to the index allocation block and the mapped, locked page it

is in, respectively. , and are NULL in this case.

To obtain a context call ntfs_index_ctx_get().

We use this context to allow ntfs_index_lookup() to return the found index and its without having to allocate a buffer and copy the and/or its into it.

When finished with the and its , call ntfs_index_ctx_put() to free the context and other associated resources.

If the index entry was modified, call flush_dcache_index_entry_page() immediately after the modification and either ntfs_index_entry_mark_dirty() or ntfs_index_entry_write() before the call to ntfs_index_ctx_put() to ensure that the changes are written to disk.