xfs: perform dax_device lookup at mount
authorDan Williams <dan.j.williams@intel.com>
Thu, 24 Aug 2017 22:12:50 +0000 (15:12 -0700)
committerDan Williams <dan.j.williams@intel.com>
Thu, 31 Aug 2017 16:31:47 +0000 (09:31 -0700)
commit486aff5e04823bb1e60c4045226eb244024b8420
treec0cc960b998086e92873d918f203a5e737e97db6
parent78f35473508118df5ea04b9515ac3f1aaec0a980
xfs: perform dax_device lookup at mount

The ->iomap_begin() operation is a hot path, so cache the
fs_dax_get_by_host() result at mount time to avoid the incurring the
hash lookup overhead on a per-i/o basis.

Reported-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
fs/xfs/xfs_aops.c
fs/xfs/xfs_aops.h
fs/xfs/xfs_buf.c
fs/xfs/xfs_buf.h
fs/xfs/xfs_iomap.c
fs/xfs/xfs_super.c