bcachefs: Add BCH_BKEY_PTRS_MAX

This now means "the maximum number of pointers within a bkey" - and
bch_devs_list is updated to use it instead of BCH_REPLICAS_MAX, since
stripes can contain more than BCH_REPLICAS_MAX pointers.
Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

fs/bcachefs/bcachefs_format.h

@@ -1363,6 +1363,8 @@ enum bch_sb_compat {
 
 #define BCH_REPLICAS_MAX		4U
 
+#define BCH_BKEY_PTRS_MAX		16U
+
 enum bch_error_actions {
 	BCH_ON_ERROR_CONTINUE		= 0,
 	BCH_ON_ERROR_RO			= 1,

fs/bcachefs/ec.c

@@ -300,7 +300,7 @@ static unsigned ec_nr_failed(struct ec_stripe_buf *buf)
 static int ec_do_recov(struct bch_fs *c, struct ec_stripe_buf *buf)
 {
 	struct bch_stripe *v = &buf->key.v;
-	unsigned i, failed[EC_STRIPE_MAX], nr_failed = 0;
+	unsigned i, failed[BCH_BKEY_PTRS_MAX], nr_failed = 0;
 	unsigned nr_data = v->nr_blocks - v->nr_redundant;
 	unsigned bytes = buf->size << 9;
 
@@ -1101,7 +1101,7 @@ static int ec_new_stripe_alloc(struct bch_fs *c, struct ec_stripe_head *h)
 	s->c		= c;
 	s->h		= h;
 	s->nr_data	= min_t(unsigned, h->nr_active_devs,
-				EC_STRIPE_MAX) - h->redundancy;
+				BCH_BKEY_PTRS_MAX) - h->redundancy;
 	s->nr_parity	= h->redundancy;
 
 	bch2_keylist_init(&s->keys, s->inline_keys);
@@ -1211,13 +1211,13 @@ static int new_stripe_alloc_buckets(struct bch_fs *c, struct ec_stripe_head *h)
 	struct open_bucket *ob;
 	unsigned i, nr_have, nr_data =
 		min_t(unsigned, h->nr_active_devs,
-		      EC_STRIPE_MAX) - h->redundancy;
+		      BCH_BKEY_PTRS_MAX) - h->redundancy;
 	bool have_cache = true;
 	int ret = 0;
 
 	devs = h->devs;
 
-	for_each_set_bit(i, h->s->blocks_allocated, EC_STRIPE_MAX) {
+	for_each_set_bit(i, h->s->blocks_allocated, BCH_BKEY_PTRS_MAX) {
 		__clear_bit(h->s->stripe.key.v.ptrs[i].dev, devs.d);
 		--nr_data;
 	}

fs/bcachefs/ec.h

@@ -71,9 +71,9 @@ struct ec_stripe_buf {
 	/* might not be buffering the entire stripe: */
 	unsigned		offset;
 	unsigned		size;
-	unsigned long		valid[BITS_TO_LONGS(EC_STRIPE_MAX)];
+	unsigned long		valid[BITS_TO_LONGS(BCH_BKEY_PTRS_MAX)];
 
-	void			*data[EC_STRIPE_MAX];
+	void			*data[BCH_BKEY_PTRS_MAX];
 
 	union {
 		struct bkey_i_stripe	key;
@@ -101,10 +101,10 @@ struct ec_stripe_new {
 	bool			existing_stripe;
 	u64			existing_stripe_idx;
 
-	unsigned long		blocks_allocated[BITS_TO_LONGS(EC_STRIPE_MAX)];
+	unsigned long		blocks_allocated[BITS_TO_LONGS(BCH_BKEY_PTRS_MAX)];
 
 	struct open_buckets	blocks;
-	u8			data_block_idx[EC_STRIPE_MAX];
+	u8			data_block_idx[BCH_BKEY_PTRS_MAX];
 	struct open_buckets	parity;
 	struct disk_reservation	res;
 

fs/bcachefs/ec_types.h

@@ -4,11 +4,9 @@
 
 #include <linux/llist.h>
 
-#define EC_STRIPE_MAX	16
-
 struct bch_replicas_padded {
 	struct bch_replicas_entry	e;
-	u8				pad[EC_STRIPE_MAX];
+	u8				pad[BCH_BKEY_PTRS_MAX];
 };
 
 struct stripe {
@@ -24,7 +22,7 @@ struct stripe {
 	unsigned		dirty:1;
 	unsigned		on_heap:1;
 	u8			blocks_nonempty;
-	u16			block_sectors[EC_STRIPE_MAX];
+	u16			block_sectors[BCH_BKEY_PTRS_MAX];
 
 	struct bch_replicas_padded r;
 };

fs/bcachefs/super_types.h

@@ -21,7 +21,7 @@ struct bch_devs_mask {
 
 struct bch_devs_list {
 	u8			nr;
-	u8			devs[BCH_REPLICAS_MAX + 1];
+	u8			devs[BCH_BKEY_PTRS_MAX];
 };
 
 struct bch_member_cpu {