drbd: implicitly truncate cpu-mask

Don't error out with misleading "out of memory"
if the cpu-mask has more bits set than there are CPUs.
Just truncate to nr_cpu_ids implicitly.

Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>

1 files changed, 14 insertions, 0 deletions

diff --git a/drivers/block/drbd/drbd_main.c b/drivers/block/drbd/drbd_main.c
index 9712bcc8e069..9b465bb68487 100644
--- a/drivers/block/drbd/drbd_main.c
+++ b/drivers/block/drbd/drbd_main.c
@@ -2541,6 +2541,20 @@ int set_resource_options(struct drbd_resource *resource, struct res_opts *res_op
         if (nr_cpu_ids > 1 && res_opts->cpu_mask[0] != 0) {
                 err = bitmap_parse(res_opts->cpu_mask, DRBD_CPU_MASK_SIZE,
                                    cpumask_bits(new_cpu_mask), nr_cpu_ids);
+                if (err == -EOVERFLOW) {
+                        /* So what. mask it out. */
+                        cpumask_var_t tmp_cpu_mask;
+                        if (zalloc_cpumask_var(&tmp_cpu_mask, GFP_KERNEL)) {
+                                cpumask_setall(tmp_cpu_mask);
+                                cpumask_and(new_cpu_mask, new_cpu_mask, tmp_cpu_mask);
+                                drbd_warn(resource, "Overflow in bitmap_parse(%.12s%s), truncating to %u bits\n",
+                                        res_opts->cpu_mask,
+                                        strlen(res_opts->cpu_mask) > 12 ? "..." : "",
+                                        nr_cpu_ids);
+                                free_cpumask_var(tmp_cpu_mask);
+                                err = 0;
+                        }
+                }
                 if (err) {
                         drbd_warn(resource, "bitmap_parse() failed with %d\n", err);
                         /* retcode = ERR_CPU_MASK_PARSE; */