btrfs: zoned: calculate max_extent_size properly on non-zoned setup

Since commit 559218d43ec9 ("block: pre-calculate max_zone_append_sectors"),
queue_limits's max_zone_append_sectors is default to be 0 and it is only
updated when there is a zoned device. So, we have
lim->max_zone_append_sectors = 0 when there is no zoned device in the
filesystem.

That leads to fs_info->max_zone_append_size and thus
fs_info->max_extent_size to be 0, which is wrong and can for example
lead to a divide by zero in count_max_extents().

Fix this by only capping fs_info->max_extent_size to
fs_info->max_zone_append_size when it is non-zero.

Based on a patch from Naohiro Aota <[email protected]>, from which
much of this commit message is stolen as well.

Reported-by: Shinichiro Kawasaki <[email protected]>
Fixes: 559218d43ec9 ("block: pre-calculate max_zone_append_sectors")
Tested-by: Shinichiro Kawasaki <[email protected]>
Reviewed-by: Johannes Thumshirn <[email protected]>
Reviewed-by: Naohiro Aota <[email protected]>
Signed-off-by: Christoph Hellwig <[email protected]>
Signed-off-by: David Sterba <[email protected]>

0 files changed, 0 insertions, 0 deletions