5.15-stable review patch. If anyone has any objections, please let me know.
------------------
From: Gwendal Grignou <gwendal@xxxxxxxxxxxx>
commit eb48e9fc0028bed94a40a9352d065909f19e333c upstream.
Prevent a division by 0 when monitoring is not enabled.
Fixes: 1d8613a23f3c ("scsi: ufs: core: Introduce HBA performance monitor sysfs nodes")
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Gwendal Grignou <gwendal@xxxxxxxxxxxx>
Link: https://lore.kernel.org/r/20241120062522.917157-1-gwendal@xxxxxxxxxxxx
Reviewed-by: Can Guo <quic_cang@xxxxxxxxxxx>
Signed-off-by: Martin K. Petersen <martin.petersen@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/scsi/ufs/ufs-sysfs.c | 6 ++++++
1 file changed, 6 insertions(+)
--- a/drivers/scsi/ufs/ufs-sysfs.c
+++ b/drivers/scsi/ufs/ufs-sysfs.c
@@ -371,6 +371,9 @@ static ssize_t read_req_latency_avg_show
struct ufs_hba *hba = dev_get_drvdata(dev);
struct ufs_hba_monitor *m = &hba->monitor;
+ if (!m->nr_req[READ])
+ return sysfs_emit(buf, "0\n");
+
return sysfs_emit(buf, "%llu\n", div_u64(ktime_to_us(m->lat_sum[READ]),
m->nr_req[READ]));
}
@@ -438,6 +441,9 @@ static ssize_t write_req_latency_avg_sho
struct ufs_hba *hba = dev_get_drvdata(dev);
struct ufs_hba_monitor *m = &hba->monitor;
+ if (!m->nr_req[WRITE])
+ return sysfs_emit(buf, "0\n");
+
return sysfs_emit(buf, "%llu\n", div_u64(ktime_to_us(m->lat_sum[WRITE]),
m->nr_req[WRITE]));
}
