1 files changed, 48 insertions, 0 deletions

diff --git a/fs/ocfs2/suballoc.c b/fs/ocfs2/suballoc.c
index 602c05eae7c5..c9661c477869 100644
--- a/fs/ocfs2/suballoc.c
+++ b/fs/ocfs2/suballoc.c
@@ -1579,6 +1579,48 @@ out:
         return ret;
 }
 
+static int ocfs2_bg_discontig_trim_by_rec(struct ocfs2_suballoc_result *res,
+                                          struct ocfs2_extent_rec *rec,
+                                          struct ocfs2_chain_list *cl)
+{
+        unsigned int bpc = le16_to_cpu(cl->cl_bpc);
+        unsigned int bitoff = le32_to_cpu(rec->e_cpos) * bpc;
+        unsigned int bitcount = le32_to_cpu(rec->e_leaf_clusters) * bpc;
+
+        if (res->sr_bit_offset < bitoff)
+                return 0;
+        if (res->sr_bit_offset >= (bitoff + bitcount))
+                return 0;
+        if ((res->sr_bit_offset + res->sr_bits) > (bitoff + bitcount))
+                res->sr_bits = (bitoff + bitcount) - res->sr_bit_offset;
+        return 1;
+}
+
+static void ocfs2_bg_discontig_trim_result(struct ocfs2_alloc_context *ac,
+                                           struct ocfs2_group_desc *bg,
+                                           struct ocfs2_suballoc_result *res)
+{
+        int i;
+        struct ocfs2_extent_rec *rec;
+        struct ocfs2_dinode *di = (struct ocfs2_dinode *)ac->ac_bh->b_data;
+        struct ocfs2_chain_list *cl = &di->id2.i_chain;
+
+        if (!ocfs2_supports_discontig_bh(OCFS2_SB(ac->ac_inode->i_sb)))
+                return;
+
+        if (ocfs2_is_cluster_bitmap(ac->ac_inode))
+                return;
+
+        if (!bg->bg_list.l_next_free_rec)
+                return;
+
+        for (i = 0; i < le16_to_cpu(bg->bg_list.l_next_free_rec); i++) {
+                rec = &bg->bg_list.l_recs[i];
+                if (ocfs2_bg_discontig_trim_by_rec(res, rec, cl))
+                        break;
+        }
+}
+
 static int ocfs2_search_one_group(struct ocfs2_alloc_context *ac,
                                   handle_t *handle,
                                   u32 bits_wanted,
@@ -1608,6 +1650,9 @@ static int ocfs2_search_one_group(struct ocfs2_alloc_context *ac,
                 goto out;
         }
 
+        if (!ret)
+                ocfs2_bg_discontig_trim_result(ac, gd, res);
+
         ret = ocfs2_alloc_dinode_update_counts(alloc_inode, handle, ac->ac_bh,
                                                res->sr_bits,
                                                le16_to_cpu(gd->bg_chain));
@@ -1697,6 +1742,9 @@ static int ocfs2_search_chain(struct ocfs2_alloc_context *ac,
         res->sr_bg_blkno = le64_to_cpu(bg->bg_blkno);
 
         BUG_ON(res->sr_bits == 0);
+        if (!status)
+                ocfs2_bg_discontig_trim_result(ac, bg, res);
+
 
         /*
          * Keep track of previous block descriptor read. When