Btrfs: move read only block groups onto their own list V2

[cascardo/linux.git] / fs / btrfs / extent-tree.c

diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
index 47c1ba1..cf3460e 100644 (file)
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -3504,6 +3504,7 @@ static int update_space_info(struct btrfs_fs_info *info, u64 flags,
        found->chunk_alloc = 0;
        found->flush = 0;
        init_waitqueue_head(&found->wait);
+       INIT_LIST_HEAD(&found->ro_bgs);
 
        ret = kobject_init_and_add(&found->kobj, &space_info_ktype,
                                    info->space_info_kobj, "%s",
@@ -8511,6 +8512,7 @@ static int set_block_group_ro(struct btrfs_block_group_cache *cache, int force)
            min_allocable_bytes <= sinfo->total_bytes) {
                sinfo->bytes_readonly += num_bytes;
                cache->ro = 1;
+               list_add_tail(&cache->ro_list, &sinfo->ro_bgs);
                ret = 0;
        }
 out:
@@ -8565,15 +8567,20 @@ int btrfs_force_chunk_alloc(struct btrfs_trans_handle *trans,
 
 /*
  * helper to account the unused space of all the readonly block group in the
- * list. takes mirrors into account.
+ * space_info. takes mirrors into account.
  */
-static u64 __btrfs_get_ro_block_group_free_space(struct list_head *groups_list)
+u64 btrfs_account_ro_block_groups_free_space(struct btrfs_space_info *sinfo)
 {
        struct btrfs_block_group_cache *block_group;
        u64 free_bytes = 0;
        int factor;
 
-       list_for_each_entry(block_group, groups_list, list) {
+       /* It's df, we don't care if it's racey */
+       if (list_empty(&sinfo->ro_bgs))
+               return 0;
+
+       spin_lock(&sinfo->lock);
+       list_for_each_entry(block_group, &sinfo->ro_bgs, ro_list) {
                spin_lock(&block_group->lock);
 
                if (!block_group->ro) {
@@ -8594,26 +8601,6 @@ static u64 __btrfs_get_ro_block_group_free_space(struct list_head *groups_list)
 
                spin_unlock(&block_group->lock);
        }
-
-       return free_bytes;
-}
-
-/*
- * helper to account the unused space of all the readonly block group in the
- * space_info. takes mirrors into account.
- */
-u64 btrfs_account_ro_block_groups_free_space(struct btrfs_space_info *sinfo)
-{
-       int i;
-       u64 free_bytes = 0;
-
-       spin_lock(&sinfo->lock);
-
-       for (i = 0; i < BTRFS_NR_RAID_TYPES; i++)
-               if (!list_empty(&sinfo->block_groups[i]))
-                       free_bytes += __btrfs_get_ro_block_group_free_space(
-                                               &sinfo->block_groups[i]);
-
        spin_unlock(&sinfo->lock);
 
        return free_bytes;
@@ -8633,6 +8620,7 @@ void btrfs_set_block_group_rw(struct btrfs_root *root,
                    cache->bytes_super - btrfs_block_group_used(&cache->item);
        sinfo->bytes_readonly -= num_bytes;
        cache->ro = 0;
+       list_del_init(&cache->ro_list);
        spin_unlock(&cache->lock);
        spin_unlock(&sinfo->lock);
 }
@@ -9002,6 +8990,7 @@ btrfs_create_block_group_cache(struct btrfs_root *root, u64 start, u64 size)
        INIT_LIST_HEAD(&cache->list);
        INIT_LIST_HEAD(&cache->cluster_list);
        INIT_LIST_HEAD(&cache->bg_list);
+       INIT_LIST_HEAD(&cache->ro_list);
        btrfs_init_free_space_ctl(cache);
 
        return cache;
@@ -9411,6 +9400,7 @@ int btrfs_remove_block_group(struct btrfs_trans_handle *trans,
         * are still on the list after taking the semaphore
         */
        list_del_init(&block_group->list);
+       list_del_init(&block_group->ro_list);
        if (list_empty(&block_group->space_info->block_groups[index])) {
                kobj = block_group->space_info->block_group_kobjs[index];
                block_group->space_info->block_group_kobjs[index] = NULL;