jbd2: abort instead of waiting for nonexistent transaction (23f8b79e) · Commits · 戴 / test

The __jbd2_log_wait_for_space function sits in a loop checkpointing transactions until there is sufficient space free in the journal. However, if there are no transactions to be processed (e.g. because the free space calculation is wrong due to a corrupted filesystem) it will never progress. Check for space being required when no transactions are outstanding and abort the journal instead of endlessly looping. This patch fixes the bug reported by Sami Liedes at: http://bugzilla.kernel.org/show_bug.cgi?id=10976 Signed-off-by:

Duane Griffin <duaneg@dghda.com> Cc: Sami Liedes <sliedes@cc.hut.fi> Cc: <linux-ext4@vger.kernel.org> Signed-off-by:

Andrew Morton <akpm@linux-foundation.org> Signed-off-by:

"Theodore Ts'o" <tytso@mit.edu>

fs/jbd2/checkpoint.c

+17 −2

Original line number	Diff line number	Diff line
		@@ -126,14 +126,29 @@ void __jbd2_log_wait_for_space(journal_t *journal)

		/*
		* Test again, another process may have checkpointed while we
		* were waiting for the checkpoint lock
		* were waiting for the checkpoint lock. If there are no
		* outstanding transactions there is nothing to checkpoint and
		* we can't make progress. Abort the journal in this case.
		*/
		spin_lock(&journal->j_state_lock);
		spin_lock(&journal->j_list_lock);
		nblocks = jbd_space_needed(journal);
		if (__jbd2_log_space_left(journal) < nblocks) {
		int chkpt = journal->j_checkpoint_transactions != NULL;

		spin_unlock(&journal->j_list_lock);
		spin_unlock(&journal->j_state_lock);
		if (chkpt) {
		jbd2_log_do_checkpoint(journal);
		} else {
		printk(KERN_ERR "%s: no transactions\n",
		__func__);
		jbd2_journal_abort(journal, 0);
		}

		spin_lock(&journal->j_state_lock);
		} else {
		spin_unlock(&journal->j_list_lock);
		}
		mutex_unlock(&journal->j_checkpoint_mutex);
		}

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