc_gens:
+       case BCH_DATA_need_discard:
+               return true;
+       default:
+               return false;
+       }
+}
+
+static inline bool data_type_is_hidden(enum bch_data_type type)
+{
+       switch (type) {
+       case BCH_DATA_sb:
+       case BCH_DATA_journal:
+               return true;
+       default:
+               return false;
+       }
+}
+
+struct bch_replicas_entry_v0 {
+       __u8                    data_type;
+       __u8                    nr_devs;
+       __u8                    devs[];
+} __packed;
+
+struct bch_sb_field_replicas_v0 {
+       struct bch_sb_field     field;
+       struct bch_replicas_entry_v0 entries[];
+} __packed __aligned(8);
+
 struct bch_replicas_entry {
-       u8                      data_type;
-       u8                      nr;
-       u8                      devs[0];
-};
+       __u8                    data_type;
+       __u8                    nr_devs;
+       __u8                    nr_required;
+       __u8                    devs[];
+} __packed;
+
+#define replicas_entry_bytes(_i)                                       \
+       (offsetof(typeof(*(_i)), devs) + (_i)->nr_devs)
 
 struct bch_sb_field_replicas {
        struct bch_sb_field     field;
-       struct bch_replicas_entry entries[0];
+       struct bch_replicas_entry entries[];
+} __packed __aligned(8);
+
+/* BCH_SB_FIELD_quota: */
+
+struct bch_sb_quota_counter {
+       __le32                          timelimit;
+       __le32                          warnlimit;
+};
+
+struct bch_sb_quota_type {
+       __le64                          flags;
+       struct bch_sb_quota_counter     c[Q_COUNTERS];
+};
+
+struct bch_sb_field_quota {
+       struct bch_sb_field             field;
+       struct bch_sb_quota_type        q[QTYP_NR];
+} __packed __aligned(8);
+
+/* BCH_SB_FIELD_disk_groups: */
+
+#define BCH_SB_LABEL_SIZE              32
+
+struct bch_disk_group {
+       __u8                    label[BCH_SB_LABEL_SIZE];
+       __le64                  flags[2];
+} __packed __aligned(8);
+
+LE64_BITMASK(BCH_GROUP_DELETED,                struct bch_disk_group, flags[0], 0,  1)
+LE64_BITMASK(BCH_GROUP_DATA_ALLOWED,   struct bch_disk_group, flags[0], 1,  6)
+LE64_BITMASK(BCH_GROUP_PARENT,         struct bch_disk_group, flags[0], 6, 24)
+
+struct bch_sb_field_disk_groups {
+       struct bch_sb_field     field;
+       struct bch_disk_group   entries[0];
+} __packed __aligned(8);
+
+/* BCH_SB_FIELD_counters */
+
+#define BCH_PERSISTENT_COUNTERS()                              \
+       x(io_read,                                      0)      \
+       x(io_write,                                     1)      \
+       x(io_move,                                      2)      \
+       x(bucket_invalidate,                            3)      \
+       x(bucket_discard,                               4)      \
+       x(bucket_alloc,                                 5)      \
+       x(bucket_alloc_fail,                            6)      \
+       x(btree_cache_scan,                             7)      \
+       x(btree_cache_reap,                             8)      \
+       x(btree_cache_cannibalize,                      9)      \
+       x(btree_cache_cannibalize_lock,                 10)     \
+       x(btree_cache_cannibalize_lock_fail,            11)     \
+       x(btree_cache_cannibalize_unlock,               12)     \
+       x(btree_node_write,                             13)     \
+       x(btree_node_read,                              14)     \
+       x(btree_node_compact,                           15)     \
+       x(btree_node_merge,                             16)     \
+       x(btree_node_split,                             17)     \
+       x(btree_node_rewrite,                           18)     \
+       x(btree_node_alloc,                             19)     \
+       x(btree_node_free,                              20)     \
+       x(btree_node_set_root,                          21)     \
+       x(btree_path_relock_fail,                       22)     \
+       x(btree_path_upgrade_fail,                      23)     \
+       x(btree_reserve_get_fail,                       24)     \
+       x(journal_entry_full,                           25)     \
+       x(journal_full,                                 26)     \
+       x(journal_reclaim_finish,                       27)     \
+       x(journal_reclaim_start,                        28)     \
+       x(journal_write,                                29)     \
+       x(read_promote,                                 30)     \
+       x(read_bounce,                                  31)     \
+       x(read_split,                                   33)     \
+       x(read_retry,                                   32)     \
+       x(read_reuse_race,                              34)     \
+       x(move_extent_read,                             35)     \
+       x(move_extent_write,                            36)     \
+       x(move_extent_finish,                           37)     \
+       x(move_extent_fail,                             38)     \
+       x(move_extent_alloc_mem_fail,                   39)     \
+       x(copygc,                                       40)     \
+       x(copygc_wait,                                  41)     \
+       x(gc_gens_end,                                  42)     \
+       x(gc_gens_start,                                43)     \
+       x(trans_blocked_journal_reclaim,                44)     \
+       x(trans_restart_btree_node_reused,              45)     \
+       x(trans_restart_btree_node_split,               46)     \
+       x(trans_restart_fault_inject,                   47)     \
+       x(trans_restart_iter_upgrade,                   48)     \
+       x(trans_restart_journal_preres_get,             49)     \
+       x(trans_restart_journal_reclaim,                50)     \
+       x(trans_restart_journal_res_get,                51)     \
+       x(trans_restart_key_cache_key_realloced,        52)     \
+       x(trans_restart_key_cache_raced,                53)     \
+       x(trans_restart_mark_replicas,                  54)     \
+       x(trans_restart_mem_realloced,                  55)     \
+       x(trans_restart_memory_allocation_failure,      56)     \
+       x(trans_restart_relock,                         57)     \
+       x(trans_restart_relock_after_fill,              58)     \
+       x(trans_restart_relock_key_cache_fill,          59)     \
+       x(trans_restart_relock_next_node,               60)     \
+       x(trans_restart_relock_parent_for_fill,         61)     \
+       x(trans_restart_relock_path,                    62)     \
+       x(trans_restart_relock_path_intent,             63)     \
+       x(trans_restart_too_many_iters,                 64)     \
+       x(trans_restart_traverse,                       65)     \
+       x(trans_restart_upgrade,                        66)     \
+       x(trans_restart_would_deadlock,                 67)     \
+       x(trans_restart_would_deadlock_write,           68)     \
+       x(trans_restart_injected,                       69)     \
+       x(trans_restart_key_cache_upgrade,              70)     \
+       x(trans_traverse_all,                           71)     \
+       x(transaction_commit,                           72)     \
+       x(write_super,                                  73)     \
+       x(trans_restart_would_deadlock_recursion_limit, 74)     \
+       x(trans_restart_write_buffer_flush,             75)     \
+       x(trans_restart_split_race,                     76)
+
+enum bch_persistent_counters {
+#define x(t, n, ...) BCH_COUNTER_##t,
+       BCH_PERSISTENT_COUNTERS()
+#undef x
+       BCH_COUNTER_NR
+};
+
+struct bch_sb_field_counters {
+       struct bch_sb_field     field;
+       __le64                  d[0];
 };
 
+/*
+ * On clean shutdown, store btree roots and current journal sequence number in
+ * the superblock:
+ */
+struct jset_entry {
+       __le16                  u64s;
+       __u8                    btree_id;
+       __u8                    level;
+       __u8                    type; /* designates what this jset holds */
+       __u8                    pad[3];
+
+       union {
+               struct bkey_i   start[0];
+               __u64           _data[0];
+       };
+};
+
+struct bch_sb_field_clean {
+       struct bch_sb_field     field;
+
+       __le32                  flags;
+       __le16                  _read_clock; /* no longer used */
+       __le16                  _write_clock;
+       __le64                  journal_seq;
+
+       union {
+               struct jset_entry start[0];
+               __u64           _data[0];
+       };
+};
+
+struct journal_seq_blacklist_entry {
+       __le64                  start;
+       __le64                  end;
+};
+
+struct bch_sb_field_journal_seq_blacklist {
+       struct bch_sb_field     field;
+
+       union {
+               struct journal_seq_blacklist_entry start[0];
+               __u64           _data[0];
+       };
+};
+
+/* Superblock: */
+
+/*
+ * New versioning scheme:
+ * One common version number for all on disk data structures - superblock, btree
+ * nodes, journal entries
+ */
+#define BCH_JSET_VERSION_OLD                   2
+#define BCH_BSET_VERSION_OLD                   3
+
+#define BCH_METADATA_VERSIONS()                                \
+       x(bkey_renumber,                10)             \
+       x(inode_btree_change,           11)             \
+       x(snapshot,                     12)             \
+       x(inode_backpointers,           13)             \
+       x(btree_ptr_sectors_written,    14)             \
+       x(snapshot_2,                   15)             \
+       x(reflink_p_fix,                16)             \
+       x(subvol_dirent,                17)             \
+       x(inode_v2,                     18)             \
+       x(freespace,                    19)             \
+       x(alloc_v4,                     20)             \
+       x(new_data_types,               21)             \
+       x(backpointers,                 22)             \
+       x(inode_v3,                     23)             \
+       x(unwritten_extents,            24)             \
+       x(bucket_gens,                  25)             \
+       x(lru_v2,                       26)             \
+       x(fragmentation_lru,            27)             \
+       x(no_bps_in_alloc_keys,         28)             \
+       x(snapshot_trees,               29)
+
+enum bcachefs_metadata_version {
+       bcachefs_metadata_version_min = 9,
+#define x(t, n)        bcachefs_metadata_version_##t = n,
+       BCH_METADATA_VERSIONS()
+#undef x
+       bcachefs_metadata_version_max
+};
+
+static const unsigned bcachefs_metadata_required_upgrade_below = bcachefs_metadata_version_snapshot_trees;
+
+#define bcachefs_metadata_version_current      (bcachefs_metadata_version_max - 1)
+
+#define BCH_SB_SECTOR                  8
+#define BCH_SB_MEMBERS_MAX             64 /* XXX kill */
+
+struct bch_sb_layout {
+       uuid_le                 magic;  /* bcachefs superblock UUID */
+       __u8                    layout_type;
+       __u8                    sb_max_size_bits; /* base 2 of 512 byte sectors */
+       __u8                    nr_superblocks;
+       __u8                    pad[5];
+       __le64                  sb_offset[61];
+} __packed __aligned(8);
+
+#define BCH_SB_LAYOUT_SECTOR   7
+
 /*
  * @offset     - sector where this sb was written
  * @version    - on disk format version
- * @magic      - identifies as a bcachefs superblock (BCACHE_MAGIC)
+ * @version_min        - Oldest metadata version this filesystem contains; so we can
+ *               safely drop compatibility code and refuse to mount filesystems
+ *               we'd need it for
+ * @magic      - identifies as a bcachefs superblock (BCHFS_MAGIC)
  * @seq                - incremented each time superblock is written
  * @uuid       - used for generating various magic numbers and identifying
  *                member devices, never changes
@@ -906,7 +1624,9 @@ struct bch_sb_field_replicas {
  */
 struct bch_sb {
        struct bch_csum         csum;
-       __le64                  version;
+       __le16                  version;
+       __le16                  version_min;
+       __le16                  pad[2];
        uuid_le                 magic;
        uuid_le                 uuid;
        uuid_le                 user_uuid;
@@ -933,7 +1653,7 @@ struct bch_sb {
                struct bch_sb_field start[0];
                __le64          _data[0];
        };
-} __attribute__((packed, aligned(8)));
+} __packed __aligned(8);
 
 /*
  * Flags:
@@ -966,6 +1686,14 @@ LE64_BITMASK(BCH_SB_META_REPLICAS_WANT,   struct bch_sb, flags[0], 48, 52);
 LE64_BITMASK(BCH_SB_DATA_REPLICAS_WANT,        struct bch_sb, flags[0], 52, 56);
 
 LE64_BITMASK(BCH_SB_POSIX_ACL,         struct bch_sb, flags[0], 56, 57);
+LE64_BITMASK(BCH_SB_USRQUOTA,          struct bch_sb, flags[0], 57, 58);
+LE64_BITMASK(BCH_SB_GRPQUOTA,          struct bch_sb, flags[0], 58, 59);
+LE64_BITMASK(BCH_SB_PRJQUOTA,          struct bch_sb, flags[0], 59, 60);
+
+LE64_BITMASK(BCH_SB_HAS_ERRORS,                struct bch_sb, flags[0], 60, 61);
+LE64_BITMASK(BCH_SB_HAS_TOPOLOGY_ERRORS,struct bch_sb, flags[0], 61, 62);
+
+LE64_BITMASK(BCH_SB_BIG_ENDIAN,                struct bch_sb, flags[0], 62, 63);
 
 LE64_BITMASK(BCH_SB_STR_HASH_TYPE,     struct bch_sb, flags[1],  0,  4);
 LE64_BITMASK(BCH_SB_COMPRESSION_TYPE,  struct bch_sb, flags[1],  4,  8);
@@ -984,56 +1712,210 @@ LE64_BITMASK(BCH_SB_ENCODED_EXTENT_MAX_BITS,
 LE64_BITMASK(BCH_SB_META_REPLICAS_REQ, struct bch_sb, flags[1], 20, 24);
 LE64_BITMASK(BCH_SB_DATA_REPLICAS_REQ, struct bch_sb, flags[1], 24, 28);
 
-/* Features: */
-enum bch_sb_features {
-       BCH_FEATURE_LZ4                 = 0,
-       BCH_FEATURE_GZIP                = 1,
+LE64_BITMASK(BCH_SB_PROMOTE_TARGET,    struct bch_sb, flags[1], 28, 40);
+LE64_BITMASK(BCH_SB_FOREGROUND_TARGET, struct bch_sb, flags[1], 40, 52);
+LE64_BITMASK(BCH_SB_BACKGROUND_TARGET, struct bch_sb, flags[1], 52, 64);
+
+LE64_BITMASK(BCH_SB_BACKGROUND_COMPRESSION_TYPE,
+                                       struct bch_sb, flags[2],  0,  4);
+LE64_BITMASK(BCH_SB_GC_RESERVE_BYTES,  struct bch_sb, flags[2],  4, 64);
+
+LE64_BITMASK(BCH_SB_ERASURE_CODE,      struct bch_sb, flags[3],  0, 16);
+LE64_BITMASK(BCH_SB_METADATA_TARGET,   struct bch_sb, flags[3], 16, 28);
+LE64_BITMASK(BCH_SB_SHARD_INUMS,       struct bch_sb, flags[3], 28, 29);
+LE64_BITMASK(BCH_SB_INODES_USE_KEY_CACHE,struct bch_sb, flags[3], 29, 30);
+LE64_BITMASK(BCH_SB_JOURNAL_FLUSH_DELAY,struct bch_sb, flags[3], 30, 62);
+LE64_BITMASK(BCH_SB_JOURNAL_FLUSH_DISABLED,struct bch_sb, flags[3], 62, 63);
+LE64_BITMASK(BCH_SB_JOURNAL_RECLAIM_DELAY,struct bch_sb, flags[4], 0, 32);
+LE64_BITMASK(BCH_SB_JOURNAL_TRANSACTION_NAMES,struct bch_sb, flags[4], 32, 33);
+LE64_BITMASK(BCH_SB_NOCOW,             struct bch_sb, flags[4], 33, 34);
+LE64_BITMASK(BCH_SB_WRITE_BUFFER_SIZE, struct bch_sb, flags[4], 34, 54);
+
+/*
+ * Features:
+ *
+ * journal_seq_blacklist_v3:   gates BCH_SB_FIELD_journal_seq_blacklist
+ * reflink:                    gates KEY_TYPE_reflink
+ * inline_data:                        gates KEY_TYPE_inline_data
+ * new_siphash:                        gates BCH_STR_HASH_siphash
+ * new_extent_overwrite:       gates BTREE_NODE_NEW_EXTENT_OVERWRITE
+ */
+#define BCH_SB_FEATURES()                      \
+       x(lz4,                          0)      \
+       x(gzip,                         1)      \
+       x(zstd,                         2)      \
+       x(atomic_nlink,                 3)      \
+       x(ec,                           4)      \
+       x(journal_seq_blacklist_v3,     5)      \
+       x(reflink,                      6)      \
+       x(new_siphash,                  7)      \
+       x(inline_data,                  8)      \
+       x(new_extent_overwrite,         9)      \
+       x(incompressible,               10)     \
+       x(btree_ptr_v2,                 11)     \
+       x(extents_above_btree_updates,  12)     \
+       x(btree_updates_journalled,     13)     \
+       x(reflink_inline_data,          14)     \
+       x(new_varint,                   15)     \
+       x(journal_no_flush,             16)     \
+       x(alloc_v2,                     17)     \
+       x(extents_across_btree_nodes,   18)
+
+#define BCH_SB_FEATURES_ALWAYS                         \
+       ((1ULL << BCH_FEATURE_new_extent_overwrite)|    \
+        (1ULL << BCH_FEATURE_extents_above_btree_updates)|\
+        (1ULL << BCH_FEATURE_btree_updates_journalled)|\
+        (1ULL << BCH_FEATURE_alloc_v2)|\
+        (1ULL << BCH_FEATURE_extents_across_btree_nodes))
+
+#define BCH_SB_FEATURES_ALL                            \
+       (BCH_SB_FEATURES_ALWAYS|                        \
+        (1ULL << BCH_FEATURE_new_siphash)|             \
+        (1ULL << BCH_FEATURE_btree_ptr_v2)|            \
+        (1ULL << BCH_FEATURE_new_varint)|              \
+        (1ULL << BCH_FEATURE_journal_no_flush))
+
+enum bch_sb_feature {
+#define x(f, n) BCH_FEATURE_##f,
+       BCH_SB_FEATURES()
+#undef x
+       BCH_FEATURE_NR,
+};
+
+#define BCH_SB_COMPAT()                                        \
+       x(alloc_info,                           0)      \
+       x(alloc_metadata,                       1)      \
+       x(extents_above_btree_updates_done,     2)      \
+       x(bformat_overflow_done,                3)
+
+enum bch_sb_compat {
+#define x(f, n) BCH_COMPAT_##f,
+       BCH_SB_COMPAT()
+#undef x
+       BCH_COMPAT_NR,
 };
 
 /* options: */
 
 #define BCH_REPLICAS_MAX               4U
 
-#if 0
-#define BCH_ERROR_ACTIONS()                                    \
-       x(BCH_ON_ERROR_CONTINUE,        0, "continue")          \
-       x(BCH_ON_ERROR_RO,              1, "remount-ro")        \
-       x(BCH_ON_ERROR_PANIC,           2, "panic")             \
-       x(BCH_NR_ERROR_ACTIONS,         3, NULL)
+#define BCH_BKEY_PTRS_MAX              16U
+
+#define BCH_ERROR_ACTIONS()            \
+       x(continue,             0)      \
+       x(ro,                   1)      \
+       x(panic,                2)
 
 enum bch_error_actions {
-#define x(_opt, _nr, _str)     _opt = _nr,
+#define x(t, n) BCH_ON_ERROR_##t = n,
        BCH_ERROR_ACTIONS()
 #undef x
+       BCH_ON_ERROR_NR
 };
-#endif
 
-enum bch_error_actions {
-       BCH_ON_ERROR_CONTINUE           = 0,
-       BCH_ON_ERROR_RO                 = 1,
-       BCH_ON_ERROR_PANIC              = 2,
-       BCH_NR_ERROR_ACTIONS            = 3,
+#define BCH_STR_HASH_TYPES()           \
+       x(crc32c,               0)      \
+       x(crc64,                1)      \
+       x(siphash_old,          2)      \
+       x(siphash,              3)
+
+enum bch_str_hash_type {
+#define x(t, n) BCH_STR_HASH_##t = n,
+       BCH_STR_HASH_TYPES()
+#undef x
+       BCH_STR_HASH_NR
+};
+
+#define BCH_STR_HASH_OPTS()            \
+       x(crc32c,               0)      \
+       x(crc64,                1)      \
+       x(siphash,              2)
+
+enum bch_str_hash_opts {
+#define x(t, n) BCH_STR_HASH_OPT_##t = n,
+       BCH_STR_HASH_OPTS()
+#undef x
+       BCH_STR_HASH_OPT_NR
+};
+
+#define BCH_CSUM_TYPES()                       \
+       x(none,                         0)      \
+       x(crc32c_nonzero,               1)      \
+       x(crc64_nonzero,                2)      \
+       x(chacha20_poly1305_80,         3)      \
+       x(chacha20_poly1305_128,        4)      \
+       x(crc32c,                       5)      \
+       x(crc64,                        6)      \
+       x(xxhash,                       7)
+
+enum bch_csum_type {
+#define x(t, n) BCH_CSUM_##t = n,
+       BCH_CSUM_TYPES()
+#undef x
+       BCH_CSUM_NR
 };
 
+static const unsigned bch_crc_bytes[] = {
+       [BCH_CSUM_none]                         = 0,
+       [BCH_CSUM_crc32c_nonzero]               = 4,
+       [BCH_CSUM_crc32c]                       = 4,
+       [BCH_CSUM_crc64_nonzero]                = 8,
+       [BCH_CSUM_crc64]                        = 8,
+       [BCH_CSUM_xxhash]                       = 8,
+       [BCH_CSUM_chacha20_poly1305_80]         = 10,
+       [BCH_CSUM_chacha20_poly1305_128]        = 16,
+};
+
+static inline _Bool bch2_csum_type_is_encryption(enum bch_csum_type type)
+{
+       switch (type) {
+       case BCH_CSUM_chacha20_poly1305_80:
+       case BCH_CSUM_chacha20_poly1305_128:
+               return true;
+       default:
+               return false;
+       }
+}
+
+#define BCH_CSUM_OPTS()                        \
+       x(none,                 0)      \
+       x(crc32c,               1)      \
+       x(crc64,                2)      \
+       x(xxhash,               3)
+
 enum bch_csum_opts {
-       BCH_CSUM_OPT_NONE               = 0,
-       BCH_CSUM_OPT_CRC32C             = 1,
-       BCH_CSUM_OPT_CRC64              = 2,
-       BCH_CSUM_OPT_NR                 = 3,
+#define x(t, n) BCH_CSUM_OPT_##t = n,
+       BCH_CSUM_OPTS()
+#undef x
+       BCH_CSUM_OPT_NR
 };
 
-enum bch_str_hash_opts {
-       BCH_STR_HASH_CRC32C             = 0,
-       BCH_STR_HASH_CRC64              = 1,
-       BCH_STR_HASH_SIPHASH            = 2,
-       BCH_STR_HASH_NR                 = 3,
+#define BCH_COMPRESSION_TYPES()                \
+       x(none,                 0)      \
+       x(lz4_old,              1)      \
+       x(gzip,                 2)      \
+       x(lz4,                  3)      \
+       x(zstd,                 4)      \
+       x(incompressible,       5)
+
+enum bch_compression_type {
+#define x(t, n) BCH_COMPRESSION_TYPE_##t = n,
+       BCH_COMPRESSION_TYPES()
+#undef x
+       BCH_COMPRESSION_TYPE_NR
 };
 
+#define BCH_COMPRESSION_OPTS()         \
+       x(none,         0)              \
+       x(lz4,          1)              \
+       x(gzip,         2)              \
+       x(zstd,         3)
+
 enum bch_compression_opts {
-       BCH_COMPRESSION_OPT_NONE        = 0,
-       BCH_COMPRESSION_OPT_LZ4         = 1,
-       BCH_COMPRESSION_OPT_GZIP        = 2,
-       BCH_COMPRESSION_OPT_NR          = 3,
+#define x(t, n) BCH_COMPRESSION_OPT_##t = n,
+       BCH_COMPRESSION_OPTS()
+#undef x
+       BCH_COMPRESSION_OPT_NR
 };
 
 /*
@@ -1046,6 +1928,9 @@ enum bch_compression_opts {
 #define BCACHE_MAGIC                                                   \
        UUID_LE(0xf67385c6, 0x1a4e, 0xca45,                             \
                0x82, 0x65, 0xf5, 0x7f, 0x48, 0xba, 0x6d, 0x81)
+#define BCHFS_MAGIC                                                    \
+       UUID_LE(0xf67385c6, 0xce66, 0xa990,                             \
+               0xd9, 0x6a, 0x60, 0xcf, 0x80, 0x3d, 0xf7, 0xef)
 
 #define BCACHEFS_STATFS_MAGIC          0xca451a4e
 
@@ -1055,6 +1940,7 @@ enum bch_compression_opts {
 static inline __le64 __bch2_sb_magic(struct bch_sb *sb)
 {
        __le64 ret;
+
        memcpy(&ret, &sb->uuid, sizeof(ret));
        return ret;
 }
@@ -1071,44 +1957,107 @@ static inline __u64 __bset_magic(struct bch_sb *sb)
 
 /* Journal */
 
-#define BCACHE_JSET_VERSION_UUIDv1     1
-#define BCACHE_JSET_VERSION_UUID       1       /* Always latest UUID format */
-#define BCACHE_JSET_VERSION_JKEYS      2
-#define BCACHE_JSET_VERSION            2
+#define JSET_KEYS_U64s (sizeof(struct jset_entry) / sizeof(__u64))
 
-struct jset_entry {
-       __le16                  u64s;
-       __u8                    btree_id;
-       __u8                    level;
-       __u8                    type; /* designates what this jset holds */
-       __u8                    pad[3];
+#define BCH_JSET_ENTRY_TYPES()                 \
+       x(btree_keys,           0)              \
+       x(btree_root,           1)              \
+       x(prio_ptrs,            2)              \
+       x(blacklist,            3)              \
+       x(blacklist_v2,         4)              \
+       x(usage,                5)              \
+       x(data_usage,           6)              \
+       x(clock,                7)              \
+       x(dev_usage,            8)              \
+       x(log,                  9)              \
+       x(overwrite,            10)
 
-       union {
-               struct bkey_i   start[0];
-               __u64           _data[0];
-       };
+enum {
+#define x(f, nr)       BCH_JSET_ENTRY_##f      = nr,
+       BCH_JSET_ENTRY_TYPES()
+#undef x
+       BCH_JSET_ENTRY_NR
 };
 
-#define JSET_KEYS_U64s (sizeof(struct jset_entry) / sizeof(__u64))
+/*
+ * Journal sequence numbers can be blacklisted: bsets record the max sequence
+ * number of all the journal entries they contain updates for, so that on
+ * recovery we can ignore those bsets that contain index updates newer that what
+ * made it into the journal.
+ *
+ * This means that we can't reuse that journal_seq - we have to skip it, and
+ * then record that we skipped it so that the next time we crash and recover we
+ * don't think there was a missing journal entry.
+ */
+struct jset_entry_blacklist {
+       struct jset_entry       entry;
+       __le64                  seq;
+};
 
-enum {
-       JOURNAL_ENTRY_BTREE_KEYS                = 0,
-       JOURNAL_ENTRY_BTREE_ROOT                = 1,
-       JOURNAL_ENTRY_PRIO_PTRS                 = 2, /* Obsolete */
+struct jset_entry_blacklist_v2 {
+       struct jset_entry       entry;
+       __le64                  start;
+       __le64                  end;
+};
 
-       /*
-        * Journal sequence numbers can be blacklisted: bsets record the max
-        * sequence number of all the journal entries they contain updates for,
-        * so that on recovery we can ignore those bsets that contain index
-        * updates newer that what made it into the journal.
-        *
-        * This means that we can't reuse that journal_seq - we have to skip it,
-        * and then record that we skipped it so that the next time we crash and
-        * recover we don't think there was a missing journal entry.
-        */
-       JOURNAL_ENTRY_JOURNAL_SEQ_BLACKLISTED   = 3,
+#define BCH_FS_USAGE_TYPES()                   \
+       x(reserved,             0)              \
+       x(inodes,               1)              \
+       x(key_version,          2)
+
+enum {
+#define x(f, nr)       BCH_FS_USAGE_##f        = nr,
+       BCH_FS_USAGE_TYPES()
+#undef x
+       BCH_FS_USAGE_NR
 };
 
+struct jset_entry_usage {
+       struct jset_entry       entry;
+       __le64                  v;
+} __packed;
+
+struct jset_entry_data_usage {
+       struct jset_entry       entry;
+       __le64                  v;
+       struct bch_replicas_entry r;
+} __packed;
+
+struct jset_entry_clock {
+       struct jset_entry       entry;
+       __u8                    rw;
+       __u8                    pad[7];
+       __le64                  time;
+} __packed;
+
+struct jset_entry_dev_usage_type {
+       __le64                  buckets;
+       __le64                  sectors;
+       __le64                  fragmented;
+} __packed;
+
+struct jset_entry_dev_usage {
+       struct jset_entry       entry;
+       __le32                  dev;
+       __u32                   pad;
+
+       __le64                  buckets_ec;
+       __le64                  _buckets_unavailable; /* No longer used */
+
+       struct jset_entry_dev_usage_type d[];
+} __packed;
+
+static inline unsigned jset_entry_dev_usage_nr_types(struct jset_entry_dev_usage *u)
+{
+       return (vstruct_bytes(&u->entry) - sizeof(struct jset_entry_dev_usage)) /
+               sizeof(struct jset_entry_dev_usage_type);
+}
+
+struct jset_entry_log {
+       struct jset_entry       entry;
+       u8                      d[];
+} __packed;
+
 /*
  * On disk format for a journal entry:
  * seq is monotonically increasing; every journal entry has its own unique
@@ -1131,8 +2080,8 @@ struct jset {
 
        __u8                    encrypted_start[0];
 
-       __le16                  read_clock;
-       __le16                  write_clock;
+       __le16                  _read_clock; /* no longer used */
+       __le16                  _write_clock;
 
        /* Sequence number of oldest dirty journal entry */
        __le64                  last_seq;
@@ -1142,42 +2091,45 @@ struct jset {
                struct jset_entry start[0];
                __u64           _data[0];
        };
-} __attribute__((packed, aligned(8)));
+} __packed __aligned(8);
 
 LE32_BITMASK(JSET_CSUM_TYPE,   struct jset, flags, 0, 4);
 LE32_BITMASK(JSET_BIG_ENDIAN,  struct jset, flags, 4, 5);
+LE32_BITMASK(JSET_NO_FLUSH,    struct jset, flags, 5, 6);
 
-#define BCH_JOURNAL_BUCKETS_MIN                20
+#define BCH_JOURNAL_BUCKETS_MIN                8
 
 /* Btree: */
 
-#define DEFINE_BCH_BTREE_IDS()                                 \
-       DEF_BTREE_ID(EXTENTS,   0, "extents")                   \
-       DEF_BTREE_ID(INODES,    1, "inodes")                    \
-       DEF_BTREE_ID(DIRENTS,   2, "dirents")                   \
-       DEF_BTREE_ID(XATTRS,    3, "xattrs")                    \
-       DEF_BTREE_ID(ALLOC,     4, "alloc")
-
-#define DEF_BTREE_ID(kwd, val, name) BTREE_ID_##kwd = val,
+#define BCH_BTREE_IDS()                                \
+       x(extents,              0)              \
+       x(inodes,               1)              \
+       x(dirents,              2)              \
+       x(xattrs,               3)              \
+       x(alloc,                4)              \
+       x(quotas,               5)              \
+       x(stripes,              6)              \
+       x(reflink,              7)              \
+       x(subvolumes,           8)              \
+       x(snapshots,            9)              \
+       x(lru,                  10)             \
+       x(freespace,            11)             \
+       x(need_discard,         12)             \
+       x(backpointers,         13)             \
+       x(bucket_gens,          14)             \
+       x(snapshot_trees,       15)
 
 enum btree_id {
-       DEFINE_BCH_BTREE_IDS()
+#define x(kwd, val) BTREE_ID_##kwd = val,
+       BCH_BTREE_IDS()
+#undef x
        BTREE_ID_NR
 };
 
-#undef DEF_BTREE_ID
-
 #define BTREE_MAX_DEPTH                4U
 
 /* Btree nodes */
 
-/* Version 1: Seed pointer into btree node checksum
- */
-#define BCACHE_BSET_CSUM               1
-#define BCACHE_BSET_KEY_v1             2
-#define BCACHE_BSET_JOURNAL_SEQ                3
-#define BCACHE_BSET_VERSION            3
-
 /*
  * Btree nodes
  *
@@ -1204,7 +2156,7 @@ struct bset {
                struct bkey_packed start[0];
                __u64           _data[0];
        };
-} __attribute__((packed, aligned(8)));
+} __packed __aligned(8);
 
 LE32_BITMASK(BSET_CSUM_TYPE,   struct bset, flags, 0, 4);
 
@@ -1212,6 +2164,9 @@ LE32_BITMASK(BSET_BIG_ENDIAN,     struct bset, flags, 4, 5);
 LE32_BITMASK(BSET_SEPARATE_WHITEOUTS,
                                struct bset, flags, 5, 6);
 
+/* Sector offset within the btree node: */
+LE32_BITMASK(BSET_OFFSET,      struct bset, flags, 16, 32);
+
 struct btree_node {
        struct bch_csum         csum;
        __le64                  magic;
@@ -1222,7 +2177,7 @@ struct btree_node {
        /* Closed interval: */
        struct bpos             min_key;
        struct bpos             max_key;
-       struct bch_extent_ptr   ptr;
+       struct bch_extent_ptr   _ptr; /* not used anymore */
        struct bkey_format      format;
 
        union {
@@ -1234,10 +2189,14 @@ struct btree_node {
 
        };
        };
-} __attribute__((packed, aligned(8)));
+} __packed __aligned(8);
 
-LE64_BITMASK(BTREE_NODE_ID,    struct btree_node, flags, 0, 4);
-LE64_BITMASK(BTREE_NODE_LEVEL, struct btree_node, flags, 4, 8);
+LE64_BITMASK(BTREE_NODE_ID,    struct btree_node, flags,  0,  4);
+LE64_BITMASK(BTREE_NODE_LEVEL, struct btree_node, flags,  4,  8);
+LE64_BITMASK(BTREE_NODE_NEW_EXTENT_OVERWRITE,
+                               struct btree_node, flags,  8,  9);
+/* 9-32 unused */
+LE64_BITMASK(BTREE_NODE_SEQ,   struct btree_node, flags, 32, 64);
 
 struct btree_node_entry {
        struct bch_csum         csum;
@@ -1251,35 +2210,6 @@ struct btree_node_entry {
 
        };
        };
-} __attribute__((packed, aligned(8)));
-
-/* Obsolete: */
-
-struct prio_set {
-       struct bch_csum         csum;
-
-       __le64                  magic;
-       __le32                  nonce[3];
-       __le16                  version;
-       __le16                  flags;
-
-       __u8                    encrypted_start[0];
-
-       __le64                  next_bucket;
-
-       struct bucket_disk {
-               __le16          prio[2];
-               __u8            gen;
-       } __attribute__((packed)) data[];
-} __attribute__((packed, aligned(8)));
-
-LE32_BITMASK(PSET_CSUM_TYPE,   struct prio_set, flags, 0, 4);
-
-#define PSET_MAGIC             __cpu_to_le64(0x6750e15f87337f91ULL)
-
-static inline __u64 __pset_magic(struct bch_sb *sb)
-{
-       return __le64_to_cpu(__bch2_sb_magic(sb) ^ PSET_MAGIC);
-}
+} __packed __aligned(8);
 
 #endif /* _BCACHEFS_FORMAT_H */