btrfs: add might_sleep() annotations

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[ Upstream commit a4c853af0c ]

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: 3ed51857a5 ("btrfs: add a sanity check for btrfs root in btrfs_search_slot()")
Signed-off-by: Sasha Levin <sashal@kernel.org>

...

This commit is contained in:

ChenXiaoSong 2022-11-16 22:23:53 +08:00 • committed by Greg Kroah-Hartman

parent dcbcd9c88e

commit 1dfc86bea8

1 changed files with 4 additions and 0 deletions

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fs/btrfs/ctree.c

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