xfs: simplify iext overflow checking and upgrade

Currently the calls to xfs_iext_count_may_overflow and
xfs_iext_count_upgrade are always paired.  Merge them into a single
function to simplify the callers and the actual check and upgrade
logic itself.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: "Darrick J. Wong" <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Chandan Babu R <chandanbabu@kernel.org>

fs/xfs/libxfs/xfs_attr.c

@@ -1050,10 +1050,7 @@ xfs_attr_set(
 		return error;
 
 	if (op != XFS_ATTRUPDATE_REMOVE || xfs_inode_hasattr(dp)) {
-		error = xfs_iext_count_may_overflow(dp, XFS_ATTR_FORK,
-				XFS_IEXT_ATTR_MANIP_CNT(rmt_blks));
-		if (error == -EFBIG)
-			error = xfs_iext_count_upgrade(args->trans, dp,
+		error = xfs_iext_count_extend(args->trans, dp, XFS_ATTR_FORK,
 				XFS_IEXT_ATTR_MANIP_CNT(rmt_blks));
 		if (error)
 			goto out_trans_cancel;

fs/xfs/libxfs/xfs_bmap.c

@@ -4651,10 +4651,7 @@ xfs_bmapi_convert_one_delalloc(
 	xfs_ilock(ip, XFS_ILOCK_EXCL);
 	xfs_trans_ijoin(tp, ip, 0);
 
-	error = xfs_iext_count_may_overflow(ip, whichfork,
-			XFS_IEXT_ADD_NOSPLIT_CNT);
-	if (error == -EFBIG)
-		error = xfs_iext_count_upgrade(tp, ip,
+	error = xfs_iext_count_extend(tp, ip, whichfork,
 			XFS_IEXT_ADD_NOSPLIT_CNT);
 	if (error)
 		goto out_trans_cancel;

fs/xfs/libxfs/xfs_inode_fork.c

@@ -765,53 +765,46 @@ xfs_ifork_verify_local_attr(
 	return 0;
 }
 
+/*
+ * Check if the inode fork supports adding nr_to_add more extents.
+ *
+ * If it doesn't but we can upgrade it to large extent counters, do the upgrade.
+ * If we can't upgrade or are already using big counters but still can't fit the
+ * additional extents, return -EFBIG.
+ */
 int
-xfs_iext_count_may_overflow(
+xfs_iext_count_extend(
+	struct xfs_trans	*tp,
 	struct xfs_inode	*ip,
 	int			whichfork,
-	int			nr_to_add)
+	uint			nr_to_add)
 {
+	struct xfs_mount	*mp = ip->i_mount;
+	bool			has_large =
+		xfs_inode_has_large_extent_counts(ip);
 	struct xfs_ifork	*ifp = xfs_ifork_ptr(ip, whichfork);
-	uint64_t		max_exts;
 	uint64_t		nr_exts;
 
+	ASSERT(nr_to_add <= XFS_MAX_EXTCNT_UPGRADE_NR);
+
 	if (whichfork == XFS_COW_FORK)
 		return 0;
 
-	max_exts = xfs_iext_max_nextents(xfs_inode_has_large_extent_counts(ip),
-				whichfork);
-
-	if (XFS_TEST_ERROR(false, ip->i_mount, XFS_ERRTAG_REDUCE_MAX_IEXTENTS))
-		max_exts = 10;
-
+	/* no point in upgrading if if_nextents overflows */
 	nr_exts = ifp->if_nextents + nr_to_add;
-	if (nr_exts < ifp->if_nextents || nr_exts > max_exts)
+	if (nr_exts < ifp->if_nextents)
 		return -EFBIG;
 
-	return 0;
-}
-
-/*
- * Upgrade this inode's extent counter fields to be able to handle a potential
- * increase in the extent count by nr_to_add.  Normally this is the same
- * quantity that caused xfs_iext_count_may_overflow() to return -EFBIG.
- */
-int
-xfs_iext_count_upgrade(
-	struct xfs_trans	*tp,
-	struct xfs_inode	*ip,
-	uint			nr_to_add)
-{
-	ASSERT(nr_to_add <= XFS_MAX_EXTCNT_UPGRADE_NR);
-
-	if (!xfs_has_large_extent_counts(ip->i_mount) ||
-	    xfs_inode_has_large_extent_counts(ip) ||
-	    XFS_TEST_ERROR(false, ip->i_mount, XFS_ERRTAG_REDUCE_MAX_IEXTENTS))
+	if (XFS_TEST_ERROR(false, mp, XFS_ERRTAG_REDUCE_MAX_IEXTENTS) &&
+	    nr_exts > 10)
 		return -EFBIG;
 
+	if (nr_exts > xfs_iext_max_nextents(has_large, whichfork)) {
+		if (has_large || !xfs_has_large_extent_counts(mp))
+			return -EFBIG;
 		ip->i_diflags2 |= XFS_DIFLAG2_NREXT64;
 		xfs_trans_log_inode(tp, ip, XFS_ILOG_CORE);
-
+	}
 	return 0;
 }
 

fs/xfs/libxfs/xfs_inode_fork.h

@@ -256,10 +256,8 @@ extern void xfs_ifork_init_cow(struct xfs_inode *ip);
 
 int xfs_ifork_verify_local_data(struct xfs_inode *ip);
 int xfs_ifork_verify_local_attr(struct xfs_inode *ip);
-int xfs_iext_count_may_overflow(struct xfs_inode *ip, int whichfork,
-		int nr_to_add);
-int xfs_iext_count_upgrade(struct xfs_trans *tp, struct xfs_inode *ip,
-		uint nr_to_add);
+int xfs_iext_count_extend(struct xfs_trans *tp, struct xfs_inode *ip,
+		int whichfork, uint nr_to_add);
 bool xfs_ifork_is_realtime(struct xfs_inode *ip, int whichfork);
 
 /* returns true if the fork has extents but they are not read in yet. */

fs/xfs/xfs_bmap_item.c

@@ -524,9 +524,7 @@ xfs_bmap_recover_work(
 	else
 		iext_delta = XFS_IEXT_PUNCH_HOLE_CNT;
 
-	error = xfs_iext_count_may_overflow(ip, work->bi_whichfork, iext_delta);
-	if (error == -EFBIG)
-		error = xfs_iext_count_upgrade(tp, ip, iext_delta);
+	error = xfs_iext_count_extend(tp, ip, work->bi_whichfork, iext_delta);
 	if (error)
 		goto err_cancel;
 

fs/xfs/xfs_bmap_util.c

@@ -710,10 +710,7 @@ xfs_alloc_file_space(
 		if (error)
 			break;
 
-		error = xfs_iext_count_may_overflow(ip, XFS_DATA_FORK,
-				XFS_IEXT_ADD_NOSPLIT_CNT);
-		if (error == -EFBIG)
-			error = xfs_iext_count_upgrade(tp, ip,
+		error = xfs_iext_count_extend(tp, ip, XFS_DATA_FORK,
 				XFS_IEXT_ADD_NOSPLIT_CNT);
 		if (error)
 			goto error;
@@ -771,10 +768,8 @@ xfs_unmap_extent(
 	if (error)
 		return error;
 
-	error = xfs_iext_count_may_overflow(ip, XFS_DATA_FORK,
+	error = xfs_iext_count_extend(tp, ip, XFS_DATA_FORK,
 			XFS_IEXT_PUNCH_HOLE_CNT);
-	if (error == -EFBIG)
-		error = xfs_iext_count_upgrade(tp, ip, XFS_IEXT_PUNCH_HOLE_CNT);
 	if (error)
 		goto out_trans_cancel;
 
@@ -1050,10 +1045,8 @@ xfs_insert_file_space(
 	xfs_ilock(ip, XFS_ILOCK_EXCL);
 	xfs_trans_ijoin(tp, ip, 0);
 
-	error = xfs_iext_count_may_overflow(ip, XFS_DATA_FORK,
+	error = xfs_iext_count_extend(tp, ip, XFS_DATA_FORK,
 			XFS_IEXT_PUNCH_HOLE_CNT);
-	if (error == -EFBIG)
-		error = xfs_iext_count_upgrade(tp, ip, XFS_IEXT_PUNCH_HOLE_CNT);
 	if (error)
 		goto out_trans_cancel;
 
@@ -1279,23 +1272,17 @@ xfs_swap_extent_rmap(
 			trace_xfs_swap_extent_rmap_remap_piece(tip, &uirec);
 
 			if (xfs_bmap_is_real_extent(&uirec)) {
-				error = xfs_iext_count_may_overflow(ip,
+				error = xfs_iext_count_extend(tp, ip,
 						XFS_DATA_FORK,
 						XFS_IEXT_SWAP_RMAP_CNT);
-				if (error == -EFBIG)
-					error = xfs_iext_count_upgrade(tp, ip,
-							XFS_IEXT_SWAP_RMAP_CNT);
 				if (error)
 					goto out;
 			}
 
 			if (xfs_bmap_is_real_extent(&irec)) {
-				error = xfs_iext_count_may_overflow(tip,
+				error = xfs_iext_count_extend(tp, tip,
 						XFS_DATA_FORK,
 						XFS_IEXT_SWAP_RMAP_CNT);
-				if (error == -EFBIG)
-					error = xfs_iext_count_upgrade(tp, ip,
-							XFS_IEXT_SWAP_RMAP_CNT);
 				if (error)
 					goto out;
 			}

fs/xfs/xfs_dquot.c

@@ -341,10 +341,7 @@ xfs_dquot_disk_alloc(
 		goto err_cancel;
 	}
 
-	error = xfs_iext_count_may_overflow(quotip, XFS_DATA_FORK,
-			XFS_IEXT_ADD_NOSPLIT_CNT);
-	if (error == -EFBIG)
-		error = xfs_iext_count_upgrade(tp, quotip,
+	error = xfs_iext_count_extend(tp, quotip, XFS_DATA_FORK,
 			XFS_IEXT_ADD_NOSPLIT_CNT);
 	if (error)
 		goto err_cancel;

fs/xfs/xfs_iomap.c

@@ -299,9 +299,7 @@ xfs_iomap_write_direct(
 	if (error)
 		return error;
 
-	error = xfs_iext_count_may_overflow(ip, XFS_DATA_FORK, nr_exts);
-	if (error == -EFBIG)
-		error = xfs_iext_count_upgrade(tp, ip, nr_exts);
+	error = xfs_iext_count_extend(tp, ip, XFS_DATA_FORK, nr_exts);
 	if (error)
 		goto out_trans_cancel;
 
@@ -617,10 +615,7 @@ xfs_iomap_write_unwritten(
 		if (error)
 			return error;
 
-		error = xfs_iext_count_may_overflow(ip, XFS_DATA_FORK,
-				XFS_IEXT_WRITE_UNWRITTEN_CNT);
-		if (error == -EFBIG)
-			error = xfs_iext_count_upgrade(tp, ip,
+		error = xfs_iext_count_extend(tp, ip, XFS_DATA_FORK,
 				XFS_IEXT_WRITE_UNWRITTEN_CNT);
 		if (error)
 			goto error_on_bmapi_transaction;

fs/xfs/xfs_reflink.c

@@ -754,10 +754,7 @@ xfs_reflink_end_cow_extent(
 	del = got;
 	xfs_trim_extent(&del, *offset_fsb, end_fsb - *offset_fsb);
 
-	error = xfs_iext_count_may_overflow(ip, XFS_DATA_FORK,
-			XFS_IEXT_REFLINK_END_COW_CNT);
-	if (error == -EFBIG)
-		error = xfs_iext_count_upgrade(tp, ip,
+	error = xfs_iext_count_extend(tp, ip, XFS_DATA_FORK,
 			XFS_IEXT_REFLINK_END_COW_CNT);
 	if (error)
 		goto out_cancel;
@@ -1258,9 +1255,7 @@ xfs_reflink_remap_extent(
 	if (dmap_written)
 		++iext_delta;
 
-	error = xfs_iext_count_may_overflow(ip, XFS_DATA_FORK, iext_delta);
-	if (error == -EFBIG)
-		error = xfs_iext_count_upgrade(tp, ip, iext_delta);
+	error = xfs_iext_count_extend(tp, ip, XFS_DATA_FORK, iext_delta);
 	if (error)
 		goto out_cancel;
 

fs/xfs/xfs_rtalloc.c

@@ -695,10 +695,7 @@ xfs_growfs_rt_alloc(
 		xfs_ilock(ip, XFS_ILOCK_EXCL);
 		xfs_trans_ijoin(tp, ip, XFS_ILOCK_EXCL);
 
-		error = xfs_iext_count_may_overflow(ip, XFS_DATA_FORK,
-				XFS_IEXT_ADD_NOSPLIT_CNT);
-		if (error == -EFBIG)
-			error = xfs_iext_count_upgrade(tp, ip,
+		error = xfs_iext_count_extend(tp, ip, XFS_DATA_FORK,
 				XFS_IEXT_ADD_NOSPLIT_CNT);
 		if (error)
 			goto out_trans_cancel;