xfs: pass perag to xfs_read_agf

We have the perag in most places we call xfs_read_agf, so pass the
perag instead of a mount/agno pair.
Signed-off-by: NDave Chinner <dchinner@redhat.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NDarrick J. Wong <djwong@kernel.org>

fs/xfs/libxfs/xfs_alloc.c

@@ -3051,27 +3051,25 @@ const struct xfs_buf_ops xfs_agf_buf_ops = {
 /*
  * Read in the allocation group header (free/alloc section).
  */
-int					/* error */
+int
 xfs_read_agf(
-	struct xfs_mount	*mp,	/* mount point structure */
-	struct xfs_trans	*tp,	/* transaction pointer */
-	xfs_agnumber_t		agno,	/* allocation group number */
-	int			flags,	/* XFS_BUF_ */
-	struct xfs_buf		**bpp)	/* buffer for the ag freelist header */
+	struct xfs_perag	*pag,
+	struct xfs_trans	*tp,
+	int			flags,
+	struct xfs_buf		**agfbpp)
 {
-	int		error;
+	struct xfs_mount	*mp = pag->pag_mount;
+	int			error;
 
-	trace_xfs_read_agf(mp, agno);
+	trace_xfs_read_agf(pag->pag_mount, pag->pag_agno);
 
-	ASSERT(agno != NULLAGNUMBER);
 	error = xfs_trans_read_buf(mp, tp, mp->m_ddev_targp,
-			XFS_AG_DADDR(mp, agno, XFS_AGF_DADDR(mp)),
-			XFS_FSS_TO_BB(mp, 1), flags, bpp, &xfs_agf_buf_ops);
+			XFS_AG_DADDR(mp, pag->pag_agno, XFS_AGF_DADDR(mp)),
+			XFS_FSS_TO_BB(mp, 1), flags, agfbpp, &xfs_agf_buf_ops);
 	if (error)
 		return error;
 
-	ASSERT(!(*bpp)->b_error);
-	xfs_buf_set_ref(*bpp, XFS_AGF_REF);
+	xfs_buf_set_ref(*agfbpp, XFS_AGF_REF);
 	return 0;
 }
 
@@ -3097,7 +3095,7 @@ xfs_alloc_read_agf(
 	/* We don't support trylock when freeing. */
 	ASSERT((flags & (XFS_ALLOC_FLAG_FREEING | XFS_ALLOC_FLAG_TRYLOCK)) !=
 			(XFS_ALLOC_FLAG_FREEING | XFS_ALLOC_FLAG_TRYLOCK));
-	error = xfs_read_agf(pag->pag_mount, tp, pag->pag_agno,
+	error = xfs_read_agf(pag, tp,
 			(flags & XFS_ALLOC_FLAG_TRYLOCK) ? XBF_TRYLOCK : 0,
 			&agfbp);
 	if (error)

fs/xfs/libxfs/xfs_alloc.h

@@ -185,8 +185,8 @@ xfs_alloc_get_rec(
 	xfs_extlen_t		*len,	/* output: length of extent */
 	int			*stat);	/* output: success/failure */
 
-int xfs_read_agf(struct xfs_mount *mp, struct xfs_trans *tp,
-			xfs_agnumber_t agno, int flags, struct xfs_buf **bpp);
+int xfs_read_agf(struct xfs_perag *pag, struct xfs_trans *tp, int flags,
+		struct xfs_buf **agfbpp);
 int xfs_alloc_read_agf(struct xfs_perag *pag, struct xfs_trans *tp, int flags,
 		struct xfs_buf **agfbpp);
 int xfs_alloc_read_agfl(struct xfs_mount *mp, struct xfs_trans *tp,