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| author | Stefan Haberland <sth@linux.ibm.com> | 2020-12-17 18:59:06 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2020-12-29 15:47:05 +0300 |
| commit | bc46e8030d6b1c3f6f4fd01c646e81a73f8066af (patch) | |
| tree | 5e3a596fd7c0c7624f950902e38ab210b6636e15 | |
| parent | 369b707afb69d804d4dc6237016269a1417056fd (diff) | |
| download | linux-bc46e8030d6b1c3f6f4fd01c646e81a73f8066af.tar.xz | |
s390/dasd: fix list corruption of pavgroup group list
commit 0ede91f83aa335da1c3ec68eb0f9e228f269f6d8 upstream.
dasd_alias_add_device() moves devices to the active_devices list in case
of a scheduled LCU update regardless if they have previously been in a
pavgroup or not.
Example: device A and B are in the same pavgroup.
Device A has already been in a pavgroup and the private->pavgroup pointer
is set and points to a valid pavgroup. While going through dasd_add_device
it is moved from the pavgroup to the active_devices list.
In parallel device B might be removed from the same pavgroup in
remove_device_from_lcu() which in turn checks if the group is empty
and deletes it accordingly because device A has already been removed from
there.
When now device A enters remove_device_from_lcu() it is tried to remove it
from the pavgroup again because the pavgroup pointer is still set and again
the empty group will be cleaned up which leads to a list corruption.
Fix by setting private->pavgroup to NULL in dasd_add_device.
If the device has been the last device on the pavgroup an empty pavgroup
remains but this will be cleaned up by the scheduled lcu_update which
iterates over all existing pavgroups.
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>
| -rw-r--r-- | drivers/s390/block/dasd_alias.c | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/drivers/s390/block/dasd_alias.c b/drivers/s390/block/dasd_alias.c index b4f86305792d..19c569f4b957 100644 --- a/drivers/s390/block/dasd_alias.c +++ b/drivers/s390/block/dasd_alias.c @@ -634,6 +634,7 @@ int dasd_alias_add_device(struct dasd_device *device) } if (lcu->flags & UPDATE_PENDING) { list_move(&device->alias_list, &lcu->active_devices); + private->pavgroup = NULL; _schedule_lcu_update(lcu, device); } spin_unlock_irqrestore(&lcu->lock, flags); |