Let's add some more sanity checking now that onlining/offlining code works completely on section basis. This will make sure that we will never try to online/offline sections that are already (or partially) in the desired state.
Signed-off-by: David Hildenbrand <[email protected]> --- include/linux/mmzone.h | 2 ++ mm/memory_hotplug.c | 5 +++++ mm/sparse.c | 28 ++++++++++++++++++++++++++++ 3 files changed, 35 insertions(+) diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h index 0859130e4db8..addfa41c047a 100644 --- a/include/linux/mmzone.h +++ b/include/linux/mmzone.h @@ -1228,6 +1228,8 @@ static inline int online_section_nr(unsigned long nr) } #ifdef CONFIG_MEMORY_HOTPLUG +bool mem_sections_online(unsigned long pfn, unsigned long end_pfn); +bool mem_sections_offline(unsigned long pfn, unsigned long end_pfn); void online_mem_sections(unsigned long start_pfn, unsigned long end_pfn); #ifdef CONFIG_MEMORY_HOTREMOVE void offline_mem_sections(unsigned long start_pfn, unsigned long end_pfn); diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c index 30d2fa42b0bb..3dc6d2a309c2 100644 --- a/mm/memory_hotplug.c +++ b/mm/memory_hotplug.c @@ -901,6 +901,8 @@ int __ref online_pages(unsigned long pfn, unsigned long nr_pages, int online_typ return -EINVAL; if (!IS_ALIGNED(nr_pages, PAGES_PER_SECTION)) return -EINVAL; + if (!mem_sections_offline(pfn, pfn + nr_pages)) + return -EINVAL; /* * We can't use pfn_to_nid() because nid might be stored in struct page @@ -1609,6 +1611,9 @@ int offline_pages(unsigned long start_pfn, unsigned long nr_pages) return -EINVAL; if (!IS_ALIGNED(nr_pages, PAGES_PER_SECTION)) return -EINVAL; + if (!mem_sections_online(start_pfn, end_pfn)) + return -EINVAL; + /* This makes hotplug much easier...and readable. we assume this for now. .*/ if (!test_pages_in_a_zone(start_pfn, end_pfn, &valid_start, &valid_end)) diff --git a/mm/sparse.c b/mm/sparse.c index 10b07eea9a6e..44693cf38ca9 100644 --- a/mm/sparse.c +++ b/mm/sparse.c @@ -520,6 +520,34 @@ void __init sparse_init(void) #ifdef CONFIG_MEMORY_HOTPLUG +/* check if all mem sections are online */ +bool mem_sections_online(unsigned long pfn, unsigned long end_pfn) +{ + for (; pfn < end_pfn; pfn += PAGES_PER_SECTION) { + unsigned long section_nr = pfn_to_section_nr(pfn); + + if (WARN_ON(!valid_section_nr(section_nr))) + continue; + if (!online_section_nr(section_nr)) + return false; + } + return true; +} + +/* check if all mem sections are offline */ +bool mem_sections_offline(unsigned long pfn, unsigned long end_pfn) +{ + for (; pfn < end_pfn; pfn += PAGES_PER_SECTION) { + unsigned long section_nr = pfn_to_section_nr(pfn); + + if (WARN_ON(!valid_section_nr(section_nr))) + continue; + if (online_section_nr(section_nr)) + return false; + } + return true; +} + /* Mark all memory sections within the pfn range as online */ void online_mem_sections(unsigned long start_pfn, unsigned long end_pfn) { -- 2.17.1
