xfs: Pre-calculate per-AG agbno geometry

There is a lot of overhead in functions like xfs_verify_agbno() that
repeatedly calculate the geometry limits of an AG. These can be
pre-calculated as they are static and the verification context has
a per-ag context it can quickly reference.

In the case of xfs_verify_agbno(), we now always have a perag
context handy, so we can store the AG length and the minimum valid
block in the AG in the perag. This means we don't have to calculate
it on every call and it can be inlined in callers if we move it
to xfs_ag.h.

Move xfs_ag_block_count() to xfs_ag.c because it's really a
per-ag function and not an XFS type function. We need a little
bit of rework that is specific to xfs_initialise_perag() to allow
growfs to calculate the new perag sizes before we've updated the
primary superblock during the grow (chicken/egg situation).

Note that we leave the original xfs_verify_agbno in place in
xfs_types.c as a static function as other callers in that file do
not have per-ag contexts so still need to go the long way. It's been
renamed to xfs_verify_agno_agbno() to indicate it takes both an agno
and an agbno to differentiate it from new function.

Future commits will make similar changes for other per-ag geometry
validation functions.

Further:

$ size --totals fs/xfs/built-in.a
	   text    data     bss     dec     hex filename
before	1483006	 329588	    572	1813166	 1baaae	(TOTALS)
after	1482185	 329588	    572	1812345	 1ba779	(TOTALS)

This rework reduces the binary size by ~820 bytes, indicating
that much less work is being done to bounds check the agbno values
against on per-ag geometry information.

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

1 files changed, 10 insertions, 15 deletions

diff --git a/fs/xfs/libxfs/xfs_btree.c b/fs/xfs/libxfs/xfs_btree.c
index 2eecc49fc1b2..06ab364d2de3 100644
--- a/fs/xfs/libxfs/xfs_btree.c
+++ b/fs/xfs/libxfs/xfs_btree.c
@@ -91,10 +91,9 @@ xfs_btree_check_lblock_siblings(
 
 static inline xfs_failaddr_t
 xfs_btree_check_sblock_siblings(
-	struct xfs_mount	*mp,
+	struct xfs_perag	*pag,
 	struct xfs_btree_cur	*cur,
 	int			level,
-	xfs_agnumber_t		agno,
 	xfs_agblock_t		agbno,
 	__be32			dsibling)
 {
@@ -110,7 +109,7 @@ xfs_btree_check_sblock_siblings(
 		if (!xfs_btree_check_sptr(cur, sibling, level + 1))
 			return __this_address;
 	} else {
-		if (!xfs_verify_agbno(mp, agno, sibling))
+		if (!xfs_verify_agbno(pag, sibling))
 			return __this_address;
 	}
 	return NULL;
@@ -195,11 +194,11 @@ __xfs_btree_check_sblock(
 	struct xfs_buf		*bp)
 {
 	struct xfs_mount	*mp = cur->bc_mp;
+	struct xfs_perag	*pag = cur->bc_ag.pag;
 	xfs_btnum_t		btnum = cur->bc_btnum;
 	int			crc = xfs_has_crc(mp);
 	xfs_failaddr_t		fa;
 	xfs_agblock_t		agbno = NULLAGBLOCK;
-	xfs_agnumber_t		agno = NULLAGNUMBER;
 
 	if (crc) {
 		if (!uuid_equal(&block->bb_u.s.bb_uuid, &mp->m_sb.sb_meta_uuid))
@@ -217,16 +216,14 @@ __xfs_btree_check_sblock(
 	    cur->bc_ops->get_maxrecs(cur, level))
 		return __this_address;
 
-	if (bp) {
+	if (bp)
 		agbno = xfs_daddr_to_agbno(mp, xfs_buf_daddr(bp));
-		agno = xfs_daddr_to_agno(mp, xfs_buf_daddr(bp));
-	}
 
-	fa = xfs_btree_check_sblock_siblings(mp, cur, level, agno, agbno,
+	fa = xfs_btree_check_sblock_siblings(pag, cur, level, agbno,
 			block->bb_u.s.bb_leftsib);
 	if (!fa)
-		fa = xfs_btree_check_sblock_siblings(mp, cur, level, agno,
-				 agbno, block->bb_u.s.bb_rightsib);
+		fa = xfs_btree_check_sblock_siblings(pag, cur, level, agbno,
+				block->bb_u.s.bb_rightsib);
 	return fa;
 }
 
@@ -288,7 +285,7 @@ xfs_btree_check_sptr(
 {
 	if (level <= 0)
 		return false;
-	return xfs_verify_agbno(cur->bc_mp, cur->bc_ag.pag->pag_agno, agbno);
+	return xfs_verify_agbno(cur->bc_ag.pag, agbno);
 }
 
 /*
@@ -4595,7 +4592,6 @@ xfs_btree_sblock_verify(
 {
 	struct xfs_mount	*mp = bp->b_mount;
 	struct xfs_btree_block	*block = XFS_BUF_TO_BLOCK(bp);
-	xfs_agnumber_t		agno;
 	xfs_agblock_t		agbno;
 	xfs_failaddr_t		fa;
 
@@ -4604,12 +4600,11 @@ xfs_btree_sblock_verify(
 		return __this_address;
 
 	/* sibling pointer verification */
-	agno = xfs_daddr_to_agno(mp, xfs_buf_daddr(bp));
 	agbno = xfs_daddr_to_agbno(mp, xfs_buf_daddr(bp));
-	fa = xfs_btree_check_sblock_siblings(mp, NULL, -1, agno, agbno,
+	fa = xfs_btree_check_sblock_siblings(bp->b_pag, NULL, -1, agbno,
 			block->bb_u.s.bb_leftsib);
 	if (!fa)
-		fa = xfs_btree_check_sblock_siblings(mp, NULL, -1, agno, agbno,
+		fa = xfs_btree_check_sblock_siblings(bp->b_pag, NULL, -1, agbno,
 				block->bb_u.s.bb_rightsib);
 	return fa;
 }