mm, memory_hotplug: __offline_pages fix wrong locking

Michal Hocko · torvalds · commit e3df4c6e4836 · 2019-02-01T15:46:23.000-08:00
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@kernel.org Fixes: 7960509 ("mm, memory_hotplug: print reason for the offlining failure") Signed-off-by: Michal Hocko <mhocko@suse.com> Reported-by: Jan Kara <jack@suse.cz> Reviewed-by: Jan Kara <jack@suse.cz> Tested-by: Jan Kara <jack@suse.cz> Reviewed-by: Oscar Salvador <osalvador@suse.de> Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c
@@ -1570,7 +1570,6 @@ static int __ref __offline_pages(unsigned long start_pfn,
 	   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(unsigned long start_pfn,
 				       MIGRATE_MOVABLE,
 				       SKIP_HWPOISON | REPORT_FAILURE);
 	if (ret) {
-		mem_hotplug_done();
 		reason = "failure to isolate range";
 		goto failed_removal;
 	}
