ext4: fix error handling in migrate
Set i_nlink to zero for temporary inode from very beginning.
otherwise we may fail to start new journal handle and this
inode will be unreferenced but with i_nlink == 1
Since we hold inode reference it can not be pruned.
Also add missed journal_start retval check.
Signed-off-by: Dmitry Monakhov <dmonakhov@openvz.org>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
diff --git a/fs/ext4/migrate.c b/fs/ext4/migrate.c
index 46a4101..8b87bd0 100644
--- a/fs/ext4/migrate.c
+++ b/fs/ext4/migrate.c
@@ -503,14 +503,10 @@
}
i_size_write(tmp_inode, i_size_read(inode));
/*
- * We don't want the inode to be reclaimed
- * if we got interrupted in between. We have
- * this tmp inode carrying reference to the
- * data blocks of the original file. We set
- * the i_nlink to zero at the last stage after
- * switching the original file to extent format
+ * Set the i_nlink to zero so it will be deleted later
+ * when we drop inode reference.
*/
- tmp_inode->i_nlink = 1;
+ tmp_inode->i_nlink = 0;
ext4_ext_tree_init(handle, tmp_inode);
ext4_orphan_add(handle, tmp_inode);
@@ -537,6 +533,16 @@
up_read((&EXT4_I(inode)->i_data_sem));
handle = ext4_journal_start(inode, 1);
+ if (IS_ERR(handle)) {
+ /*
+ * It is impossible to update on-disk structures without
+ * a handle, so just rollback in-core changes and live other
+ * work to orphan_list_cleanup()
+ */
+ ext4_orphan_del(NULL, tmp_inode);
+ retval = PTR_ERR(handle);
+ goto out;
+ }
ei = EXT4_I(inode);
i_data = ei->i_data;
@@ -618,15 +624,8 @@
/* Reset the extent details */
ext4_ext_tree_init(handle, tmp_inode);
-
- /*
- * Set the i_nlink to zero so that
- * generic_drop_inode really deletes the
- * inode
- */
- tmp_inode->i_nlink = 0;
-
ext4_journal_stop(handle);
+out:
unlock_new_inode(tmp_inode);
iput(tmp_inode);