xfs: merge xfs_bmap_read_extents into xfs_iread_extents

xfs_iread_extents is just a trivial wrapper, there is no good reason
to keep the two separate.

[darrick: minor fixups having left xfs_bmbt_validate_extent intact]

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
diff --git a/fs/xfs/libxfs/xfs_bmap.c b/fs/xfs/libxfs/xfs_bmap.c
index bf23de8..26518aa 100644
--- a/fs/xfs/libxfs/xfs_bmap.c
+++ b/fs/xfs/libxfs/xfs_bmap.c
@@ -1164,33 +1164,37 @@ xfs_bmap_add_attrfork(
  */
 
 /*
- * Read in the extents to if_extents.
- * All inode fields are set up by caller, we just traverse the btree
- * and copy the records in. If the file system cannot contain unwritten
- * extents, the records are checked for no "state" flags.
+ * Read in extents from a btree-format inode.
  */
-int					/* error */
-xfs_bmap_read_extents(
-	xfs_trans_t		*tp,	/* transaction pointer */
-	xfs_inode_t		*ip,	/* incore inode */
-	int			whichfork) /* data or attr fork */
+int
+xfs_iread_extents(
+	struct xfs_trans	*tp,
+	struct xfs_inode	*ip,
+	int			whichfork)
 {
-	struct xfs_btree_block	*block;	/* current btree block */
-	xfs_fsblock_t		bno;	/* block # of "block" */
-	xfs_buf_t		*bp;	/* buffer for "block" */
-	int			error;	/* error return value */
-	xfs_extnum_t		i, j;	/* index into the extents list */
-	xfs_ifork_t		*ifp;	/* fork structure */
-	int			level;	/* btree level, for checking */
-	xfs_mount_t		*mp;	/* file system mount structure */
-	__be64			*pp;	/* pointer to block address */
-	/* REFERENCED */
-	xfs_extnum_t		room;	/* number of entries there's room for */
+	struct xfs_mount	*mp = ip->i_mount;
 	int			state = xfs_bmap_fork_to_state(whichfork);
+	struct xfs_ifork	*ifp = XFS_IFORK_PTR(ip, whichfork);
+	xfs_extnum_t		nextents = XFS_IFORK_NEXTENTS(ip, whichfork);
+	struct xfs_btree_block	*block = ifp->if_broot;
+	xfs_fsblock_t		bno;
+	struct xfs_buf		*bp;
+	xfs_extnum_t		i, j;
+	int			level;
+	__be64			*pp;
+	int			error;
 
-	mp = ip->i_mount;
-	ifp = XFS_IFORK_PTR(ip, whichfork);
-	block = ifp->if_broot;
+	ASSERT(xfs_isilocked(ip, XFS_ILOCK_EXCL));
+
+	if (unlikely(XFS_IFORK_FORMAT(ip, whichfork) != XFS_DINODE_FMT_BTREE)) {
+		XFS_ERROR_REPORT(__func__, XFS_ERRLEVEL_LOW, mp);
+		return -EFSCORRUPTED;
+	}
+
+	ifp->if_bytes = 0;
+	ifp->if_real_bytes = 0;
+	xfs_iext_add(ifp, 0, nextents);
+
 	/*
 	 * Root level must use BMAP_BROOT_PTR_ADDR macro to get ptr out.
 	 */
@@ -1207,21 +1211,22 @@ xfs_bmap_read_extents(
 		error = xfs_btree_read_bufl(mp, tp, bno, 0, &bp,
 				XFS_BMAP_BTREE_REF, &xfs_bmbt_buf_ops);
 		if (error)
-			return error;
+			goto out;
 		block = XFS_BUF_TO_BLOCK(bp);
 		if (level == 0)
 			break;
 		pp = XFS_BMBT_PTR_ADDR(mp, block, 1, mp->m_bmap_dmxr[1]);
 		bno = be64_to_cpu(*pp);
 		XFS_WANT_CORRUPTED_GOTO(mp,
-			XFS_FSB_SANITY_CHECK(mp, bno), error0);
+			XFS_FSB_SANITY_CHECK(mp, bno), out_brelse);
 		xfs_trans_brelse(tp, bp);
 	}
+
 	/*
 	 * Here with bp and block set to the leftmost leaf node in the tree.
 	 */
-	room = xfs_iext_count(ifp);
 	i = 0;
+
 	/*
 	 * Loop over all leaf nodes.  Copy information to the extent records.
 	 */
@@ -1231,14 +1236,15 @@ xfs_bmap_read_extents(
 		xfs_extnum_t	num_recs;
 
 		num_recs = xfs_btree_get_numrecs(block);
-		if (unlikely(i + num_recs > room)) {
-			ASSERT(i + num_recs <= room);
+		if (unlikely(i + num_recs > nextents)) {
+			ASSERT(i + num_recs <= nextents);
 			xfs_warn(ip->i_mount,
 				"corrupt dinode %Lu, (btree extents).",
 				(unsigned long long) ip->i_ino);
-			XFS_CORRUPTION_ERROR("xfs_bmap_read_extents(1)",
+			XFS_CORRUPTION_ERROR(__func__,
 				XFS_ERRLEVEL_LOW, ip->i_mount, block);
-			goto error0;
+			error = -EFSCORRUPTED;
+			goto out_brelse;
 		}
 		/*
 		 * Read-ahead the next leaf block, if any.
@@ -1258,7 +1264,8 @@ xfs_bmap_read_extents(
 			if (!xfs_bmbt_validate_extent(mp, whichfork, trp)) {
 				XFS_ERROR_REPORT("xfs_bmap_read_extents(2)",
 						 XFS_ERRLEVEL_LOW, mp);
-				goto error0;
+				error = -EFSCORRUPTED;
+				goto out_brelse;
 			}
 			trace_xfs_read_extent(ip, i, state, _THIS_IP_);
 		}
@@ -1272,16 +1279,24 @@ xfs_bmap_read_extents(
 		error = xfs_btree_read_bufl(mp, tp, bno, 0, &bp,
 				XFS_BMAP_BTREE_REF, &xfs_bmbt_buf_ops);
 		if (error)
-			return error;
+			goto out;
 		block = XFS_BUF_TO_BLOCK(bp);
 	}
-	if (i != XFS_IFORK_NEXTENTS(ip, whichfork))
-		return -EFSCORRUPTED;
+
+	if (i != XFS_IFORK_NEXTENTS(ip, whichfork)) {
+		error = -EFSCORRUPTED;
+		goto out;
+	}
 	ASSERT(i == xfs_iext_count(ifp));
+
+	ifp->if_flags |= XFS_IFEXTENTS;
 	return 0;
-error0:
+
+out_brelse:
 	xfs_trans_brelse(tp, bp);
-	return -EFSCORRUPTED;
+out:
+	xfs_iext_destroy(ifp);
+	return error;
 }
 
 /*