bcachefs: Factor out darray resize slowpath

Move the slowpath (actually growing the darray) to an out-of-line
function; also, add some helpers for the upcoming btree write buffer
rewrite.

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

1 files changed, 21 insertions, 0 deletions

diff --git a/fs/bcachefs/darray.c b/fs/bcachefs/darray.c
new file mode 100644
index 000000000000..aae07be1d911
--- /dev/null
+++ b/fs/bcachefs/darray.c
@@ -0,0 +1,21 @@
+// SPDX-License-Identifier: GPL-2.0
+
+#include <linux/log2.h>
+#include <linux/slab.h>
+#include "darray.h"
+
+int __bch2_darray_resize(darray_void *d, size_t element_size, size_t new_size, gfp_t gfp)
+{
+	if (new_size > d->size) {
+		new_size = roundup_pow_of_two(new_size);
+
+		void *data = krealloc_array(d->data, new_size, element_size, gfp);
+		if (!data)
+			return -ENOMEM;
+
+		d->data	= data;
+		d->size = new_size;
+	}
+
+	return 0;
+}