3 files changed, 81 insertions, 28 deletions

diff --git a/fs/ocfs2/alloc.c b/fs/ocfs2/alloc.c
index b8fc95d10630..7c879fc7834f 100644
--- a/fs/ocfs2/alloc.c
+++ b/fs/ocfs2/alloc.c
@@ -6974,7 +6974,7 @@ static int ocfs2_do_truncate(struct ocfs2_super *osb,
                                         ocfs2_blocks_to_clusters(osb->sb,
                                                                  delete_blk),
                                         clusters_to_del, meta_ac,
-                                        &tc->tc_dealloc);
+                                        &tc->tc_dealloc, 1);
                 else
                         status = ocfs2_truncate_log_append(osb, handle,
                                                            delete_blk,
diff --git a/fs/ocfs2/refcounttree.c b/fs/ocfs2/refcounttree.c
index 4e7df8b8fd4f..0a92436557e3 100644
--- a/fs/ocfs2/refcounttree.c
+++ b/fs/ocfs2/refcounttree.c
@@ -2076,7 +2076,8 @@ static int __ocfs2_decrease_refcount(handle_t *handle,
                                      struct buffer_head *ref_root_bh,
                                      u64 cpos, u32 len,
                                      struct ocfs2_alloc_context *meta_ac,
-                                     struct ocfs2_cached_dealloc_ctxt *dealloc)
+                                     struct ocfs2_cached_dealloc_ctxt *dealloc,
+                                     int delete)
 {
         int ret = 0, index = 0;
         struct ocfs2_refcount_rec rec;
@@ -2084,9 +2085,10 @@ static int __ocfs2_decrease_refcount(handle_t *handle,
         struct super_block *sb = ocfs2_metadata_cache_get_super(ci);
         struct buffer_head *ref_leaf_bh = NULL;
 
-        mlog(0, "Tree owner %llu, decrease refcount start %llu, len %u\n",
+        mlog(0, "Tree owner %llu, decrease refcount start %llu, "
+             "len %u, delete %u\n",
              (unsigned long long)ocfs2_metadata_cache_owner(ci),
-             (unsigned long long)cpos, len);
+             (unsigned long long)cpos, len, delete);
 
         while (len) {
                 ret = ocfs2_get_refcount_rec(ci, ref_root_bh,
@@ -2099,6 +2101,8 @@ static int __ocfs2_decrease_refcount(handle_t *handle,
 
                 r_count = le32_to_cpu(rec.r_refcount);
                 BUG_ON(r_count == 0);
+                if (!delete)
+                        BUG_ON(r_count > 1);
 
                 r_len = min((u64)(cpos + len), le64_to_cpu(rec.r_cpos) +
                               le32_to_cpu(rec.r_clusters)) - cpos;
@@ -2112,7 +2116,7 @@ static int __ocfs2_decrease_refcount(handle_t *handle,
                         goto out;
                 }
 
-                if (le32_to_cpu(rec.r_refcount) == 1) {
+                if (le32_to_cpu(rec.r_refcount) == 1 && delete) {
                         ret = ocfs2_cache_cluster_dealloc(dealloc,
                                           ocfs2_clusters_to_blocks(sb, cpos),
                                                           r_len);
@@ -2137,7 +2141,8 @@ out:
 int ocfs2_decrease_refcount(struct inode *inode,
                             handle_t *handle, u32 cpos, u32 len,
                             struct ocfs2_alloc_context *meta_ac,
-                            struct ocfs2_cached_dealloc_ctxt *dealloc)
+                            struct ocfs2_cached_dealloc_ctxt *dealloc,
+                            int delete)
 {
         int ret;
         u64 ref_blkno;
@@ -2167,7 +2172,7 @@ int ocfs2_decrease_refcount(struct inode *inode,
         }
 
         ret = __ocfs2_decrease_refcount(handle, &tree->rf_ci, ref_root_bh,
-                                        cpos, len, meta_ac, dealloc);
+                                        cpos, len, meta_ac, dealloc, delete);
         if (ret)
                 mlog_errno(ret);
 out:
@@ -2974,10 +2979,16 @@ static int ocfs2_make_clusters_writable(struct super_block *sb,
                                         u32 cpos, u32 p_cluster,
                                         u32 num_clusters, unsigned int e_flags)
 {
-        int ret, credits =  0;
+        int ret, delete, index, credits =  0;
         u32 new_bit, new_len;
+        unsigned int set_len;
         struct ocfs2_super *osb = OCFS2_SB(sb);
         handle_t *handle;
+        struct buffer_head *ref_leaf_bh = NULL;
+        struct ocfs2_refcount_rec rec;
+
+        mlog(0, "cpos %u, p_cluster %u, num_clusters %u, e_flags %u\n",
+             cpos, p_cluster, num_clusters, e_flags);
 
         ret = ocfs2_lock_refcount_allocators(sb, p_cluster, num_clusters,
                                              &context->di_et,
@@ -2998,35 +3009,75 @@ static int ocfs2_make_clusters_writable(struct super_block *sb,
         }
 
         while (num_clusters) {
-                ret = __ocfs2_claim_clusters(osb, handle, context->data_ac,
-                                             1, num_clusters,
-                                             &new_bit, &new_len);
+                ret = ocfs2_get_refcount_rec(context->ref_ci,
+                                             context->ref_root_bh,
+                                             p_cluster, num_clusters,
+                                             &rec, &index, &ref_leaf_bh);
                 if (ret) {
                         mlog_errno(ret);
                         goto out_commit;
                 }
 
-                ret = ocfs2_replace_clusters(handle, context,
-                                             cpos, p_cluster, new_bit,
-                                             new_len, e_flags);
+                BUG_ON(!rec.r_refcount);
+                set_len = min((u64)p_cluster + num_clusters,
+                              le64_to_cpu(rec.r_cpos) +
+                              le32_to_cpu(rec.r_clusters)) - p_cluster;
+
+                /*
+                 * There are many different situation here.
+                 * 1. If refcount == 1, remove the flag and don't COW.
+                 * 2. If refcount > 1, allocate clusters.
+                 *    Here we may not allocate r_len once at a time, so continue
+                 *    until we reach num_clusters.
+                 */
+                if (le32_to_cpu(rec.r_refcount) == 1) {
+                        delete = 0;
+                        ret = ocfs2_clear_ext_refcount(handle, &context->di_et,
+                                                       cpos, p_cluster,
+                                                       set_len, e_flags,
+                                                       context->meta_ac,
+                                                       &context->dealloc);
+                        if (ret) {
+                                mlog_errno(ret);
+                                goto out_commit;
+                        }
+                } else {
+                        delete = 1;
+
+                        ret = __ocfs2_claim_clusters(osb, handle,
+                                                     context->data_ac,
+                                                     1, set_len,
+                                                     &new_bit, &new_len);
+                        if (ret) {
+                                mlog_errno(ret);
+                                goto out_commit;
+                        }
+
+                        ret = ocfs2_replace_clusters(handle, context,
+                                                     cpos, p_cluster, new_bit,
+                                                     new_len, e_flags);
+                        if (ret) {
+                                mlog_errno(ret);
+                                goto out_commit;
+                        }
+                        set_len = new_len;
+                }
+
+                ret = __ocfs2_decrease_refcount(handle, context->ref_ci,
+                                                context->ref_root_bh,
+                                                p_cluster, set_len,
+                                                context->meta_ac,
+                                                &context->dealloc, delete);
                 if (ret) {
                         mlog_errno(ret);
                         goto out_commit;
                 }
 
-                cpos += new_len;
-                p_cluster += new_len;
-                num_clusters -= new_len;
-        }
-
-        ret = __ocfs2_decrease_refcount(handle, context->ref_ci,
-                                        context->ref_root_bh,
-                                        p_cluster, num_clusters,
-                                        context->meta_ac,
-                                        &context->dealloc);
-        if (ret) {
-                mlog_errno(ret);
-                goto out_commit;
+                cpos += set_len;
+                p_cluster += set_len;
+                num_clusters -= set_len;
+                brelse(ref_leaf_bh);
+                ref_leaf_bh = NULL;
         }
 
         /*
@@ -3049,6 +3100,7 @@ out:
                 ocfs2_free_alloc_context(context->meta_ac);
                 context->meta_ac = NULL;
         }
+        brelse(ref_leaf_bh);
 
         return ret;
 }
diff --git a/fs/ocfs2/refcounttree.h b/fs/ocfs2/refcounttree.h
index 9960878134df..a8c15b0b2307 100644
--- a/fs/ocfs2/refcounttree.h
+++ b/fs/ocfs2/refcounttree.h
@@ -44,7 +44,8 @@ void ocfs2_unlock_refcount_tree(struct ocfs2_super *osb,
 int ocfs2_decrease_refcount(struct inode *inode,
                             handle_t *handle, u32 cpos, u32 len,
                             struct ocfs2_alloc_context *meta_ac,
-                            struct ocfs2_cached_dealloc_ctxt *dealloc);
+                            struct ocfs2_cached_dealloc_ctxt *dealloc,
+                            int delete);
 int ocfs2_prepare_refcount_change_for_del(struct inode *inode,
                                           struct buffer_head *di_bh,
                                           u64 phys_blkno,