On 07/14/2017 06:30 PM, Darrick J. Wong wrote:
> If we're metadumping to stdout, we don't want xfs_db's various dbprintf
> statements dumping to stdout because that'll corrupt the metadump.
> Therefore, let outf point to the existing stdout and redirect stdout to
> stderr for the duration of the dump operation.
>
> Reported-by: David Shaw <dshaw@xxxxxxxxxxxxxxx>
> Signed-off-by: Darrick J. Wong <darrick.wong@xxxxxxxxxx>
> ---
> db/metadump.c | 9 +++++++--
> 1 file changed, 7 insertions(+), 2 deletions(-)
>
> diff --git a/db/metadump.c b/db/metadump.c
> index e046f60..e6e153d 100644
> --- a/db/metadump.c
> +++ b/db/metadump.c
> @@ -2874,6 +2874,7 @@ metadump_f(
> xfs_agnumber_t agno;
> int c;
> int start_iocur_sp;
> + bool stdout_metadump = false;
> char *p;
>
> exitcode = 1;
> @@ -2989,6 +2990,8 @@ metadump_f(
> return 0;
> }
> outf = stdout;
> + stdout = stderr;
> + stdout_metadump = true;
Ok, I ... guess? xfs_metadump already takes pains to
print to stderr as appropriate; see print_warning(), and comments
about where "wornings" should go.
But in this case I guess it's the guts of db / dbprintf that caused the
problems, right? ... yup you said that in the commit message.
I suppose a comment:
/* Move stdout to stderr so thta xfs_db warnings don't pollute metadump stream */
or something would help the future reader know why you had to do this.
it feels a little hacky but I don't really see a particularly better way I guess.
-Eric
> } else {
> outf = fopen(argv[optind], "wb");
> if (outf == NULL) {
> @@ -3020,9 +3023,11 @@ metadump_f(
> exitcode = write_index() < 0;
>
> if (progress_since_warning)
> - fputc('\n', (outf == stdout) ? stderr : stdout);
> + fputc('\n', stdout_metadump ? stderr : stdout);
>
> - if (outf != stdout)
> + if (stdout_metadump)
> + stdout = outf;
> + else
> fclose(outf);
>
> /* cleanup iocur stack */
>
--
To unsubscribe from this list: send the line "unsubscribe linux-xfs" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
