xfs: clean up XFS_MIN_FREELIST macros

We no longer calculate the minimum freelist size from the on-disk
AGF, so we don't need the macros used for this. That means the
nested macros can be cleaned up, and turn this into an actual
function so the logic is clear and concise. This will make it much
easier to add support for the rmap btree when the time comes.

This also gets rid of the XFS_AG_MAXLEVELS macro used by these
freelist macros as it is simply a wrapper around a single variable.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>

fs/xfs/libxfs/xfs_alloc.c

@@ -1838,6 +1838,23 @@ xfs_alloc_longest_free_extent(
 	return pag->pagf_flcount > 0 || pag->pagf_longest > 0;
 }
 
+unsigned int
+xfs_alloc_min_freelist(
+	struct xfs_mount	*mp,
+	struct xfs_perag	*pag)
+{
+	unsigned int		min_free;
+
+	/* space needed by-bno freespace btree */
+	min_free = min_t(unsigned int, pag->pagf_levels[XFS_BTNUM_BNOi] + 1,
+				       mp->m_ag_maxlevels);
+	/* space needed by-size freespace btree */
+	min_free += min_t(unsigned int, pag->pagf_levels[XFS_BTNUM_CNTi] + 1,
+				       mp->m_ag_maxlevels);
+
+	return min_free;
+}
+
 /*
  * Check if the operation we are fixing up the freelist for should go ahead or
  * not. If we are freeing blocks, we always allow it, otherwise the allocation
@@ -1912,7 +1929,7 @@ xfs_alloc_fix_freelist(
 		goto out_agbp_relse;
 	}
 
-	need = XFS_MIN_FREELIST_PAG(pag, mp);
+	need = xfs_alloc_min_freelist(mp, pag);
 	if (!xfs_alloc_space_available(args, need, flags))
 		goto out_agbp_relse;
 
@@ -1931,9 +1948,8 @@ xfs_alloc_fix_freelist(
 		}
 	}
 
-
 	/* If there isn't enough total space or single-extent, reject it. */
-	need = XFS_MIN_FREELIST_PAG(pag, mp);
+	need = xfs_alloc_min_freelist(mp, pag);
 	if (!xfs_alloc_space_available(args, need, flags))
 		goto out_agbp_relse;
 

fs/xfs/libxfs/xfs_alloc.h

@@ -130,6 +130,8 @@ typedef struct xfs_alloc_arg {
 
 xfs_extlen_t xfs_alloc_longest_free_extent(struct xfs_mount *mp,
 		struct xfs_perag *pag, xfs_extlen_t need);
+unsigned int xfs_alloc_min_freelist(struct xfs_mount *mp,
+		struct xfs_perag *pag);
 
 /*
  * Compute and fill in value of m_ag_maxlevels.

fs/xfs/libxfs/xfs_bmap.c

@@ -3508,7 +3508,7 @@ xfs_bmap_longest_free_extent(
 	}
 
 	longest = xfs_alloc_longest_free_extent(mp, pag,
-						XFS_MIN_FREELIST_PAG(pag, mp));
+					xfs_alloc_min_freelist(mp, pag));
 	if (*blen < longest)
 		*blen = longest;
 

fs/xfs/libxfs/xfs_format.h

@@ -758,19 +758,6 @@ typedef struct xfs_agfl {
 
 #define XFS_AGFL_CRC_OFF	offsetof(struct xfs_agfl, agfl_crc)
 
-
-#define	XFS_AG_MAXLEVELS(mp)		((mp)->m_ag_maxlevels)
-#define	XFS_MIN_FREELIST_RAW(bl,cl,mp)	\
-	(MIN(bl + 1, XFS_AG_MAXLEVELS(mp)) + MIN(cl + 1, XFS_AG_MAXLEVELS(mp)))
-#define	XFS_MIN_FREELIST(a,mp)		\
-	(XFS_MIN_FREELIST_RAW(		\
-		be32_to_cpu((a)->agf_levels[XFS_BTNUM_BNOi]), \
-		be32_to_cpu((a)->agf_levels[XFS_BTNUM_CNTi]), mp))
-#define	XFS_MIN_FREELIST_PAG(pag,mp)	\
-	(XFS_MIN_FREELIST_RAW(		\
-		(unsigned int)(pag)->pagf_levels[XFS_BTNUM_BNOi], \
-		(unsigned int)(pag)->pagf_levels[XFS_BTNUM_CNTi], mp))
-
 #define XFS_AGB_TO_FSB(mp,agno,agbno)	\
 	(((xfs_fsblock_t)(agno) << (mp)->m_sb.sb_agblklog) | (agbno))
 #define	XFS_FSB_TO_AGNO(mp,fsbno)	\

fs/xfs/libxfs/xfs_trans_resv.h

@@ -73,9 +73,9 @@ struct xfs_trans_resv {
  * 2 trees * (2 blocks/level * max depth - 1) * block size
  */
 #define	XFS_ALLOCFREE_LOG_RES(mp,nx) \
-	((nx) * (2 * XFS_FSB_TO_B((mp), 2 * XFS_AG_MAXLEVELS(mp) - 1)))
+	((nx) * (2 * XFS_FSB_TO_B((mp), 2 * (mp)->m_ag_maxlevels - 1)))
 #define	XFS_ALLOCFREE_LOG_COUNT(mp,nx) \
-	((nx) * (2 * (2 * XFS_AG_MAXLEVELS(mp) - 1)))
+	((nx) * (2 * (2 * (mp)->m_ag_maxlevels - 1)))
 
 /*
  * Per-directory log reservation for any directory change.

fs/xfs/libxfs/xfs_trans_space.h

@@ -67,7 +67,7 @@
 #define	XFS_DIOSTRAT_SPACE_RES(mp, v)	\
 	(XFS_EXTENTADD_SPACE_RES(mp, XFS_DATA_FORK) + (v))
 #define	XFS_GROWFS_SPACE_RES(mp)	\
-	(2 * XFS_AG_MAXLEVELS(mp))
+	(2 * (mp)->m_ag_maxlevels)
 #define	XFS_GROWFSRT_SPACE_RES(mp,b)	\
 	((b) + XFS_EXTENTADD_SPACE_RES(mp, XFS_DATA_FORK))
 #define	XFS_LINK_SPACE_RES(mp,nl)	\

fs/xfs/xfs_filestream.c

@@ -197,7 +197,7 @@ xfs_filestream_pick_ag(
 		}
 
 		longest = xfs_alloc_longest_free_extent(mp, pag,
-						XFS_MIN_FREELIST_PAG(pag, mp));
+					xfs_alloc_min_freelist(mp, pag));
 		if (((minlen && longest >= minlen) ||
 		     (!minlen && pag->pagf_freeblks >= minfree)) &&
 		    (!pag->pagf_metadata || !(flags & XFS_PICK_USERDATA) ||