4.4-stable review patch. If anyone has any objections, please let me know.
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From: Bart Van Assche bart.vanassche@wdc.com
commit 1214fd7b497400d200e3f4e64e2338b303a20949 upstream.
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: Bart 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: Johannes Thumshirn jthumshirn@suse.de Reviewed-by: Johannes Thumshirn jthumshirn@suse.de Signed-off-by: Martin K. Petersen martin.petersen@oracle.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- drivers/scsi/sr.c | 29 +++++++++++++++++++++-------- 1 file changed, 21 insertions(+), 8 deletions(-)
--- a/drivers/scsi/sr.c +++ b/drivers/scsi/sr.c @@ -520,18 +520,26 @@ static int sr_init_command(struct scsi_c static int sr_block_open(struct block_device *bdev, fmode_t mode) { struct scsi_cd *cd; + struct scsi_device *sdev; int ret = -ENXIO;
+ cd = scsi_cd_get(bdev->bd_disk); + if (!cd) + goto out; + + sdev = cd->device; + scsi_autopm_get_device(sdev); check_disk_change(bdev);
mutex_lock(&sr_mutex); - cd = scsi_cd_get(bdev->bd_disk); - if (cd) { - ret = cdrom_open(&cd->cdi, bdev, mode); - if (ret) - scsi_cd_put(cd); - } + ret = cdrom_open(&cd->cdi, bdev, mode); mutex_unlock(&sr_mutex); + + scsi_autopm_put_device(sdev); + if (ret) + scsi_cd_put(cd); + +out: return ret; }
@@ -559,6 +567,8 @@ static int sr_block_ioctl(struct block_d if (ret) goto out;
+ scsi_autopm_get_device(sdev); + /* * Send SCSI addressing ioctls directly to mid level, send other * ioctls to cdrom/block level. @@ -567,15 +577,18 @@ static int sr_block_ioctl(struct block_d case SCSI_IOCTL_GET_IDLUN: case SCSI_IOCTL_GET_BUS_NUMBER: ret = scsi_ioctl(sdev, cmd, argp); - goto out; + goto put; }
ret = cdrom_ioctl(&cd->cdi, bdev, mode, cmd, arg); if (ret != -ENOSYS) - goto out; + goto put;
ret = scsi_ioctl(sdev, cmd, argp);
+put: + scsi_autopm_put_device(sdev); + out: mutex_unlock(&sr_mutex); return ret;