6.1-stable review patch. If anyone has any objections, please let me know.
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From: ChenXiaoSong chenxiaosong2@huawei.com
[ Upstream commit a4c853af0c511d7e0f7cb306bbc8a4f1dbdb64ca ]
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 chenxiaosong2@huawei.com Reviewed-by: David Sterba dsterba@suse.com Signed-off-by: David Sterba dsterba@suse.com Stable-dep-of: 3ed51857a50f ("btrfs: add a sanity check for btrfs root in btrfs_search_slot()") Signed-off-by: Sasha Levin sashal@kernel.org --- fs/btrfs/ctree.c | 4 ++++ 1 file changed, 4 insertions(+)
diff --git a/fs/btrfs/ctree.c b/fs/btrfs/ctree.c index 66d1f34c3fc69..46550c26e6844 100644 --- a/fs/btrfs/ctree.c +++ b/fs/btrfs/ctree.c @@ -78,6 +78,8 @@ 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); }
@@ -1984,6 +1986,8 @@ 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);