• Bart Van Assche's avatar
    scsi: sr: Avoid that opening a CD-ROM hangs with runtime power management enabled · 1214fd7b
    Bart Van Assche authored
    Surround scsi_execute() calls with scsi_autopm_get_device() and
    scsi_autopm_put_device(). Note: removing sr_mutex protection from the
    scsi_cd_get() and scsi_cd_put() calls is safe because the purpose of
    sr_mutex is to serialize cdrom_*() calls.
    
    This patch avoids that complaints similar to the following appear in the
    kernel log if runtime power management is enabled:
    
    INFO: task systemd-udevd:650 blocked for more than 120 seconds.
         Not tainted 4.18.0-rc7-dbg+ #1
    "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
    systemd-udevd   D28176   650    513 0x00000104
    Call Trace:
    __schedule+0x444/0xfe0
    schedule+0x4e/0xe0
    schedule_preempt_disabled+0x18/0x30
    __mutex_lock+0x41c/0xc70
    mutex_lock_nested+0x1b/0x20
    __blkdev_get+0x106/0x970
    blkdev_get+0x22c/0x5a0
    blkdev_open+0xe9/0x100
    do_dentry_open.isra.19+0x33e/0x570
    vfs_open+0x7c/0xd0
    path_openat+0x6e3/0x1120
    do_filp_open+0x11c/0x1c0
    do_sys_open+0x208/0x2d0
    __x64_sys_openat+0x59/0x70
    do_syscall_64+0x77/0x230
    entry_SYSCALL_64_after_hwframe+0x49/0xbe
    Signed-off-by: default avatarBart Van Assche <bart.vanassche@wdc.com>
    Cc: Maurizio Lombardi <mlombard@redhat.com>
    Cc: Johannes Thumshirn <jthumshirn@suse.de>
    Cc: Alan Stern <stern@rowland.harvard.edu>
    Cc: <stable@vger.kernel.org>
    Tested-by: default avatarJohannes Thumshirn <jthumshirn@suse.de>
    Reviewed-by: default avatarJohannes Thumshirn <jthumshirn@suse.de>
    Signed-off-by: default avatarMartin K. Petersen <martin.petersen@oracle.com>
    1214fd7b
sr.c 25.9 KB