bcachefs: Limit pointers to being in only one stripe

This make the disk accounting code saner, and it's not clear why we'd
ever want the same data to be in multiple stripes simultaneously.

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

6 files changed, 29 insertions, 38 deletions

diff --git a/fs/bcachefs/buckets.c b/fs/bcachefs/buckets.c
index af5062f34d7d..56c389e31db4 100644
--- a/fs/bcachefs/buckets.c
+++ b/fs/bcachefs/buckets.c
@@ -1027,7 +1027,6 @@ static int bch2_mark_extent(struct bch_fs *c, struct bkey_s_c k,
 	struct extent_ptr_decoded p;
 	struct bch_replicas_padded r;
 	s64 dirty_sectors = 0;
-	unsigned i;
 	int ret;
 
 	r.e.data_type	= data_type;
@@ -1047,17 +1046,15 @@ static int bch2_mark_extent(struct bch_fs *c, struct bkey_s_c k,
 			if (!stale)
 				update_cached_sectors(c, fs_usage, p.ptr.dev,
 						      disk_sectors);
-		} else if (!p.ec_nr) {
+		} else if (!p.has_ec) {
 			dirty_sectors	       += disk_sectors;
 			r.e.devs[r.e.nr_devs++]	= p.ptr.dev;
 		} else {
-			for (i = 0; i < p.ec_nr; i++) {
-				ret = bch2_mark_stripe_ptr(c, p.ec[i],
-						data_type, fs_usage,
-						disk_sectors, flags);
-				if (ret)
-					return ret;
-			}
+			ret = bch2_mark_stripe_ptr(c, p.ec,
+					data_type, fs_usage,
+					disk_sectors, flags);
+			if (ret)
+				return ret;
 
 			r.e.nr_required = 0;
 		}
@@ -1564,7 +1561,6 @@ static int bch2_trans_mark_extent(struct btree_trans *trans,
 	struct bch_replicas_padded r;
 	s64 dirty_sectors = 0;
 	bool stale;
-	unsigned i;
 	int ret;
 
 	r.e.data_type	= data_type;
@@ -1589,16 +1585,14 @@ static int bch2_trans_mark_extent(struct btree_trans *trans,
 			if (!stale)
 				update_cached_sectors_list(trans, p.ptr.dev,
 							   disk_sectors);
-		} else if (!p.ec_nr) {
+		} else if (!p.has_ec) {
 			dirty_sectors	       += disk_sectors;
 			r.e.devs[r.e.nr_devs++]	= p.ptr.dev;
 		} else {
-			for (i = 0; i < p.ec_nr; i++) {
-				ret = bch2_trans_mark_stripe_ptr(trans, p.ec[i],
-						disk_sectors, data_type);
-				if (ret)
-					return ret;
-			}
+			ret = bch2_trans_mark_stripe_ptr(trans, p.ec,
+					disk_sectors, data_type);
+			if (ret)
+				return ret;
 
 			r.e.nr_required = 0;
 		}
diff --git a/fs/bcachefs/ec.c b/fs/bcachefs/ec.c
index 215d47580743..ee9f62abbba6 100644
--- a/fs/bcachefs/ec.c
+++ b/fs/bcachefs/ec.c
@@ -433,10 +433,9 @@ int bch2_ec_read_extent(struct bch_fs *c, struct bch_read_bio *rbio)
 
 	closure_init_stack(&cl);
 
-	BUG_ON(!rbio->pick.idx ||
-	       rbio->pick.idx - 1 >= rbio->pick.ec_nr);
+	BUG_ON(!rbio->pick.has_ec);
 
-	stripe_idx = rbio->pick.ec[rbio->pick.idx - 1].idx;
+	stripe_idx = rbio->pick.ec.idx;
 
 	buf = kzalloc(sizeof(*buf), GFP_NOIO);
 	if (!buf)
diff --git a/fs/bcachefs/extents.c b/fs/bcachefs/extents.c
index bb3177ac44c8..dcd70994e14b 100644
--- a/fs/bcachefs/extents.c
+++ b/fs/bcachefs/extents.c
@@ -67,7 +67,7 @@ unsigned bch2_bkey_nr_dirty_ptrs(struct bkey_s_c k)
 static unsigned bch2_extent_ptr_durability(struct bch_fs *c,
 					   struct extent_ptr_decoded p)
 {
-	unsigned i, durability = 0;
+	unsigned durability = 0;
 	struct bch_dev *ca;
 
 	if (p.ptr.cached)
@@ -78,16 +78,16 @@ static unsigned bch2_extent_ptr_durability(struct bch_fs *c,
 	if (ca->mi.state != BCH_MEMBER_STATE_FAILED)
 		durability = max_t(unsigned, durability, ca->mi.durability);
 
-	for (i = 0; i < p.ec_nr; i++) {
+	if (p.has_ec) {
 		struct stripe *s =
-			genradix_ptr(&c->stripes[0], p.ec[i].idx);
+			genradix_ptr(&c->stripes[0], p.ec.idx);
 
 		if (WARN_ON(!s))
-			continue;
+			goto out;
 
 		durability = max_t(unsigned, durability, s->nr_redundant);
 	}
-
+out:
 	return durability;
 }
 
@@ -206,10 +206,10 @@ int bch2_bkey_pick_read_device(struct bch_fs *c, struct bkey_s_c k,
 			p.idx++;
 
 		if (force_reconstruct_read(c) &&
-		    !p.idx && p.ec_nr)
+		    !p.idx && p.has_ec)
 			p.idx++;
 
-		if (p.idx >= p.ec_nr + 1)
+		if (p.idx >= (unsigned) p.has_ec + 1)
 			continue;
 
 		if (ret > 0 && !ptr_better(c, p, *pick))
@@ -1544,7 +1544,6 @@ void bch2_extent_ptr_decoded_append(struct bkey_i *k,
 	struct bch_extent_crc_unpacked crc =
 		bch2_extent_crc_unpack(&k->k, NULL);
 	union bch_extent_entry *pos;
-	unsigned i;
 
 	if (!bch2_crc_unpacked_cmp(crc, p->crc)) {
 		pos = ptrs.start;
@@ -1563,9 +1562,9 @@ found:
 	p->ptr.type = 1 << BCH_EXTENT_ENTRY_ptr;
 	__extent_entry_insert(k, pos, to_entry(&p->ptr));
 
-	for (i = 0; i < p->ec_nr; i++) {
-		p->ec[i].type = 1 << BCH_EXTENT_ENTRY_stripe_ptr;
-		__extent_entry_insert(k, pos, to_entry(&p->ec[i]));
+	if (p->has_ec) {
+		p->ec.type = 1 << BCH_EXTENT_ENTRY_stripe_ptr;
+		__extent_entry_insert(k, pos, to_entry(&p->ec));
 	}
 }
 
diff --git a/fs/bcachefs/extents.h b/fs/bcachefs/extents.h
index 613d76af69d9..67abc3c8be54 100644
--- a/fs/bcachefs/extents.h
+++ b/fs/bcachefs/extents.h
@@ -228,7 +228,7 @@ struct bkey_ptrs {
 	__label__ out;							\
 									\
 	(_ptr).idx	= 0;						\
-	(_ptr).ec_nr	= 0;						\
+	(_ptr).has_ec	= false;					\
 									\
 	__bkey_extent_entry_for_each_from(_entry, _end, _entry)		\
 		switch (extent_entry_type(_entry)) {			\
@@ -242,7 +242,8 @@ struct bkey_ptrs {
 					entry_to_crc(_entry));		\
 			break;						\
 		case BCH_EXTENT_ENTRY_stripe_ptr:			\
-			(_ptr).ec[(_ptr).ec_nr++] = _entry->stripe_ptr;	\
+			(_ptr).ec = _entry->stripe_ptr;			\
+			(_ptr).has_ec	= true;				\
 			break;						\
 		}							\
 out:									\
diff --git a/fs/bcachefs/extents_types.h b/fs/bcachefs/extents_types.h
index a8dd6952d989..43d6c341ecca 100644
--- a/fs/bcachefs/extents_types.h
+++ b/fs/bcachefs/extents_types.h
@@ -21,10 +21,10 @@ struct bch_extent_crc_unpacked {
 
 struct extent_ptr_decoded {
 	unsigned			idx;
-	unsigned			ec_nr;
+	bool				has_ec;
 	struct bch_extent_crc_unpacked	crc;
 	struct bch_extent_ptr		ptr;
-	struct bch_extent_stripe_ptr	ec[4];
+	struct bch_extent_stripe_ptr	ec;
 };
 
 struct bch_io_failures {
diff --git a/fs/bcachefs/replicas.c b/fs/bcachefs/replicas.c
index bb9da2bb5a92..cb5ebb87c701 100644
--- a/fs/bcachefs/replicas.c
+++ b/fs/bcachefs/replicas.c
@@ -84,10 +84,8 @@ static void extent_to_replicas(struct bkey_s_c k,
 		if (p.ptr.cached)
 			continue;
 
-		if (p.ec_nr) {
+		if (p.has_ec)
 			r->nr_required = 0;
-			break;
-		}
 
 		r->devs[r->nr_devs++] = p.ptr.dev;
 	}