[PATCH] block: restore the old set_task_ioprio() behaviour wrt PF_EXITING

Jiri Slaby
2022-03-28T08:59:37Z

PF_EXITING tasks were silently ignored before the below commits.
Continue doing so. Otherwise python-psutil tests fail:
ERROR: psutil.tests.test_process.TestProcess.test_zombie_process
----------------------------------------------------------------------
Traceback (most recent call last):
File "/home/abuild/rpmbuild/BUILD/psutil-5.9.0/build/lib.linux-x86_64-3.9/psutil/_pslinux.py", line 1661, in wrapper
return fun(self, *args, **kwargs)
File "/home/abuild/rpmbuild/BUILD/psutil-5.9.0/build/lib.linux-x86_64-3.9/psutil/_pslinux.py", line 2133, in ionice_set
return cext.proc_ioprio_set(self.pid, ioclass, value)
ProcessLookupError: [Errno 3] No such process

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
File "/home/abuild/rpmbuild/BUILD/psutil-5.9.0/psutil/tests/test_process.py", line 1313, in test_zombie_process
succeed_or_zombie_p_exc(fun)
File "/home/abuild/rpmbuild/BUILD/psutil-5.9.0/psutil/tests/test_process.py", line 1288, in succeed_or_zombie_p_exc
return fun()
File "/home/abuild/rpmbuild/BUILD/psutil-5.9.0/build/lib.linux-x86_64-3.9/psutil/__init__.py", line 792, in ionice
return self._proc.ionice_set(ioclass, value)
File "/home/abuild/rpmbuild/BUILD/psutil-5.9.0/build/lib.linux-x86_64-3.9/psutil/_pslinux.py", line 1665, in wrapper
raise NoSuchProcess(self.pid, self._name)
psutil.NoSuchProcess: process no longer exists (pid=2057)

Cc: Christoph Hellwig <hch@lst.de>
Cc: Jan Kara <jack@suse.cz>
Cc: Jens Axboe <axboe@kernel.dk>
Fixes: 5fc11eebb4 (block: open code create_task_io_context in set_task_ioprio)
Fixes: a957b61254 (block: fix error in handling dead task for ioprio setting)
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
---
block/blk-ioc.c | 3 +--
1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/block/blk-ioc.c b/block/blk-ioc.c
index 11f49f78db32..df9cfe4ca532 100644
--- a/block/blk-ioc.c
+++ b/block/blk-ioc.c
@@ -280,7 +280,6 @@ int set_task_ioprio(struct task_struct *task, int ioprio)

task_lock(task);
if (task->flags & PF_EXITING) {
- err = -ESRCH;
kmem_cache_free(iocontext_cachep, ioc);
goto out;
}
@@ -292,7 +291,7 @@ int set_task_ioprio(struct task_struct *task, int ioprio)
task->io_context->ioprio = ioprio;
out:
task_unlock(task);
- return err;
+ return 0;
}
EXPORT_SYMBOL_GPL(set_task_ioprio);

--
2.35.1