From a4c853af0c511d7e0f7cb306bbc8a4f1dbdb64ca Mon Sep 17 00:00:00 2001 From: ChenXiaoSong Date: Wed, 16 Nov 2022 22:23:53 +0800 Subject: [PATCH] btrfs: add might_sleep() annotations Add annotations to functions that might sleep due to allocations or IO and could be called from various contexts. In case of btrfs_search_slot it's not obvious why it would sleep: btrfs_search_slot setup_nodes_for_search reada_for_balance btrfs_readahead_node_child btrfs_readahead_tree_block btrfs_find_create_tree_block alloc_extent_buffer kmem_cache_zalloc /* allocate memory non-atomically, might sleep */ kmem_cache_alloc(GFP_NOFS|__GFP_NOFAIL|__GFP_ZERO) read_extent_buffer_pages submit_extent_page /* disk IO, might sleep */ submit_one_bio Other examples where the sleeping could happen is in 3 places might sleep in update_qgroup_limit_item(), as shown below: update_qgroup_limit_item btrfs_alloc_path /* allocate memory non-atomically, might sleep */ kmem_cache_zalloc(btrfs_path_cachep, GFP_NOFS) Signed-off-by: ChenXiaoSong Reviewed-by: David Sterba Signed-off-by: David Sterba --- fs/btrfs/ctree.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/fs/btrfs/ctree.c b/fs/btrfs/ctree.c index 76b99bcc849d..4754c9101a4c 100644 --- a/fs/btrfs/ctree.c +++ b/fs/btrfs/ctree.c @@ -184,6 +184,8 @@ size_t __attribute_const__ btrfs_get_num_csums(void) struct btrfs_path *btrfs_alloc_path(void) { + might_sleep(); + return kmem_cache_zalloc(btrfs_path_cachep, GFP_NOFS); } @@ -2046,6 +2048,8 @@ int btrfs_search_slot(struct btrfs_trans_handle *trans, struct btrfs_root *root, int min_write_lock_level; int prev_cmp; + might_sleep(); + lowest_level = p->lowest_level; WARN_ON(lowest_level && ins_len > 0); WARN_ON(p->nodes[0] != NULL); -- 2.11.0