From: Stefan Haberland sth@linux.ibm.com
commit a29ea01653493b94ea12bb2b89d1564a265081b6 upstream.
Prevent _lcu_update from adding a device to a pavgroup if the LCU still requires an update. The data is not reliable any longer and in parallel devices might have been moved on the lists already. This might lead to list corruptions or invalid PAV grouping. Only add devices to a pavgroup if the LCU is up to date. Additional steps are taken by the scheduled lcu update.
Fixes: 8e09f21574ea ("[S390] dasd: add hyper PAV support to DASD device driver, part 1") Cc: stable@vger.kernel.org Signed-off-by: Stefan Haberland sth@linux.ibm.com Reviewed-by: Jan Hoeppner hoeppner@linux.ibm.com Signed-off-by: Jens Axboe axboe@kernel.dk Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- drivers/s390/block/dasd_alias.c | 9 +++++++++ 1 file changed, 9 insertions(+)
--- a/drivers/s390/block/dasd_alias.c +++ b/drivers/s390/block/dasd_alias.c @@ -511,6 +511,14 @@ static int _lcu_update(struct dasd_devic return rc;
spin_lock_irqsave(&lcu->lock, flags); + /* + * there is another update needed skip the remaining handling + * the data might already be outdated + * but especially do not add the device to an LCU with pending + * update + */ + if (lcu->flags & NEED_UAC_UPDATE) + goto out; lcu->pav = NO_PAV; for (i = 0; i < MAX_DEVICES_PER_LCU; ++i) { switch (lcu->uac->unit[i].ua_type) { @@ -529,6 +537,7 @@ static int _lcu_update(struct dasd_devic alias_list) { _add_device_to_lcu(lcu, device, refdev); } +out: spin_unlock_irqrestore(&lcu->lock, flags); return 0; }