[lvm-devel] [PATCH 08/29] Fix memory leak in error path

[Zdenek Kabelac]

Nicely hidden memory leak in error path.
outf() is macro which uses out_text() and does automagical return_0.
This would leak tag_buffer.

As there was a repeating code for tags output - create _out_tags().

Signed-off-by: Zdenek Kabelac <zkabelac at redhat.com>
---
 lib/format_text/export.c |   56 ++++++++++++++++++++++-----------------------
 1 files changed, 27 insertions(+), 29 deletions(-)

diff --git a/lib/format_text/export.c b/lib/format_text/export.c
index d49090c..8ddfa85 100644
--- a/lib/format_text/export.c
+++ b/lib/format_text/export.c
@@ -363,10 +363,27 @@ static int _print_flag_config(struct formatter *f, uint64_t status, int type)
 	return 1;
 }
 
+
+static int _out_tags(struct formatter *f, struct dm_list *tags)
+{
+	char *tag_buffer;
+
+	if (!dm_list_empty(tags)) {
+		if (!(tag_buffer = alloc_printed_tags(tags)))
+			return_0;
+		if (!out_text(f, "tags = %s", tag_buffer)) {
+			dm_free(tag_buffer);
+			return_0;
+		}
+		dm_free(tag_buffer);
+	}
+
+	return 1;
+}
+
 static int _print_vg(struct formatter *f, struct volume_group *vg)
 {
 	char buffer[4096];
-	char *tag_buffer = NULL;
 
 	if (!id_write_format(&vg->id, buffer, sizeof(buffer)))
 		return_0;
@@ -378,12 +395,8 @@ static int _print_vg(struct formatter *f, struct volume_group *vg)
 	if (!_print_flag_config(f, vg->status, VG_FLAGS))
 		return_0;
 
-	if (!dm_list_empty(&vg->tags)) {
-		if (!(tag_buffer = alloc_printed_tags(&vg->tags)))
-			return_0;
-		outf(f, "tags = %s", tag_buffer);
-		dm_free(tag_buffer);
-	}
+	if (!_out_tags(f, &vg->tags))
+		return_0;
 
 	if (vg->system_id && *vg->system_id)
 		outf(f, "system_id = \"%s\"", vg->system_id);
@@ -428,7 +441,7 @@ static int _print_pvs(struct formatter *f, struct volume_group *vg)
 	struct pv_list *pvl;
 	struct physical_volume *pv;
 	char buffer[4096];
-	char *buf, *tag_buffer = NULL;
+	char *buf;
 	const char *name;
 
 	outf(f, "physical_volumes {");
@@ -462,12 +475,8 @@ static int _print_pvs(struct formatter *f, struct volume_group *vg)
 		if (!_print_flag_config(f, pv->status, PV_FLAGS))
 			return_0;
 
-		if (!dm_list_empty(&pv->tags)) {
-			if (!(tag_buffer = alloc_printed_tags(&pv->tags)))
-				return_0;
-			outf(f, "tags = %s", tag_buffer);
-			dm_free(tag_buffer);
-		}
+		if (!_out_tags(f, &pv->tags))
+			return_0;
 
 		outsize(f, pv->size, "dev_size = %" PRIu64, pv->size);
 
@@ -487,8 +496,6 @@ static int _print_pvs(struct formatter *f, struct volume_group *vg)
 static int _print_segment(struct formatter *f, struct volume_group *vg,
 			  int count, struct lv_segment *seg)
 {
-	char *tag_buffer = NULL;
-
 	outf(f, "segment%u {", count);
 	_inc_indent(f);
 
@@ -499,12 +506,8 @@ static int _print_segment(struct formatter *f, struct volume_group *vg,
 	outnl(f);
 	outf(f, "type = \"%s\"", seg->segtype->name);
 
-	if (!dm_list_empty(&seg->tags)) {
-		if (!(tag_buffer = alloc_printed_tags(&seg->tags)))
-			return_0;
-		outf(f, "tags = %s", tag_buffer);
-		dm_free(tag_buffer);
-	}
+	if (!_out_tags(f, &seg->tags))
+		return_0;
 
 	if (seg->segtype->ops->text_export &&
 	    !seg->segtype->ops->text_export(seg, f))
@@ -557,7 +560,6 @@ static int _print_lv(struct formatter *f, struct logical_volume *lv)
 {
 	struct lv_segment *seg;
 	char buffer[4096];
-	char *tag_buffer = NULL;
 	int seg_count;
 
 	outnl(f);
@@ -573,12 +575,8 @@ static int _print_lv(struct formatter *f, struct logical_volume *lv)
 	if (!_print_flag_config(f, lv->status, LV_FLAGS))
 		return_0;
 
-	if (!dm_list_empty(&lv->tags)) {
-		if (!(tag_buffer = alloc_printed_tags(&lv->tags)))
-			return_0;
-		outf(f, "tags = %s", tag_buffer);
-		dm_free(tag_buffer);
-	}
+	if (!_out_tags(f, &lv->tags))
+		return_0;
 
 	if (lv->alloc != ALLOC_INHERIT)
 		outf(f, "allocation_policy = \"%s\"",
-- 
1.7.3.2