Re: [PATCH] scsi: Fix incorrect usage of shost_for_each_device

From: Hannes Reinecke
Date: Thu Jun 04 2020 - 02:06:01 EST


On 5/18/20 9:44 AM, Ye Bin wrote:
shost_for_each_device(sdev, shost) \
for ((sdev) = __scsi_iterate_devices((shost), NULL); \
(sdev); \
(sdev) = __scsi_iterate_devices((shost), (sdev)))

When terminating shost_for_each_device() iteration with break or return,
scsi_device_put() should be used to prevent stale scsi device references from
being left behind.

Signed-off-by: Ye Bin <yebin10@xxxxxxxxxx>
---
drivers/scsi/scsi_error.c | 2 ++
drivers/scsi/scsi_lib.c | 4 +++-
2 files changed, 5 insertions(+), 1 deletion(-)

diff --git a/drivers/scsi/scsi_error.c b/drivers/scsi/scsi_error.c
index 978be1602f71..927b1e641842 100644
--- a/drivers/scsi/scsi_error.c
+++ b/drivers/scsi/scsi_error.c
@@ -1412,6 +1412,7 @@ static int scsi_eh_stu(struct Scsi_Host *shost,
sdev_printk(KERN_INFO, sdev,
"%s: skip START_UNIT, past eh deadline\n",
current->comm));
+ scsi_device_put(sdev);
break;
}
stu_scmd = NULL;
@@ -1478,6 +1479,7 @@ static int scsi_eh_bus_device_reset(struct Scsi_Host *shost,
sdev_printk(KERN_INFO, sdev,
"%s: skip BDR, past eh deadline\n",
current->comm));
+ scsi_device_put(sdev);
break;
}
bdr_scmd = NULL;
diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c
index be1a4a9a5fca..173bc7fc2836 100644
--- a/drivers/scsi/scsi_lib.c
+++ b/drivers/scsi/scsi_lib.c
@@ -2859,8 +2859,10 @@ scsi_host_unblock(struct Scsi_Host *shost, int new_state)
shost_for_each_device(sdev, shost) {
ret = scsi_internal_device_unblock(sdev, new_state);
- if (ret)
+ if (ret) {
+ scsi_device_put(sdev);
break;
+ }
}
return ret;
}

Reviewed-by: Hannes Reinecke <hare@xxxxxxx>

Cheers,

Hannes
--
Dr. Hannes Reinecke Teamlead Storage & Networking
hare@xxxxxxx +49 911 74053 688
SUSE Software Solutions GmbH, Maxfeldstr. 5, 90409 NÃrnberg
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