[RFC v2 36/83] Journal: Lite journal recovery.

Andiry Xu
2018-03-10T18:21:02Z

fs/nova/journal.c | 55 +++++++++++++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 55 insertions(+)

diff --git a/fs/nova/journal.c b/fs/nova/journal.c
index 75d590f..f31de97 100644
--- a/fs/nova/journal.c
+++ b/fs/nova/journal.c
@@ -106,3 +106,58 @@ static int nova_check_journal_entries(struct super_block *sb,

return 0;
}
+
+/**************************** Journal Recovery ******************************/
+
+static void nova_undo_journal_entry(struct super_block *sb,
+ struct nova_lite_journal_entry *entry)
+{
+ u64 addr, value;
+
+ addr = le64_to_cpu(entry->data1);
+ value = le64_to_cpu(entry->data2);
+
+ *(u64 *)nova_get_block(sb, addr) = (u64)value;
+ nova_flush_buffer((void *)nova_get_block(sb, addr), CACHELINE_SIZE, 0);
+}
+
+static void nova_undo_lite_journal_entry(struct super_block *sb,
+ struct nova_lite_journal_entry *entry)
+{
+ u64 type;
+
+ type = le64_to_cpu(entry->type);
+
+ switch (type) {
+ case JOURNAL_INODE:
+ /* Currently unused */
+ break;
+ case JOURNAL_ENTRY:
+ nova_undo_journal_entry(sb, entry);
+ break;
+ default:
+ nova_dbg("%s: unknown data type %llu\n", __func__, type);
+ break;
+ }
+}
+
+/* Roll back all journal enries */
+static int nova_recover_lite_journal(struct super_block *sb,
+ struct journal_ptr_pair *pair)
+{
+ struct nova_lite_journal_entry *entry;
+ u64 temp;
+
+ temp = pair->journal_head;
+ while (temp != pair->journal_tail) {
+ entry = (struct nova_lite_journal_entry *)nova_get_block(sb,
+ temp);
+ nova_undo_lite_journal_entry(sb, entry);
+ temp = next_lite_journal(temp);
+ }
+
+ pair->journal_tail = pair->journal_head;
+ nova_flush_buffer(&pair->journal_head, CACHELINE_SIZE, 1);
+
+ return 0;
+}
--
2.7.4