[LogFS] Only write journal if dirty
This prevents unnecessary journal writes. More importantly it prevents
an oops due to a journal write on failed mount.
diff --git a/fs/logfs/journal.c b/fs/logfs/journal.c
index c0e7d63..57eb4fb 100644
--- a/fs/logfs/journal.c
+++ b/fs/logfs/journal.c
@@ -724,14 +724,17 @@
* bit wasteful, but robustness is more important. With this we can *always*
* erase all journal segments except the one containing the most recent commit.
*/
-void logfs_write_anchor(struct inode *inode)
+void logfs_write_anchor(struct super_block *sb)
{
- struct super_block *sb = inode->i_sb;
struct logfs_super *super = logfs_super(sb);
struct logfs_area *area = super->s_journal_area;
int i, err;
- BUG_ON(logfs_super(sb)->s_flags & LOGFS_SB_FLAG_SHUTDOWN);
+ if (!(super->s_flags & LOGFS_SB_FLAG_DIRTY))
+ return;
+ super->s_flags &= ~LOGFS_SB_FLAG_DIRTY;
+
+ BUG_ON(super->s_flags & LOGFS_SB_FLAG_SHUTDOWN);
mutex_lock(&super->s_journal_mutex);
/* Do this first or suffer corruption */
@@ -821,7 +824,7 @@
area->a_is_open = 0;
area->a_used_bytes = 0;
/* Write journal */
- logfs_write_anchor(super->s_master_inode);
+ logfs_write_anchor(sb);
/* Write superblocks */
err = logfs_write_sb(sb);
BUG_ON(err);