f2fs: introduce __check_rb_tree_consistence

Introduce __check_rb_tree_consistence to check consistence of rb-tree
based discard cache in runtime.

Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

diff --git a/fs/f2fs/extent_cache.c b/fs/f2fs/extent_cache.c
index 221ad08..2f98d70 100644 (file)
--- a/fs/f2fs/extent_cache.c
+++ b/fs/f2fs/extent_cache.c
@@ -159,6 +159,38 @@ lookup_neighbors:
        return re;
 }
 
+bool __check_rb_tree_consistence(struct f2fs_sb_info *sbi,
+                                               struct rb_root *root)
+{
+#ifdef CONFIG_F2FS_CHECK_FS
+       struct rb_node *cur = rb_first(root), *next;
+       struct rb_entry *cur_re, *next_re;
+
+       if (!cur)
+               return true;
+
+       while (cur) {
+               next = rb_next(cur);
+               if (!next)
+                       return true;
+
+               cur_re = rb_entry(cur, struct rb_entry, rb_node);
+               next_re = rb_entry(next, struct rb_entry, rb_node);
+
+               if (cur_re->ofs + cur_re->len > next_re->ofs) {
+                       f2fs_msg(sbi->sb, KERN_INFO, "inconsistent rbtree, "
+                               "cur(%u, %u) next(%u, %u)",
+                               cur_re->ofs, cur_re->len,
+                               next_re->ofs, next_re->len);
+                       return false;
+               }
+
+               cur = next;
+       }
+#endif
+       return true;
+}
+
 static struct kmem_cache *extent_tree_slab;
 static struct kmem_cache *extent_node_slab;
 

diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
index d81a365..2525691 100644 (file)
--- a/fs/f2fs/f2fs.h
+++ b/fs/f2fs/f2fs.h
@@ -2620,6 +2620,8 @@ struct rb_entry *__lookup_rb_tree_ret(struct rb_root *root,
                struct rb_entry **prev_entry, struct rb_entry **next_entry,
                struct rb_node ***insert_p, struct rb_node **insert_parent,
                bool force);
+bool __check_rb_tree_consistence(struct f2fs_sb_info *sbi,
+                                               struct rb_root *root);
 unsigned int f2fs_shrink_extent_tree(struct f2fs_sb_info *sbi, int nr_shrink);
 bool f2fs_init_extent_tree(struct inode *inode, struct f2fs_extent *i_ext);
 void f2fs_drop_extent_tree(struct inode *inode);

diff --git a/fs/f2fs/segment.c b/fs/f2fs/segment.c
index 8da49a1..f882716 100644 (file)
--- a/fs/f2fs/segment.c
+++ b/fs/f2fs/segment.c
@@ -833,6 +833,7 @@ static void __punch_discard_cmd(struct f2fs_sb_info *sbi,
        if (blkaddr > di.lstart) {
                dc->len = blkaddr - dc->lstart;
                __relocate_discard_cmd(dcc, dc);
+               f2fs_bug_on(sbi, !__check_rb_tree_consistence(sbi, &dcc->root));
                modified = true;
        }
 
@@ -842,11 +843,15 @@ static void __punch_discard_cmd(struct f2fs_sb_info *sbi,
                                        di.start + blkaddr + 1 - di.lstart,
                                        di.lstart + di.len - 1 - blkaddr,
                                        NULL, NULL);
+                       f2fs_bug_on(sbi,
+                               !__check_rb_tree_consistence(sbi, &dcc->root));
                } else {
                        dc->lstart++;
                        dc->len--;
                        dc->start++;
                        __relocate_discard_cmd(dcc, dc);
+                       f2fs_bug_on(sbi,
+                               !__check_rb_tree_consistence(sbi, &dcc->root));
                }
        }
 }
@@ -906,6 +911,8 @@ static void __update_discard_tree_range(struct f2fs_sb_info *sbi,
                        __is_discard_back_mergeable(&di, &prev_dc->di)) {
                        prev_dc->di.len += di.len;
                        __relocate_discard_cmd(dcc, prev_dc);
+                       f2fs_bug_on(sbi,
+                               !__check_rb_tree_consistence(sbi, &dcc->root));
                        di = prev_dc->di;
                        tdc = prev_dc;
                        merged = true;
@@ -920,13 +927,17 @@ static void __update_discard_tree_range(struct f2fs_sb_info *sbi,
                        __relocate_discard_cmd(dcc, next_dc);
                        if (tdc)
                                __remove_discard_cmd(sbi, tdc);
-
+                       f2fs_bug_on(sbi,
+                               !__check_rb_tree_consistence(sbi, &dcc->root));
                        merged = true;
                }
 
-               if (!merged)
+               if (!merged) {
                        __insert_discard_tree(sbi, bdev, di.lstart, di.start,
                                                        di.len, NULL, NULL);
+                       f2fs_bug_on(sbi,
+                               !__check_rb_tree_consistence(sbi, &dcc->root));
+               }
  next:
                prev_dc = next_dc;
                if (!prev_dc)