xfs: drop the AGI being passed to xfs_check_agi_freecount

From: Dave Chinner <dchinner@redhat.com>

Stephen Rothwell reported this compiler warning from linux-next:

fs/xfs/libxfs/xfs_ialloc.c: In function 'xfs_difree_finobt':
fs/xfs/libxfs/xfs_ialloc.c:2032:20: warning: unused variable 'agi' [-Wunused-variable]
 2032 |  struct xfs_agi   *agi = agbp->b_addr;

Which is fallout from agno -> perag conversions that were done in
this function. xfs_check_agi_freecount() is the only user of "agi"
in xfs_difree_finobt() now, and it only uses the agi to get the
current free inode count. We hold that in the perag structure, so
there's not need to directly reference the raw AGI to get this
information.

The btree cursor being passed to xfs_check_agi_freecount() has a
reference to the perag being operated on, so use that directly in
xfs_check_agi_freecount() rather than passing an AGI.

Fixes: 7b13c515 ("xfs: use perag for ialloc btree cursors")
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Carlos Maiolino <cmaiolino@redhat.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Darrick J. Wong <djwong@kernel.org>

fs/xfs/libxfs/xfs_ialloc.c

@@ -214,10 +214,9 @@ xfs_inobt_insert(
  * Verify that the number of free inodes in the AGI is correct.
  */
 #ifdef DEBUG
-STATIC int
+static int
 xfs_check_agi_freecount(
-	struct xfs_btree_cur	*cur,
-	struct xfs_agi		*agi)
+	struct xfs_btree_cur	*cur)
 {
 	if (cur->bc_nlevels == 1) {
 		xfs_inobt_rec_incore_t rec;
@@ -243,12 +242,12 @@ xfs_check_agi_freecount(
 		} while (i == 1);
 
 		if (!XFS_FORCED_SHUTDOWN(cur->bc_mp))
-			ASSERT(freecount == be32_to_cpu(agi->agi_freecount));
+			ASSERT(freecount == cur->bc_ag.pag->pagi_freecount);
 	}
 	return 0;
 }
 #else
-#define xfs_check_agi_freecount(cur, agi)	0
+#define xfs_check_agi_freecount(cur)	0
 #endif
 
 /*
@@ -1014,7 +1013,7 @@ xfs_dialloc_ag_inobt(
 	if (!pagino)
 		pagino = be32_to_cpu(agi->agi_newino);
 
-	error = xfs_check_agi_freecount(cur, agi);
+	error = xfs_check_agi_freecount(cur);
 	if (error)
 		goto error0;
 
@@ -1234,7 +1233,7 @@ xfs_dialloc_ag_inobt(
 	xfs_ialloc_log_agi(tp, agbp, XFS_AGI_FREECOUNT);
 	pag->pagi_freecount--;
 
-	error = xfs_check_agi_freecount(cur, agi);
+	error = xfs_check_agi_freecount(cur);
 	if (error)
 		goto error0;
 
@@ -1461,7 +1460,7 @@ xfs_dialloc_ag(
 
 	cur = xfs_inobt_init_cursor(mp, tp, agbp, pag, XFS_BTNUM_FINO);
 
-	error = xfs_check_agi_freecount(cur, agi);
+	error = xfs_check_agi_freecount(cur);
 	if (error)
 		goto error_cur;
 
@@ -1504,7 +1503,7 @@ xfs_dialloc_ag(
 	 */
 	icur = xfs_inobt_init_cursor(mp, tp, agbp, pag, XFS_BTNUM_INO);
 
-	error = xfs_check_agi_freecount(icur, agi);
+	error = xfs_check_agi_freecount(icur);
 	if (error)
 		goto error_icur;
 
@@ -1522,10 +1521,10 @@ xfs_dialloc_ag(
 
 	xfs_trans_mod_sb(tp, XFS_TRANS_SB_IFREE, -1);
 
-	error = xfs_check_agi_freecount(icur, agi);
+	error = xfs_check_agi_freecount(icur);
 	if (error)
 		goto error_icur;
-	error = xfs_check_agi_freecount(cur, agi);
+	error = xfs_check_agi_freecount(cur);
 	if (error)
 		goto error_icur;
 
@@ -1911,7 +1910,7 @@ xfs_difree_inobt(
 	 */
 	cur = xfs_inobt_init_cursor(mp, tp, agbp, pag, XFS_BTNUM_INO);
 
-	error = xfs_check_agi_freecount(cur, agi);
+	error = xfs_check_agi_freecount(cur);
 	if (error)
 		goto error0;
 
@@ -2004,7 +2003,7 @@ xfs_difree_inobt(
 		xfs_trans_mod_sb(tp, XFS_TRANS_SB_IFREE, 1);
 	}
 
-	error = xfs_check_agi_freecount(cur, agi);
+	error = xfs_check_agi_freecount(cur);
 	if (error)
 		goto error0;
 
@@ -2029,7 +2028,6 @@ xfs_difree_finobt(
 	xfs_agino_t			agino,
 	struct xfs_inobt_rec_incore	*ibtrec) /* inobt record */
 {
-	struct xfs_agi			*agi = agbp->b_addr;
 	struct xfs_btree_cur		*cur;
 	struct xfs_inobt_rec_incore	rec;
 	int				offset = agino - ibtrec->ir_startino;
@@ -2114,7 +2112,7 @@ xfs_difree_finobt(
 	}
 
 out:
-	error = xfs_check_agi_freecount(cur, agi);
+	error = xfs_check_agi_freecount(cur);
 	if (error)
 		goto error;