1 /* SPDX-License-Identifier: GPL-2.0 */ 2 #ifndef IOPRIO_H 3 #define IOPRIO_H 4 5 #include <linux/sched.h> 6 #include <linux/sched/rt.h> 7 #include <linux/iocontext.h> 8 9 #include <uapi/linux/ioprio.h> 10 11 /* 12 * Default IO priority. 13 */ 14 #define IOPRIO_DEFAULT IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, IOPRIO_BE_NORM) 15 16 /* 17 * Check that a priority value has a valid class. 18 */ 19 static inline bool ioprio_valid(unsigned short ioprio) 20 { 21 unsigned short class = IOPRIO_PRIO_CLASS(ioprio); 22 23 return class > IOPRIO_CLASS_NONE && class <= IOPRIO_CLASS_IDLE; 24 } 25 26 /* 27 * if process has set io priority explicitly, use that. if not, convert 28 * the cpu scheduler nice value to an io priority 29 */ 30 static inline int task_nice_ioprio(struct task_struct *task) 31 { 32 return (task_nice(task) + 20) / 5; 33 } 34 35 /* 36 * This is for the case where the task hasn't asked for a specific IO class. 37 * Check for idle and rt task process, and return appropriate IO class. 38 */ 39 static inline int task_nice_ioclass(struct task_struct *task) 40 { 41 if (task->policy == SCHED_IDLE) 42 return IOPRIO_CLASS_IDLE; 43 else if (task_is_realtime(task)) 44 return IOPRIO_CLASS_RT; 45 else 46 return IOPRIO_CLASS_BE; 47 } 48 49 /* 50 * If the calling process has set an I/O priority, use that. Otherwise, return 51 * the default I/O priority. 52 */ 53 static inline int get_current_ioprio(void) 54 { 55 struct io_context *ioc = current->io_context; 56 57 if (ioc) 58 return ioc->ioprio; 59 return IOPRIO_DEFAULT; 60 } 61 62 /* 63 * For inheritance, return the highest of the two given priorities 64 */ 65 extern int ioprio_best(unsigned short aprio, unsigned short bprio); 66 67 extern int set_task_ioprio(struct task_struct *task, int ioprio); 68 69 #ifdef CONFIG_BLOCK 70 extern int ioprio_check_cap(int ioprio); 71 #else 72 static inline int ioprio_check_cap(int ioprio) 73 { 74 return -ENOTBLK; 75 } 76 #endif /* CONFIG_BLOCK */ 77 78 #endif 79