Re: [RFC patch 29/41] btrfs: ref-verify: Simplify stack trace retrieval

From: Alexander Potapenko
Date: Wed Apr 10 2019 - 09:47:42 EST


On Wed, Apr 10, 2019 at 1:06 PM Thomas Gleixner <tglx@xxxxxxxxxxxxx> wrote:
>
> Replace the indirection through struct stack_trace with an invocation of
> the storage array based interface.
>
> Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
> Cc: David Sterba <dsterba@xxxxxxxx>
> Cc: Chris Mason <clm@xxxxxx>
> Cc: Josef Bacik <josef@xxxxxxxxxxxxxx>
> Cc: linux-btrfs@xxxxxxxxxxxxxxx
> ---
> fs/btrfs/ref-verify.c | 15 ++-------------
> 1 file changed, 2 insertions(+), 13 deletions(-)
>
> --- a/fs/btrfs/ref-verify.c
> +++ b/fs/btrfs/ref-verify.c
> @@ -205,28 +205,17 @@ static struct root_entry *lookup_root_en
> #ifdef CONFIG_STACKTRACE
> static void __save_stack_trace(struct ref_action *ra)
> {
> - struct stack_trace stack_trace;
> -
> - stack_trace.max_entries = MAX_TRACE;
> - stack_trace.nr_entries = 0;
> - stack_trace.entries = ra->trace;
> - stack_trace.skip = 2;
> - save_stack_trace(&stack_trace);
> - ra->trace_len = stack_trace.nr_entries;
> + ra->trace_len = stack_trace_save(ra->trace, MAX_TRACE, 2);
Now that stack_trace.skip is gone, it's unclear what this "2" stands for.
Maybe add an inline comment saying it's skipnr?
(This is probably valid for all other stack_trace_save() callsites)
> }
>
> static void __print_stack_trace(struct btrfs_fs_info *fs_info,
> struct ref_action *ra)
> {
> - struct stack_trace trace;
> -
> if (ra->trace_len == 0) {
> btrfs_err(fs_info, " ref-verify: no stacktrace");
> return;
> }
> - trace.nr_entries = ra->trace_len;
> - trace.entries = ra->trace;
> - print_stack_trace(&trace, 2);
> + stack_trace_print(ra->trace, ra->trace_len, 2);
> }
> #else
> static void inline __save_stack_trace(struct ref_action *ra)
>
>


--
Alexander Potapenko
Software Engineer

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