ext4: remove restrictive checks for EOFBLOCKS_FL

We are going to remove the EOFBLOCKS_FL flag in the future, so this is
the first part of the removal. We can not remove it entirely just now,
since the e2fsck is still checking for it and it might cause headache to
some people. Instead, remove the restrictive checks now and the rest
later, when the new e2fsck code is out and common enough.

This is also needed because punch hole already breaks the EOFBLOCKS_FL
semantics, so it might cause the some troubles. So simply remove it.

Signed-off-by: Lukas Czerner <lczerner@redhat.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c
index d075f34..1421938 100644
--- a/fs/ext4/extents.c
+++ b/fs/ext4/extents.c
@@ -3293,11 +3293,13 @@
 	depth = ext_depth(inode);
 	eh = path[depth].p_hdr;
 
-	if (unlikely(!eh->eh_entries)) {
-		EXT4_ERROR_INODE(inode, "eh->eh_entries == 0 and "
-				 "EOFBLOCKS_FL set");
-		return -EIO;
-	}
+	/*
+	 * We're going to remove EOFBLOCKS_FL entirely in future so we
+	 * do not care for this case anymore. Simply remove the flag
+	 * if there are no extents.
+	 */
+	if (unlikely(!eh->eh_entries))
+		goto out;
 	last_ex = EXT_LAST_EXTENT(eh);
 	/*
 	 * We should clear the EOFBLOCKS_FL flag if we are writing the
@@ -3321,6 +3323,7 @@
 	for (i = depth-1; i >= 0; i--)
 		if (path[i].p_idx != EXT_LAST_INDEX(path[i].p_hdr))
 			return 0;
+out:
 	ext4_clear_inode_flag(inode, EXT4_INODE_EOFBLOCKS);
 	return ext4_mark_inode_dirty(handle, inode);
 }