From: Michal Hocko <mhocko@xxxxxxxx> Subject: mm, memory_hotplug: __offline_pages fix wrong locking Jan has noticed that we do double unlock on some failure paths when offlining a page range. This is indeed the case when test_pages_in_a_zone respp. start_isolate_page_range fail. This was an omission when forward porting the debugging patch from an older kernel. Fix the issue by dropping mem_hotplug_done from the failure condition and keeping the single unlock in the catch all failure path. Link: http://lkml.kernel.org/r/20190115120307.22768-1-mhocko@xxxxxxxxxx Fixes: 7960509329c2 ("mm, memory_hotplug: print reason for the offlining failure") Signed-off-by: Michal Hocko <mhocko@xxxxxxxx> Reported-by: Jan Kara <jack@xxxxxxx> Reviewed-by: Jan Kara <jack@xxxxxxx> Tested-by: Jan Kara <jack@xxxxxxx> Reviewed-by: Oscar Salvador <osalvador@xxxxxxx> Reviewed-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- mm/memory_hotplug.c | 2 -- 1 file changed, 2 deletions(-) --- a/mm/memory_hotplug.c~mm-memory_hotplug-__offline_pages-fix-wrong-locking +++ a/mm/memory_hotplug.c @@ -1570,7 +1570,6 @@ static int __ref __offline_pages(unsigne we assume this for now. .*/ if (!test_pages_in_a_zone(start_pfn, end_pfn, &valid_start, &valid_end)) { - mem_hotplug_done(); ret = -EINVAL; reason = "multizone range"; goto failed_removal; @@ -1585,7 +1584,6 @@ static int __ref __offline_pages(unsigne MIGRATE_MOVABLE, SKIP_HWPOISON | REPORT_FAILURE); if (ret) { - mem_hotplug_done(); reason = "failure to isolate range"; goto failed_removal; } _
