Re: [PATCH v7 09/23] scsi: sd: Do not issue commands to suspended disks on shutdown

[Bart Van Assche <bvanassche@acm.org>]

On 9/26/23 01:14, Damien Le Moal wrote:
> If an error occurs when resuming a host adapter before the devices
> attached to the adapter are resumed, the adapter low level driver may
> remove the scsi host, resulting in a call to sd_remove() for the
> disks of the host. This in turn results in a call to sd_shutdown() which
> will issue a synchronize cache command and a start stop unit command to
> spindown the disk. sd_shutdown() issues the commands only if the device
> is not already runtime suspended but does not check the power state for
> system-wide suspend/resume. That is, the commands may be issued with the
> device in a suspended state, which causes PM resume to hang, forcing a
> reset of the machine to recover.
> 
> Fix this by tracking the suspended state of a disk by introducing the
> suspended boolean field in the scsi_disk structure. This flag is set to
> true when the disk is suspended is sd_suspend_common() and resumed with
> sd_resume(). When suspended is true, sd_shutdown() is not executed from
> sd_remove().


Reviewed-by: Bart Van Assche <bvanassche@acm.org>