Historically, we declared pointer type to our types:
typedef struct _virXXX virXXX;
typedef virXXX *virXXXPtr;
But usefulness of such declaration is questionable, at best.
Unfortunately, we can't drop every such declaration - we have to
carry some over, because they are part of public API (e.g.
virDomainPtr). But for internal types - we can do drop them and
use what every other C project uses 'virXXX *'.
This change was generated by a very ugly shell script that
generated sed script which was then called over each file in the
repository. For the shell script refer to the cover letter:
https://listman.redhat.com/archives/libvir-list/2021-March/msg00537.html
Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
Reviewed-by: Peter Krempa <pkrempa@redhat.com>
It was reported that the performance of tunnelled migration and
volume upload/download regressed in 6.9.0, when the virt-ssh-helper
is used for remote SSH tunnelling instead of netcat.
When seeing data available to read from stdin, or the socket,
the current code will allocate at most 1k of extra space in
the buffer it has.
After writing data to the socket, or stdout, if more than 1k
of extra space is in the buffer, it will reallocate to free
up that space.
This results in a huge number of mallocs when doing I/O, as
well as a huge number of syscalls since at most 1k of data
will be read/written at a time.
Also if writing blocks for some reason, it will continue to
read data with no memory bound which is bad.
This changes the code to use a 1 MB fixed size buffer in each
direction. If that buffer becomes full, it will update the
watches to stop reading more data. It will never reallocate
the buffer at runtime.
This increases the performance by orders of magnitude.
Reviewed-by: Daniel Henrique Barboza <danielhb413@gmail.com>
Tested-by: Christian Ehrhardt <christian.ehrhardt@canonical.com>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
When accessing libvirtd over a SSH tunnel, the remote driver needs a way
to proxy the SSH input/output stream to a suitable libvirt daemon. This
is currently done by spawning netcat, pointing it to the libvirtd socket
path. This is problematic for a number of reasons:
- The socket path varies according to the --prefix chosen at build
time. The remote client is seeing the local prefix, but what we
need is the remote prefix
- The socket path varies according to remote env variables, such as
the XDG_RUNTIME_DIR location. Again we see the local XDG_RUNTIME_DIR
value, but what we need is the remote value (if any)
- The remote driver doesn't know whether it must connect to the legacy
libvirtd or the modular daemons, so must always assume legacy
libvirtd for back-compat. This means we'll always end up using the
virtproxyd daemon adding an extra hop in the RPC layer.
- We can not able to autospawn the libvirtd daemon for session mode
access
To address these problems this patch introduces the 'virtd-ssh-helper'
program which takes the URI for the remote driver as a CLI parameter.
It then figures out which daemon to connect to and its socket path,
using the same code that the remote driver client would on the remote
host's build of libvirt.
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
