diff options
| -rw-r--r-- | fs/btrfs/ctree.c | 17 | ||||
| -rw-r--r-- | fs/btrfs/extent-tree.c | 16 |
2 files changed, 23 insertions, 10 deletions
diff --git a/fs/btrfs/ctree.c b/fs/btrfs/ctree.c index 2ee43b6a4f09..539901fb5165 100644 --- a/fs/btrfs/ctree.c +++ b/fs/btrfs/ctree.c @@ -1014,9 +1014,26 @@ static noinline int __btrfs_cow_block(struct btrfs_trans_handle *trans, if ((root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID) && parent) parent_start = parent->start; + /* + * If we are COWing a node/leaf from the extent, chunk or device trees, + * make sure that we do not finish block group creation of pending block + * groups. We do this to avoid a deadlock. + * COWing can result in allocation of a new chunk, and flushing pending + * block groups (btrfs_create_pending_block_groups()) can be triggered + * when finishing allocation of a new chunk. Creation of a pending block + * group modifies the extent, chunk and device trees, therefore we could + * deadlock with ourselves since we are holding a lock on an extent + * buffer that btrfs_create_pending_block_groups() may try to COW later. + */ + if (root == fs_info->extent_root || + root == fs_info->chunk_root || + root == fs_info->dev_root) + trans->can_flush_pending_bgs = false; + cow = btrfs_alloc_tree_block(trans, root, parent_start, root->root_key.objectid, &disk_key, level, search_start, empty_size); + trans->can_flush_pending_bgs = true; if (IS_ERR(cow)) return PTR_ERR(cow); diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c index a4cd0221bc8d..b6d930356dd3 100644 --- a/fs/btrfs/extent-tree.c +++ b/fs/btrfs/extent-tree.c @@ -2954,7 +2954,6 @@ int btrfs_run_delayed_refs(struct btrfs_trans_handle *trans, struct btrfs_delayed_ref_head *head; int ret; int run_all = count == (unsigned long)-1; - bool can_flush_pending_bgs = trans->can_flush_pending_bgs; /* We'll clean this up in btrfs_cleanup_transaction */ if (trans->aborted) @@ -2971,7 +2970,6 @@ again: #ifdef SCRAMBLE_DELAYED_REFS delayed_refs->run_delayed_start = find_middle(&delayed_refs->root); #endif - trans->can_flush_pending_bgs = false; ret = __btrfs_run_delayed_refs(trans, count); if (ret < 0) { btrfs_abort_transaction(trans, ret); @@ -3002,7 +3000,6 @@ again: goto again; } out: - trans->can_flush_pending_bgs = can_flush_pending_bgs; return 0; } @@ -4589,11 +4586,9 @@ out: * the block groups that were made dirty during the lifetime of the * transaction. */ - if (trans->can_flush_pending_bgs && - trans->chunk_bytes_reserved >= (u64)SZ_2M) { + if (trans->chunk_bytes_reserved >= (u64)SZ_2M) btrfs_create_pending_block_groups(trans); - btrfs_trans_release_chunk_metadata(trans); - } + return ret; } @@ -10132,9 +10127,10 @@ void btrfs_create_pending_block_groups(struct btrfs_trans_handle *trans) struct btrfs_block_group_item item; struct btrfs_key key; int ret = 0; - bool can_flush_pending_bgs = trans->can_flush_pending_bgs; - trans->can_flush_pending_bgs = false; + if (!trans->can_flush_pending_bgs) + return; + while (!list_empty(&trans->new_bgs)) { block_group = list_first_entry(&trans->new_bgs, struct btrfs_block_group_cache, @@ -10159,7 +10155,7 @@ void btrfs_create_pending_block_groups(struct btrfs_trans_handle *trans) next: list_del_init(&block_group->bg_list); } - trans->can_flush_pending_bgs = can_flush_pending_bgs; + btrfs_trans_release_chunk_metadata(trans); } int btrfs_make_block_group(struct btrfs_trans_handle *trans, u64 bytes_used, |