xfs: split the agf_roots and agf_levels arrays

Using arrays of largely unrelated fields that use the btree number
as index is not very robust.  Split the arrays into three separate
fields instead.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Darrick J. Wong <djwong@kernel.org>

1 files changed, 19 insertions, 30 deletions

diff --git a/fs/xfs/libxfs/xfs_alloc.c b/fs/xfs/libxfs/xfs_alloc.c
index 91553a54dc30..7300dc219589 100644
--- a/fs/xfs/libxfs/xfs_alloc.c
+++ b/fs/xfs/libxfs/xfs_alloc.c
@@ -2335,8 +2335,9 @@ xfs_alloc_min_freelist(
 	struct xfs_perag	*pag)
 {
 	/* AG btrees have at least 1 level. */
-	static const uint8_t	fake_levels[XFS_BTNUM_AGF] = {1, 1, 1};
-	const uint8_t		*levels = pag ? pag->pagf_levels : fake_levels;
+	const unsigned int	bno_level = pag ? pag->pagf_bno_level : 1;
+	const unsigned int	cnt_level = pag ? pag->pagf_cnt_level : 1;
+	const unsigned int	rmap_level = pag ? pag->pagf_rmap_level : 1;
 	unsigned int		min_free;
 
 	ASSERT(mp->m_alloc_maxlevels > 0);
@@ -2363,16 +2364,12 @@ xfs_alloc_min_freelist(
 	 */
 
 	/* space needed by-bno freespace btree */
-	min_free = min_t(unsigned int, levels[XFS_BTNUM_BNOi] + 1,
-				       mp->m_alloc_maxlevels) * 2 - 2;
+	min_free = min(bno_level + 1, mp->m_alloc_maxlevels) * 2 - 2;
 	/* space needed by-size freespace btree */
-	min_free += min_t(unsigned int, levels[XFS_BTNUM_CNTi] + 1,
-				       mp->m_alloc_maxlevels) * 2 - 2;
+	min_free += min(cnt_level + 1, mp->m_alloc_maxlevels) * 2 - 2;
 	/* space needed reverse mapping used space btree */
 	if (xfs_has_rmapbt(mp))
-		min_free += min_t(unsigned int, levels[XFS_BTNUM_RMAPi] + 1,
-						mp->m_rmap_maxlevels) * 2 - 2;
-
+		min_free += min(rmap_level + 1, mp->m_rmap_maxlevels) * 2 - 2;
 	return min_free;
 }
 
@@ -3056,8 +3053,8 @@ xfs_alloc_log_agf(
 		offsetof(xfs_agf_t, agf_versionnum),
 		offsetof(xfs_agf_t, agf_seqno),
 		offsetof(xfs_agf_t, agf_length),
-		offsetof(xfs_agf_t, agf_roots[0]),
-		offsetof(xfs_agf_t, agf_levels[0]),
+		offsetof(xfs_agf_t, agf_bno_root),   /* also cnt/rmap root */
+		offsetof(xfs_agf_t, agf_bno_level),  /* also cnt/rmap levels */
 		offsetof(xfs_agf_t, agf_flfirst),
 		offsetof(xfs_agf_t, agf_fllast),
 		offsetof(xfs_agf_t, agf_flcount),
@@ -3236,12 +3233,10 @@ xfs_agf_verify(
 	    be32_to_cpu(agf->agf_freeblks) > agf_length)
 		return __this_address;
 
-	if (be32_to_cpu(agf->agf_levels[XFS_BTNUM_BNO]) < 1 ||
-	    be32_to_cpu(agf->agf_levels[XFS_BTNUM_CNT]) < 1 ||
-	    be32_to_cpu(agf->agf_levels[XFS_BTNUM_BNO]) >
-						mp->m_alloc_maxlevels ||
-	    be32_to_cpu(agf->agf_levels[XFS_BTNUM_CNT]) >
-						mp->m_alloc_maxlevels)
+	if (be32_to_cpu(agf->agf_bno_level) < 1 ||
+	    be32_to_cpu(agf->agf_cnt_level) < 1 ||
+	    be32_to_cpu(agf->agf_bno_level) > mp->m_alloc_maxlevels ||
+	    be32_to_cpu(agf->agf_cnt_level) > mp->m_alloc_maxlevels)
 		return __this_address;
 
 	if (xfs_has_lazysbcount(mp) &&
@@ -3252,9 +3247,8 @@ xfs_agf_verify(
 		if (be32_to_cpu(agf->agf_rmap_blocks) > agf_length)
 			return __this_address;
 
-		if (be32_to_cpu(agf->agf_levels[XFS_BTNUM_RMAP]) < 1 ||
-		    be32_to_cpu(agf->agf_levels[XFS_BTNUM_RMAP]) >
-							mp->m_rmap_maxlevels)
+		if (be32_to_cpu(agf->agf_rmap_level) < 1 ||
+		    be32_to_cpu(agf->agf_rmap_level) > mp->m_rmap_maxlevels)
 			return __this_address;
 	}
 
@@ -3380,12 +3374,9 @@ xfs_alloc_read_agf(
 		pag->pagf_btreeblks = be32_to_cpu(agf->agf_btreeblks);
 		pag->pagf_flcount = be32_to_cpu(agf->agf_flcount);
 		pag->pagf_longest = be32_to_cpu(agf->agf_longest);
-		pag->pagf_levels[XFS_BTNUM_BNOi] =
-			be32_to_cpu(agf->agf_levels[XFS_BTNUM_BNOi]);
-		pag->pagf_levels[XFS_BTNUM_CNTi] =
-			be32_to_cpu(agf->agf_levels[XFS_BTNUM_CNTi]);
-		pag->pagf_levels[XFS_BTNUM_RMAPi] =
-			be32_to_cpu(agf->agf_levels[XFS_BTNUM_RMAPi]);
+		pag->pagf_bno_level = be32_to_cpu(agf->agf_bno_level);
+		pag->pagf_cnt_level = be32_to_cpu(agf->agf_cnt_level);
+		pag->pagf_rmap_level = be32_to_cpu(agf->agf_rmap_level);
 		pag->pagf_refcount_level = be32_to_cpu(agf->agf_refcount_level);
 		if (xfs_agfl_needs_reset(pag->pag_mount, agf))
 			set_bit(XFS_AGSTATE_AGFL_NEEDS_RESET, &pag->pag_opstate);
@@ -3414,10 +3405,8 @@ xfs_alloc_read_agf(
 		ASSERT(pag->pagf_btreeblks == be32_to_cpu(agf->agf_btreeblks));
 		ASSERT(pag->pagf_flcount == be32_to_cpu(agf->agf_flcount));
 		ASSERT(pag->pagf_longest == be32_to_cpu(agf->agf_longest));
-		ASSERT(pag->pagf_levels[XFS_BTNUM_BNOi] ==
-		       be32_to_cpu(agf->agf_levels[XFS_BTNUM_BNOi]));
-		ASSERT(pag->pagf_levels[XFS_BTNUM_CNTi] ==
-		       be32_to_cpu(agf->agf_levels[XFS_BTNUM_CNTi]));
+		ASSERT(pag->pagf_bno_level == be32_to_cpu(agf->agf_bno_level));
+		ASSERT(pag->pagf_cnt_level == be32_to_cpu(agf->agf_cnt_level));
 	}
 #endif
 	if (agfbpp)