From: Darrick J. Wong <djwong@kernel.org>
Date: Mon, 27 Jul 2026 05:26:06 +0000 (-0700)
Subject: xfs: fix allocated inodes that show up in the unlinked list
X-Git-Tag: v7.2-rc7~29^2~8
X-Git-Url: http://git.ipfire.org/gitweb/?a=commitdiff_plain;h=68ab37650ce5195b4f4f8466444a36a78207840c;p=thirdparty%2Fkernel%2Flinux.git

xfs: fix allocated inodes that show up in the unlinked list

If an allocated inode shows up in the unlinked list, we need to get it
completely off the list.  Set the corrected next/prev pointers such that
the inode will not look like it should be on an unlinked list at all.

Cc: stable@vger.kernel.org # v6.10
Fixes: ab97f4b1c03075 ("xfs: repair AGI unlinked inode bucket lists")
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Carlos Maiolino <cem@kernel.org>
---

diff --git a/fs/xfs/scrub/agheader_repair.c b/fs/xfs/scrub/agheader_repair.c
index 8514d2d7e3ce..41de5cf87352 100644
--- a/fs/xfs/scrub/agheader_repair.c
+++ b/fs/xfs/scrub/agheader_repair.c
@@ -979,6 +979,13 @@ err:
 	return error;
 }
 
+/*
+ * Magic value that means "not unlinked" because xfarrays don't support storing
+ * totally zeroed elements.  There can't be a cluster that starts in daddr 0 so
+ * there can't be an inode #1 either.
+ */
+#define LINKED_AGINO	(0x1)
+
 /*
  * Record a forwards unlinked chain pointer from agino -> next_agino in our
  * staging information.
@@ -1362,6 +1369,35 @@ xrep_iunlink_resolve_bucket(
 			break;
 		}
 
+		if (VFS_I(ip)->i_nlink != 0) {
+			/*
+			 * Inode is linked somewhere!  Blow out both unlinked
+			 * list pointers, advance the list, and pretend we
+			 * didn't see this inode.  Clear it from iunlink_bmp
+			 * because it's linked.
+			 */
+			trace_xrep_iunlink_resolve_allocated(sc->sa.pag,
+					bucket, prev_agino, next_agino);
+
+			error = xrep_iunlink_store_next(ragi, next_agino,
+					NULLAGINO);
+			if (error)
+				return error;
+
+			error = xrep_iunlink_store_prev(ragi, next_agino,
+					LINKED_AGINO);
+			if (error)
+				return error;
+
+			error = xagino_bitmap_clear(&ragi->iunlink_bmp,
+					next_agino, 1);
+			if (error)
+				return error;
+
+			next_agino = ip->i_next_unlinked;
+			continue;
+		}
+
 		if (next_agino % XFS_AGI_UNLINKED_BUCKETS != bucket) {
 			/*
 			 * Inode is in the wrong bucket.  Advance the list,
@@ -1540,6 +1576,24 @@ xrep_iunlink_rebuild_buckets(
 			xrep_iunlink_add_lost_inodes, ragi);
 }
 
+static inline void
+set_inode_prev_unlinked(
+	struct xfs_inode	*ip,
+	xfs_agino_t		prev_agino)
+{
+	/*
+	 * Magic value that means "not unlinked" because xfarrays don't support
+	 * storing totally zeroed elements.
+	 */
+	if (prev_agino == LINKED_AGINO)
+		prev_agino = 0;
+
+	if (ip->i_prev_unlinked != prev_agino) {
+		trace_xrep_iunlink_relink_prev(ip, prev_agino);
+		ip->i_prev_unlinked = prev_agino;
+	}
+}
+
 /* Update i_next_iunlinked for the inode @agino. */
 STATIC int
 xrep_iunlink_relink_next(
@@ -1573,8 +1627,7 @@ xrep_iunlink_relink_next(
 		if (error)
 			goto out_rele;
 
-		trace_xrep_iunlink_relink_prev(ip, prev_agino);
-		ip->i_prev_unlinked = prev_agino;
+		set_inode_prev_unlinked(ip, prev_agino);
 	}
 
 	/* Update the forward pointer. */
@@ -1641,11 +1694,7 @@ xrep_iunlink_relink_prev(
 		ip->i_next_unlinked = next_agino;
 	}
 
-	/* Update the backward pointer. */
-	if (ip->i_prev_unlinked != prev_agino) {
-		trace_xrep_iunlink_relink_prev(ip, prev_agino);
-		ip->i_prev_unlinked = prev_agino;
-	}
+	set_inode_prev_unlinked(ip, prev_agino);
 
 out_rele:
 	/*
diff --git a/fs/xfs/scrub/trace.h b/fs/xfs/scrub/trace.h
index d5d39d82749e..00fbe1b9c235 100644
--- a/fs/xfs/scrub/trace.h
+++ b/fs/xfs/scrub/trace.h
@@ -3542,6 +3542,7 @@ DEFINE_REPAIR_IUNLINK_RESOLVE_EVENT(xrep_iunlink_resolve_uncached);
 DEFINE_REPAIR_IUNLINK_RESOLVE_EVENT(xrep_iunlink_resolve_wronglist);
 DEFINE_REPAIR_IUNLINK_RESOLVE_EVENT(xrep_iunlink_resolve_nolist);
 DEFINE_REPAIR_IUNLINK_RESOLVE_EVENT(xrep_iunlink_resolve_ok);
+DEFINE_REPAIR_IUNLINK_RESOLVE_EVENT(xrep_iunlink_resolve_allocated);
 
 TRACE_EVENT(xrep_iunlink_relink_next,
 	TP_PROTO(struct xfs_inode *ip, xfs_agino_t next_agino),