diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c index 546bf1146b2d..cc80f2a97a0b 100644 --- a/fs/btrfs/volumes.c +++ b/fs/btrfs/volumes.c @@ -7558,6 +7558,19 @@ int btrfs_read_chunk_tree(struct btrfs_fs_info *fs_info) */ fs_info->fs_devices->total_rw_bytes = 0; + /* + * Lockdep complains about possible circular locking dependency between + * a disk's open_mutex (struct gendisk.open_mutex), the rw semaphores + * used for freeze procection of a fs (struct super_block.s_writers), + * which we take when starting a transaction, and extent buffers of the + * chunk tree if we call read_one_dev() while holding a lock on an + * extent buffer of the chunk tree. Since we are mounting the filesystem + * and at this point there can't be any concurrent task modifying the + * chunk tree, to keep it simple, just skip locking on the chunk tree. + */ + ASSERT(!test_bit(BTRFS_FS_OPEN, &fs_info->flags)); + path->skip_locking = 1; + /* * Read all device items, and then all the chunk items. All * device items are found before any chunk item (their object id @@ -7583,10 +7596,6 @@ int btrfs_read_chunk_tree(struct btrfs_fs_info *fs_info) goto error; break; } - /* - * The nodes on level 1 are not locked but we don't need to do - * that during mount time as nothing else can access the tree - */ node = path->nodes[1]; if (node) { if (last_ra_node != node->start) { @@ -7614,7 +7623,6 @@ int btrfs_read_chunk_tree(struct btrfs_fs_info *fs_info) * requirement for chunk allocation, see the comment on * top of btrfs_chunk_alloc() for details. */ - ASSERT(!test_bit(BTRFS_FS_OPEN, &fs_info->flags)); chunk = btrfs_item_ptr(leaf, slot, struct btrfs_chunk); ret = read_one_chunk(&found_key, leaf, chunk); if (ret)