Re: [PATCH v3 0/8] util: Introduce qemu_get_runtime_dir()

[Akihiko Odaki <akihiko.odaki@daynix.com>]

Hi,

This patch series has been forgotten for a while but can still be 
applied. Can anyone review it?

Regards,
Akihiko Odaki

On 2023/09/21 16:54, Akihiko Odaki wrote:
> qemu_get_runtime_dir() returns a dynamically allocated directory path
> that is appropriate for storing runtime files. It corresponds to "run"
> directory in Unix.
> 
> With a tree-wide search, it was found that there are several cases
> where such a functionality is implemented so let's have one as a common
> utlity function.
> 
> A notable feature of qemu_get_runtime_dir() is that it uses
> $XDG_RUNTIME_DIR if available. While the function is often called by
> executables which requires root privileges, it is still possible that
> they are called from a user without privilege to write the system
> runtime directory. In fact, I decided to write this patch when I ran
> virtiofsd in a Linux namespace created by a normal user and realized
> it tries to write the system runtime directory, not writable in this
> case. $XDG_RUNTIME_DIR should provide a writable directory in such
> cases.
> 
> This function does not use qemu_get_local_state_dir() or its logic
> for Windows. Actually the implementation of qemu_get_local_state_dir()
> for Windows seems not right as it calls g_get_system_data_dirs(),
> which refers to $XDG_DATA_DIRS. In Unix terminology, it is basically
> "/usr/share", not "/var", which qemu_get_local_state_dir() is intended
> to provide. Instead, this function try to use the following in order:
> - $XDG_RUNTIME_DIR
> - LocalAppData folder
> - get_relocated_path(CONFIG_QEMU_LOCALSTATEDIR "/run")
> 
> This function does not use g_get_user_runtime_dir() either as it
> falls back to g_get_user_cache_dir() when $XDG_DATA_DIRS is not
> available. In the case, we rather use:
> get_relocated_path(CONFIG_QEMU_LOCALSTATEDIR "/run")
> 
> V2 -> V3:
>    Rebase to the current master.
>    Dropped patch "qga: Remove platform GUID definitions" since it is
>    irrelevant.
> 
> V1 -> V2:
>    Rebased to the current master since Patchew complains.
> 
> Akihiko Odaki (8):
>    util: Introduce qemu_get_runtime_dir()
>    ivshmem-server: Use qemu_get_runtime_dir()
>    contrib/rdmacm-mux: Use qemu_get_runtime_dir()
>    qga: Use qemu_get_runtime_dir()
>    scsi: Use qemu_get_runtime_dir()
>    module: Use qemu_get_runtime_dir()
>    util: Remove qemu_get_local_state_dir()
>    spice-app: Use qemu_get_runtime_dir()
> 
>   include/qemu/osdep.h           | 10 +++++++---
>   contrib/ivshmem-server/main.c  | 20 ++++++++++++++++----
>   contrib/rdmacm-mux/main.c      | 22 ++++++++++++++--------
>   qga/main.c                     |  9 ++++-----
>   scsi/qemu-pr-helper.c          |  6 +++---
>   ui/spice-app.c                 |  4 ++--
>   util/module.c                  |  3 ++-
>   util/oslib-posix.c             |  9 +++++++--
>   util/oslib-win32.c             | 24 ++++++++++++++++++++----
>   contrib/rdmacm-mux/meson.build |  2 +-
>   10 files changed, 76 insertions(+), 33 deletions(-)
>