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mirror of https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git synced 2026-01-14 10:32:46 +00:00
torvalds-linux/include/uapi/linux/blktrace_api.h
Chaitanya Kulkarni bc49af56ee blktrace: add support for REQ_OP_WRITE_ZEROES tracing
Currently, REQ_OP_WRITE_ZEROES operations are not handled in the
blktrace infrastructure, resulting in incorrect or missing operation
labels in ftrace blktrace output. This manifests as write-zeroes
operations appearing with incorrect labels like "N" instead of a
proper "WZ" designation.

This patch adds complete support for REQ_OP_WRITE_ZEROES across the
blktrace infrastructure:

Add BLK_TC_WRITE_ZEROES trace category in blktrace_api.h and update
BLK_TC_END_V2 marker accordingly
Map REQ_OP_WRITE_ZEROES to BLK_TC_WRITE_ZEROES in __blk_add_trace()
to ensure proper trace event categorization
Update fill_rwbs() to generate "WZ" label for write-zeroes operations
in ftrace output, making them easily identifiable
Add "write-zeroes" string mapping in act_to_str array for debugfs
filter interface
Update blk_fill_rwbs() to handle REQ_OP_WRITE_ZEROES for block layer
event tracing

With this fix, write-zeroes operations are now correctly traced and
displayed.

===========================================================
BEFORE THIS PATCH
===========================================================
blkdiscard -z -o 0 -l 40960 /dev/nvme0n1
   blkdiscard-3809 [030] .....  1212.253701: block_bio_queue: 259,0 NS 0 + 80 [blkdiscard]
   blkdiscard-3809 [030] .....  1212.253703: block_getrq: 259,0 NS 0 + 80 [blkdiscard]
   blkdiscard-3809 [030] .....  1212.253704: block_io_start: 259,0 NS 40960 () 0 + 80 be,0,4 [blkdiscard]
   blkdiscard-3809 [030] .....  1212.253704: block_plug: [blkdiscard]
   blkdiscard-3809 [030] .....  1212.253706: block_unplug: [blkdiscard] 1
   blkdiscard-3809 [030] .....  1212.253706: block_rq_insert: 259,0 NS 40960 () 0 + 80 be,0,4 [blkdiscard]
kworker/30:1H-566  [030] .....  1212.253726: block_rq_issue: 259,0 NS 40960 () 0 + 80 be,0,4 [kworker/30:1H]
       <idle>-0    [030] d.h1.  1212.253957: block_rq_complete: 259,0 NS () 0 + 80 be,0,4 [0]
       <idle>-0    [030] dNh1.  1212.253960: block_io_done: 259,0 NS 0 () 0 + 0 none,0,0 [swapper/30]

Trace Event Breakdown:
 Event             | Device | Op  | Sector | Sectors | Byte Size | Calculation

 block_bio_queue   | 259,0  | NS  | 0      | 80      | -         | 80 × 512 = 40,960
 block_getrq       | 259,0  | NS  | 0      | 80      | -         | 80 × 512 = 40,960
 block_io_start    | 259,0  | NS  | 0      | 80      | 40960     | Direct from trace
 block_rq_insert   | 259,0  | NS  | 0      | 80      | 40960     | Direct from trace
 block_rq_issue    | 259,0  | NS  | 0      | 80      | 40960     | Direct from trace
 block_rq_complete | 259,0  | NS  | 0      | 80      | -         | 80 × 512 = 40,960
 block_io_done     | 259,0  | NS  | 0      | 0       | 0         | Completion (no data)

  Total Bytes Transferred: Sectors: 80 Bytes: 80 × 512 = 40,960 bytes

===========================================================
AFTER THIS PATCH
===========================================================
blkdiscard -z -o 0 -l 40960 /dev/nvme0n1

   blkdiscard-2477 [020] .....   960.989131: block_bio_queue: 259,0 WZS 0 + 80 [blkdiscard]
   blkdiscard-2477 [020] .....   960.989134: block_getrq: 259,0 WZS 0 + 80 [blkdiscard]
   blkdiscard-2477 [020] .....   960.989135: block_io_start: 259,0 WZS 40960 () 0 + 80 be,0,4 [blkdiscard]
   blkdiscard-2477 [020] .....   960.989138: block_plug: [blkdiscard]
   blkdiscard-2477 [020] .....   960.989140: block_unplug: [blkdiscard] 1
   blkdiscard-2477 [020] .....   960.989141: block_rq_insert: 259,0 WZS 40960 () 0 + 80 be,0,4 [blkdiscard]
kworker/20:1H-736  [020] .....   960.989166: block_rq_issue: 259,0 WZS 40960 () 0 + 80 be,0,4 [kworker/20:1H]
       <idle>-0    [020] d.h1.   960.989476: block_rq_complete: 259,0 WZS () 0 + 80 be,0,4 [0]
       <idle>-0    [020] dNh1.   960.989482: block_io_done: 259,0 WZS 0 () 0 + 0 none,0,0 [swapper/20]

Trace Event Breakdown:
 Event             | Device | Op  | Sector | Sectors | Byte Size | Calculation

 block_bio_queue   | 259,0  | WZS | 0      | 80      | -         | 80 × 512 = 40,960
 block_getrq       | 259,0  | WZS | 0      | 80      | -         | 80 × 512 = 40,960
 block_io_start    | 259,0  | WZS | 0      | 80      | 40960     | Direct from trace
 block_rq_insert   | 259,0  | WZS | 0      | 80      | 40960     | Direct from trace
 block_rq_issue    | 259,0  | WZS | 0      | 80      | 40960     | Direct from trace
 block_rq_complete | 259,0  | WZS | 0      | 80      | -         | 80 × 512 = 40,960
 block_io_done     | 259,0  | WZS | 0      | 0       | 0         | Completion (no data)

  Total Bytes Transferred: Sectors: 80 Bytes: 80 × 512 = 40,960 bytes

Tested with ftrace blktrace on NVMe devices using blkdiscard with
the -z (write-zeroes) flag.

Signed-off-by: Chaitanya Kulkarni <ckulkarnilinux@gmail.com>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2025-11-03 08:30:56 -07:00

198 lines
6.3 KiB
C

/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
#ifndef _UAPIBLKTRACE_H
#define _UAPIBLKTRACE_H
#include <linux/types.h>
/*
* Trace categories
*/
enum blktrace_cat {
BLK_TC_READ = 1 << 0, /* reads */
BLK_TC_WRITE = 1 << 1, /* writes */
BLK_TC_FLUSH = 1 << 2, /* flush */
BLK_TC_SYNC = 1 << 3, /* sync IO */
BLK_TC_SYNCIO = BLK_TC_SYNC,
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_DISCARD = 1 << 13, /* discard requests */
BLK_TC_DRV_DATA = 1 << 14, /* binary per-driver data */
BLK_TC_FUA = 1 << 15, /* fua requests */
BLK_TC_END_V1 = 1 << 15, /* we've run out of bits! */
BLK_TC_ZONE_APPEND = 1ull << 16, /* zone append */
BLK_TC_ZONE_RESET = 1ull << 17, /* zone reset */
BLK_TC_ZONE_RESET_ALL = 1ull << 18, /* zone reset all */
BLK_TC_ZONE_FINISH = 1ull << 19, /* zone finish */
BLK_TC_ZONE_OPEN = 1ull << 20, /* zone open */
BLK_TC_ZONE_CLOSE = 1ull << 21, /* zone close */
BLK_TC_WRITE_ZEROES = 1ull << 22, /* write-zeroes */
BLK_TC_END_V2 = 1ull << 22,
};
#define BLK_TC_SHIFT (16)
#define BLK_TC_ACT(act) ((u64)(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, /* unused, was: bio was bounced */
__BLK_TA_REMAP, /* bio was remapped */
__BLK_TA_ABORT, /* request aborted */
__BLK_TA_DRV_DATA, /* driver-specific binary data */
__BLK_TA_ZONE_PLUG, /* zone write plug was plugged */
__BLK_TA_ZONE_UNPLUG, /* zone write plug was unplugged */
__BLK_TA_CGROUP = 1 << 8, /* from a cgroup*/
};
/*
* Notify events.
*/
enum blktrace_notify {
__BLK_TN_PROCESS = 0, /* establish pid/name mapping */
__BLK_TN_TIMESTAMP, /* include system clock */
__BLK_TN_MESSAGE, /* Character string message */
__BLK_TN_CGROUP = __BLK_TA_CGROUP, /* from a cgroup */
};
/*
* 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_TA_ABORT (__BLK_TA_ABORT | BLK_TC_ACT(BLK_TC_QUEUE))
#define BLK_TA_DRV_DATA (__BLK_TA_DRV_DATA | BLK_TC_ACT(BLK_TC_DRV_DATA))
#define BLK_TA_ZONE_APPEND (__BLK_TA_COMPLETE |\
BLK_TC_ACT(BLK_TC_ZONE_APPEND))
#define BLK_TA_ZONE_PLUG (__BLK_TA_ZONE_PLUG | BLK_TC_ACT(BLK_TC_QUEUE))
#define BLK_TA_ZONE_UNPLUG (__BLK_TA_ZONE_UNPLUG |\
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_TN_MESSAGE (__BLK_TN_MESSAGE | BLK_TC_ACT(BLK_TC_NOTIFY))
#define BLK_IO_TRACE_MAGIC 0x65617400
#define BLK_IO_TRACE_VERSION 0x07
#define BLK_IO_TRACE2_VERSION 0x08
/*
* The trace itself
*/
struct blk_io_trace {
__u32 magic; /* MAGIC << 8 | version */
__u32 sequence; /* event number */
__u64 time; /* in nanoseconds */
__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 */
/* cgroup id will be stored here if exists */
};
struct blk_io_trace2 {
__u32 magic; /* MAGIC << 8 | BLK_IO_TRACE2_VERSION */
__u32 sequence; /* event number */
__u64 time; /* in nanoseconds */
__u64 sector; /* disk offset */
__u32 bytes; /* transfer length */
__u32 pid; /* who did it */
__u64 action; /* what happened */
__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 */
__u8 pad[12];
/* cgroup id will be stored here if it exists */
};
/*
* The remap event
*/
struct blk_io_trace_remap {
__be32 device_from;
__be32 device_to;
__be64 sector_from;
};
enum {
Blktrace_setup = 1,
Blktrace_running,
Blktrace_stopped,
};
#define BLKTRACE_BDEV_SIZE 32
#define BLKTRACE_BDEV_SIZE2 64
/*
* User setup structure passed with BLKTRACESETUP
*/
struct blk_user_trace_setup {
char name[BLKTRACE_BDEV_SIZE]; /* output */
__u16 act_mask; /* input */
__u32 buf_size; /* input */
__u32 buf_nr; /* input */
__u64 start_lba;
__u64 end_lba;
__u32 pid;
};
/*
* User setup structure passed with BLKTRACESETUP2
*/
struct blk_user_trace_setup2 {
char name[BLKTRACE_BDEV_SIZE2]; /* output */
__u64 act_mask; /* input */
__u32 buf_size; /* input */
__u32 buf_nr; /* input */
__u64 start_lba;
__u64 end_lba;
__u32 pid;
__u32 flags; /* currently unused */
__u64 reserved[11];
};
#endif /* _UAPIBLKTRACE_H */