bcachefs: Prep work for variable size btree node buffers

bcachefs btree nodes are big - typically 256k - and btree roots are
pinned in memory. As we're now up to 18 btrees, we now have significant
memory overhead in mostly empty btree roots.

And in the future we're going to start enforcing that certain btree node
boundaries exist, to solve lock contention issues - analagous to XFS's
AGIs.

Thus, we need to start allocating smaller btree node buffers when we
can. This patch changes code that refers to the filesystem constant
c->opts.btree_node_size to refer to the btree node buffer size -
btree_buf_bytes() - where appropriate.

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

1 files changed, 8 insertions, 8 deletions

diff --git a/fs/bcachefs/debug.c b/fs/bcachefs/debug.c
index d6418948495f..cadda9bbe4a4 100644
--- a/fs/bcachefs/debug.c
+++ b/fs/bcachefs/debug.c
@@ -44,19 +44,19 @@ static bool bch2_btree_verify_replica(struct bch_fs *c, struct btree *b,
 		return false;
 
 	bio = bio_alloc_bioset(ca->disk_sb.bdev,
-			       buf_pages(n_sorted, btree_bytes(c)),
+			       buf_pages(n_sorted, btree_buf_bytes(b)),
 			       REQ_OP_READ|REQ_META,
 			       GFP_NOFS,
 			       &c->btree_bio);
 	bio->bi_iter.bi_sector	= pick.ptr.offset;
-	bch2_bio_map(bio, n_sorted, btree_bytes(c));
+	bch2_bio_map(bio, n_sorted, btree_buf_bytes(b));
 
 	submit_bio_wait(bio);
 
 	bio_put(bio);
 	percpu_ref_put(&ca->io_ref);
 
-	memcpy(n_ondisk, n_sorted, btree_bytes(c));
+	memcpy(n_ondisk, n_sorted, btree_buf_bytes(b));
 
 	v->written = 0;
 	if (bch2_btree_node_read_done(c, ca, v, false, &saw_error) || saw_error)
@@ -137,7 +137,7 @@ void __bch2_btree_verify(struct bch_fs *c, struct btree *b)
 	mutex_lock(&c->verify_lock);
 
 	if (!c->verify_ondisk) {
-		c->verify_ondisk = kvpmalloc(btree_bytes(c), GFP_KERNEL);
+		c->verify_ondisk = kvpmalloc(btree_buf_bytes(b), GFP_KERNEL);
 		if (!c->verify_ondisk)
 			goto out;
 	}
@@ -199,19 +199,19 @@ void bch2_btree_node_ondisk_to_text(struct printbuf *out, struct bch_fs *c,
 		return;
 	}
 
-	n_ondisk = kvpmalloc(btree_bytes(c), GFP_KERNEL);
+	n_ondisk = kvpmalloc(btree_buf_bytes(b), GFP_KERNEL);
 	if (!n_ondisk) {
 		prt_printf(out, "memory allocation failure\n");
 		goto out;
 	}
 
 	bio = bio_alloc_bioset(ca->disk_sb.bdev,
-			       buf_pages(n_ondisk, btree_bytes(c)),
+			       buf_pages(n_ondisk, btree_buf_bytes(b)),
 			       REQ_OP_READ|REQ_META,
 			       GFP_NOFS,
 			       &c->btree_bio);
 	bio->bi_iter.bi_sector	= pick.ptr.offset;
-	bch2_bio_map(bio, n_ondisk, btree_bytes(c));
+	bch2_bio_map(bio, n_ondisk, btree_buf_bytes(b));
 
 	ret = submit_bio_wait(bio);
 	if (ret) {
@@ -293,7 +293,7 @@ void bch2_btree_node_ondisk_to_text(struct printbuf *out, struct bch_fs *c,
 out:
 	if (bio)
 		bio_put(bio);
-	kvpfree(n_ondisk, btree_bytes(c));
+	kvpfree(n_ondisk, btree_buf_bytes(b));
 	percpu_ref_put(&ca->io_ref);
 }