[PATCH v4 09/16] blktrace: add definitions for struct blk_io_trace2

Johannes Thumshirn posted 16 patches 3 months, 3 weeks ago
There is a newer version of this series
[PATCH v4 09/16] blktrace: add definitions for struct blk_io_trace2
Posted by Johannes Thumshirn 3 months, 3 weeks ago
Add definitions for the extended version of the blktrace protocol using a
wider action type to be able to record new actions in the kernel.

Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
---
 include/uapi/linux/blktrace_api.h | 16 ++++++++++++++++
 kernel/trace/blktrace.c           |  1 +
 2 files changed, 17 insertions(+)

diff --git a/include/uapi/linux/blktrace_api.h b/include/uapi/linux/blktrace_api.h
index a6958708d477..3a771b9802aa 100644
--- a/include/uapi/linux/blktrace_api.h
+++ b/include/uapi/linux/blktrace_api.h
@@ -94,6 +94,7 @@ enum blktrace_notify {
 
 #define BLK_IO_TRACE_MAGIC	0x65617400
 #define BLK_IO_TRACE_VERSION	0x07
+#define BLK_IO_TRACE2_VERSION	0x08
 
 /*
  * The trace itself
@@ -113,6 +114,21 @@ struct blk_io_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 exists */
+};
 /*
  * The remap event
  */
diff --git a/kernel/trace/blktrace.c b/kernel/trace/blktrace.c
index d1532df84cc8..185f19c9f772 100644
--- a/kernel/trace/blktrace.c
+++ b/kernel/trace/blktrace.c
@@ -1616,6 +1616,7 @@ static int __init init_blk_tracer(void)
 
 	BUILD_BUG_ON(__alignof__(struct blk_user_trace_setup2) %
 		     __alignof__(long));
+	BUILD_BUG_ON(__alignof__(struct blk_io_trace2) % __alignof__(long));
 
 	return 0;
 }
-- 
2.51.0
Re: [PATCH v4 09/16] blktrace: add definitions for struct blk_io_trace2
Posted by Damien Le Moal 3 months, 3 weeks ago
On 10/20/25 22:41, Johannes Thumshirn wrote:
> Add definitions for the extended version of the blktrace protocol using a
> wider action type to be able to record new actions in the kernel.
> 
> Reviewed-by: Christoph Hellwig <hch@lst.de>
> Signed-off-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>

One nit below.

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


> +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 exists */

s/if exists/if it exists

-- 
Damien Le Moal
Western Digital Research