Currently the code contains multiple places where callers expect the errno
to be valid (implied by calling pr_perror to log file IO errors) after
calling open_img_file(), read_fp() and write_fp() helpers. Problem there
is that those helpers can destroy the errno courtesy of themselves
emitting log messages via fprintf.
Furthermore, the callers then sometimes invent the errors to return back
to the caller, or even outside of the plugin.
On top of that there is no benefit to buffered file IO given the plugin
reads and writes in buffer object size chunks, so it it preferrable to
just go direct and avoid any possibility of extra copying to and from libc
temporary buffers.
So lets just convert it all in one swoop to POSIX IO and make sure correct
errnos are always propagated to the caller (including to CRIU core).
Hopefully this removes all instances of incorrect pr_perror log messages.
Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin@igalia.com>
Reviewed-By: David Francis <David.Francis@amd.com> # v1
---
v2:
* Handle short reads and writes.
* Add O_TRUNC.
v3:
* Handle EINTR and EAGAIN.
* Set errno on len == 0.
* Use %zu for size_t printing.
v4:
* Drop shadowed ret.
* Drop needless casts.
Given that dump and restore of KFD vs DRM forks into completely parallel
flows inside the respective plugin callbacks, lets split it out by
extracting into helpers. This de-clutters the code flow and makes it
obvious which part is done where.
Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin@igalia.com>
Reviewed-By: David Francis <David.Francis@amd.com>
Consolidate to one fclose() call with the extra bonus the inconsequential
file descriptor leak is eliminated.
Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin@igalia.com>
Reviewed-By: David Francis <David.Francis@amd.com>
Close the file when either memory allocation or a file read fails in
amdgpu_plugin_dmabuf_restore.
Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin@igalia.com>
Free the protobuf message and buffer when returning early from
amdgpu_plugin_dmabuf_restore() on failure to find a dmabuf fd.
Signed-off-by: Radostin Stoyanov <rstoyanov@fedoraproject.org>
When the amdgpu plugin is called for restore of a file img,
we don't initially know if it's a kfd or drm file. So we first
try to open a kfd file, and if that fails, we assume it's
a drm file. That failure leads to a lot of error messages like
Error amdgpu_plugin: amdgpu-kfd-141.img: Failed to open for read
For this normal behaviour.
Add an option on open_img_file to suppress this error when
we aren't sure if the file we're trying to open exists.
Signed-off-by: David Francis <David.Francis@amd.com>
Use `return 0` on success in `post_dump_dmabuf_check()` for consistency
with other functions.
Co-authored-by: Andrei Vagin <avagin@google.com>
Signed-off-by: David Francis <David.Francis@amd.com>
Signed-off-by: Radostin Stoyanov <rstoyanov@fedoraproject.org>
These pr_info lines begin with "CC3" and "TWI" were not meant to be
included in the patch.
Co-authored-by: Andrei Vagin <avagin@google.com>
Signed-off-by: David Francis <David.Francis@amd.com>
Signed-off-by: Radostin Stoyanov <rstoyanov@fedoraproject.org>
amdgpu libraries that use dmabuf fd to share GPU memory between
processes close the dmabuf fds immediately after using them.
However, it is possible that checkpoint of a process catches one
of the dmabuf fds open. In that case, the amdgpu plugin needs
to handle it.
The checkpoint of the dmabuf fd does require the device file
it was exported from to have already been dumped
To identify which device this dmabuf fd was exprted from, attempt
to import it on each device, then record the dmabuf handle
it imports as. This handle can be used to restore it.
Signed-off-by: David Francis <David.Francis@amd.com>
