linux-kernel - Re: rework check_disk

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <730eced4-c804-a78f-3d52-2a448dbd1b84@interlog.com>
Date:   Wed, 2 Sep 2020 11:38:45 -0400
From:   Douglas Gilbert <dgilbert@...erlog.com>
To:     Christoph Hellwig <hch@....de>, Jens Axboe <axboe@...nel.dk>
Cc:     Denis Efremov <efremov@...ux.com>, Tim Waugh <tim@...erelk.net>,
        Michal Simek <michal.simek@...inx.com>,
        Borislav Petkov <bp@...en8.de>,
        "David S. Miller" <davem@...emloft.net>,
        Song Liu <song@...nel.org>,
        "Martin K. Petersen" <martin.petersen@...cle.com>,
        Finn Thain <fthain@...egraphics.com.au>,
        Michael Schmitz <schmitzmic@...il.com>,
        linux-m68k@...ts.linux-m68k.org, linux-block@...r.kernel.org,
        linux-kernel@...r.kernel.org, linux-ide@...r.kernel.org,
        linux-raid@...r.kernel.org, linux-scsi@...r.kernel.org,
        linux-fsdevel@...r.kernel.org
Subject: Re: rework check_disk_change()

On 2020-09-02 10:11 a.m., Christoph Hellwig wrote:
> Hi Jens,
> 
> this series replaced the not very nice check_disk_change() function with
> a new bdev_media_changed that avoids having the ->revalidate_disk call
> at its end.  As a result ->revalidate_disk can be removed from a lot of
> drivers.
> 

For over 20 years the sg driver has been carrying this snippet that hangs
off the completion callback:

        if (driver_stat & DRIVER_SENSE) {
                 struct scsi_sense_hdr ssh;

                 if (scsi_normalize_sense(sbp, sense_len, &ssh)) {
                         if (!scsi_sense_is_deferred(&ssh)) {
                                 if (ssh.sense_key == UNIT_ATTENTION) {
                                         if (sdp->device->removable)
                                                 sdp->device->changed = 1;
                                 }
                         }
                 }
         }

Is it needed? The unit attention (UA) may not be associated with the
device changing. Shouldn't the SCSI mid-level monitor UAs if they
impact the state of a scsi_device object?

Doug Gilbert