During hibernation, the sdevs are suspended automatically in drivers/scsi/scsi_pm.c before storvsc_suspend(), so after storvsc_suspend(), there is no disk I/O from the file systems, but there can still be disk I/O from the kernel space, e.g. disk_check_events() -> sr_block_check_events() -> cdrom_check_events() can still submit I/O to the storvsc driver, which causes a paic of NULL pointer dereference, since storvsc has closed the vmbus channel in storvsc_suspend(): refer to the below links for more info: https://lkml.org/lkml/2020/4/10/47 https://lkml.org/lkml/2020/4/17/1103 Fix the panic by blocking/unblocking all the I/O queues properly. Note: this patch depends on another patch "scsi: core: Allow the state change from SDEV_QUIESCE to SDEV_BLOCK" (refer to the second link above). Fixes: 56fb10585934 ("scsi: storvsc: Add the support of hibernation") Signed-off-by: Dexuan Cui <decui@xxxxxxxxxxxxx> --- drivers/scsi/storvsc_drv.c | 10 ++++++++++ 1 file changed, 10 insertions(+) diff --git a/drivers/scsi/storvsc_drv.c b/drivers/scsi/storvsc_drv.c index fb41636519ee..fd51d2f03778 100644 --- a/drivers/scsi/storvsc_drv.c +++ b/drivers/scsi/storvsc_drv.c @@ -1948,6 +1948,11 @@ static int storvsc_suspend(struct hv_device *hv_dev) struct storvsc_device *stor_device = hv_get_drvdata(hv_dev); struct Scsi_Host *host = stor_device->host; struct hv_host_device *host_dev = shost_priv(host); + int ret; + + ret = scsi_host_block(host); + if (ret) + return ret; storvsc_wait_to_drain(stor_device); @@ -1968,10 +1973,15 @@ static int storvsc_suspend(struct hv_device *hv_dev) static int storvsc_resume(struct hv_device *hv_dev) { + struct storvsc_device *stor_device = hv_get_drvdata(hv_dev); + struct Scsi_Host *host = stor_device->host; int ret; ret = storvsc_connect_to_vsp(hv_dev, storvsc_ringbuffer_size, hv_dev_is_fc(hv_dev)); + if (!ret) + ret = scsi_host_unblock(host, SDEV_RUNNING); + return ret; } -- 2.19.1
