bcachefs: move replica_set from bch_dev to bch_fs

This is needed for the next patch - the write submit path has to be able
to allocate a replica bio even when we weren't able to get a ref on the
device.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

fs/bcachefs/bcachefs.h

@@ -569,9 +569,6 @@ struct bch_dev {
 
 	struct bch_devs_mask	self;
 
-	/* biosets used in cloned bios for writing multiple replicas */
-	struct bio_set		replica_set;
-
 	/*
 	 * Buckets:
 	 * Per-bucket arrays are protected by c->mark_lock, bucket_lock and
@@ -995,6 +992,7 @@ struct bch_fs {
 	struct bio_set		bio_read;
 	struct bio_set		bio_read_split;
 	struct bio_set		bio_write;
+	struct bio_set		replica_set;
 	struct mutex		bio_bounce_pages_lock;
 	mempool_t		bio_bounce_pages;
 	struct bucket_nocow_lock_table

fs/bcachefs/io_write.c

@@ -412,8 +412,7 @@ void bch2_submit_wbio_replicas(struct bch_write_bio *wbio, struct bch_fs *c,
 		struct bch_dev *ca = bch2_dev_bkey_exists(c, ptr->dev);
 
 		if (to_entry(ptr + 1) < ptrs.end) {
-			n = to_wbio(bio_alloc_clone(NULL, &wbio->bio,
-						GFP_NOFS, &ca->replica_set));
+			n = to_wbio(bio_alloc_clone(NULL, &wbio->bio, GFP_NOFS, &c->replica_set));
 
 			n->bio.bi_end_io	= wbio->bio.bi_end_io;
 			n->bio.bi_private	= wbio->bio.bi_private;
@@ -1667,13 +1666,14 @@ void bch2_write_op_to_text(struct printbuf *out, struct bch_write_op *op)
 void bch2_fs_io_write_exit(struct bch_fs *c)
 {
 	mempool_exit(&c->bio_bounce_pages);
+	bioset_exit(&c->replica_set);
 	bioset_exit(&c->bio_write);
 }
 
 int bch2_fs_io_write_init(struct bch_fs *c)
 {
-	if (bioset_init(&c->bio_write, 1, offsetof(struct bch_write_bio, bio),
-			BIOSET_NEED_BVECS))
+	if (bioset_init(&c->bio_write,   1, offsetof(struct bch_write_bio, bio), BIOSET_NEED_BVECS) ||
+	    bioset_init(&c->replica_set, 4, offsetof(struct bch_write_bio, bio), 0))
 		return -BCH_ERR_ENOMEM_bio_write_init;
 
 	if (mempool_init_page_pool(&c->bio_bounce_pages,

fs/bcachefs/super.c

@@ -1193,7 +1193,6 @@ static void bch2_dev_free(struct bch_dev *ca)
 	bch2_dev_journal_exit(ca);
 
 	free_percpu(ca->io_done);
-	bioset_exit(&ca->replica_set);
 	bch2_dev_buckets_free(ca);
 	free_page((unsigned long) ca->sb_read_scratch);
 
@@ -1317,8 +1316,6 @@ static struct bch_dev *__bch2_dev_alloc(struct bch_fs *c,
 			    PERCPU_REF_INIT_DEAD, GFP_KERNEL) ||
 	    !(ca->sb_read_scratch = (void *) __get_free_page(GFP_KERNEL)) ||
 	    bch2_dev_buckets_alloc(c, ca) ||
-	    bioset_init(&ca->replica_set, 4,
-			offsetof(struct bch_write_bio, bio), 0) ||
 	    !(ca->io_done	= alloc_percpu(*ca->io_done)))
 		goto err;