From: Li Nan <linan122@xxxxxxxxxx>
When the throttle of bps is not enabled, tg_bps_limit() returns U64_MAX,
which is be used in calculate_bytes_allowed(), and divide 0 error will
happen.
To fix it, only calculate allowed value when the throttle of bps/iops is
enabled and the value will be used.
Fixes: e8368b57c006 ("blk-throttle: use calculate_io/bytes_allowed() for throtl_trim_slice()")
Reported-by: Changhui Zhong <czhong@xxxxxxxxxx>
Closes: https://lore.kernel.org/all/CAGVVp+Vt6idZtxfU9jF=VSbu145Wi-d-WnAZx_hEfOL8yLZgBA@xxxxxxxxxxxxxx
Signed-off-by: Li Nan <linan122@xxxxxxxxxx>
---
block/blk-throttle.c | 19 ++++++++++++-------
1 file changed, 12 insertions(+), 7 deletions(-)
diff --git a/block/blk-throttle.c b/block/blk-throttle.c
index 38a881cf97d0..3c9a74ab9f0e 100644
--- a/block/blk-throttle.c
+++ b/block/blk-throttle.c
@@ -730,8 +730,10 @@ static u64 calculate_bytes_allowed(u64 bps_limit, unsigned long jiffy_elapsed)
static inline void throtl_trim_slice(struct throtl_grp *tg, bool rw)
{
unsigned long time_elapsed;
- long long bytes_trim;
- int io_trim;
+ long long bytes_trim = 0;
+ int io_trim = 0;
+ u64 bps_limit;
+ u32 iops_limit;
BUG_ON(time_before(tg->slice_end[rw], tg->slice_start[rw]));
@@ -758,11 +760,14 @@ static inline void throtl_trim_slice(struct throtl_grp *tg, bool rw)
if (!time_elapsed)
return;
- bytes_trim = calculate_bytes_allowed(tg_bps_limit(tg, rw),
- time_elapsed) +
- tg->carryover_bytes[rw];
- io_trim = calculate_io_allowed(tg_iops_limit(tg, rw), time_elapsed) +
- tg->carryover_ios[rw];
+ bps_limit = tg_bps_limit(tg, rw);
+ iops_limit = tg_iops_limit(tg, rw);
+ if (tg->bytes_disp[rw] > 0 && bps_limit != U64_MAX)
+ bytes_trim = calculate_bytes_allowed(bps_limit,
+ time_elapsed) + tg->carryover_bytes[rw];
+ if (tg->io_disp[rw] > 0 && iops_limit != UINT_MAX)
+ io_trim = calculate_io_allowed(iops_limit, time_elapsed) +
+ tg->carryover_ios[rw];
if (bytes_trim <= 0 && io_trim <= 0)
return;
--
2.39.2
