From 8368a6019d5bbb8b56c140029dcf5ea570b638f1 Mon Sep 17 00:00:00 2001
From: "Darrick J. Wong" <darrick.wong@oracle.com>
Date: Mon, 8 Jan 2018 10:51:00 -0800
Subject: xfs: refactor long-format btree header verification routines

Create two helper functions to verify the headers of a long format
btree block.  We'll use this later for the realtime rmapbt.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
---
 fs/xfs/libxfs/xfs_bmap_btree.c | 22 ++-------------------
 fs/xfs/libxfs/xfs_btree.c      | 45 ++++++++++++++++++++++++++++++++++++++++++
 fs/xfs/libxfs/xfs_btree.h      |  3 +++
 3 files changed, 50 insertions(+), 20 deletions(-)

(limited to 'fs')

diff --git a/fs/xfs/libxfs/xfs_bmap_btree.c b/fs/xfs/libxfs/xfs_bmap_btree.c
index 00472e184e7c..862be9c5eb08 100644
--- a/fs/xfs/libxfs/xfs_bmap_btree.c
+++ b/fs/xfs/libxfs/xfs_bmap_btree.c
@@ -435,17 +435,11 @@ xfs_bmbt_verify(
 
 	switch (block->bb_magic) {
 	case cpu_to_be32(XFS_BMAP_CRC_MAGIC):
-		if (!xfs_sb_version_hascrc(&mp->m_sb))
-			return false;
-		if (!uuid_equal(&block->bb_u.l.bb_uuid, &mp->m_sb.sb_meta_uuid))
-			return false;
-		if (be64_to_cpu(block->bb_u.l.bb_blkno) != bp->b_bn)
-			return false;
 		/*
 		 * XXX: need a better way of verifying the owner here. Right now
 		 * just make sure there has been one set.
 		 */
-		if (be64_to_cpu(block->bb_u.l.bb_owner) == 0)
+		if (!xfs_btree_lblock_v5hdr_verify(bp, XFS_RMAP_OWN_UNKNOWN))
 			return false;
 		/* fall through */
 	case cpu_to_be32(XFS_BMAP_MAGIC):
@@ -464,20 +458,8 @@ xfs_bmbt_verify(
 	level = be16_to_cpu(block->bb_level);
 	if (level > max(mp->m_bm_maxlevels[0], mp->m_bm_maxlevels[1]))
 		return false;
-	if (be16_to_cpu(block->bb_numrecs) > mp->m_bmap_dmxr[level != 0])
-		return false;
-
-	/* sibling pointer verification */
-	if (!block->bb_u.l.bb_leftsib ||
-	    (block->bb_u.l.bb_leftsib != cpu_to_be64(NULLFSBLOCK) &&
-	     !xfs_verify_fsbno(mp, be64_to_cpu(block->bb_u.l.bb_leftsib))))
-		return false;
-	if (!block->bb_u.l.bb_rightsib ||
-	    (block->bb_u.l.bb_rightsib != cpu_to_be64(NULLFSBLOCK) &&
-	     !xfs_verify_fsbno(mp, be64_to_cpu(block->bb_u.l.bb_rightsib))))
-		return false;
 
-	return true;
+	return xfs_btree_lblock_verify(bp, mp->m_bmap_dmxr[level != 0]);
 }
 
 static void
diff --git a/fs/xfs/libxfs/xfs_btree.c b/fs/xfs/libxfs/xfs_btree.c
index 54c0a927a0fa..95d4c355c466 100644
--- a/fs/xfs/libxfs/xfs_btree.c
+++ b/fs/xfs/libxfs/xfs_btree.c
@@ -4529,6 +4529,51 @@ xfs_btree_change_owner(
 			&bbcoi);
 }
 
+/* Verify the v5 fields of a long-format btree block. */
+bool
+xfs_btree_lblock_v5hdr_verify(
+	struct xfs_buf		*bp,
+	uint64_t		owner)
+{
+	struct xfs_mount	*mp = bp->b_target->bt_mount;
+	struct xfs_btree_block	*block = XFS_BUF_TO_BLOCK(bp);
+
+	if (!xfs_sb_version_hascrc(&mp->m_sb))
+		return false;
+	if (!uuid_equal(&block->bb_u.l.bb_uuid, &mp->m_sb.sb_meta_uuid))
+		return false;
+	if (block->bb_u.l.bb_blkno != cpu_to_be64(bp->b_bn))
+		return false;
+	if (owner != XFS_RMAP_OWN_UNKNOWN &&
+	    be64_to_cpu(block->bb_u.l.bb_owner) != owner)
+		return false;
+	return true;
+}
+
+/* Verify a long-format btree block. */
+bool
+xfs_btree_lblock_verify(
+	struct xfs_buf		*bp,
+	unsigned int		max_recs)
+{
+	struct xfs_mount	*mp = bp->b_target->bt_mount;
+	struct xfs_btree_block	*block = XFS_BUF_TO_BLOCK(bp);
+
+	/* numrecs verification */
+	if (be16_to_cpu(block->bb_numrecs) > max_recs)
+		return false;
+
+	/* sibling pointer verification */
+	if (block->bb_u.l.bb_leftsib != cpu_to_be64(NULLFSBLOCK) &&
+	    !xfs_verify_fsbno(mp, be64_to_cpu(block->bb_u.l.bb_leftsib)))
+		return false;
+	if (block->bb_u.l.bb_rightsib != cpu_to_be64(NULLFSBLOCK) &&
+	    !xfs_verify_fsbno(mp, be64_to_cpu(block->bb_u.l.bb_rightsib)))
+		return false;
+
+	return true;
+}
+
 /**
  * xfs_btree_sblock_v5hdr_verify() -- verify the v5 fields of a short-format
  *				      btree block
diff --git a/fs/xfs/libxfs/xfs_btree.h b/fs/xfs/libxfs/xfs_btree.h
index b495381b629f..5f86ee14cc66 100644
--- a/fs/xfs/libxfs/xfs_btree.h
+++ b/fs/xfs/libxfs/xfs_btree.h
@@ -494,6 +494,9 @@ static inline int xfs_btree_get_level(struct xfs_btree_block *block)
 
 bool xfs_btree_sblock_v5hdr_verify(struct xfs_buf *bp);
 bool xfs_btree_sblock_verify(struct xfs_buf *bp, unsigned int max_recs);
+bool xfs_btree_lblock_v5hdr_verify(struct xfs_buf *bp, uint64_t owner);
+bool xfs_btree_lblock_verify(struct xfs_buf *bp, unsigned int max_recs);
+
 uint xfs_btree_compute_maxlevels(struct xfs_mount *mp, uint *limits,
 				 unsigned long len);
 xfs_extlen_t xfs_btree_calc_size(struct xfs_mount *mp, uint *limits,
-- 
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