[PATCH 1/4] repair: access helpers for on-disk inobt record freecount

[Brian Foster]

The on-disk inobt record has two formats depending on whether sparse
inode support is enabled or not. If so, the freecount field is a single
byte and does not require byte-conversion. Otherwise, it is a 4-byte
field and does.

Create the inorec_[get|set]_freecount() helpers to abstract this detail
away from the core repair code.

Signed-off-by: Brian Foster <bfoster at redhat.com>
---
 repair/incore.h | 28 ++++++++++++++++++++++++++++
 repair/phase5.c | 12 +++++++-----
 repair/scan.c   | 15 +++------------
 3 files changed, 38 insertions(+), 17 deletions(-)

diff --git a/repair/incore.h b/repair/incore.h
index 5a63e1e..c92475e 100644
--- a/repair/incore.h
+++ b/repair/incore.h
@@ -591,4 +591,32 @@ typedef struct bm_cursor  {
 
 void init_bm_cursor(bmap_cursor_t *cursor, int num_level);
 
+/*
+ * On-disk inobt record helpers. The sparse inode record format has a single
+ * byte freecount. The older format has a 32-bit freecount and thus byte
+ * conversion is necessary.
+ */
+
+static inline int
+inorec_get_freecount(
+	struct xfs_mount	*mp,
+	struct xfs_inobt_rec	*rp)
+{
+	if (xfs_sb_version_hassparseinodes(&mp->m_sb))
+		return rp->ir_u.sp.ir_freecount;
+	return be32_to_cpu(rp->ir_u.f.ir_freecount);
+}
+
+static inline void
+inorec_set_freecount(
+	struct xfs_mount	*mp,
+	struct xfs_inobt_rec	*rp,
+	int			freecount)
+{
+	if (xfs_sb_version_hassparseinodes(&mp->m_sb))
+		rp->ir_u.sp.ir_freecount = freecount;
+	else
+		rp->ir_u.f.ir_freecount = cpu_to_be32(freecount);
+}
+
 #endif /* XFS_REPAIR_INCORE_H */
diff --git a/repair/phase5.c b/repair/phase5.c
index 0601810..7372734 100644
--- a/repair/phase5.c
+++ b/repair/phase5.c
@@ -1258,11 +1258,14 @@ build_ino_tree(xfs_mount_t *mp, xfs_agnumber_t agno,
 				inocnt++;
 			}
 
-			if (!xfs_sb_version_hassparseinodes(&mp->m_sb)) {
-				bt_rec[j].ir_u.f.ir_freecount =
-							cpu_to_be32(finocnt);
+			/*
+			 * Set the freecount and check whether we need to update
+			 * the sparse format fields. Otherwise, skip to the next
+			 * record.
+			 */
+			inorec_set_freecount(mp, &bt_rec[j], finocnt);
+			if (!xfs_sb_version_hassparseinodes(&mp->m_sb))
 				goto nextrec;
-			}
 
 			/*
 			 * Convert the 64-bit in-core sparse inode state to the
@@ -1280,7 +1283,6 @@ build_ino_tree(xfs_mount_t *mp, xfs_agnumber_t agno,
 				sparse >>= XFS_INODES_PER_HOLEMASK_BIT;
 			}
 
-			bt_rec[j].ir_u.sp.ir_freecount = finocnt;
 			bt_rec[j].ir_u.sp.ir_count = inocnt;
 			bt_rec[j].ir_u.sp.ir_holemask = cpu_to_be16(holemask);
 
diff --git a/repair/scan.c b/repair/scan.c
index e3895c2..1a6f0c5 100644
--- a/repair/scan.c
+++ b/repair/scan.c
@@ -786,10 +786,7 @@ scan_single_ino_chunk(
 	off = XFS_AGINO_TO_OFFSET(mp, ino);
 	agbno = XFS_AGINO_TO_AGBNO(mp, ino);
 	lino = XFS_AGINO_TO_INO(mp, agno, ino);
-	if (xfs_sb_version_hassparseinodes(&mp->m_sb))
-		freecount = rp->ir_u.sp.ir_freecount;
-	else
-		freecount = be32_to_cpu(rp->ir_u.f.ir_freecount);
+	freecount = inorec_get_freecount(mp, rp);
 
 	/*
 	 * on multi-block block chunks, all chunks start
@@ -987,10 +984,7 @@ scan_single_finobt_chunk(
 	off = XFS_AGINO_TO_OFFSET(mp, ino);
 	agbno = XFS_AGINO_TO_AGBNO(mp, ino);
 	lino = XFS_AGINO_TO_INO(mp, agno, ino);
-	if (xfs_sb_version_hassparseinodes(&mp->m_sb))
-		freecount = rp->ir_u.sp.ir_freecount;
-	else
-		freecount = be32_to_cpu(rp->ir_u.f.ir_freecount);
+	freecount = inorec_get_freecount(mp, rp);
 
 	/*
 	 * on multi-block block chunks, all chunks start at the beginning of the
@@ -1331,10 +1325,7 @@ _("inode btree block claimed (state %d), agno %d, bno %d, suspect %d\n"),
 		 * the block.  skip processing of bogus records.
 		 */
 		for (i = 0; i < numrecs; i++) {
-			if (xfs_sb_version_hassparseinodes(&mp->m_sb))
-				freecount = rp[i].ir_u.sp.ir_freecount;
-			else
-				freecount = be32_to_cpu(rp[i].ir_u.f.ir_freecount);
+			freecount = inorec_get_freecount(mp, &rp[i]);
 
 			if (magic == XFS_IBT_MAGIC ||
 			    magic == XFS_IBT_CRC_MAGIC) {
-- 
1.9.3