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| author | Stefan Haberland <sth@linux.ibm.com> | 2020-12-17 16:59:07 +0100 |
|---|---|---|
| committer | Jens Axboe <axboe@kernel.dk> | 2020-12-17 21:41:30 +0100 |
| commit | 53a7f655834c7c335bf683f248208d4fbe4b47bc (patch) | |
| tree | 348e7994fa9b053a297b1ba5b542316703f57126 /drivers/s390/block/dasd_alias.c | |
| parent | s390/dasd: fix list corruption of pavgroup group list (diff) | |
| download | linux-53a7f655834c7c335bf683f248208d4fbe4b47bc.tar.xz linux-53a7f655834c7c335bf683f248208d4fbe4b47bc.zip | |
s390/dasd: fix list corruption of lcu list
In dasd_alias_disconnect_device_from_lcu the device is removed from any
list on the LCU. Afterwards the LCU is removed from the lcu list if it
does not contain devices any longer.
The lcu->lock protects the lcu from parallel updates. But to cancel all
workers and wait for completion the lcu->lock has to be unlocked.
If two devices are removed in parallel and both are removed from the LCU
the first device that takes the lcu->lock again will delete the LCU because
it is already empty but the second device also tries to free the LCU which
leads to a list corruption of the lcu list.
Fix by removing the device right before the lcu is checked without
unlocking the lcu->lock in between.
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>
Diffstat (limited to 'drivers/s390/block/dasd_alias.c')
| -rw-r--r-- | drivers/s390/block/dasd_alias.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/drivers/s390/block/dasd_alias.c b/drivers/s390/block/dasd_alias.c index 60344e13e87b..dc78a523a69f 100644 --- a/drivers/s390/block/dasd_alias.c +++ b/drivers/s390/block/dasd_alias.c @@ -256,7 +256,6 @@ void dasd_alias_disconnect_device_from_lcu(struct dasd_device *device) return; device->discipline->get_uid(device, &uid); spin_lock_irqsave(&lcu->lock, flags); - list_del_init(&device->alias_list); /* make sure that the workers don't use this device */ if (device == lcu->suc_data.device) { spin_unlock_irqrestore(&lcu->lock, flags); @@ -283,6 +282,7 @@ void dasd_alias_disconnect_device_from_lcu(struct dasd_device *device) spin_lock_irqsave(&aliastree.lock, flags); spin_lock(&lcu->lock); + list_del_init(&device->alias_list); if (list_empty(&lcu->grouplist) && list_empty(&lcu->active_devices) && list_empty(&lcu->inactive_devices)) { |