Re: [PATCH RFC 1/2] tracing/block: cleanup rwbs filling in trace events

From: Coly Li
Date: Wed May 06 2020 - 03:07:25 EST


On 2020/5/4 23:16, Konstantin Khlebnikov wrote:
> Define BLK_RWBS_LEN in blktrace_api.h
> Bcache events use shorter 6 char buffer which could overflow.
>
> Also remove unsed "bytes" argument.
>
> Signed-off-by: Konstantin Khlebnikov <khlebnikov@xxxxxxxxxxxxxx>

The patch is good for me, it can be directly handled by block layer
maintainer and skip me.

Reviewed-by: Coly Li <colyli@xxxxxxx>


Thank you.

Coly Li


> ---
> include/linux/blktrace_api.h | 4 +-
> include/trace/events/bcache.h | 20 +++++-----
> include/trace/events/block.h | 84 ++++++++++++++++++++---------------------
> kernel/trace/blktrace.c | 2 -
> 4 files changed, 55 insertions(+), 55 deletions(-)
>
> diff --git a/include/linux/blktrace_api.h b/include/linux/blktrace_api.h
> index 3b6ff5902edc..ea9da15d32d9 100644
> --- a/include/linux/blktrace_api.h
> +++ b/include/linux/blktrace_api.h
> @@ -120,7 +120,9 @@ struct compat_blk_user_trace_setup {
>
> #endif
>
> -extern void blk_fill_rwbs(char *rwbs, unsigned int op, int bytes);
> +#define BLK_RWBS_LEN 8
> +
> +extern void blk_fill_rwbs(char *rwbs, unsigned int op);
>
> static inline sector_t blk_rq_trace_sector(struct request *rq)
> {
> diff --git a/include/trace/events/bcache.h b/include/trace/events/bcache.h
> index 0bddea663b3b..7440d704c200 100644
> --- a/include/trace/events/bcache.h
> +++ b/include/trace/events/bcache.h
> @@ -18,7 +18,7 @@ DECLARE_EVENT_CLASS(bcache_request,
> __field(sector_t, sector )
> __field(dev_t, orig_sector )
> __field(unsigned int, nr_sector )
> - __array(char, rwbs, 6 )
> + __array(char, rwbs, BLK_RWBS_LEN )
> ),
>
> TP_fast_assign(
> @@ -28,7 +28,7 @@ DECLARE_EVENT_CLASS(bcache_request,
> __entry->sector = bio->bi_iter.bi_sector;
> __entry->orig_sector = bio->bi_iter.bi_sector - 16;
> __entry->nr_sector = bio->bi_iter.bi_size >> 9;
> - blk_fill_rwbs(__entry->rwbs, bio->bi_opf, bio->bi_iter.bi_size);
> + blk_fill_rwbs(__entry->rwbs, bio->bi_opf);
> ),
>
> TP_printk("%d,%d %s %llu + %u (from %d,%d @ %llu)",
> @@ -95,14 +95,14 @@ DECLARE_EVENT_CLASS(bcache_bio,
> __field(dev_t, dev )
> __field(sector_t, sector )
> __field(unsigned int, nr_sector )
> - __array(char, rwbs, 6 )
> + __array(char, rwbs, BLK_RWBS_LEN )
> ),
>
> TP_fast_assign(
> __entry->dev = bio_dev(bio);
> __entry->sector = bio->bi_iter.bi_sector;
> __entry->nr_sector = bio->bi_iter.bi_size >> 9;
> - blk_fill_rwbs(__entry->rwbs, bio->bi_opf, bio->bi_iter.bi_size);
> + blk_fill_rwbs(__entry->rwbs, bio->bi_opf);
> ),
>
> TP_printk("%d,%d %s %llu + %u",
> @@ -128,7 +128,7 @@ TRACE_EVENT(bcache_read,
> __field(dev_t, dev )
> __field(sector_t, sector )
> __field(unsigned int, nr_sector )
> - __array(char, rwbs, 6 )
> + __array(char, rwbs, BLK_RWBS_LEN )
> __field(bool, cache_hit )
> __field(bool, bypass )
> ),
> @@ -137,7 +137,7 @@ TRACE_EVENT(bcache_read,
> __entry->dev = bio_dev(bio);
> __entry->sector = bio->bi_iter.bi_sector;
> __entry->nr_sector = bio->bi_iter.bi_size >> 9;
> - blk_fill_rwbs(__entry->rwbs, bio->bi_opf, bio->bi_iter.bi_size);
> + blk_fill_rwbs(__entry->rwbs, bio->bi_opf);
> __entry->cache_hit = hit;
> __entry->bypass = bypass;
> ),
> @@ -158,7 +158,7 @@ TRACE_EVENT(bcache_write,
> __field(u64, inode )
> __field(sector_t, sector )
> __field(unsigned int, nr_sector )
> - __array(char, rwbs, 6 )
> + __array(char, rwbs, BLK_RWBS_LEN )
> __field(bool, writeback )
> __field(bool, bypass )
> ),
> @@ -168,7 +168,7 @@ TRACE_EVENT(bcache_write,
> __entry->inode = inode;
> __entry->sector = bio->bi_iter.bi_sector;
> __entry->nr_sector = bio->bi_iter.bi_size >> 9;
> - blk_fill_rwbs(__entry->rwbs, bio->bi_opf, bio->bi_iter.bi_size);
> + blk_fill_rwbs(__entry->rwbs, bio->bi_opf);
> __entry->writeback = writeback;
> __entry->bypass = bypass;
> ),
> @@ -229,7 +229,7 @@ TRACE_EVENT(bcache_journal_write,
> __field(dev_t, dev )
> __field(sector_t, sector )
> __field(unsigned int, nr_sector )
> - __array(char, rwbs, 6 )
> + __array(char, rwbs, BLK_RWBS_LEN )
> __field(u32, nr_keys )
> ),
>
> @@ -238,7 +238,7 @@ TRACE_EVENT(bcache_journal_write,
> __entry->sector = bio->bi_iter.bi_sector;
> __entry->nr_sector = bio->bi_iter.bi_size >> 9;
> __entry->nr_keys = keys;
> - blk_fill_rwbs(__entry->rwbs, bio->bi_opf, bio->bi_iter.bi_size);
> + blk_fill_rwbs(__entry->rwbs, bio->bi_opf);
> ),
>
> TP_printk("%d,%d %s %llu + %u keys %u",
> diff --git a/include/trace/events/block.h b/include/trace/events/block.h
> index 81b43f5bdf23..aac9a5c0e2cc 100644
> --- a/include/trace/events/block.h
> +++ b/include/trace/events/block.h
> @@ -10,7 +10,6 @@
> #include <linux/buffer_head.h>
> #include <linux/tracepoint.h>
>
> -#define RWBS_LEN 8
>
> DECLARE_EVENT_CLASS(block_buffer,
>
> @@ -81,7 +80,7 @@ TRACE_EVENT(block_rq_requeue,
> __field( dev_t, dev )
> __field( sector_t, sector )
> __field( unsigned int, nr_sector )
> - __array( char, rwbs, RWBS_LEN )
> + __array( char, rwbs, BLK_RWBS_LEN )
> __dynamic_array( char, cmd, 1 )
> ),
>
> @@ -90,7 +89,7 @@ TRACE_EVENT(block_rq_requeue,
> __entry->sector = blk_rq_trace_sector(rq);
> __entry->nr_sector = blk_rq_trace_nr_sectors(rq);
>
> - blk_fill_rwbs(__entry->rwbs, rq->cmd_flags, blk_rq_bytes(rq));
> + blk_fill_rwbs(__entry->rwbs, rq->cmd_flags);
> __get_str(cmd)[0] = '\0';
> ),
>
> @@ -124,7 +123,7 @@ TRACE_EVENT(block_rq_complete,
> __field( sector_t, sector )
> __field( unsigned int, nr_sector )
> __field( int, error )
> - __array( char, rwbs, RWBS_LEN )
> + __array( char, rwbs, BLK_RWBS_LEN )
> __dynamic_array( char, cmd, 1 )
> ),
>
> @@ -134,7 +133,7 @@ TRACE_EVENT(block_rq_complete,
> __entry->nr_sector = nr_bytes >> 9;
> __entry->error = error;
>
> - blk_fill_rwbs(__entry->rwbs, rq->cmd_flags, nr_bytes);
> + blk_fill_rwbs(__entry->rwbs, rq->cmd_flags);
> __get_str(cmd)[0] = '\0';
> ),
>
> @@ -156,7 +155,7 @@ DECLARE_EVENT_CLASS(block_rq,
> __field( sector_t, sector )
> __field( unsigned int, nr_sector )
> __field( unsigned int, bytes )
> - __array( char, rwbs, RWBS_LEN )
> + __array( char, rwbs, BLK_RWBS_LEN )
> __array( char, comm, TASK_COMM_LEN )
> __dynamic_array( char, cmd, 1 )
> ),
> @@ -167,7 +166,7 @@ DECLARE_EVENT_CLASS(block_rq,
> __entry->nr_sector = blk_rq_trace_nr_sectors(rq);
> __entry->bytes = blk_rq_bytes(rq);
>
> - blk_fill_rwbs(__entry->rwbs, rq->cmd_flags, blk_rq_bytes(rq));
> + blk_fill_rwbs(__entry->rwbs, rq->cmd_flags);
> __get_str(cmd)[0] = '\0';
> memcpy(__entry->comm, current->comm, TASK_COMM_LEN);
> ),
> @@ -232,7 +231,7 @@ TRACE_EVENT(block_bio_bounce,
> __field( dev_t, dev )
> __field( sector_t, sector )
> __field( unsigned int, nr_sector )
> - __array( char, rwbs, RWBS_LEN )
> + __array( char, rwbs, BLK_RWBS_LEN )
> __array( char, comm, TASK_COMM_LEN )
> ),
>
> @@ -240,7 +239,7 @@ TRACE_EVENT(block_bio_bounce,
> __entry->dev = bio_dev(bio);
> __entry->sector = bio->bi_iter.bi_sector;
> __entry->nr_sector = bio_sectors(bio);
> - blk_fill_rwbs(__entry->rwbs, bio->bi_opf, bio->bi_iter.bi_size);
> + blk_fill_rwbs(__entry->rwbs, bio->bi_opf);
> memcpy(__entry->comm, current->comm, TASK_COMM_LEN);
> ),
>
> @@ -266,11 +265,11 @@ TRACE_EVENT(block_bio_complete,
> TP_ARGS(q, bio, error),
>
> TP_STRUCT__entry(
> - __field( dev_t, dev )
> - __field( sector_t, sector )
> - __field( unsigned, nr_sector )
> - __field( int, error )
> - __array( char, rwbs, RWBS_LEN)
> + __field( dev_t, dev )
> + __field( sector_t, sector )
> + __field( unsigned, nr_sector )
> + __field( int, error )
> + __array( char, rwbs, BLK_RWBS_LEN )
> ),
>
> TP_fast_assign(
> @@ -278,7 +277,7 @@ TRACE_EVENT(block_bio_complete,
> __entry->sector = bio->bi_iter.bi_sector;
> __entry->nr_sector = bio_sectors(bio);
> __entry->error = error;
> - blk_fill_rwbs(__entry->rwbs, bio->bi_opf, bio->bi_iter.bi_size);
> + blk_fill_rwbs(__entry->rwbs, bio->bi_opf);
> ),
>
> TP_printk("%d,%d %s %llu + %u [%d]",
> @@ -297,7 +296,7 @@ DECLARE_EVENT_CLASS(block_bio_merge,
> __field( dev_t, dev )
> __field( sector_t, sector )
> __field( unsigned int, nr_sector )
> - __array( char, rwbs, RWBS_LEN )
> + __array( char, rwbs, BLK_RWBS_LEN )
> __array( char, comm, TASK_COMM_LEN )
> ),
>
> @@ -305,7 +304,7 @@ DECLARE_EVENT_CLASS(block_bio_merge,
> __entry->dev = bio_dev(bio);
> __entry->sector = bio->bi_iter.bi_sector;
> __entry->nr_sector = bio_sectors(bio);
> - blk_fill_rwbs(__entry->rwbs, bio->bi_opf, bio->bi_iter.bi_size);
> + blk_fill_rwbs(__entry->rwbs, bio->bi_opf);
> memcpy(__entry->comm, current->comm, TASK_COMM_LEN);
> ),
>
> @@ -364,7 +363,7 @@ TRACE_EVENT(block_bio_queue,
> __field( dev_t, dev )
> __field( sector_t, sector )
> __field( unsigned int, nr_sector )
> - __array( char, rwbs, RWBS_LEN )
> + __array( char, rwbs, BLK_RWBS_LEN )
> __array( char, comm, TASK_COMM_LEN )
> ),
>
> @@ -372,7 +371,7 @@ TRACE_EVENT(block_bio_queue,
> __entry->dev = bio_dev(bio);
> __entry->sector = bio->bi_iter.bi_sector;
> __entry->nr_sector = bio_sectors(bio);
> - blk_fill_rwbs(__entry->rwbs, bio->bi_opf, bio->bi_iter.bi_size);
> + blk_fill_rwbs(__entry->rwbs, bio->bi_opf);
> memcpy(__entry->comm, current->comm, TASK_COMM_LEN);
> ),
>
> @@ -392,7 +391,7 @@ DECLARE_EVENT_CLASS(block_get_rq,
> __field( dev_t, dev )
> __field( sector_t, sector )
> __field( unsigned int, nr_sector )
> - __array( char, rwbs, RWBS_LEN )
> + __array( char, rwbs, BLK_RWBS_LEN )
> __array( char, comm, TASK_COMM_LEN )
> ),
>
> @@ -400,8 +399,7 @@ DECLARE_EVENT_CLASS(block_get_rq,
> __entry->dev = bio ? bio_dev(bio) : 0;
> __entry->sector = bio ? bio->bi_iter.bi_sector : 0;
> __entry->nr_sector = bio ? bio_sectors(bio) : 0;
> - blk_fill_rwbs(__entry->rwbs,
> - bio ? bio->bi_opf : 0, __entry->nr_sector);
> + blk_fill_rwbs(__entry->rwbs, bio ? bio->bi_opf : 0);
> memcpy(__entry->comm, current->comm, TASK_COMM_LEN);
> ),
>
> @@ -524,18 +522,18 @@ TRACE_EVENT(block_split,
> TP_ARGS(q, bio, new_sector),
>
> TP_STRUCT__entry(
> - __field( dev_t, dev )
> - __field( sector_t, sector )
> - __field( sector_t, new_sector )
> - __array( char, rwbs, RWBS_LEN )
> - __array( char, comm, TASK_COMM_LEN )
> + __field( dev_t, dev )
> + __field( sector_t, sector )
> + __field( sector_t, new_sector )
> + __array( char, rwbs, BLK_RWBS_LEN )
> + __array( char, comm, TASK_COMM_LEN )
> ),
>
> TP_fast_assign(
> __entry->dev = bio_dev(bio);
> __entry->sector = bio->bi_iter.bi_sector;
> __entry->new_sector = new_sector;
> - blk_fill_rwbs(__entry->rwbs, bio->bi_opf, bio->bi_iter.bi_size);
> + blk_fill_rwbs(__entry->rwbs, bio->bi_opf);
> memcpy(__entry->comm, current->comm, TASK_COMM_LEN);
> ),
>
> @@ -564,12 +562,12 @@ TRACE_EVENT(block_bio_remap,
> TP_ARGS(q, bio, dev, from),
>
> TP_STRUCT__entry(
> - __field( dev_t, dev )
> - __field( sector_t, sector )
> - __field( unsigned int, nr_sector )
> - __field( dev_t, old_dev )
> - __field( sector_t, old_sector )
> - __array( char, rwbs, RWBS_LEN)
> + __field( dev_t, dev )
> + __field( sector_t, sector )
> + __field( unsigned int, nr_sector )
> + __field( dev_t, old_dev )
> + __field( sector_t, old_sector )
> + __array( char, rwbs, BLK_RWBS_LEN )
> ),
>
> TP_fast_assign(
> @@ -578,7 +576,7 @@ TRACE_EVENT(block_bio_remap,
> __entry->nr_sector = bio_sectors(bio);
> __entry->old_dev = dev;
> __entry->old_sector = from;
> - blk_fill_rwbs(__entry->rwbs, bio->bi_opf, bio->bi_iter.bi_size);
> + blk_fill_rwbs(__entry->rwbs, bio->bi_opf);
> ),
>
> TP_printk("%d,%d %s %llu + %u <- (%d,%d) %llu",
> @@ -608,13 +606,13 @@ TRACE_EVENT(block_rq_remap,
> TP_ARGS(q, rq, dev, from),
>
> TP_STRUCT__entry(
> - __field( dev_t, dev )
> - __field( sector_t, sector )
> - __field( unsigned int, nr_sector )
> - __field( dev_t, old_dev )
> - __field( sector_t, old_sector )
> - __field( unsigned int, nr_bios )
> - __array( char, rwbs, RWBS_LEN)
> + __field( dev_t, dev )
> + __field( sector_t, sector )
> + __field( unsigned int, nr_sector )
> + __field( dev_t, old_dev )
> + __field( sector_t, old_sector )
> + __field( unsigned int, nr_bios )
> + __array( char, rwbs, BLK_RWBS_LEN )
> ),
>
> TP_fast_assign(
> @@ -624,7 +622,7 @@ TRACE_EVENT(block_rq_remap,
> __entry->old_dev = dev;
> __entry->old_sector = from;
> __entry->nr_bios = blk_rq_count_bios(rq);
> - blk_fill_rwbs(__entry->rwbs, rq->cmd_flags, blk_rq_bytes(rq));
> + blk_fill_rwbs(__entry->rwbs, rq->cmd_flags);
> ),
>
> TP_printk("%d,%d %s %llu + %u <- (%d,%d) %llu %u",
> diff --git a/kernel/trace/blktrace.c b/kernel/trace/blktrace.c
> index ca39dc3230cb..dd10667d4164 100644
> --- a/kernel/trace/blktrace.c
> +++ b/kernel/trace/blktrace.c
> @@ -1935,7 +1935,7 @@ void blk_trace_remove_sysfs(struct device *dev)
>
> #ifdef CONFIG_EVENT_TRACING
>
> -void blk_fill_rwbs(char *rwbs, unsigned int op, int bytes)
> +void blk_fill_rwbs(char *rwbs, unsigned int op)
> {
> int i = 0;
>
>