bcachefs: Initial commit

Initially forked from drivers/md/bcache, bcachefs is a new copy-on-write
filesystem with every feature you could possibly want.

Website: https://bcachefs.org

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

1 files changed, 90 insertions, 0 deletions

diff --git a/fs/bcachefs/alloc_types.h b/fs/bcachefs/alloc_types.h
new file mode 100644
index 000000000000..035c50052167
--- /dev/null
+++ b/fs/bcachefs/alloc_types.h
@@ -0,0 +1,90 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _BCACHEFS_ALLOC_TYPES_H
+#define _BCACHEFS_ALLOC_TYPES_H
+
+#include <linux/mutex.h>
+#include <linux/spinlock.h>
+
+#include "clock_types.h"
+#include "fifo.h"
+
+/* There's two of these clocks, one for reads and one for writes: */
+struct bucket_clock {
+	/*
+	 * "now" in (read/write) IO time - incremented whenever we do X amount
+	 * of reads or writes.
+	 *
+	 * Goes with the bucket read/write prios: when we read or write to a
+	 * bucket we reset the bucket's prio to the current hand; thus hand -
+	 * prio = time since bucket was last read/written.
+	 *
+	 * The units are some amount (bytes/sectors) of data read/written, and
+	 * the units can change on the fly if we need to rescale to fit
+	 * everything in a u16 - your only guarantee is that the units are
+	 * consistent.
+	 */
+	u16			hand;
+	u16			max_last_io;
+
+	int			rw;
+
+	struct io_timer		rescale;
+	struct mutex		lock;
+};
+
+/* There is one reserve for each type of btree, one for prios and gens
+ * and one for moving GC */
+enum alloc_reserve {
+	RESERVE_ALLOC		= -1,
+	RESERVE_BTREE		= 0,
+	RESERVE_MOVINGGC	= 1,
+	RESERVE_NONE		= 2,
+	RESERVE_NR		= 3,
+};
+
+typedef FIFO(long)	alloc_fifo;
+
+/* Enough for 16 cache devices, 2 tiers and some left over for pipelining */
+#define OPEN_BUCKETS_COUNT	256
+#define WRITE_POINT_COUNT	32
+
+struct open_bucket {
+	spinlock_t		lock;
+	atomic_t		pin;
+	u8			freelist;
+	bool			valid;
+	bool			on_partial_list;
+	unsigned		sectors_free;
+	struct bch_extent_ptr	ptr;
+};
+
+struct write_point {
+	struct hlist_node	node;
+	struct mutex		lock;
+	u64			last_used;
+	unsigned long		write_point;
+	enum bch_data_type	type;
+
+	u8			nr_ptrs;
+	u8			first_ptr;
+
+	/* calculated based on how many pointers we're actually going to use: */
+	unsigned		sectors_free;
+
+	struct open_bucket	*ptrs[BCH_REPLICAS_MAX * 2];
+	u64			next_alloc[BCH_SB_MEMBERS_MAX];
+};
+
+struct write_point_specifier {
+	unsigned long		v;
+};
+
+struct alloc_heap_entry {
+	size_t			bucket;
+	size_t			nr;
+	unsigned long		key;
+};
+
+typedef HEAP(struct alloc_heap_entry) alloc_heap;
+
+#endif /* _BCACHEFS_ALLOC_TYPES_H */