ocfs2: Try to free truncate log when meeting ENOSPC in write.

Recently, one of our colleagues meet with a problem that if we
write/delete a 32mb files repeatly, we will get an ENOSPC in
the end. And the corresponding bug is 1288.
http://oss.oracle.com/bugzilla/show_bug.cgi?id=1288

The real problem is that although we have freed the clusters,
they are in truncate log and they will be summed up so that
we can free them once in a whole.

So this patch just try to resolve it. In case we see -ENOSPC
in ocfs2_write_begin_no_lock, we will check whether the truncate
log has enough clusters for our need, if yes, we will try to
flush the truncate log at that point and try again. This method
is inspired by Mark Fasheh <mfasheh@suse.com>. Thanks.

Cc: Mark Fasheh <mfasheh@suse.com>
Signed-off-by: Tao Ma <tao.ma@oracle.com>
Signed-off-by: Joel Becker <joel.becker@oracle.com>

1 files changed, 3 insertions, 0 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;