Commit 62594f18 authored Apr 11, 2021 by Gustavo A. R. Silva Committed by Jens Axboe Apr 11, 2021

bcache: Use 64-bit arithmetic instead of 32-bit



Cast multiple variables to (int64_t) in order to give the compiler
complete information about the proper arithmetic to use. Notice that
these variables are being used in contexts that expect expressions of
type int64_t  (64 bit, signed). And currently, such expressions are
being evaluated using 32-bit arithmetic.

Fixes: d0cf9503 ("octeontx2-pf: ethtool fec mode support")
Addresses-Coverity-ID: 1501724 ("Unintentional integer overflow")
Addresses-Coverity-ID: 1501725 ("Unintentional integer overflow")
Addresses-Coverity-ID: 1501726 ("Unintentional integer overflow")
Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Signed-off-by: Coly Li <colyli@suse.de>
Link: https://lore.kernel.org/r/20210411134316.80274-7-colyli@suse.de


Signed-off-by: Jens Axboe <axboe@kernel.dk>

parent 9c9b81c4

drivers/md/bcache/writeback.c

+3 −3

Original line number	Diff line number	Diff line
		@@ -110,13 +110,13 @@ static void __update_writeback_rate(struct cached_dev *dc)
		int64_t fps;

		if (c->gc_stats.in_use <= BCH_WRITEBACK_FRAGMENT_THRESHOLD_MID) {
		fp_term = dc->writeback_rate_fp_term_low *
		fp_term = (int64_t)dc->writeback_rate_fp_term_low *
		(c->gc_stats.in_use - BCH_WRITEBACK_FRAGMENT_THRESHOLD_LOW);
		} else if (c->gc_stats.in_use <= BCH_WRITEBACK_FRAGMENT_THRESHOLD_HIGH) {
		fp_term = dc->writeback_rate_fp_term_mid *
		fp_term = (int64_t)dc->writeback_rate_fp_term_mid *
		(c->gc_stats.in_use - BCH_WRITEBACK_FRAGMENT_THRESHOLD_MID);
		} else {
		fp_term = dc->writeback_rate_fp_term_high *
		fp_term = (int64_t)dc->writeback_rate_fp_term_high *
		(c->gc_stats.in_use - BCH_WRITEBACK_FRAGMENT_THRESHOLD_HIGH);
		}
		fps = div_s64(dirty, dirty_buckets) * fp_term;