[Tarantool-patches] [PATCH v2] fio: fix race condition in mktree

[Igor Munkin]

Hello,

Thanks, LGTM.

Cced Sasha Tu. to proceed with the patch.

On 13.01.20, HustonMmmavr wrote:
> Despite the lack of documentation, fio.mktree() was designed to work
> similar to mkdir -p: it creates the directory along with it's parents
> and doesn't complain about existing ones.
> 
> But this function was subject to a race if two different processes were
> trying to create the same directory at the same time. It was caused by
> the fact that directory existence check and its creation aren't atomic.
> 
> This patch fixes the race by impoving error handling: it's not an error
> if directory exists, even if it was created by someone else and mktree
> failed.
> 
> Related to https://github.com/tarantool/doc/issues/1063

Side note: you can mention the ticket from other repo queue the
following way:
| Relates to tarantool/doc#1063

> Closes #4660
> ---
> branch: https://github.com/tarantool/tarantool/tree/HustonMmmavr/gh-4660-fix-fio-mktree-race
> 
>  src/lua/fio.lua | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/src/lua/fio.lua b/src/lua/fio.lua
> index cb224f3d0..c9aeac951 100644
> --- a/src/lua/fio.lua
> +++ b/src/lua/fio.lua
> @@ -364,7 +364,7 @@ fio.mktree = function(path, mode)
>          local stat = fio.stat(current_dir)
>          if stat == nil then
>              local st, err = fio.mkdir(current_dir, mode)
> -            if err ~= nil  then
> +            if err ~= nil and not fio.path.is_dir(current_dir) then
>                  return false, string.format("Error creating directory %s: %s",
>                      current_dir, tostring(err))
>              end
> -- 
> 2.23.0
> 

-- 
Best regards,
IM