On Thu, Nov 14, 2019 at 08:01:46PM +0000, Dmitry Monakhov wrote:
> Trace's macro __print_flags() produce raw event's decraration w/o knowing actual
> flags value
>
> cat /sys/kernel/debug/tracing/events/ext4/ext4_ext_map_blocks_exit/format
> ..
> __print_flags(REC->mflags, "", { (1 << BH_New),
>
> For that reason we have to explicitly define it via special macro TRACE_DEFINE_ENUM()
> Also add missed EXTENT_STATUS_REFERENCED flag.
>
> #Before patch
> ext4:ext4_ext_map_blocks_exit: dev 253,0 ino 2 flags lblk 0 pblk 4177 len 1 mflags 0x20 ret 1
> ext4:ext4_ext_map_blocks_exit: dev 253,0 ino 12 flags CREATE lblk 0 pblk 34304 len 1 mflags 0x60 ret 1
>
> #With patch
> ext4:ext4_ext_map_blocks_exit: dev 253,0 ino 2 flags lblk 0 pblk 4177 len 1 mflags M ret 1
> ext4:ext4_ext_map_blocks_exit: dev 253,0 ino 12 flags CREATE lblk 0 pblk 34816 len 1 mflags NM ret 1
>
> Signed-off-by: Dmitry Monakhov <dmonakhov@xxxxxxxxx>
> ---
> include/trace/events/ext4.h | 19 ++++++++++++++++++-
> 1 file changed, 18 insertions(+), 1 deletion(-)
>
> diff --git a/include/trace/events/ext4.h b/include/trace/events/ext4.h
> index 182c9fe..3bf7128 100644
> --- a/include/trace/events/ext4.h
> +++ b/include/trace/events/ext4.h
> @@ -48,6 +48,16 @@ struct partial_cluster;
> { EXT4_GET_BLOCKS_KEEP_SIZE, "KEEP_SIZE" }, \
> { EXT4_GET_BLOCKS_ZERO, "ZERO" })
>
> +/*
> + * __print_flags() requires that all enum values be wrapped in the
> + * TRACE_DEFINE_ENUM macro so that the enum value can be encoded in the ftrace
> + * ring buffer.
> + */
> +TRACE_DEFINE_ENUM(BH_New);
> +TRACE_DEFINE_ENUM(BH_Mapped);
> +TRACE_DEFINE_ENUM(BH_Unwritten);
> +TRACE_DEFINE_ENUM(BH_Boundary);
> +
> #define show_mflags(flags) __print_flags(flags, "", \
> { EXT4_MAP_NEW, "N" }, \
> { EXT4_MAP_MAPPED, "M" }, \
> @@ -62,11 +72,18 @@ struct partial_cluster;
> { EXT4_FREE_BLOCKS_NOFREE_FIRST_CLUSTER,"1ST_CLUSTER" },\
> { EXT4_FREE_BLOCKS_NOFREE_LAST_CLUSTER, "LAST_CLUSTER" })
>
> +TRACE_DEFINE_ENUM(ES_WRITTEN_B);
> +TRACE_DEFINE_ENUM(ES_UNWRITTEN_B);
> +TRACE_DEFINE_ENUM(ES_DELAYED_B);
> +TRACE_DEFINE_ENUM(ES_HOLE_B);
> +TRACE_DEFINE_ENUM(ES_REFERENCED_B);
I wonder if it's worth leaving a comment wherever this enum is defined
warning developers to keep this TRACE_DEFINE_NUM list (and the string
mapping) up to date?
--D
> #define show_extent_status(status) __print_flags(status, "", \
> { EXTENT_STATUS_WRITTEN, "W" }, \
> { EXTENT_STATUS_UNWRITTEN, "U" }, \
> { EXTENT_STATUS_DELAYED, "D" }, \
> - { EXTENT_STATUS_HOLE, "H" })
> + { EXTENT_STATUS_HOLE, "H" }, \
> + { EXTENT_STATUS_REFERENCED, "R" })
>
> #define show_falloc_mode(mode) __print_flags(mode, "|", \
> { FALLOC_FL_KEEP_SIZE, "KEEP_SIZE"}, \
> --
> 2.7.4
>
