| Message ID | 20180821104418.12710-6-david@redhat.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | mm: online/offline_pages called w.o. mem_hotplug_lock | expand |
Reviewed-by: Pavel Tatashin <pavel.tatashin@microsoft.com> On 8/21/18 6:44 AM, David Hildenbrand wrote: > 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 <paulus@samba.org> > Cc: Michael Ellerman <mpe@ellerman.id.au> > Cc: Rashmica Gupta <rashmica.g@gmail.com> > Cc: Balbir Singh <bsingharora@gmail.com> > Cc: Michael Neuling <mikey@neuling.org> > Signed-off-by: David Hildenbrand <david@redhat.com> > --- > 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; > } > >
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; }
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 <paulus@samba.org> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Rashmica Gupta <rashmica.g@gmail.com> Cc: Balbir Singh <bsingharora@gmail.com> Cc: Michael Neuling <mikey@neuling.org> Signed-off-by: David Hildenbrand <david@redhat.com> --- arch/powerpc/platforms/powernv/memtrace.c | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-)