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authorBart Van Assche <bart.vanassche@wdc.com>2018-08-02 20:44:42 +0300
committerMartin K. Petersen <martin.petersen@oracle.com>2018-08-03 20:53:51 +0300
commit1214fd7b497400d200e3f4e64e2338b303a20949 (patch)
tree821a5ceab8732ec48ae182834d1684dcfdd7aeb0 /drivers/scsi
parent09c2f95ad404bc6e9995f5bce04ae85d0fffc534 (diff)
downloadlinux-1214fd7b497400d200e3f4e64e2338b303a20949.tar.xz
scsi: sr: Avoid that opening a CD-ROM hangs with runtime power management enabled
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>
Diffstat (limited to 'drivers/scsi')
-rw-r--r--drivers/scsi/sr.c29
1 files changed, 21 insertions, 8 deletions
diff --git a/drivers/scsi/sr.c b/drivers/scsi/sr.c
index 3f3cb72e0c0c..d0389b20574d 100644
--- a/drivers/scsi/sr.c
+++ b/drivers/scsi/sr.c
@@ -523,18 +523,26 @@ static int sr_init_command(struct scsi_cmnd *SCpnt)
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;
}
@@ -562,6 +570,8 @@ static int sr_block_ioctl(struct block_device *bdev, fmode_t mode, unsigned cmd,
if (ret)
goto out;
+ scsi_autopm_get_device(sdev);
+
/*
* Send SCSI addressing ioctls directly to mid level, send other
* ioctls to cdrom/block level.
@@ -570,15 +580,18 @@ static int sr_block_ioctl(struct block_device *bdev, fmode_t mode, unsigned cmd,
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;