bcachefs: bch_acct_compression

This adds per-compression-type accounting of compressed and uncompressed
size as well as number of extents - meaning we can now see compression
ratio (without walking the whole filesystem).
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

fs/bcachefs/buckets.c

@@ -707,13 +707,18 @@ static int __trigger_extent(struct btree_trans *trans,
 	s64 replicas_sectors = 0;
 	int ret = 0;
 
-	struct disk_accounting_pos acc = {
+	struct disk_accounting_pos acc_replicas_key = {
 		.type			= BCH_DISK_ACCOUNTING_replicas,
 		.replicas.data_type	= data_type,
 		.replicas.nr_devs	= 0,
 		.replicas.nr_required	= 1,
 	};
 
+	struct disk_accounting_pos acct_compression_key = {
+		.type			= BCH_DISK_ACCOUNTING_compression,
+	};
+	u64 compression_acct[3] = { 1, 0, 0 };
+
 	bkey_for_each_ptr_decode(k.k, ptrs, p, entry) {
 		s64 disk_sectors = 0;
 		ret = bch2_trigger_pointer(trans, btree_id, level, k, p, entry, &disk_sectors, flags);
@@ -722,15 +727,16 @@ static int __trigger_extent(struct btree_trans *trans,
 
 		bool stale = ret > 0;
 
+		if (p.ptr.cached && stale)
+			continue;
+
 		if (p.ptr.cached) {
-			if (!stale) {
-				ret = bch2_mod_dev_cached_sectors(trans, p.ptr.dev, disk_sectors, gc);
-				if (ret)
-					return ret;
-			}
+			ret = bch2_mod_dev_cached_sectors(trans, p.ptr.dev, disk_sectors, gc);
+			if (ret)
+				return ret;
 		} else if (!p.has_ec) {
 			replicas_sectors       += disk_sectors;
-			acc.replicas.devs[acc.replicas.nr_devs++] = p.ptr.dev;
+			acc_replicas_key.replicas.devs[acc_replicas_key.replicas.nr_devs++] = p.ptr.dev;
 		} else {
 			ret = bch2_trigger_stripe_ptr(trans, k, p, data_type, disk_sectors, flags);
 			if (ret)
@@ -741,12 +747,43 @@ static int __trigger_extent(struct btree_trans *trans,
 			 * if so they're not required for mounting if we have an
 			 * erasure coded pointer in this extent:
 			 */
-			acc.replicas.nr_required = 0;
+			acc_replicas_key.replicas.nr_required = 0;
+		}
+
+		if (acct_compression_key.compression.type &&
+		    acct_compression_key.compression.type != p.crc.compression_type) {
+			if (flags & BTREE_TRIGGER_overwrite)
+				bch2_u64s_neg(compression_acct, ARRAY_SIZE(compression_acct));
+
+			ret = bch2_disk_accounting_mod(trans, &acct_compression_key, compression_acct,
+						       ARRAY_SIZE(compression_acct), gc);
+			if (ret)
+				return ret;
+
+			compression_acct[0] = 1;
+			compression_acct[1] = 0;
+			compression_acct[2] = 0;
 		}
+
+		acct_compression_key.compression.type = p.crc.compression_type;
+		if (p.crc.compression_type) {
+			compression_acct[1] += p.crc.uncompressed_size;
+			compression_acct[2] += p.crc.compressed_size;
+		}
+	}
+
+	if (acc_replicas_key.replicas.nr_devs) {
+		ret = bch2_disk_accounting_mod(trans, &acc_replicas_key, &replicas_sectors, 1, gc);
+		if (ret)
+			return ret;
 	}
 
-	if (acc.replicas.nr_devs) {
-		ret = bch2_disk_accounting_mod(trans, &acc, &replicas_sectors, 1, gc);
+	if (acct_compression_key.compression.type) {
+		if (flags & BTREE_TRIGGER_overwrite)
+			bch2_u64s_neg(compression_acct, ARRAY_SIZE(compression_acct));
+
+		ret = bch2_disk_accounting_mod(trans, &acct_compression_key, compression_acct,
+					       ARRAY_SIZE(compression_acct), gc);
 		if (ret)
 			return ret;
 	}

fs/bcachefs/disk_accounting.c

@@ -6,6 +6,7 @@
 #include "btree_update.h"
 #include "btree_write_buffer.h"
 #include "buckets.h"
+#include "compress.h"
 #include "disk_accounting.h"
 #include "error.h"
 #include "journal_io.h"
@@ -142,6 +143,9 @@ void bch2_accounting_key_to_text(struct printbuf *out, struct disk_accounting_po
 		prt_printf(out, "dev=%u data_type=", k->dev_data_type.dev);
 		bch2_prt_data_type(out, k->dev_data_type.data_type);
 		break;
+	case BCH_DISK_ACCOUNTING_compression:
+		bch2_prt_compression_type(out, k->compression.type);
+		break;
 	}
 }
 

fs/bcachefs/disk_accounting_format.h

@@ -99,7 +99,8 @@ static inline bool data_type_is_hidden(enum bch_data_type type)
 	x(nr_inodes,		0)		\
 	x(persistent_reserved,	1)		\
 	x(replicas,		2)		\
-	x(dev_data_type,	3)
+	x(dev_data_type,	3)		\
+	x(compression,		4)
 
 enum disk_accounting_type {
 #define x(f, nr)	BCH_DISK_ACCOUNTING_##f	= nr,
@@ -124,6 +125,10 @@ struct bch_dev_stripe_buckets {
 	__u8			dev;
 };
 
+struct bch_acct_compression {
+	__u8			type;
+};
+
 struct disk_accounting_pos {
 	union {
 	struct {
@@ -134,6 +139,7 @@ struct disk_accounting_pos {
 		struct bch_replicas_entry_v1	replicas;
 		struct bch_dev_data_type	dev_data_type;
 		struct bch_dev_stripe_buckets	dev_stripe_buckets;
+		struct bch_acct_compression	compression;
 		};
 	};
 		struct bpos			_pad;