On Mon, May 24, 2021 at 05:25:55PM +0200, Greg Kroah-Hartman wrote:
From: Johannes Thumshirn johannes.thumshirn@wdc.com
commit 764c7c9a464b68f7c6a5a9ec0b923176a05e8e8f upstream.
When multiple processes write data to the same block group on a compressed zoned filesystem, the underlying device could report I/O errors and data corruption is possible.
This happens because on a zoned file system, compressed data writes where sent to the device via a REQ_OP_WRITE instead of a REQ_OP_ZONE_APPEND operation. But with REQ_OP_WRITE and parallel submission it cannot be guaranteed that the data is always submitted aligned to the underlying zone's write pointer.
The change to using REQ_OP_ZONE_APPEND instead of REQ_OP_WRITE on a zoned filesystem is non intrusive on a regular file system or when submitting to a conventional zone on a zoned filesystem, as it is guarded by btrfs_use_zone_append.
Reported-by: David Sterba dsterba@suse.com Fixes: 9d294a685fbc ("btrfs: zoned: enable to mount ZONED incompat flag") CC: stable@vger.kernel.org # 5.12.x: e380adfc213a13: btrfs: zoned: pass start block to btrfs_use_zone_append CC: stable@vger.kernel.org # 5.12.x Signed-off-by: Johannes Thumshirn johannes.thumshirn@wdc.com Signed-off-by: David Sterba dsterba@suse.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
We found a bug in this patch, please drop it from 5.12 queue.