1 files changed, 41 insertions, 22 deletions

diff --git a/fs/btrfs/qgroup.c b/fs/btrfs/qgroup.c
index 5279fdae7142..9e119552ed32 100644
--- a/fs/btrfs/qgroup.c
+++ b/fs/btrfs/qgroup.c
@@ -1463,6 +1463,7 @@ struct btrfs_qgroup_extent_record
         u64 bytenr = record->bytenr;
 
         assert_spin_locked(&delayed_refs->lock);
+        trace_btrfs_qgroup_insert_dirty_extent(record);
 
         while (*p) {
                 parent_node = *p;
@@ -1594,6 +1595,9 @@ static int qgroup_update_counters(struct btrfs_fs_info *fs_info,
                 cur_old_count = btrfs_qgroup_get_old_refcnt(qg, seq);
                 cur_new_count = btrfs_qgroup_get_new_refcnt(qg, seq);
 
+                trace_qgroup_update_counters(qg->qgroupid, cur_old_count,
+                                             cur_new_count);
+
                 /* Rfer update part */
                 if (cur_old_count == 0 && cur_new_count > 0) {
                         qg->rfer += num_bytes;
@@ -1683,6 +1687,9 @@ btrfs_qgroup_account_extent(struct btrfs_trans_handle *trans,
                 goto out_free;
         BUG_ON(!fs_info->quota_root);
 
+        trace_btrfs_qgroup_account_extent(bytenr, num_bytes, nr_old_roots,
+                                          nr_new_roots);
+
         qgroups = ulist_alloc(GFP_NOFS);
         if (!qgroups) {
                 ret = -ENOMEM;
@@ -1752,6 +1759,8 @@ int btrfs_qgroup_account_extents(struct btrfs_trans_handle *trans,
                 record = rb_entry(node, struct btrfs_qgroup_extent_record,
                                   node);
 
+                trace_btrfs_qgroup_account_extents(record);
+
                 if (!ret) {
                         /*
                          * Use (u64)-1 as time_seq to do special search, which
@@ -1842,8 +1851,10 @@ out:
 }
 
 /*
- * copy the acounting information between qgroups. This is necessary when a
- * snapshot or a subvolume is created
+ * Copy the acounting information between qgroups. This is necessary
+ * when a snapshot or a subvolume is created. Throwing an error will
+ * cause a transaction abort so we take extra care here to only error
+ * when a readonly fs is a reasonable outcome.
  */
 int btrfs_qgroup_inherit(struct btrfs_trans_handle *trans,
                          struct btrfs_fs_info *fs_info, u64 srcid, u64 objectid,
@@ -1873,15 +1884,15 @@ int btrfs_qgroup_inherit(struct btrfs_trans_handle *trans,
                        2 * inherit->num_excl_copies;
                 for (i = 0; i < nums; ++i) {
                         srcgroup = find_qgroup_rb(fs_info, *i_qgroups);
-                        if (!srcgroup) {
-                                ret = -EINVAL;
-                                goto out;
-                        }
 
-                        if ((srcgroup->qgroupid >> 48) <= (objectid >> 48)) {
-                                ret = -EINVAL;
-                                goto out;
-                        }
+                        /*
+                         * Zero out invalid groups so we can ignore
+                         * them later.
+                         */
+                        if (!srcgroup ||
+                            ((srcgroup->qgroupid >> 48) <= (objectid >> 48)))
+                                *i_qgroups = 0ULL;
+
                         ++i_qgroups;
                 }
         }
@@ -1916,17 +1927,19 @@ int btrfs_qgroup_inherit(struct btrfs_trans_handle *trans,
          */
         if (inherit) {
                 i_qgroups = (u64 *)(inherit + 1);
-                for (i = 0; i < inherit->num_qgroups; ++i) {
+                for (i = 0; i < inherit->num_qgroups; ++i, ++i_qgroups) {
+                        if (*i_qgroups == 0)
+                                continue;
                         ret = add_qgroup_relation_item(trans, quota_root,
                                                        objectid, *i_qgroups);
-                        if (ret)
+                        if (ret && ret != -EEXIST)
                                 goto out;
                         ret = add_qgroup_relation_item(trans, quota_root,
                                                        *i_qgroups, objectid);
-                        if (ret)
+                        if (ret && ret != -EEXIST)
                                 goto out;
-                        ++i_qgroups;
                 }
+                ret = 0;
         }
 
 
@@ -1987,17 +2000,22 @@ int btrfs_qgroup_inherit(struct btrfs_trans_handle *trans,
 
         i_qgroups = (u64 *)(inherit + 1);
         for (i = 0; i < inherit->num_qgroups; ++i) {
-                ret = add_relation_rb(quota_root->fs_info, objectid,
-                                      *i_qgroups);
-                if (ret)
-                        goto unlock;
+                if (*i_qgroups) {
+                        ret = add_relation_rb(quota_root->fs_info, objectid,
+                                              *i_qgroups);
+                        if (ret)
+                                goto unlock;
+                }
                 ++i_qgroups;
         }
 
-        for (i = 0; i <  inherit->num_ref_copies; ++i) {
+        for (i = 0; i <  inherit->num_ref_copies; ++i, i_qgroups += 2) {
                 struct btrfs_qgroup *src;
                 struct btrfs_qgroup *dst;
 
+                if (!i_qgroups[0] || !i_qgroups[1])
+                        continue;
+
                 src = find_qgroup_rb(fs_info, i_qgroups[0]);
                 dst = find_qgroup_rb(fs_info, i_qgroups[1]);
 
@@ -2008,12 +2026,14 @@ int btrfs_qgroup_inherit(struct btrfs_trans_handle *trans,
 
                 dst->rfer = src->rfer - level_size;
                 dst->rfer_cmpr = src->rfer_cmpr - level_size;
-                i_qgroups += 2;
         }
-        for (i = 0; i <  inherit->num_excl_copies; ++i) {
+        for (i = 0; i <  inherit->num_excl_copies; ++i, i_qgroups += 2) {
                 struct btrfs_qgroup *src;
                 struct btrfs_qgroup *dst;
 
+                if (!i_qgroups[0] || !i_qgroups[1])
+                        continue;
+
                 src = find_qgroup_rb(fs_info, i_qgroups[0]);
                 dst = find_qgroup_rb(fs_info, i_qgroups[1]);
 
@@ -2024,7 +2044,6 @@ int btrfs_qgroup_inherit(struct btrfs_trans_handle *trans,
 
                 dst->excl = src->excl + level_size;
                 dst->excl_cmpr = src->excl_cmpr + level_size;
-                i_qgroups += 2;
         }
 
 unlock: