6.15-stable review patch. If anyone has any objections, please let me know.
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From: Guenter Roeck linux@roeck-us.net
[ Upstream commit e2ba58ccc9099514380c3300cbc0750b5055fc1c ]
Upstream commit 53889bcaf536 ("block: make __get_task_ioprio() easier to read") changes the IO priority returned to the caller if no IO context is defined for the task. Prior to this commit, the returned IO priority was determined by task_nice_ioclass() and task_nice_ioprio(). Now it is always IOPRIO_DEFAULT, which translates to IOPRIO_CLASS_NONE with priority 0. However, task_nice_ioclass() returns IOPRIO_CLASS_IDLE, IOPRIO_CLASS_RT, or IOPRIO_CLASS_BE depending on the task scheduling policy, and task_nice_ioprio() returns a value determined by task_nice(). This causes regressions in test code checking the IO priority and class of IO operations on tasks with no IO context.
Fix the problem by returning the IO priority calculated from task_nice_ioclass() and task_nice_ioprio() if no IO context is defined to match earlier behavior.
Fixes: 53889bcaf536 ("block: make __get_task_ioprio() easier to read") Cc: Jens Axboe axboe@kernel.dk Cc: Bart Van Assche bvanassche@acm.org Signed-off-by: Guenter Roeck linux@roeck-us.net Reviewed-by: Yu Kuai yukuai3@huawei.com Reviewed-by: Damien Le Moal dlemoal@kernel.org Link: https://lore.kernel.org/r/20250731044953.1852690-1-linux@roeck-us.net Signed-off-by: Jens Axboe axboe@kernel.dk Signed-off-by: Sasha Levin sashal@kernel.org --- include/linux/ioprio.h | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/include/linux/ioprio.h b/include/linux/ioprio.h index b25377b6ea98..5210e8371238 100644 --- a/include/linux/ioprio.h +++ b/include/linux/ioprio.h @@ -60,7 +60,8 @@ static inline int __get_task_ioprio(struct task_struct *p) int prio;
if (!ioc) - return IOPRIO_DEFAULT; + return IOPRIO_PRIO_VALUE(task_nice_ioclass(p), + task_nice_ioprio(p));
if (p != current) lockdep_assert_held(&p->alloc_lock);