-
Hidehiro Kawai authored
When a checkpointing IO fails, current JBD2 code doesn't check the error and continue journaling. This means latest metadata can be lost from both the journal and filesystem. This patch leaves the failed metadata blocks in the journal space and aborts journaling in the case of jbd2_log_do_checkpoint(). To achieve this, we need to do: 1. don't remove the failed buffer from the checkpoint list where in the case of __try_to_free_cp_buf() because it may be released or overwritten by a later transaction 2. jbd2_log_do_checkpoint() is the last chance, remove the failed buffer from the checkpoint list and abort the journal 3. when checkpointing fails, don't update the journal super block to prevent the journaled contents from being cleaned. For safety, don't update j_tail and j_tail_sequence either 4. when checkpointing fails, notify this error to the ext4 layer so that ext4 don't clear the needs_recovery flag, otherwise the journaled contents are ignored and cleaned in the recovery phase 5. if the recovery fails, keep the needs_recovery flag 6. prevent jbd2_cleanup_journal_tail() from being called between __jbd2_journal_drop_transaction() and jbd2_journal_abort() (a possible race issue between jbd2_log_do_checkpoint()s called by jbd2_journal_flush() and __jbd2_log_wait_for_space()) Signed-off-by:
Hidehiro Kawai <hidehiro.kawai.ez@hitachi.com> Signed-off-by:
Theodore Ts'o <tytso@mit.edu>
44519faf