[PATCH 6.18.y 1/2] xfs: hoist per-bucket unlinked list check to helper

[Sasha Levin <sashal@kernel.org>]

From: "Darrick J. Wong" <djwong@kernel.org>

[ Upstream commit 7cdafd8f10ebdf745ba6046b9fa67490c343a17f ]

In the next patch we're going to make this loop more exciting, so hoist
the code to a helper function to reduce clutter in the resulting code.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Carlos Maiolino <cem@kernel.org>
Stable-dep-of: 527eaaefddb6 ("xfs: don't livelock in scrub on a circular unlinked list")
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 fs/xfs/scrub/agheader.c | 64 +++++++++++++++++++++++++++--------------
 1 file changed, 42 insertions(+), 22 deletions(-)

diff --git a/fs/xfs/scrub/agheader.c b/fs/xfs/scrub/agheader.c
index 2ac2125b83172..7c44ea7a26c95 100644
--- a/fs/xfs/scrub/agheader.c
+++ b/fs/xfs/scrub/agheader.c
@@ -932,6 +932,42 @@ xchk_agi_xref(
 	/* scrub teardown will take care of sc->sa for us */
 }
 
+/*
+ * Walk the incore unlinked list for a particular AGI bucket to construct
+ * the unlinked inode bitmap for later reconstruction of the unlinked list.
+ * Returns 1 if we should keep checking, or 0 to stop checking.
+ */
+static int
+xchk_iunlink_bucket(
+	struct xfs_scrub		*sc,
+	unsigned int			bucket,
+	xfs_agino_t			agino)
+{
+	while (agino != NULLAGINO) {
+		struct xfs_inode	*ip;
+
+		if (agino % XFS_AGI_UNLINKED_BUCKETS != bucket) {
+			xchk_block_set_corrupt(sc, sc->sa.agi_bp);
+			return 0;
+		}
+
+		ip = xfs_iunlink_lookup(sc->sa.pag, agino);
+		if (!ip) {
+			xchk_block_set_corrupt(sc, sc->sa.agi_bp);
+			return 0;
+		}
+
+		if (!xfs_inode_on_unlinked_list(ip)) {
+			xchk_block_set_corrupt(sc, sc->sa.agi_bp);
+			return 0;
+		}
+
+		agino = ip->i_next_unlinked;
+	}
+
+	return 1;
+}
+
 /*
  * Check the unlinked buckets for links to bad inodes.  We hold the AGI, so
  * there cannot be any threads updating unlinked list pointers in this AG.
@@ -942,30 +978,14 @@ xchk_iunlink(
 	struct xfs_agi		*agi)
 {
 	unsigned int		i;
-	struct xfs_inode	*ip;
 
 	for (i = 0; i < XFS_AGI_UNLINKED_BUCKETS; i++) {
-		xfs_agino_t	agino = be32_to_cpu(agi->agi_unlinked[i]);
-
-		while (agino != NULLAGINO) {
-			if (agino % XFS_AGI_UNLINKED_BUCKETS != i) {
-				xchk_block_set_corrupt(sc, sc->sa.agi_bp);
-				return;
-			}
-
-			ip = xfs_iunlink_lookup(sc->sa.pag, agino);
-			if (!ip) {
-				xchk_block_set_corrupt(sc, sc->sa.agi_bp);
-				return;
-			}
-
-			if (!xfs_inode_on_unlinked_list(ip)) {
-				xchk_block_set_corrupt(sc, sc->sa.agi_bp);
-				return;
-			}
-
-			agino = ip->i_next_unlinked;
-		}
+		int		ret;
+
+		ret = xchk_iunlink_bucket(sc, i,
+				be32_to_cpu(agi->agi_unlinked[i]));
+		if (ret < 1)
+			return;
 	}
 }
 
-- 
2.53.0