#ifndef BLKTRACE_H
#define BLKTRACE_H
#include <linux/blkdev.h>
#include <linux/relay.h>
/*
* Trace categories
*/
enum blktrace_cat {
BLK_TC_READ = 1 << 0, /* reads */
BLK_TC_WRITE = 1 << 1, /* writes */
BLK_TC_BARRIER = 1 << 2, /* barrier */
BLK_TC_SYNC = 1 << 3, /* sync IO */
BLK_TC_QUEUE = 1 << 4, /* queueing/merging */
BLK_TC_REQUEUE = 1 << 5, /* requeueing */
BLK_TC_ISSUE = 1 << 6, /* issue */
BLK_TC_COMPLETE = 1 << 7, /* completions */
BLK_TC_FS = 1 << 8, /* fs requests */
BLK_TC_PC = 1 << 9, /* pc requests */
BLK_TC_NOTIFY = 1 << 10, /* special message */
BLK_TC_AHEAD = 1 << 11, /* readahead */
BLK_TC_META = 1 << 12, /* metadata */
BLK_TC_END = 1 << 15, /* only 16-bits, reminder */
};
#define BLK_TC_SHIFT (16)
#define BLK_TC_ACT(act) ((act) << BLK_TC_SHIFT)
/*
* Basic trace actions
*/
enum blktrace_act {
__BLK_TA_QUEUE = 1, /* queued */
__BLK_TA_BACKMERGE, /* back merged to existing rq */
__BLK_TA_FRONTMERGE, /* front merge to existing rq */
__BLK_TA_GETRQ, /* allocated new request */
__BLK_TA_SLEEPRQ, /* sleeping on rq allocation */
__BLK_TA_REQUEUE, /* request requeued */
__BLK_TA_ISSUE, /* sent to driver */
__BLK_TA_COMPLETE, /* completed by driver */
__BLK_TA_PLUG, /* queue was plugged */
__BLK_TA_UNPLUG_IO, /* queue was unplugged by io */
__BLK_TA_UNPLUG_TIMER, /* queue was unplugged by timer */
__BLK_TA_INSERT, /* insert request */
__BLK_TA_SPLIT, /* bio was split */
__BLK_TA_BOUNCE, /* bio was bounced */
__BLK_TA_REMAP, /* bio was remapped */
};
/*
* Notify events.
*/
enum blktrace_notify {
__BLK_TN_PROCESS = 0, /* establish pid/name mapping */
__BLK_TN_TIMESTAMP, /* include system clock */
};
/*
* Trace actions in full. Additionally, read or write is masked
*/
#define BLK_TA_QUEUE (__BLK_TA_QUEUE | BLK_TC_ACT(BLK_TC_QUEUE))
#define BLK_TA_BACKMERGE (__BLK_TA_BACKMERGE | BLK_TC_ACT(BLK_TC_QUEUE))
#define BLK_TA_FRONTMERGE (__BLK_TA_FRONTMERGE | BLK_TC_ACT(BLK_TC_QUEUE))
#define BLK_TA_GETRQ (__BLK_TA_GETRQ | BLK_TC_ACT(BLK_TC_QUEUE))
#define BLK_TA_SLEEPRQ (__BLK_TA_SLEEPRQ | BLK_TC_ACT(BLK_TC_QUEUE))
#define BLK_TA_REQUEUE (__BLK_TA_REQUEUE | BLK_TC_ACT(BLK_TC_REQUEUE))
#define BLK_TA_ISSUE (__BLK_TA_ISSUE | BLK_TC_ACT(BLK_TC_ISSUE))
#define BLK_TA_COMPLETE (__BLK_TA_COMPLETE| BLK_TC_ACT(BLK_TC_COMPLETE))
#define BLK_TA_PLUG (__BLK_TA_PLUG | BLK_TC_ACT(BLK_TC_QUEUE))
#define BLK_TA_UNPLUG_IO (__BLK_TA_UNPLUG_IO | BLK_TC_ACT(BLK_TC_QUEUE))
#define BLK_TA_UNPLUG_TIMER (__BLK_TA_UNPLUG_TIMER | BLK_TC_ACT(BLK_TC_QUEUE))
#define BLK_TA_INSERT (__BLK_TA_INSERT | BLK_TC_ACT(BLK_TC_QUEUE))
#define BLK_TA_SPLIT (__BLK_TA_SPLIT)
#define BLK_TA_BOUNCE (__BLK_TA_BOUNCE)
#define BLK_TA_REMAP (__BLK_TA_REMAP | BLK_TC_ACT(BLK_TC_QUEUE))
#define BLK_TN_PROCESS (__BLK_TN_PROCESS | BLK_TC_ACT(BLK_TC_NOTIFY))
#define BLK_TN_TIMESTAMP (__BLK_TN_TIMESTAMP | BLK_TC_ACT(BLK_TC_NOTIFY))
#define BLK_IO_TRACE_MAGIC 0x65617400
#define BLK_IO_TRACE_VERSION 0x07
/*
* The trace itself
*/
struct blk_io_trace {
u32 magic; /* MAGIC << 8 | version */
u32 sequence; /* event number */
u64 time; /* in microseconds */
u64 sector; /* disk offset */
u32 bytes; /* transfer length */
u32 action; /* what happened */
u32 pid; /* who did it */
u32 device; /* device number */
u32 cpu; /* on what cpu did it happen */
u16 error; /* completion error */
u16 pdu_len; /* length of data after this trace */
};
/*
* The remap event
*/
struct blk_io_trace_remap {
__be32 device;
__be32 device_from;
__be64 sector;
};
enum {
Blktrace_setup = 1,
Blktrace_running,
Blktrace_stopped,
};
struct blk_trace {
int trace_state;
struct rchan *rchan;
unsigned long *sequence;
u16 act_mask;
u64 start_lba;
u64 end_lba;
u32 pid;
u32 dev;
struct dentry *dir;
struct dentry *dropped_file;
atomic_t dropped;
};
/*
* User setup structure passed with BLKTRACESTART
*/
struct blk_user_trace_setup {
char name[BDEVNAME_SIZE]; /* output */
u16 act_mask; /* input */
u32 buf_size; /* input */
u32 buf_nr; /* input */
u64 start_lba;
u64 end_lba;
u32 pid;
};
#ifdef __KERNEL__
#if defined(CONFIG_BLK_DEV_IO_TRACE)
extern int blk_trace_ioctl(struct block_device *, unsigned, char __user *);
extern void blk_trace_shutdown(struct request_queue *);
extern void __blk_add_trace(struct blk_trace *, sector_t, int, int, u32, int, int, void *);
extern int do_blk_trace_setup(struct request_queue *q,
char *name, dev_t dev, struct blk_user_trace_setup *buts);
/**
* blk_add_trace_rq - Add a trace for a request oriented action
* @q: queue the io is for
* @rq: the source request
* @what: the action
*
* Description:
* Records an action against a request. Will log the bio offset + size.
*
**/
static inline void blk_add_trace_rq(struct request_queue *q, struct request *rq,
u32 what)
{
struct blk_trace *bt = q->blk_trace;
int rw = rq->cmd_flags & 0x03;
if (likely(!bt))
return;
if (blk_pc_request(rq)) {
what |= BLK_TC_ACT(BLK_TC_PC);
__blk_add_trace(bt, 0, rq->data_len, rw, what, rq->errors, sizeof(rq->cmd), rq->cmd);
} else {
what |= BLK_TC_ACT(BLK_TC_FS);
__blk_add_trace(bt, rq->hard_sector, rq->hard_nr_sectors << 9, rw, what, rq->errors, 0, NULL);
}
}
/**
* blk_add_trace_bio - Add a trace for a bio oriented action
* @q: queue the io is for
* @bio: the source bio
* @what: the action
*
* Description:
* Records an action against a bio. Will log the bio offset + size.
*
**/
static inline void blk_add_trace_bio(struct request_queue *q, struct bio *bio,
u32 what)
{
struct blk_trace *bt = q->blk_trace;
if (likely(!bt))
return;
__blk_add_trace(bt, bio->bi_sector, bio->bi_size, bio->bi_rw, what, !bio_flagged(bio, BIO_UPTODATE), 0, NULL);
}
/**
* blk_add_trace_generic - Add a trace for a generic action
* @q: queue the io is for
* @bio: the source bio
* @rw: the data direction
* @what: the action
*
* Description:
* Records a simple trace
*
**/
static inline void blk_add_trace_generic(struct request_queue *q,
struct bio *bio, int rw, u32 what)
{
struct blk_trace *bt = q->blk_trace;
if (likely(!bt))
return;
if (bio)
blk_add_trace_bio(q, bio, what);
else
__blk_add_trace(bt, 0, 0, rw, what, 0, 0, NULL);
}
/**
* blk_add_trace_pdu_int - Add a trace for a bio with an integer payload
* @q: queue the io is for
* @what: the action
* @bio: the source bio
* @pdu: the integer payload
*
* Description:
* Adds a trace with some integer payload. This might be an unplug
* option given as the action, with the depth at unplug time given
* as the payload
*
**/
static inline void blk_add_trace_pdu_int(struct request_queue *q, u32 what,
struct bio *bio, unsigned int pdu)
{
struct blk_trace *bt = q->blk_trace;
__be64 rpdu = cpu_to_be64(pdu);
if (likely(!bt))
return;
if (bio)
__blk_add_trace(bt, bio->bi_sector, bio->bi_size, bio->bi_rw, what, !bio_flagged(bio, BIO_UPTODATE), sizeof(rpdu), &rpdu);
else
__blk_add_trace(bt, 0, 0, 0, what, 0, sizeof(rpdu), &rpdu);
}
/**
* blk_add_trace_remap - Add a trace for a remap operation
* @q: queue the io is for
* @bio: the source bio
* @dev: target device
* @from: source sector
* @to: target sector
*
* Description:
* Device mapper or raid target sometimes need to split a bio because
* it spans a stripe (or similar). Add a trace for that action.
*
**/
static inline void blk_add_trace_remap(struct request_queue *q, struct bio *bio,
dev_t dev, sector_t from, sector_t to)
{
struct blk_trace *bt = q->blk_trace;
struct blk_io_trace_remap r;
if (likely(!bt))
return;
r.device = cpu_to_be32(dev);
r.device_from = cpu_to_be32(bio->bi_bdev->bd_dev);
r.sector = cpu_to_be64(to);
__blk_add_trace(bt, from, bio->bi_size, bio->bi_rw, BLK_TA_REMAP, !bio_flagged(bio, BIO_UPTODATE), sizeof(r), &r);
}
extern int blk_trace_setup(struct request_queue *q, char *name, dev_t dev,
char __user *arg);
extern int blk_trace_startstop(struct request_queue *q, int start);
extern int blk_trace_remove(struct request_queue *q);
#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_trace_rq(q, rq, what) do { } while (0)
#define blk_add_trace_bio(q, rq, what) do { } while (0)
#define blk_add_trace_generic(q, rq, rw, what) do { } while (0)
#define blk_add_trace_pdu_int(q, what, bio, pdu) do { } while (0)
#define blk_add_trace_remap(q, bio, dev, f, t) do {} while (0)
#define do_blk_trace_setup(q, name, dev, buts) (-ENOTTY)
#define blk_trace_setup(q, name, dev, arg) (-ENOTTY)
#define blk_trace_startstop(q, start) (-ENOTTY)
#define blk_trace_remove(q) (-ENOTTY)
#endif /* CONFIG_BLK_DEV_IO_TRACE */
#endif /* __KERNEL__ */
#endif
