jbd2: Call the commit callback before the transaction could get dropped (6c20ec85) · Commits · 戴 / test

The transaction can potentially get dropped if there are no buffers that need to be written. Make sure we call the commit callback before potentially deciding to drop the transaction. Also avoid dereferencing the commit_transaction pointer in the marker for the same reason. This patch fixes the bug reported by Eric Paris at: http://bugzilla.kernel.org/show_bug.cgi?id=11838 Signed-off-by:

"Theodore Ts'o" <tytso@mit.edu> Acked-by:

Eric Sandeen <sandeen@redhat.com> Tested-by:

Eric Paris <eparis@redhat.com>

fs/jbd2/commit.c

+4 −4

Original line number	Diff line number	Diff line
		@@ -974,6 +974,9 @@ restart_loop:
		journal->j_committing_transaction = NULL;
		spin_unlock(&journal->j_state_lock);

		if (journal->j_commit_callback)
		journal->j_commit_callback(journal, commit_transaction);

		if (commit_transaction->t_checkpoint_list == NULL &&
		commit_transaction->t_checkpoint_io_list == NULL) {
		__jbd2_journal_drop_transaction(journal, commit_transaction);
		@@ -995,11 +998,8 @@ restart_loop:
		}
		spin_unlock(&journal->j_list_lock);

		if (journal->j_commit_callback)
		journal->j_commit_callback(journal, commit_transaction);

		trace_mark(jbd2_end_commit, "dev %s transaction %d head %d",
		journal->j_devname, commit_transaction->t_tid,
		journal->j_devname, journal->j_commit_sequence,
		journal->j_tail_sequence);
		jbd_debug(1, "JBD: commit %d complete, head %d\n",
		journal->j_commit_sequence, journal->j_tail_sequence);

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