1 files changed, 37 insertions, 0 deletions

diff --git a/fs/ocfs2/alloc.c b/fs/ocfs2/alloc.c
index 460c0cedab3a..7dabbc31060e 100644
--- a/fs/ocfs2/alloc.c
+++ b/fs/ocfs2/alloc.c
@@ -6106,6 +6106,43 @@ void ocfs2_schedule_truncate_log_flush(struct ocfs2_super *osb,
         }
 }
 
+/*
+ * Try to flush truncate logs if we can free enough clusters from it.
+ * As for return value, "< 0" means error, "0" no space and "1" means
+ * we have freed enough spaces and let the caller try to allocate again.
+ */
+int ocfs2_try_to_free_truncate_log(struct ocfs2_super *osb,
+                                        unsigned int needed)
+{
+        tid_t target;
+        int ret = 0;
+        unsigned int truncated_clusters;
+
+        inode_lock(osb->osb_tl_inode);
+        truncated_clusters = osb->truncated_clusters;
+        inode_unlock(osb->osb_tl_inode);
+
+        /*
+         * Check whether we can succeed in allocating if we free
+         * the truncate log.
+         */
+        if (truncated_clusters < needed)
+                goto out;
+
+        ret = ocfs2_flush_truncate_log(osb);
+        if (ret) {
+                mlog_errno(ret);
+                goto out;
+        }
+
+        if (jbd2_journal_start_commit(osb->journal->j_journal, &target)) {
+                jbd2_log_wait_commit(osb->journal->j_journal, target);
+                ret = 1;
+        }
+out:
+        return ret;
+}
+
 static int ocfs2_get_truncate_log_info(struct ocfs2_super *osb,
                                        int slot_num,
                                        struct inode **tl_inode,