[PATCH 3/5] xfs: add a xfs_group_type_buftarg helper

[Christoph Hellwig <hch@xxxxxx>]

Generalize the xfs_group_type helper in the discard code to return a buftarg
and move it to xfs_mount.h, and use the result in xfs_dax_notify_dev_failure.

Signed-off-by: Christoph Hellwig <hch@xxxxxx>
Reviewed-by: John Garry <john.g.garry@xxxxxxxxxx>
Reviewed-by: "Darrick J. Wong" <djwong@xxxxxxxxxx>
---
 fs/xfs/xfs_discard.c        | 29 +++++++----------------------
 fs/xfs/xfs_mount.h          | 17 +++++++++++++++++
 fs/xfs/xfs_notify_failure.c |  3 +--
 3 files changed, 25 insertions(+), 24 deletions(-)

diff --git a/fs/xfs/xfs_discard.c b/fs/xfs/xfs_discard.c
index 94d0873bcd62..603d51365645 100644
--- a/fs/xfs/xfs_discard.c
+++ b/fs/xfs/xfs_discard.c
@@ -103,24 +103,6 @@ xfs_discard_endio(
 	bio_put(bio);
 }
 
-static inline struct block_device *
-xfs_group_bdev(
-	const struct xfs_group	*xg)
-{
-	struct xfs_mount	*mp = xg->xg_mount;
-
-	switch (xg->xg_type) {
-	case XG_TYPE_AG:
-		return mp->m_ddev_targp->bt_bdev;
-	case XG_TYPE_RTG:
-		return mp->m_rtdev_targp->bt_bdev;
-	default:
-		ASSERT(0);
-		break;
-	}
-	return NULL;
-}
-
 /*
  * Walk the discard list and issue discards on all the busy extents in the
  * list. We plug and chain the bios so that we only need a single completion
@@ -138,11 +120,14 @@ xfs_discard_extents(
 
 	blk_start_plug(&plug);
 	list_for_each_entry(busyp, &extents->extent_list, list) {
-		trace_xfs_discard_extent(busyp->group, busyp->bno,
-				busyp->length);
+		struct xfs_group	*xg = busyp->group;
+		struct xfs_buftarg	*btp =
+			xfs_group_type_buftarg(xg->xg_mount, xg->xg_type);
+
+		trace_xfs_discard_extent(xg, busyp->bno, busyp->length);
 
-		error = __blkdev_issue_discard(xfs_group_bdev(busyp->group),
-				xfs_gbno_to_daddr(busyp->group, busyp->bno),
+		error = __blkdev_issue_discard(btp->bt_bdev,
+				xfs_gbno_to_daddr(xg, busyp->bno),
 				XFS_FSB_TO_BB(mp, busyp->length),
 				GFP_KERNEL, &bio);
 		if (error && error != -EOPNOTSUPP) {
diff --git a/fs/xfs/xfs_mount.h b/fs/xfs/xfs_mount.h
index d85084f9f317..97de44c32272 100644
--- a/fs/xfs/xfs_mount.h
+++ b/fs/xfs/xfs_mount.h
@@ -802,4 +802,21 @@ static inline void xfs_mod_sb_delalloc(struct xfs_mount *mp, int64_t delta)
 int xfs_set_max_atomic_write_opt(struct xfs_mount *mp,
 		unsigned long long new_max_bytes);
 
+static inline struct xfs_buftarg *
+xfs_group_type_buftarg(
+	struct xfs_mount	*mp,
+	enum xfs_group_type	type)
+{
+	switch (type) {
+	case XG_TYPE_AG:
+		return mp->m_ddev_targp;
+	case XG_TYPE_RTG:
+		return mp->m_rtdev_targp;
+	default:
+		ASSERT(0);
+		break;
+	}
+	return NULL;
+}
+
 #endif	/* __XFS_MOUNT_H__ */
diff --git a/fs/xfs/xfs_notify_failure.c b/fs/xfs/xfs_notify_failure.c
index 3545dc1d953c..42e9c72b85c0 100644
--- a/fs/xfs/xfs_notify_failure.c
+++ b/fs/xfs/xfs_notify_failure.c
@@ -253,8 +253,7 @@ xfs_dax_notify_dev_failure(
 		return -EOPNOTSUPP;
 	}
 
-	error = xfs_dax_translate_range(type == XG_TYPE_RTG ?
-			mp->m_rtdev_targp : mp->m_ddev_targp,
+	error = xfs_dax_translate_range(xfs_group_type_buftarg(mp, type),
 			offset, len, &daddr, &bblen);
 	if (error)
 		return error;
-- 
2.47.2