Jan Höppner 31efa3b5b5 s390/dasd: Fix zero write for FBA devices
commit 709192d531e5b0a91f20aa14abfe2fc27ddd47af upstream.

A discard request that writes zeros using the global kernel internal
ZERO_PAGE will fail for machines with more than 2GB of memory due to the
location of the ZERO_PAGE.

Fix this by using a driver owned global zero page allocated with GFP_DMA
flag set.

Fixes: 28b841b3a7cb ("s390/dasd: Add discard support for FBA devices")
Signed-off-by: Jan Höppner <hoeppner@linux.ibm.com>
Reviewed-by: Stefan Haberland <sth@linux.ibm.com>
Cc: <stable@vger.kernel.org> # 4.14+
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-10-01 13:18:23 +02:00
..
2019-07-05 15:19:10 -07:00
2019-06-04 15:03:46 +02:00