xfs: rename m_ag_maxlevels to m_allocbt_maxlevels

Years ago when XFS was thought to be much more simple, we introduced
m_ag_maxlevels to specify the maximum btree height of per-AG btrees for
a given filesystem mount.  Then we observed that inode btrees don't
actually have the same height and split that off; and now we have rmap
and refcount btrees with much different geometries and separate
maxlevels variables.

The 'ag' part of the name doesn't make much sense anymore, so rename
this to m_alloc_maxlevels to reinforce that this is the maximum height
of the *free space* btrees.  This sets us up for the next patch, which
will add a variable to track the maximum height of all AG btrees.

(Also take the opportunity to improve adjacent comments and fix minor
style problems.)

Signed-off-by: Darrick J. Wong <[email protected]>
Reviewed-by: Dave Chinner <[email protected]>

Author: Darrick J. Wong

fs/xfs/libxfs/xfs_alloc.c

@@ -2190,13 +2190,13 @@ xfs_free_ag_extent(
  */
 
 /*
- * Compute and fill in value of m_ag_maxlevels.
+ * Compute and fill in value of m_alloc_maxlevels.
  */
 void
 xfs_alloc_compute_maxlevels(
 	xfs_mount_t	*mp)	/* file system mount structure */
 {
-	mp->m_ag_maxlevels = xfs_btree_compute_maxlevels(mp->m_alloc_mnr,
+	mp->m_alloc_maxlevels = xfs_btree_compute_maxlevels(mp->m_alloc_mnr,
 			(mp->m_sb.sb_agblocks + 1) / 2);
 }
 
@@ -2255,14 +2255,14 @@ xfs_alloc_min_freelist(
 	const uint8_t		*levels = pag ? pag->pagf_levels : fake_levels;
 	unsigned int		min_free;
 
-	ASSERT(mp->m_ag_maxlevels > 0);
+	ASSERT(mp->m_alloc_maxlevels > 0);
 
 	/* space needed by-bno freespace btree */
 	min_free = min_t(unsigned int, levels[XFS_BTNUM_BNOi] + 1,
-				       mp->m_ag_maxlevels);
+				       mp->m_alloc_maxlevels);
 	/* space needed by-size freespace btree */
 	min_free += min_t(unsigned int, levels[XFS_BTNUM_CNTi] + 1,
-				       mp->m_ag_maxlevels);
+				       mp->m_alloc_maxlevels);
 	/* space needed reverse mapping used space btree */
 	if (xfs_has_rmapbt(mp))
 		min_free += min_t(unsigned int, levels[XFS_BTNUM_RMAPi] + 1,
@@ -2903,13 +2903,16 @@ xfs_agf_verify(
 
 	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_ag_maxlevels ||
-	    be32_to_cpu(agf->agf_levels[XFS_BTNUM_CNT]) > mp->m_ag_maxlevels)
+	    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)
 		return __this_address;
 
 	if (xfs_has_rmapbt(mp) &&
 	    (be32_to_cpu(agf->agf_levels[XFS_BTNUM_RMAP]) < 1 ||
-	     be32_to_cpu(agf->agf_levels[XFS_BTNUM_RMAP]) > mp->m_rmap_maxlevels))
+	     be32_to_cpu(agf->agf_levels[XFS_BTNUM_RMAP]) >
+						mp->m_rmap_maxlevels))
 		return __this_address;
 
 	if (xfs_has_rmapbt(mp) &&

fs/xfs/libxfs/xfs_alloc.h

@@ -98,7 +98,7 @@ unsigned int xfs_alloc_min_freelist(struct xfs_mount *mp,
 		struct xfs_perag *pag);
 
 /*
- * Compute and fill in value of m_ag_maxlevels.
+ * Compute and fill in value of m_alloc_maxlevels.
  */
 void
 xfs_alloc_compute_maxlevels(

fs/xfs/libxfs/xfs_alloc_btree.c

@@ -316,7 +316,7 @@ xfs_allocbt_verify(
 	if (pag && pag->pagf_init) {
 		if (level >= pag->pagf_levels[btnum])
 			return __this_address;
-	} else if (level >= mp->m_ag_maxlevels)
+	} else if (level >= mp->m_alloc_maxlevels)
 		return __this_address;
 
 	return xfs_btree_sblock_verify(bp, mp->m_alloc_mxr[level != 0]);
@@ -477,7 +477,7 @@ xfs_allocbt_init_common(
 
 	ASSERT(btnum == XFS_BTNUM_BNO || btnum == XFS_BTNUM_CNT);
 
-	cur = xfs_btree_alloc_cursor(mp, tp, btnum, mp->m_ag_maxlevels);
+	cur = xfs_btree_alloc_cursor(mp, tp, btnum, mp->m_alloc_maxlevels);
 	cur->bc_ag.abt.active = false;
 
 	if (btnum == XFS_BTNUM_CNT) {

fs/xfs/libxfs/xfs_trans_resv.c

@@ -70,7 +70,7 @@ xfs_allocfree_log_count(
 {
 	uint		blocks;
 
-	blocks = num_ops * 2 * (2 * mp->m_ag_maxlevels - 1);
+	blocks = num_ops * 2 * (2 * mp->m_alloc_maxlevels - 1);
 	if (xfs_has_rmapbt(mp))
 		blocks += num_ops * (2 * mp->m_rmap_maxlevels - 1);
 	if (xfs_has_reflink(mp))

fs/xfs/libxfs/xfs_trans_space.h

@@ -74,7 +74,7 @@
 #define	XFS_DIOSTRAT_SPACE_RES(mp, v)	\
 	(XFS_EXTENTADD_SPACE_RES(mp, XFS_DATA_FORK) + (v))
 #define	XFS_GROWFS_SPACE_RES(mp)	\
-	(2 * (mp)->m_ag_maxlevels)
+	(2 * (mp)->m_alloc_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/scrub/agheader.c

@@ -555,11 +555,11 @@ xchk_agf(
 		xchk_block_set_corrupt(sc, sc->sa.agf_bp);
 
 	level = be32_to_cpu(agf->agf_levels[XFS_BTNUM_BNO]);
-	if (level <= 0 || level > mp->m_ag_maxlevels)
+	if (level <= 0 || level > mp->m_alloc_maxlevels)
 		xchk_block_set_corrupt(sc, sc->sa.agf_bp);
 
 	level = be32_to_cpu(agf->agf_levels[XFS_BTNUM_CNT]);
-	if (level <= 0 || level > mp->m_ag_maxlevels)
+	if (level <= 0 || level > mp->m_alloc_maxlevels)
 		xchk_block_set_corrupt(sc, sc->sa.agf_bp);
 
 	if (xfs_has_rmapbt(mp)) {

fs/xfs/scrub/agheader_repair.c

@@ -339,12 +339,12 @@ xrep_agf(
 		[XREP_AGF_BNOBT] = {
 			.rmap_owner = XFS_RMAP_OWN_AG,
 			.buf_ops = &xfs_bnobt_buf_ops,
-			.maxlevels = sc->mp->m_ag_maxlevels,
+			.maxlevels = sc->mp->m_alloc_maxlevels,
 		},
 		[XREP_AGF_CNTBT] = {
 			.rmap_owner = XFS_RMAP_OWN_AG,
 			.buf_ops = &xfs_cntbt_buf_ops,
-			.maxlevels = sc->mp->m_ag_maxlevels,
+			.maxlevels = sc->mp->m_alloc_maxlevels,
 		},
 		[XREP_AGF_RMAPBT] = {
 			.rmap_owner = XFS_RMAP_OWN_AG,

fs/xfs/xfs_mount.h

@@ -128,8 +128,8 @@ typedef struct xfs_mount {
 	uint			m_rmap_mnr[2];	/* min rmap btree records */
 	uint			m_refc_mxr[2];	/* max refc btree records */
 	uint			m_refc_mnr[2];	/* min refc btree records */
-	uint			m_ag_maxlevels;	/* XFS_AG_MAXLEVELS */
-	uint			m_bm_maxlevels[2]; /* XFS_BM_MAXLEVELS */
+	uint			m_alloc_maxlevels; /* max alloc btree levels */
+	uint			m_bm_maxlevels[2]; /* max bmap btree levels */
 	uint			m_rmap_maxlevels; /* max rmap btree levels */
 	uint			m_refc_maxlevels; /* max refcount btree level */
 	xfs_extlen_t		m_ag_prealloc_blocks; /* reserved ag blocks */