lkml.org 
[lkml]   [2011]   [Jan]   [29]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    Date
    From
    SubjectRe: [PATCH 7/8] sr: implement sr_check_events()
    On 08/12/10 19:57, Tejun Heo wrote:
    > Replace sr_media_change() with sr_check_events(). It normally only
    > uses GET_EVENT_STATUS_NOTIFICATION to check both media change and
    > eject request. If @clearing includes DISK_EVENT_MEDIA_CHANGE, it
    > issues TUR and compares whether media presence has changed. The SCSI
    > specific media change uevent is kept for compatibility.
    >
    > sr_media_change() was doing both media change check and revalidation.
    > The revalidation part is split into sr_block_revalidate_disk().
    >
    > Signed-off-by: Tejun Heo <tj@kernel.org>
    > Cc: Kay Sievers <kay.sievers@vrfy.org>
    > ---
    > drivers/scsi/sr.c | 147 +++++++++++++++++++++++++++++++++------------------
    > drivers/scsi/sr.h | 2 +-
    > include/scsi/scsi.h | 1 +
    > 3 files changed, 98 insertions(+), 52 deletions(-)

    This breaks growisofs:
    :-( /dev/dvd: CD_ROM_MEDIA_CHANGED ioctl failed: Inappropriate ioctl for device

    SR_CAPABILITIES in sr.c includes CDC_MEDIA_CHANGED but cdrom.c removes
    this capability in register_cdrom because there is no media_changed op:
    ENSURE(media_changed, CDC_MEDIA_CHANGED);

    The ioctl function cdrom_ioctl_media_changed() then returns -ENOSYS.

    The media_changed() function again checks this capability but never uses
    the media_changed op if the check_events op exists.

    The cdrom_media_changed() function requires the media_changed op but
    then calls media_changed().

    It looks like cdrom_select_disc() is going to dereference the NULL
    media_changed pointer if both check_events and media_changed don't
    exist.

    > diff --git a/drivers/scsi/sr.c b/drivers/scsi/sr.c
    > index f6d8ee4..1e4b9b1 100644
    > --- a/drivers/scsi/sr.c
    > +++ b/drivers/scsi/sr.c
    > @@ -104,14 +104,15 @@ static void sr_release(struct cdrom_device_info *);
    > static void get_sectorsize(struct scsi_cd *);
    > static void get_capabilities(struct scsi_cd *);
    >
    > -static int sr_media_change(struct cdrom_device_info *, int);
    > +static unsigned int sr_check_events(struct cdrom_device_info *cdi,
    > + unsigned int clearing, int slot);
    > static int sr_packet(struct cdrom_device_info *, struct packet_command *);
    >
    > static struct cdrom_device_ops sr_dops = {
    > .open = sr_open,
    > .release = sr_release,
    > .drive_status = sr_drive_status,
    > - .media_changed = sr_media_change,
    > + .check_events = sr_check_events,
    > .tray_move = sr_tray_move,
    > .lock_door = sr_lock_door,
    > .select_speed = sr_select_speed,
    > @@ -165,69 +166,96 @@ static void scsi_cd_put(struct scsi_cd *cd)
    > mutex_unlock(&sr_ref_mutex);
    > }

    --
    Simon Arlott


    \
     
     \ /
      Last update: 2011-01-30 02:29    [W:0.024 / U:30.772 seconds]
    ©2003-2016 Jasper Spaans. hosted at Digital OceanAdvertise on this site