ext4: set EXT4_EXTENTS_FL only for directory and regular files

In addition, don't inherit EXT4_EXTENTS_FL from parent directory.
If we have a directory with extent flag set and later mount the file
system with -o noextents, the files created in that directory will also
have extent flag set but we would not have called ext4_ext_tree_init for
them. This will cause error later when we are verifying the extent header

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Acked-off-by: Eric Sandeen <sandeen@redhat.com>
Signed-off-by: Mingming Cao <cmm@us.ibm.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>

fs/ext4/ialloc.c

@@ -702,7 +702,12 @@ struct inode *ext4_new_inode(handle_t *handle, struct inode * dir, int mode)
 	ei->i_dir_start_lookup = 0;
 	ei->i_disksize = 0;
 
-	ei->i_flags = EXT4_I(dir)->i_flags & ~EXT4_INDEX_FL;
+	/*
+	 * Don't inherit extent flag from directory. We set extent flag on
+	 * newly created directory and file only if -o extent mount option is
+	 * specified
+	 */
+	ei->i_flags = EXT4_I(dir)->i_flags & ~(EXT4_INDEX_FL|EXT4_EXTENTS_FL);
 	if (S_ISLNK(mode))
 		ei->i_flags &= ~(EXT4_IMMUTABLE_FL|EXT4_APPEND_FL);
 	/* dirsync only applies to directories */
@@ -745,12 +750,15 @@ struct inode *ext4_new_inode(handle_t *handle, struct inode * dir, int mode)
 		goto fail_free_drop;
 	}
 	if (test_opt(sb, EXTENTS)) {
-		EXT4_I(inode)->i_flags |= EXT4_EXTENTS_FL;
-		ext4_ext_tree_init(handle, inode);
-		err = ext4_update_incompat_feature(handle, sb,
-						EXT4_FEATURE_INCOMPAT_EXTENTS);
-		if (err)
-			goto fail;
+		/* set extent flag only for directory and file */
+		if (S_ISDIR(mode) || S_ISREG(mode)) {
+			EXT4_I(inode)->i_flags |= EXT4_EXTENTS_FL;
+			ext4_ext_tree_init(handle, inode);
+			err = ext4_update_incompat_feature(handle, sb,
+					EXT4_FEATURE_INCOMPAT_EXTENTS);
+			if (err)
+				goto fail;
+		}
 	}
 
 	ext4_debug("allocating inode %lu\n", inode->i_ino);

fs/ext4/namei.c

@@ -2220,7 +2220,6 @@ static int ext4_symlink (struct inode * dir,
 		inode->i_op = &ext4_fast_symlink_inode_operations;
 		memcpy((char*)&EXT4_I(inode)->i_data,symname,l);
 		inode->i_size = l-1;
-		EXT4_I(inode)->i_flags &= ~EXT4_EXTENTS_FL;
 	}
 	EXT4_I(inode)->i_disksize = inode->i_size;
 	err = ext4_add_nondir(handle, dentry, inode);