From: Darrick J. Wong <darrick.wong@xxxxxxxxxx>
In patch 4944defad4 ("xfs_db: redirect printfs when metadumping to
stdout"), we solved the problem of xfs_db printfs ending up in the
metadump stream by reassigning stdout for the duration of a stdout
metadump. Unfortunately, musl doesn't allow stdout to be reassigned (in
their view "extern FILE *stdout" means "extern FILE * const stdout"), so
we abandon the old approach in favor of playing games with dup() to
switch the raw file descriptors.
While we're at it, fix a regression where an unconverted outf test
allows progress info to end up in the metadump stream.
Signed-off-by: Darrick J. Wong <darrick.wong@xxxxxxxxxx>
---
db/metadump.c | 47 ++++++++++++++++++++++++++++++++++++-----------
1 file changed, 36 insertions(+), 11 deletions(-)
diff --git a/db/metadump.c b/db/metadump.c
index be2e712..227796b 100644
--- a/db/metadump.c
+++ b/db/metadump.c
@@ -78,6 +78,7 @@ static int obfuscate = 1;
static int zero_stale_data = 1;
static int show_warnings = 0;
static int progress_since_warning = 0;
+static bool stdout_metadump;
void
metadump_init(void)
@@ -137,7 +138,7 @@ print_progress(const char *fmt, ...)
va_end(ap);
buf[sizeof(buf)-1] = '\0';
- f = (outf == stdout) ? stderr : stdout;
+ f = stdout_metadump ? stderr : stdout;
fprintf(f, "\r%-59s", buf);
fflush(f);
progress_since_warning = 1;
@@ -2750,7 +2751,8 @@ metadump_f(
xfs_agnumber_t agno;
int c;
int start_iocur_sp;
- bool stdout_metadump = false;
+ int outfd = -1;
+ int ret;
char *p;
exitcode = 1;
@@ -2870,16 +2872,35 @@ metadump_f(
* metadump operation so that dbprintf and other messages
* are sent to the console instead of polluting the
* metadump stream.
+ *
+ * We get to do this the hard way because musl doesn't
+ * allow reassignment of stdout.
*/
- outf = stdout;
- stdout = stderr;
+ fflush(stdout);
+ outfd = dup(STDOUT_FILENO);
+ if (outfd < 0) {
+ perror("opening dump stream");
+ goto out;
+ }
+ ret = dup2(STDERR_FILENO, STDOUT_FILENO);
+ if (ret < 0) {
+ perror("redirecting stdout");
+ close(outfd);
+ goto out;
+ }
+ outf = fdopen(outfd, "a");
+ if (outf == NULL) {
+ fprintf(stderr, "cannot create dump stream\n");
+ dup2(outfd, 1);
+ close(outfd);
+ goto out;
+ }
stdout_metadump = true;
} else {
outf = fopen(argv[optind], "wb");
if (outf == NULL) {
print_warning("cannot create dump file");
- free(metablock);
- return 0;
+ goto out;
}
}
@@ -2907,15 +2928,19 @@ metadump_f(
if (progress_since_warning)
fputc('\n', stdout_metadump ? stderr : stdout);
- if (stdout_metadump)
- stdout = outf;
- else
- fclose(outf);
+ if (stdout_metadump) {
+ fflush(outf);
+ fflush(stdout);
+ ret = dup2(outfd, STDOUT_FILENO);
+ if (ret < 0)
+ perror("un-redirecting stdout");
+ }
+ fclose(outf);
/* cleanup iocur stack */
while (iocur_sp > start_iocur_sp)
pop_cur();
-
+out:
free(metablock);
return 0;
--
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