xfs: update BDI {io,ra}_pages values based on the RT device limits

When using XFS with a main device on an SSD that stores metadata and a RT
device to store data on a HDD, we fail to take the I/O sizes for the RT
device into accounting, leading to up to 5% slower read performance when
using an SSD for metadata vs storing data and metadata on the HDD.

Fix this up by taking the RT settings into account at mount an restoring
the old settings at unmount time, unless the BDI settings have changed
from those set by XFS.

Reported-by: Filip Blagojevic <filip.blagojevic@wdc.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Carlos Maiolino <cmaiolino@redhat.com>
Reviewed-by: Damien Le Moal <dlemoal@kernel.org>
Signed-off-by: Carlos Maiolino <cem@kernel.org>

0 files changed, 0 insertions, 0 deletions