3 files changed, 66 insertions, 1 deletions

diff --git a/fs/ocfs2/alloc.c b/fs/ocfs2/alloc.c
index 592fae5007d1..8ec418dd9e36 100644
--- a/fs/ocfs2/alloc.c
+++ b/fs/ocfs2/alloc.c
@@ -5858,6 +5858,7 @@ int ocfs2_truncate_log_append(struct ocfs2_super *osb,
 
         ocfs2_journal_dirty(handle, tl_bh);
 
+        osb->truncated_clusters += num_clusters;
 bail:
         mlog_exit(status);
         return status;
@@ -5929,6 +5930,8 @@ static int ocfs2_replay_truncate_records(struct ocfs2_super *osb,
                 i--;
         }
 
+        osb->truncated_clusters = 0;
+
 bail:
         mlog_exit(status);
         return status;
diff --git a/fs/ocfs2/aops.c b/fs/ocfs2/aops.c
index f1e962cb3b73..d55a10e2f300 100644
--- a/fs/ocfs2/aops.c
+++ b/fs/ocfs2/aops.c
@@ -1627,6 +1627,43 @@ static int ocfs2_zero_tail(struct inode *inode, struct buffer_head *di_bh,
         return ret;
 }
 
+/*
+ * 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.
+ */
+static int ocfs2_try_to_free_truncate_log(struct ocfs2_super *osb,
+                                          unsigned int needed)
+{
+        tid_t target;
+        int ret = 0;
+        unsigned int truncated_clusters;
+
+        mutex_lock(&osb->osb_tl_inode->i_mutex);
+        truncated_clusters = osb->truncated_clusters;
+        mutex_unlock(&osb->osb_tl_inode->i_mutex);
+
+        /*
+         * 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;
+}
+
 int ocfs2_write_begin_nolock(struct file *filp,
                              struct address_space *mapping,
                              loff_t pos, unsigned len, unsigned flags,
@@ -1634,7 +1671,7 @@ int ocfs2_write_begin_nolock(struct file *filp,
                              struct buffer_head *di_bh, struct page *mmap_page)
 {
         int ret, cluster_of_pages, credits = OCFS2_INODE_UPDATE_CREDITS;
-        unsigned int clusters_to_alloc, extents_to_split;
+        unsigned int clusters_to_alloc, extents_to_split, clusters_need = 0;
         struct ocfs2_write_ctxt *wc;
         struct inode *inode = mapping->host;
         struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
@@ -1643,7 +1680,9 @@ int ocfs2_write_begin_nolock(struct file *filp,
         struct ocfs2_alloc_context *meta_ac = NULL;
         handle_t *handle;
         struct ocfs2_extent_tree et;
+        int try_free = 1, ret1;
 
+try_again:
         ret = ocfs2_alloc_write_ctxt(&wc, osb, pos, len, di_bh);
         if (ret) {
                 mlog_errno(ret);
@@ -1678,6 +1717,7 @@ int ocfs2_write_begin_nolock(struct file *filp,
                 mlog_errno(ret);
                 goto out;
         } else if (ret == 1) {
+                clusters_need = wc->w_clen;
                 ret = ocfs2_refcount_cow(inode, filp, di_bh,
                                          wc->w_cpos, wc->w_clen, UINT_MAX);
                 if (ret) {
@@ -1692,6 +1732,7 @@ int ocfs2_write_begin_nolock(struct file *filp,
                 mlog_errno(ret);
                 goto out;
         }
+        clusters_need += clusters_to_alloc;
 
         di = (struct ocfs2_dinode *)wc->w_di_bh->b_data;
 
@@ -1814,6 +1855,22 @@ out:
                 ocfs2_free_alloc_context(data_ac);
         if (meta_ac)
                 ocfs2_free_alloc_context(meta_ac);
+
+        if (ret == -ENOSPC && try_free) {
+                /*
+                 * Try to free some truncate log so that we can have enough
+                 * clusters to allocate.
+                 */
+                try_free = 0;
+
+                ret1 = ocfs2_try_to_free_truncate_log(osb, clusters_need);
+                if (ret1 == 1)
+                        goto try_again;
+
+                if (ret1 < 0)
+                        mlog_errno(ret1);
+        }
+
         return ret;
 }
 
diff --git a/fs/ocfs2/ocfs2.h b/fs/ocfs2/ocfs2.h
index 70dd3b1798f1..51cd6898e7f1 100644
--- a/fs/ocfs2/ocfs2.h
+++ b/fs/ocfs2/ocfs2.h
@@ -420,6 +420,11 @@ struct ocfs2_super
         struct inode                    *osb_tl_inode;
         struct buffer_head              *osb_tl_bh;
         struct delayed_work             osb_truncate_log_wq;
+        /*
+         * How many clusters in our truncate log.
+         * It must be protected by osb_tl_inode->i_mutex.
+         */
+        unsigned int truncated_clusters;
 
         struct ocfs2_node_map           osb_recovering_orphan_dirs;
         unsigned int                    *osb_orphan_wipes;