bcachefs: KEY_TYPE_alloc_v2

This introduces a new version of KEY_TYPE_alloc, which uses the new
varint encoding introduced for inodes. This means we'll eventually be
able to support much larger bucket sizes (for SMR devices), and the
read/write time fields are expanded to 64 bits - which will be used in
the next patch to get rid of the periodic rescaling of those fields.

Also, for buckets that are members of erasure coded stripes, this adds
persistent fields for the index of the stripe they're members of and the
stripe redundancy. This is part of work to get rid of having to scan and
read into memory the alloc and stripes btrees at mount time.

Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

1 files changed, 40 insertions, 8 deletions

diff --git a/fs/bcachefs/alloc_background.h b/fs/bcachefs/alloc_background.h
index f60fcebff2ce..6fededcd9f86 100644
--- a/fs/bcachefs/alloc_background.h
+++ b/fs/bcachefs/alloc_background.h
@@ -7,12 +7,33 @@
 #include "debug.h"
 
 struct bkey_alloc_unpacked {
+	u64		bucket;
+	u8		dev;
 	u8		gen;
+	u8		oldest_gen;
+	u8		data_type;
 #define x(_name, _bits)	u##_bits _name;
-	BCH_ALLOC_FIELDS()
+	BCH_ALLOC_FIELDS_V2()
 #undef  x
 };
 
+struct bkey_alloc_buf {
+	struct bkey_i	k;
+
+	union {
+	struct {
+#define x(_name,  _bits)		+ _bits / 8
+	u8		_pad[8 + BCH_ALLOC_FIELDS_V1()];
+#undef  x
+	} _v1;
+	struct {
+#define x(_name,  _bits)		+ 8 + _bits / 8
+	u8		_pad[8 + BCH_ALLOC_FIELDS_V2()];
+#undef  x
+	} _v2;
+	};
+} __attribute__((packed, aligned(8)));
+
 /* How out of date a pointer gen is allowed to be: */
 #define BUCKET_GC_GEN_MAX	96U
 
@@ -20,23 +41,28 @@ struct bkey_alloc_unpacked {
 static inline bool bkey_alloc_unpacked_cmp(struct bkey_alloc_unpacked l,
 					   struct bkey_alloc_unpacked r)
 {
-	return l.gen != r.gen
-#define x(_name, _bits)	|| l._name != r._name
-	BCH_ALLOC_FIELDS()
+	return  l.gen != r.gen			||
+		l.oldest_gen != r.oldest_gen	||
+		l.data_type != r.data_type
+#define x(_name, ...)	|| l._name != r._name
+	BCH_ALLOC_FIELDS_V2()
 #undef  x
 	;
 }
 
 struct bkey_alloc_unpacked bch2_alloc_unpack(struct bkey_s_c);
-void bch2_alloc_pack(struct bkey_i_alloc *,
+void bch2_alloc_pack(struct bch_fs *, struct bkey_alloc_buf *,
 		     const struct bkey_alloc_unpacked);
 
 int bch2_bucket_io_time_reset(struct btree_trans *, unsigned, size_t, int);
 
 static inline struct bkey_alloc_unpacked
-alloc_mem_to_key(struct bucket *g, struct bucket_mark m)
+alloc_mem_to_key(struct btree_iter *iter,
+		 struct bucket *g, struct bucket_mark m)
 {
 	return (struct bkey_alloc_unpacked) {
+		.dev		= iter->pos.inode,
+		.bucket		= iter->pos.offset,
 		.gen		= m.gen,
 		.oldest_gen	= g->oldest_gen,
 		.data_type	= m.data_type,
@@ -49,11 +75,17 @@ alloc_mem_to_key(struct bucket *g, struct bucket_mark m)
 
 #define ALLOC_SCAN_BATCH(ca)		max_t(size_t, 1, (ca)->mi.nbuckets >> 9)
 
-const char *bch2_alloc_invalid(const struct bch_fs *, struct bkey_s_c);
+const char *bch2_alloc_v1_invalid(const struct bch_fs *, struct bkey_s_c);
+const char *bch2_alloc_v2_invalid(const struct bch_fs *, struct bkey_s_c);
 void bch2_alloc_to_text(struct printbuf *, struct bch_fs *, struct bkey_s_c);
 
 #define bch2_bkey_ops_alloc (struct bkey_ops) {		\
-	.key_invalid	= bch2_alloc_invalid,		\
+	.key_invalid	= bch2_alloc_v1_invalid,	\
+	.val_to_text	= bch2_alloc_to_text,		\
+}
+
+#define bch2_bkey_ops_alloc_v2 (struct bkey_ops) {	\
+	.key_invalid	= bch2_alloc_v2_invalid,	\
 	.val_to_text	= bch2_alloc_to_text,		\
 }