| Message ID | 20190801110630.82432-2-sth@linux.ibm.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | sending DASD patches through linux-block | expand |
On 8/1/19 5:06 AM, Stefan Haberland wrote: > After getting a storage server event that causes the DASD device driver > to update its unit address configuration during a device shutdown there is > the possibility of an endless loop in the device driver. > > In the system log there will be ongoing DASD error messages with RC: -19. > > The reason is that the loop starting the ruac request only terminates when > the retry counter is decreased to 0. But in the sleep_on function there are > early exit paths that do not decrease the retry counter. > > Prevent an endless loop by handling those cases separately. > > Remove the unnecessary do..while loop since the sleep_on function takes > care of retries by itself. Applied for 5.3, thanks.
diff --git a/drivers/s390/block/dasd_alias.c b/drivers/s390/block/dasd_alias.c index b9ce93e9df89..99f86612f775 100644 --- a/drivers/s390/block/dasd_alias.c +++ b/drivers/s390/block/dasd_alias.c @@ -383,6 +383,20 @@ suborder_not_supported(struct dasd_ccw_req *cqr) char msg_format; char msg_no; + /* + * intrc values ENODEV, ENOLINK and EPERM + * will be optained from sleep_on to indicate that no + * IO operation can be started + */ + if (cqr->intrc == -ENODEV) + return 1; + + if (cqr->intrc == -ENOLINK) + return 1; + + if (cqr->intrc == -EPERM) + return 1; + sense = dasd_get_sense(&cqr->irb); if (!sense) return 0; @@ -447,12 +461,8 @@ static int read_unit_address_configuration(struct dasd_device *device, lcu->flags &= ~NEED_UAC_UPDATE; spin_unlock_irqrestore(&lcu->lock, flags); - do { - rc = dasd_sleep_on(cqr); - if (rc && suborder_not_supported(cqr)) - return -EOPNOTSUPP; - } while (rc && (cqr->retries > 0)); - if (rc) { + rc = dasd_sleep_on(cqr); + if (rc && !suborder_not_supported(cqr)) { spin_lock_irqsave(&lcu->lock, flags); lcu->flags |= NEED_UAC_UPDATE; spin_unlock_irqrestore(&lcu->lock, flags);
After getting a storage server event that causes the DASD device driver to update its unit address configuration during a device shutdown there is the possibility of an endless loop in the device driver. In the system log there will be ongoing DASD error messages with RC: -19. The reason is that the loop starting the ruac request only terminates when the retry counter is decreased to 0. But in the sleep_on function there are early exit paths that do not decrease the retry counter. Prevent an endless loop by handling those cases separately. Remove the unnecessary do..while loop since the sleep_on function takes care of retries by itself. Fixes: 8e09f21574ea ("[S390] dasd: add hyper PAV support to DASD device driver, part 1") Cc: stable@vger.kernel.org # 2.6.25+ Signed-off-by: Stefan Haberland <sth@linux.ibm.com> Reviewed-by: Jan Hoeppner <hoeppner@linux.ibm.com> --- drivers/s390/block/dasd_alias.c | 22 ++++++++++++++++------ 1 file changed, 16 insertions(+), 6 deletions(-)