linux-stable/include/linux/blktrace_api.h
Christoph Hellwig f4a6a61cb6 blktrace: cleanup the __trace_note_message interface
Pass the cgroup_subsys_state instead of a the blkg so that blktrace
doesn't need to poke into blk-cgroup internals, and give the name a
blk prefix as the current name is way too generic for a public
interface.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Tejun Heo <tj@kernel.org>
Link: https://lore.kernel.org/r/20220420042723.1010598-9-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-05-02 14:06:20 -06:00

136 lines
3.8 KiB
C

/* SPDX-License-Identifier: GPL-2.0 */
#ifndef BLKTRACE_H
#define BLKTRACE_H
#include <linux/blk-mq.h>
#include <linux/relay.h>
#include <linux/compat.h>
#include <uapi/linux/blktrace_api.h>
#include <linux/list.h>
#if defined(CONFIG_BLK_DEV_IO_TRACE)
#include <linux/sysfs.h>
struct blk_trace {
int trace_state;
struct rchan *rchan;
unsigned long __percpu *sequence;
unsigned char __percpu *msg_data;
u16 act_mask;
u64 start_lba;
u64 end_lba;
u32 pid;
u32 dev;
struct dentry *dir;
struct list_head running_list;
atomic_t dropped;
};
extern int blk_trace_ioctl(struct block_device *, unsigned, char __user *);
extern void blk_trace_shutdown(struct request_queue *);
__printf(3, 4) void __blk_trace_note_message(struct blk_trace *bt,
struct cgroup_subsys_state *css, const char *fmt, ...);
/**
* blk_add_trace_msg - Add a (simple) message to the blktrace stream
* @q: queue the io is for
* @fmt: format to print message in
* args... Variable argument list for format
*
* Description:
* Records a (simple) message onto the blktrace stream.
*
* NOTE: BLK_TN_MAX_MSG characters are output at most.
* NOTE: Can not use 'static inline' due to presence of var args...
*
**/
#define blk_add_cgroup_trace_msg(q, css, fmt, ...) \
do { \
struct blk_trace *bt; \
\
rcu_read_lock(); \
bt = rcu_dereference((q)->blk_trace); \
if (unlikely(bt)) \
__blk_trace_note_message(bt, css, fmt, ##__VA_ARGS__);\
rcu_read_unlock(); \
} while (0)
#define blk_add_trace_msg(q, fmt, ...) \
blk_add_cgroup_trace_msg(q, NULL, fmt, ##__VA_ARGS__)
#define BLK_TN_MAX_MSG 128
static inline bool blk_trace_note_message_enabled(struct request_queue *q)
{
struct blk_trace *bt;
bool ret;
rcu_read_lock();
bt = rcu_dereference(q->blk_trace);
ret = bt && (bt->act_mask & BLK_TC_NOTIFY);
rcu_read_unlock();
return ret;
}
extern void blk_add_driver_data(struct request *rq, void *data, size_t len);
extern int blk_trace_setup(struct request_queue *q, char *name, dev_t dev,
struct block_device *bdev,
char __user *arg);
extern int blk_trace_startstop(struct request_queue *q, int start);
extern int blk_trace_remove(struct request_queue *q);
extern void blk_trace_remove_sysfs(struct device *dev);
extern int blk_trace_init_sysfs(struct device *dev);
extern struct attribute_group blk_trace_attr_group;
#else /* !CONFIG_BLK_DEV_IO_TRACE */
# define blk_trace_ioctl(bdev, cmd, arg) (-ENOTTY)
# define blk_trace_shutdown(q) do { } while (0)
# define blk_add_driver_data(rq, data, len) do {} while (0)
# define blk_trace_setup(q, name, dev, bdev, arg) (-ENOTTY)
# define blk_trace_startstop(q, start) (-ENOTTY)
# define blk_trace_remove(q) (-ENOTTY)
# define blk_add_trace_msg(q, fmt, ...) do { } while (0)
# define blk_add_cgroup_trace_msg(q, cg, fmt, ...) do { } while (0)
# define blk_trace_remove_sysfs(dev) do { } while (0)
# define blk_trace_note_message_enabled(q) (false)
static inline int blk_trace_init_sysfs(struct device *dev)
{
return 0;
}
#endif /* CONFIG_BLK_DEV_IO_TRACE */
#ifdef CONFIG_COMPAT
struct compat_blk_user_trace_setup {
char name[BLKTRACE_BDEV_SIZE];
u16 act_mask;
u32 buf_size;
u32 buf_nr;
compat_u64 start_lba;
compat_u64 end_lba;
u32 pid;
};
#define BLKTRACESETUP32 _IOWR(0x12, 115, struct compat_blk_user_trace_setup)
#endif
void blk_fill_rwbs(char *rwbs, unsigned int op);
static inline sector_t blk_rq_trace_sector(struct request *rq)
{
/*
* Tracing should ignore starting sector for passthrough requests and
* requests where starting sector didn't get set.
*/
if (blk_rq_is_passthrough(rq) || blk_rq_pos(rq) == (sector_t)-1)
return 0;
return blk_rq_pos(rq);
}
static inline unsigned int blk_rq_trace_nr_sectors(struct request *rq)
{
return blk_rq_is_passthrough(rq) ? 0 : blk_rq_sectors(rq);
}
#endif