[PATCH V2] blktrace: log dropped REQ_OP_ZONE_XXX events ver1

[PATCH V2] blktrace: log dropped REQ_OP_ZONE_XXX events ver1

[Chaitanya Kulkarni]

Add informational messages during blktrace setup when version 1 tools
are used on kernels with CONFIG_BLK_DEV_ZONED enabled. This alerts users
that REQ_OP_ZONE_* events will be dropped and suggests upgrading to
blktrace tools version 2 or later.

The warning is printed once during trace setup to inform users about
the limitation without spamming the logs during tracing operations.
Version 2 blktrace tools properly handle zone management operations
(zone reset, zone open, zone close, zone finish, zone append) that
were added for zoned block devices.

Example output:

blktests (master) # ./check blktrace
blktrace/001 (blktrace zone management command tracing)      [passed]
    runtime  0.110s  ...  3.917s
blktrace/002 (blktrace ftrace corruption with sysfs trace)   [passed]
    runtime  0.333s  ...  0.608s
blktests (master) # dmesg -c
[   57.610592] blktrace: nullb0: blktrace events for REQ_OP_ZONE_XXX will be dropped
[   57.610603] blktrace: use blktrace tools version >= 2 to track REQ_OP_ZONE_XXX

This helps users understand why zone operation traces may be missing
when using older blktrace tool versions with modern kernels that
support REQ_OP_ZONE_XXX in blktrace.

Signed-off-by: Chaitanya Kulkarni <ckulkarnilinux@gmail.com>
---
v1->v2 :-

Remove the extra () around IS_ENABLED(CONFIG_BLK_DEV_ZONED). (Jens)
Add a space after device name in first pr_info(). (Jens)

---
 kernel/trace/blktrace.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/kernel/trace/blktrace.c b/kernel/trace/blktrace.c
index e4f26ddb7ee2..4a37d9aa0481 100644
--- a/kernel/trace/blktrace.c
+++ b/kernel/trace/blktrace.c
@@ -739,6 +739,12 @@ static void blk_trace_setup_finalize(struct request_queue *q,
 	 */
 	strreplace(buts->name, '/', '_');
 
+	if (version == 1 && IS_ENABLED(CONFIG_BLK_DEV_ZONED)) {
+		pr_info("%s: blktrace events for REQ_OP_ZONE_XXX will be dropped\n",
+				name);
+		pr_info("use blktrace tools version >= 2 to track REQ_OP_ZONE_XXX\n");
+	}
+
 	bt->version = version;
 	bt->act_mask = buts->act_mask;
 	if (!bt->act_mask)
-- 
2.40.0

Re: [PATCH V2] blktrace: log dropped REQ_OP_ZONE_XXX events ver1

[Johannes Thumshirn]

On 10/28/25 6:32 PM, Chaitanya Kulkarni wrote:
> +	if (version == 1 && IS_ENABLED(CONFIG_BLK_DEV_ZONED)) {
> +		pr_info("%s: blktrace events for REQ_OP_ZONE_XXX will be dropped\n",
> +				name);
> +		pr_info("use blktrace tools version >= 2 to track REQ_OP_ZONE_XXX\n");

Jens hasn't merged the user-space part yet and I'm not sure he'll assign 
a dedicated version number for it. So I'd say hold this until he has.

Re: [PATCH V2] blktrace: log dropped REQ_OP_ZONE_XXX events ver1

[Chaitanya Kulkarni]

On 10/28/25 23:47, Johannes Thumshirn wrote:
> On 10/28/25 6:32 PM, Chaitanya Kulkarni wrote:
>> +	if (version == 1 && IS_ENABLED(CONFIG_BLK_DEV_ZONED)) {
>> +		pr_info("%s: blktrace events for REQ_OP_ZONE_XXX will be dropped\n",
>> +				name);
>> +		pr_info("use blktrace tools version >= 2 to track REQ_OP_ZONE_XXX\n");
> Jens hasn't merged the user-space part yet and I'm not sure he'll assign
> a dedicated version number for it. So I'd say hold this until he has.
>
Now Jen's has merged the userspace part, may I please get a reviewed-by if this
looks good?

-ck

Re: [PATCH V2] blktrace: log dropped REQ_OP_ZONE_XXX events ver1

[Damien Le Moal]

On 10/29/25 02:32, Chaitanya Kulkarni wrote:
> Add informational messages during blktrace setup when version 1 tools
> are used on kernels with CONFIG_BLK_DEV_ZONED enabled. This alerts users
> that REQ_OP_ZONE_* events will be dropped and suggests upgrading to
> blktrace tools version 2 or later.
> 
> The warning is printed once during trace setup to inform users about
> the limitation without spamming the logs during tracing operations.
> Version 2 blktrace tools properly handle zone management operations
> (zone reset, zone open, zone close, zone finish, zone append) that
> were added for zoned block devices.
> 
> Example output:
> 
> blktests (master) # ./check blktrace
> blktrace/001 (blktrace zone management command tracing)      [passed]
>     runtime  0.110s  ...  3.917s
> blktrace/002 (blktrace ftrace corruption with sysfs trace)   [passed]
>     runtime  0.333s  ...  0.608s
> blktests (master) # dmesg -c
> [   57.610592] blktrace: nullb0: blktrace events for REQ_OP_ZONE_XXX will be dropped
> [   57.610603] blktrace: use blktrace tools version >= 2 to track REQ_OP_ZONE_XXX
> 
> This helps users understand why zone operation traces may be missing
> when using older blktrace tool versions with modern kernels that
> support REQ_OP_ZONE_XXX in blktrace.
> 
> Signed-off-by: Chaitanya Kulkarni <ckulkarnilinux@gmail.com>
> ---
> v1->v2 :-
> 
> Remove the extra () around IS_ENABLED(CONFIG_BLK_DEV_ZONED). (Jens)
> Add a space after device name in first pr_info(). (Jens)
> 
> ---
>  kernel/trace/blktrace.c | 6 ++++++
>  1 file changed, 6 insertions(+)
> 
> diff --git a/kernel/trace/blktrace.c b/kernel/trace/blktrace.c
> index e4f26ddb7ee2..4a37d9aa0481 100644
> --- a/kernel/trace/blktrace.c
> +++ b/kernel/trace/blktrace.c
> @@ -739,6 +739,12 @@ static void blk_trace_setup_finalize(struct request_queue *q,
>  	 */
>  	strreplace(buts->name, '/', '_');
>  
> +	if (version == 1 && IS_ENABLED(CONFIG_BLK_DEV_ZONED)) {
> +		pr_info("%s: blktrace events for REQ_OP_ZONE_XXX will be dropped\n",
> +				name);
> +		pr_info("use blktrace tools version >= 2 to track REQ_OP_ZONE_XXX\n");

Please change REQ_OP_ZONE_XXX to "zone operations" in these messages. That is a
little more general, so better I think since we also trace zone write
plug/unplug events, which are not REQ_OP_ZONE_XXX.

With that done,

Reviewed-by: Damien Le Moal <dlemoal@kernel.org>

> +	}
> +
>  	bt->version = version;
>  	bt->act_mask = buts->act_mask;
>  	if (!bt->act_mask)


-- 
Damien Le Moal
Western Digital Research

Re: [PATCH V2] blktrace: log dropped REQ_OP_ZONE_XXX events ver1

[Jens Axboe]

On 12/19/25 4:55 PM, Damien Le Moal wrote:
> On 10/29/25 02:32, Chaitanya Kulkarni wrote:
>> Add informational messages during blktrace setup when version 1 tools
>> are used on kernels with CONFIG_BLK_DEV_ZONED enabled. This alerts users
>> that REQ_OP_ZONE_* events will be dropped and suggests upgrading to
>> blktrace tools version 2 or later.
>>
>> The warning is printed once during trace setup to inform users about
>> the limitation without spamming the logs during tracing operations.
>> Version 2 blktrace tools properly handle zone management operations
>> (zone reset, zone open, zone close, zone finish, zone append) that
>> were added for zoned block devices.
>>
>> Example output:
>>
>> blktests (master) # ./check blktrace
>> blktrace/001 (blktrace zone management command tracing)      [passed]
>>     runtime  0.110s  ...  3.917s
>> blktrace/002 (blktrace ftrace corruption with sysfs trace)   [passed]
>>     runtime  0.333s  ...  0.608s
>> blktests (master) # dmesg -c
>> [   57.610592] blktrace: nullb0: blktrace events for REQ_OP_ZONE_XXX will be dropped
>> [   57.610603] blktrace: use blktrace tools version >= 2 to track REQ_OP_ZONE_XXX
>>
>> This helps users understand why zone operation traces may be missing
>> when using older blktrace tool versions with modern kernels that
>> support REQ_OP_ZONE_XXX in blktrace.
>>
>> Signed-off-by: Chaitanya Kulkarni <ckulkarnilinux@gmail.com>
>> ---
>> v1->v2 :-
>>
>> Remove the extra () around IS_ENABLED(CONFIG_BLK_DEV_ZONED). (Jens)
>> Add a space after device name in first pr_info(). (Jens)
>>
>> ---
>>  kernel/trace/blktrace.c | 6 ++++++
>>  1 file changed, 6 insertions(+)
>>
>> diff --git a/kernel/trace/blktrace.c b/kernel/trace/blktrace.c
>> index e4f26ddb7ee2..4a37d9aa0481 100644
>> --- a/kernel/trace/blktrace.c
>> +++ b/kernel/trace/blktrace.c
>> @@ -739,6 +739,12 @@ static void blk_trace_setup_finalize(struct request_queue *q,
>>  	 */
>>  	strreplace(buts->name, '/', '_');
>>  
>> +	if (version == 1 && IS_ENABLED(CONFIG_BLK_DEV_ZONED)) {
>> +		pr_info("%s: blktrace events for REQ_OP_ZONE_XXX will be dropped\n",
>> +				name);
>> +		pr_info("use blktrace tools version >= 2 to track REQ_OP_ZONE_XXX\n");
> 
> Please change REQ_OP_ZONE_XXX to "zone operations" in these messages. That is a
> little more general, so better I think since we also trace zone write
> plug/unplug events, which are not REQ_OP_ZONE_XXX.

Agree, REQ_OP_ZONE_XXX means nothing in userspace.

-- 
Jens Axboe

Re: [PATCH V2] blktrace: log dropped REQ_OP_ZONE_XXX events ver1

[Chaitanya Kulkarni]

On 12/22/25 3:28 PM, Jens Axboe wrote:
>>>   	 */
>>>   	strreplace(buts->name, '/', '_');
>>>   
>>> +	if (version == 1 && IS_ENABLED(CONFIG_BLK_DEV_ZONED)) {
>>> +		pr_info("%s: blktrace events for REQ_OP_ZONE_XXX will be dropped\n",
>>> +				name);
>>> +		pr_info("use blktrace tools version >= 2 to track REQ_OP_ZONE_XXX\n");
>> Please change REQ_OP_ZONE_XXX to "zone operations" in these messages. That is a
>> little more general, so better I think since we also trace zone write
>> plug/unplug events, which are not REQ_OP_ZONE_XXX.
> Agree, REQ_OP_ZONE_XXX means nothing in userspace.
>
> -- Jens Axboe

Thanks Damien and Jens for comment.

Will send out V3 soon.

-ck