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>
diff --git a/fs/xfs/xfs_buf.c b/fs/xfs/xfs_buf.c
index 72f0384..6deb86c 100644
--- a/fs/xfs/xfs_buf.c
+++ b/fs/xfs/xfs_buf.c
@@ -1802,7 +1802,8 @@ xfs_setsize_buftarg_early(
xfs_buftarg_t *
xfs_alloc_buftarg(
struct xfs_mount *mp,
- struct block_device *bdev)
+ struct block_device *bdev,
+ struct dax_device *dax_dev)
{
xfs_buftarg_t *btp;
@@ -1811,6 +1812,7 @@ xfs_alloc_buftarg(
btp->bt_mount = mp;
btp->bt_dev = bdev->bd_dev;
btp->bt_bdev = bdev;
+ btp->bt_daxdev = dax_dev;
if (xfs_setsize_buftarg_early(btp, bdev))
goto error;