btrfs: extent-tree: Detect bytes_pinned underflow earlier

Introduce a new wrapper update_bytes_pinned to replace open coded
bytes_pinned modifiers. Now the underflows of space_info::bytes_pinned
get detected and reported.

Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Lu Fengqi <lufq.fnst@cn.fujitsu.com>
Signed-off-by: David Sterba <dsterba@suse.com>

diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
index 395d9d5..71ab8d9 100644 (file)
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -67,6 +67,7 @@ static inline void update_##name(struct btrfs_space_info *sinfo,      \
 }
 
 DECLARE_SPACE_INFO_UPDATE(bytes_may_use);
+DECLARE_SPACE_INFO_UPDATE(bytes_pinned);
 
 static int __btrfs_free_extent(struct btrfs_trans_handle *trans,
                               struct btrfs_delayed_ref_node *node, u64 parent,
@@ -6165,7 +6166,7 @@ static int update_block_group(struct btrfs_trans_handle *trans,
                        old_val -= num_bytes;
                        btrfs_set_block_group_used(&cache->item, old_val);
                        cache->pinned += num_bytes;
-                       cache->space_info->bytes_pinned += num_bytes;
+                       update_bytes_pinned(cache->space_info, num_bytes);
                        cache->space_info->bytes_used -= num_bytes;
                        cache->space_info->disk_used -= num_bytes * factor;
                        spin_unlock(&cache->lock);
@@ -6236,7 +6237,7 @@ static int pin_down_extent(struct btrfs_fs_info *fs_info,
        spin_lock(&cache->space_info->lock);
        spin_lock(&cache->lock);
        cache->pinned += num_bytes;
-       cache->space_info->bytes_pinned += num_bytes;
+       update_bytes_pinned(cache->space_info, num_bytes);
        if (reserved) {
                cache->reserved -= num_bytes;
                cache->space_info->bytes_reserved -= num_bytes;
@@ -6601,7 +6602,7 @@ static int unpin_extent_range(struct btrfs_fs_info *fs_info,
                spin_lock(&space_info->lock);
                spin_lock(&cache->lock);
                cache->pinned -= len;
-               space_info->bytes_pinned -= len;
+               update_bytes_pinned(space_info, -len);
 
                trace_btrfs_space_reservation(fs_info, "pinned",
                                              space_info->flags, len, 0);
@@ -10712,7 +10713,7 @@ void btrfs_delete_unused_bgs(struct btrfs_fs_info *fs_info)
                spin_lock(&space_info->lock);
                spin_lock(&block_group->lock);
 
-               space_info->bytes_pinned -= block_group->pinned;
+               update_bytes_pinned(space_info, -block_group->pinned);
                space_info->bytes_readonly += block_group->pinned;
                percpu_counter_add_batch(&space_info->total_bytes_pinned,
                                   -block_group->pinned,