Gitweb:
http://git.fedorahosted.org/git/?p=lvm2.git;a=commitdiff;h=6ec8854fdb051b...
Commit: 6ec8854fdb051b092d5e262dc6c6d4c2ea075cd1
Parent: 0a480c5c52bd34a1eb8337d59a7f4cc60317d2b1
Author: Bryn M. Reeves <bmr(a)redhat.com>
AuthorDate: Tue Sep 27 14:35:22 2016 +0100
Committer: Bryn M. Reeves <bmr(a)redhat.com>
CommitterDate: Tue Sep 27 14:46:00 2016 +0100
libdm: fix stats walk compatibility with older dmsetup
The current dmsetup.c handles DR_STATS and DR_STATS_META reports
separately in _display_info_cols(), meaning that the stats walk
functions are never called for these report types.
Versions before v2.02.159 have a loop using dm_stats_walk_do() and
dm_stats_walk_while(), that executes once for non-stats reports,
and once per region, or area, for DR_STATS/DR_STATS_META reports.
This older behaviour relies on the documented behaviour that the
walk functions will accept a NULL pointer as the struct dm_stats*
argument.
This was broken by commit f1f2df7b: the NULL test on dms and
dms->regions were incorrectly moved from the dm_stats_walk_end()
wrapper to the internal '_stats_walk_end()' helper.
Since the pointer is dereferenced in between these points, using
an older dmsetup with current libdm results in a segfault when
running a non-stats report:
# dmsetup info -c vg00/lvol0
Segmentation fault (core dumped)
Restore the NULL checks to the wrapper function as intended.
---
WHATS_NEW_DM | 1 +
libdm/libdm-stats.c | 6 +++---
2 files changed, 4 insertions(+), 3 deletions(-)
diff --git a/WHATS_NEW_DM b/WHATS_NEW_DM
index 29dbccc..b048f7a 100644
--- a/WHATS_NEW_DM
+++ b/WHATS_NEW_DM
@@ -1,5 +1,6 @@
Version 1.02.136 -
======================================
+ Fix stats walk segfault with dmsetup older than v1.02.129
Version 1.02.135 - 26th September 2016
======================================
diff --git a/libdm/libdm-stats.c b/libdm/libdm-stats.c
index ffd349c..75e0144 100644
--- a/libdm/libdm-stats.c
+++ b/libdm/libdm-stats.c
@@ -1526,9 +1526,6 @@ static void _stats_walk_end_areas(const struct dm_stats *dms,
uint64_t *flags,
static int _stats_walk_end(const struct dm_stats *dms, uint64_t *flags,
uint64_t *cur_r, uint64_t *cur_a, uint64_t *cur_g)
{
- if (!dms || !dms->regions)
- return 1;
-
if (*flags & DM_STATS_WALK_AREA) {
_stats_walk_end_areas(dms, flags, cur_r, cur_a, cur_g);
goto out;
@@ -1553,6 +1550,9 @@ out:
int dm_stats_walk_end(struct dm_stats *dms)
{
+ if (!dms || !dms->regions)
+ return 1;
+
if (_stats_walk_end(dms, &dms->cur_flags,
&dms->cur_region, &dms->cur_area,
&dms->cur_group)) {