On Mon 09-01-23 21:45:45, Zhihao Cheng wrote >> Following process will make data lost and could lead to a
filesystem>> corrupted problem:>>
[...]
Just a suggestion for rephrasing of the comment below
- /*
- * In any case we need to clean the dirty flag and we must
- * do it under the buffer lock to be sure we don't race
- * with running write-out.
+ * We need to clean the dirty flag and we must do it under the
+ * buffer lock to be sure we don't race with running write-out.
*/
JBUFFER_TRACE(jh, "Journalling dirty buffer");
clear_buffer_dirty(bh);
+ /*
+ * Setting jbddirty after clearing buffer dirty is necessary.
+ * Function jbd2_journal_restart() could keep buffer on
+ * BJ_Reserved list until the transaction committing, then the
+ * buffer won't be dirtied by jbd2_journal_refile_buffer()
+ * after committing, the buffer couldn't fall on disk even
+ * last checkpoint finished, which may corrupt filesystem.
+ */
As far as I understand you want to say:
/*
* The buffer is going to be added to BJ_Reserved list now
* and nothing guarantees jbd2_journal_dirty_metadata()
* will be ever called for it. So we need to set jbddirty
* bit here to make sure the buffer is dirtied and written
* out when the journaling machinery is done with it.
*/
set_buffer_jbddirty(bh);
}
Yes. The comment looks better than v3.
