[PATCH RFCv2 5/6] powerpc/powernv: hold device_hotplug_lock in memtrace_offline_pages()
From: David Hildenbrand <hidden>
Date: 2018-08-21 10:44:55
Also in:
linux-acpi, linux-mm, linuxppc-dev, lkml
Subsystem:
linux for powerpc (32-bit and 64-bit), the rest · Maintainers:
Madhavan Srinivasan, Michael Ellerman, Linus Torvalds
Let's perform all checking + offlining + removing under device_hotplug_lock, so nobody can mess with these devices via sysfs concurrently. Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <redacted> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Rashmica Gupta <redacted> Cc: Balbir Singh <bsingharora@gmail.com> Cc: Michael Neuling <redacted> Signed-off-by: David Hildenbrand <redacted> --- arch/powerpc/platforms/powernv/memtrace.c | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-)
diff --git a/arch/powerpc/platforms/powernv/memtrace.c b/arch/powerpc/platforms/powernv/memtrace.c
index ef7181d4fe68..473e59842ec5 100644
--- a/arch/powerpc/platforms/powernv/memtrace.c
+++ b/arch/powerpc/platforms/powernv/memtrace.c@@ -74,9 +74,13 @@ static bool memtrace_offline_pages(u32 nid, u64 start_pfn, u64 nr_pages) { u64 end_pfn = start_pfn + nr_pages - 1; + lock_device_hotplug(); + if (walk_memory_range(start_pfn, end_pfn, NULL, - check_memblock_online)) + check_memblock_online)) { + unlock_device_hotplug(); return false; + } walk_memory_range(start_pfn, end_pfn, (void *)MEM_GOING_OFFLINE, change_memblock_state);
@@ -84,14 +88,16 @@ static bool memtrace_offline_pages(u32 nid, u64 start_pfn, u64 nr_pages) if (offline_pages(start_pfn, nr_pages)) { walk_memory_range(start_pfn, end_pfn, (void *)MEM_ONLINE, change_memblock_state); + unlock_device_hotplug(); return false; } walk_memory_range(start_pfn, end_pfn, (void *)MEM_OFFLINE, change_memblock_state); - remove_memory(nid, start_pfn << PAGE_SHIFT, nr_pages << PAGE_SHIFT); + __remove_memory(nid, start_pfn << PAGE_SHIFT, nr_pages << PAGE_SHIFT); + unlock_device_hotplug(); return true; }
--
2.17.1